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RAM Concept CONNECT Edition V8 Update 2 (v8.2) User Manual Last Updated: December 07, 2020 Table of Contents Chapter
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RAM Concept CONNECT Edition V8 Update 2 (v8.2)
User Manual Last Updated: December 07, 2020
Table of Contents Chapter 1: Introduction .......................................................................................................... 45 1.1 1.2 1.3 1.4 1.5
1.6
Comparing with “traditional” methods .......................................................................................................................45 RAM Concept options ......................................................................................................................................................... 46 Strip Wizard ............................................................................................................................................................................ 46 Structural systems ............................................................................................................................................................... 46 Learning RAM Concept .......................................................................................................................................................47 Tutorials ........................................................................................................................................................ 47 1.5.1 Critical Chapters ......................................................................................................................................... 48 1.5.2 Know your building code ........................................................................................................................48 1.5.3 Upgrading Old Files .................................................................................................................................. 49 1.5.4 Technical support .................................................................................................................................................................49
Chapter 2: Looking at the Workspace ...................................................................................... 50 2.1 2.2 2.3
2.4 2.5 2.6 2.7 2.8
About the workspace .......................................................................................................................................................... 50 Creating and opening files ................................................................................................................................................ 51 Starting a new file ..................................................................................................................................... 51 2.2.1 Opening an existing file .......................................................................................................................... 51 2.2.2 Saving a file ..............................................................................................................................................................................51 To save and name a file for the first time ....................................................................................... 52 2.3.1 To save any open file ............................................................................................................................... 52 2.3.2 To save a file as a template ................................................................................................................... 52 2.3.3 Saving a copy of a file with a new name or location ...................................................................52 2.3.4 Reverting to a backup copy ...................................................................................................................52 2.3.5 Restoring an auto-save file ....................................................................................................................53 2.3.6 About templates .................................................................................................................................................................... 53 Expanding tool buttons ......................................................................................................................................................53 Rearranging toolbars .......................................................................................................................................................... 54 Using the right mouse button ..........................................................................................................................................54 Undoing changes ...................................................................................................................................................................54
Chapter 3: Understanding Layers ............................................................................................ 55 3.1 3.2
Modeling with objects ........................................................................................................................................................ 55 Managing layers .................................................................................................................................................................... 55 Determining which plans contain objects ...................................................................................... 57 3.2.1
Chapter 4: Using Plans and Perspectives ................................................................................. 59 4.1 4.2 4.3
4.4 4.5
RAM Concept
Using plans .............................................................................................................................................................................. 59 Creating new plans .............................................................................................................................................................. 59 Viewing perspectives .......................................................................................................................................................... 59 Setting the projection .............................................................................................................................. 60 4.3.1 Selecting the modeling ............................................................................................................................60 4.3.2 Rotating the model ................................................................................................................................... 60 4.3.3 Creating new perspectives ............................................................................................................................................... 60 Controlling views ..................................................................................................................................................................60 Zooming to magnify or diminish ........................................................................................................ 61 4.5.1
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4.6
Panning to reposition .............................................................................................................................. 61 4.5.2 View History ................................................................................................................................................ 62 4.5.3 Regenerating ............................................................................................................................................... 62 4.5.4 Setting the visible objects ...................................................................................................................... 62 4.5.5 Changing colors, font, and line type .................................................................................................. 64 4.5.6 Changing font size ..................................................................................................................................... 65 4.5.7 Changing font scale ...................................................................................................................................66 4.5.8 Setting up the grid ................................................................................................................................................................66 To make the grid visible for a plan .................................................................................................... 67 4.6.1 To change the grid settings for a plan .............................................................................................. 67 4.6.2
Chapter 5: Drawing and Editing Objects .................................................................................. 68 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8
5.9 5.10 5.11
5.12 5.13
5.14 5.15 5.16
RAM Concept
Precision drawing with snaps .........................................................................................................................................68 Drawing objects .....................................................................................................................................................................69 Entering coordinate points .............................................................................................................................................. 69 Using relative coordinates ................................................................................................................................................69 Selecting objects ....................................................................................................................................................................70 To select an object or group of objects ............................................................................................ 70 5.5.1 To select only a single object ................................................................................................................70 5.5.2 Deselecting objects .............................................................................................................................................................. 70 To deselect an object or group of objects from a selection .....................................................70 5.6.1 To deselect only a single object from a selection ........................................................................ 71 5.6.2 Filtering selected objects .................................................................................................................................................. 71 Cutting, copying, and pasting objects .......................................................................................................................... 71 To cut objects .............................................................................................................................................. 71 5.8.1 To copy objects ...........................................................................................................................................71 5.8.2 To paste objects from the clipboard ................................................................................................. 71 5.8.3 Copying and pasting objects by layer .......................................................................................................................... 72 To append objects to the layer clipboard ....................................................................................... 72 5.9.1 To paste objects from the layer clipboard ......................................................................................72 5.9.2 Editing polygon objects ......................................................................................................................................................72 To add a node to a polygonal object ..................................................................................................73 5.10.1 To delete a node from a polygonal object .......................................................................................73 5.10.2 Moving, rotating, stretching, and mirroring objects ............................................................................................. 73 To move a selection ..................................................................................................................................73 5.11.1 To stretch the selection .......................................................................................................................... 74 5.11.2 To rotate a selection .................................................................................................................................74 5.11.3 To mirror the selection ...........................................................................................................................74 5.11.4 Using the Utility tool to move and stretch ................................................................................................................. 74 To move an object by one of its grips ............................................................................................... 74 5.12.1 To stretch an object by one of its grips ............................................................................................75 5.12.2 Manipulating the model as a whole ..............................................................................................................................75 To move the entire model ..................................................................................................................... 75 5.13.1 To rotate the entire model .................................................................................................................... 75 5.13.2 To mirror the entire model ...................................................................................................................75 5.13.3 To scale the entire model .......................................................................................................................76 5.13.4 Editing object properties ...................................................................................................................................................76 Setting default properties ................................................................................................................................................. 76 Adding reference lines, dimensions, and text notes ..............................................................................................76 To draw a line ............................................................................................................................................. 77 5.16.1 To draw a dimension line ...................................................................................................................... 77 5.16.2
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5.16.3
To draw text ................................................................................................................................................ 77
Chapter 6: Viewing Objects in Text Tables ............................................................................... 78 6.1
Customizing tables ...............................................................................................................................................................79 Choosing which rows and columns to show ................................................................................. 79 6.1.1 Sizing table columns ................................................................................................................................ 80 6.1.2 Sorting table rows .....................................................................................................................................80 6.1.3
Chapter 7: Choosing Units .......................................................................................................81 7.1 7.2 7.3
About units .............................................................................................................................................................................. 81 Selecting units ........................................................................................................................................................................ 81 Selecting the default units ..................................................................................................................... 81 7.2.1 Changing the units .................................................................................................................................... 81 7.2.2 Specifying report as zero ...................................................................................................................................................82
Chapter 8: Choosing Sign Convention ......................................................................................84 8.1 8.2
Selecting sign convention ................................................................................................................................................. 84 Default sign convention ..........................................................................................................................84 8.1.1 Changing the sign convention ..............................................................................................................86 8.1.2 About plot sign convention .............................................................................................................................................. 86
Chapter 9: Specifying Material Properties ............................................................................... 88 9.1 9.2
9.3 9.4
Viewing the available materials ..................................................................................................................................... 88 Material properties ..............................................................................................................................................................89 Concrete Mix ................................................................................................................................................89 9.2.1 PT Systems ................................................................................................................................................... 90 9.2.2 Reinforcing Bars ........................................................................................................................................ 91 9.2.3 SSR Systems .................................................................................................................................................91 9.2.4 Adding and deleting materials ........................................................................................................................................92 To add materials ........................................................................................................................................ 92 9.3.1 To delete materials .................................................................................................................................... 92 9.3.2 About post-tensioning systems ...................................................................................................................................... 92
Chapter 10: Specifying loadings .............................................................................................. 94 10.1 10.2 10.3 10.4 10.5 10.6 10.7 10.8 10.9
About default loadings ....................................................................................................................................................... 94 Viewing the loadings ........................................................................................................................................................... 95 Loading properties ...............................................................................................................................................................95 About loading types .............................................................................................................................................................96 Available loading types ...................................................................................................................................................... 96 About assembly loads ..............................................................................................................................97 10.5.1 About Transfer Loading Types ............................................................................................................98 10.5.2 Changing Loading Types ................................................................................................................................................... 98 Changing Analysis ................................................................................................................................................................ 98 Adding and deleting loadings ..........................................................................................................................................99 To add a loading .........................................................................................................................................99 10.8.1 To delete a loading ....................................................................................................................................99 10.8.2 About load pattern ............................................................................................................................................................... 99 How load patterns work ......................................................................................................................100 10.9.1 When to use load pattern ....................................................................................................................101 10.9.2 How load pattern can approximate moving loads ................................................................... 102 10.9.3
Chapter 11: Specifying Load Combinations ............................................................................103
RAM Concept
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11.1 11.2 11.3 11.4 11.5 11.6 11.7 11.8
About default load combinations ................................................................................................................................103 Viewing the load combinations ................................................................................................................................... 103 Rebuilding load combinations ......................................................................................................................................105 Adding and deleting load combinations .................................................................................................................. 105 To add a load combination ................................................................................................................. 105 11.4.1 To delete a load combination ............................................................................................................. 105 11.4.2 Load combination properties ....................................................................................................................................... 106 About group load combinations .................................................................................................................................. 106 About alternate envelope factors ................................................................................................................................107 Example of Alternate Load Factors .................................................................................................108 11.7.1 Summary of load combination types .........................................................................................................................108
Chapter 12: Selecting Design Rules ....................................................................................... 112 12.1 12.2 12.3 12.4
Using rule set designs ...................................................................................................................................................... 112 Rule set design properties ............................................................................................................................................. 113 Types of active rules .........................................................................................................................................................113 Adding and deleting rule set designs ........................................................................................................................ 114 To add a rule set design ....................................................................................................................... 114 12.4.1 To delete a rule set .................................................................................................................................115 12.4.2
Chapter 13: Using a CAD Drawing ......................................................................................... 116 13.1
Importing, verifying and viewing a drawing ..........................................................................................................116 Importing a CAD file .............................................................................................................................. 116 13.1.1 Checking the imported information ............................................................................................... 116 13.1.2 Making the drawing visible on other plans .................................................................................117 13.1.3
Chapter 14: Importing a Database from the RAM Structural System ..................................... 118 14.1 14.2 14.3 14.4 14.5 14.6
14.7
What can be imported from the RAM Structural System ................................................................................. 118 Controlling which concrete members are imported .......................................................................................... 118 Definition of the “import perimeter” ............................................................................................. 119 14.2.1 About load importation ...................................................................................................................................................119 Importing a database ........................................................................................................................................................ 121 Reimporting a database .................................................................................................................................................. 124 Resolving loading conflicts .................................................................................................................125 14.5.1 To reimport from the RAM Structural System ...........................................................................126 14.5.2 Limitations, Defaults and Assumptions ................................................................................................................... 127 Limitations ................................................................................................................................................ 127 14.6.1 Defaults ....................................................................................................................................................... 127 14.6.2 Assumptions ............................................................................................................................................. 128 14.6.3 Tight integration with the RAM Structural System .............................................................................................129
Chapter 15: Data Transfer from STAAD ................................................................................. 130 15.1 15.2
STAAD Interface ................................................................................................................................................................. 130 RAM Concept Interface ....................................................................................................................................................130 Data Transfer Paths ............................................................................................................................... 130 15.2.1 New file options in RAM Concept .................................................................................................... 130 15.2.2 Update file options in RAM Concept ...............................................................................................132 15.2.3
Chapter 16: Data Transfer from ISM ......................................................................................133 16.1
RAM Concept
What is ISM? .........................................................................................................................................................................133 Purpose ....................................................................................................................................................... 133 16.1.1
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16.2
16.3
ISM and Application Data ....................................................................................................................133 16.1.2 ISM Sync Tools Overview ............................................................................................................................................... 134 Create ISM Repository ..........................................................................................................................134 16.2.1 Create RAM Concept File .....................................................................................................................135 16.2.2 Update ISM Repository ........................................................................................................................ 137 16.2.3 Update RAM Concept Model .............................................................................................................. 137 16.2.4 Import and Export Details ............................................................................................................................................. 137 Filtering ...................................................................................................................................................... 137 16.3.1 The ISM Model ......................................................................................................................................... 139 16.3.2 Slabs and Openings ................................................................................................................................139 16.3.3 Support Members ...................................................................................................................................141 16.3.4 ISM Section Shapes ................................................................................................................................ 142 16.3.5 ISM Load Cases and Loads ..................................................................................................................143 16.3.6 Member Loading ..................................................................................................................................... 146 16.3.7 Rebar ............................................................................................................................................................147 16.3.8 ISM Options dialog .................................................................................................................................. 149 16.3.9
Chapter 17: Data Transfer from API ........................................................................................ 151 Chapter 18: Bentley iTwin Services Features ...........................................................................152 18.1 18.2 18.3
What is iTwin Design Review? ...................................................................................................................................... 152 Applications of iTwins Design Review .......................................................................................................................152 Starting an iTwin Design Review Session ................................................................................................................ 153
Chapter 19: Bentley CONNECT Features ..................................................................................154 19.1
19.2 19.3 19.4
CONNECTED Project Association .................................................................................................................................154 To Associate a CONNECTED Project with Your File ................................................................. 154 19.1.1 To Disassociate a CONNECTED Project from a File .................................................................. 155 19.1.2 Assign Project dialog ..............................................................................................................................156 19.1.3 Register a CONNECTED Project .........................................................................................................156 19.1.4 Bentley CONNECT Advisor ............................................................................................................................................ 158 Automated Updates via the CONNECTION Client .................................................................................................159 Subscription Entitlement Service ................................................................................................................................ 159
Chapter 20: Defining the Structure ........................................................................................160 20.1 20.2 20.3
20.4 20.5 20.6 20.7 20.8 20.9 20.10
RAM Concept
Using the Mesh Input Layer ...........................................................................................................................................160 About columns and walls ............................................................................................................................................... 160 Column properties .............................................................................................................................................................160 General column properties .................................................................................................................160 20.3.1 Meshing column properties ............................................................................................................... 162 20.3.2 Live load reduction column properties .........................................................................................162 20.3.3 Drawing columns ............................................................................................................................................................... 162 To draw a column ...................................................................................................................................163 20.4.1 To copy columns from below to above ......................................................................................... 163 20.4.2 Wall properties ................................................................................................................................................................... 163 Drawing walls ......................................................................................................................................................................164 To draw a wall ..........................................................................................................................................164 20.6.1 To copy walls from below to above ................................................................................................ 164 20.6.2 About point and line supports ......................................................................................................................................165 Point support properties ................................................................................................................................................ 165 Drawing point supports .................................................................................................................................................. 165 Line support properties .................................................................................................................................................. 166
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20.11 20.12 20.13 20.14 20.15 20.16 20.17 20.18 20.19 20.20 20.21 20.22 20.23 20.24 20.25 20.26 20.27
Drawing line supports ..................................................................................................................................................... 166 About springs .......................................................................................................................................................................167 Point spring properties ................................................................................................................................................... 167 Drawing point springs ..................................................................................................................................................... 167 Line spring properties ..................................................................................................................................................... 168 Drawing line springs ........................................................................................................................................................ 168 Area spring properties .................................................................................................................................................... 168 Drawing area springs ....................................................................................................................................................... 169 About floor areas and members .................................................................................................................................. 170 The priority method .............................................................................................................................. 170 20.19.1 Meshing beams as slabs .......................................................................................................................170 20.19.2 Slab area properties ..........................................................................................................................................................172 Drawing slab areas ............................................................................................................................................................174 About beams ........................................................................................................................................................................ 175 Beam properties .................................................................................................................................................................175 Drawing beams ................................................................................................................................................................... 176 To draw a beam .......................................................................................................................................176 20.24.1 To define mitered corners on a beam ............................................................................................177 20.24.2 Slab opening properties ..................................................................................................................................................177 Drawing slab openings .................................................................................................................................................... 177 Checking the structure definition ............................................................................................................................... 177
Chapter 21: Generating the Mesh ......................................................................................... 178 21.1
21.2
Generating the mesh automatically ........................................................................................................................... 178 Deciding what mesh element size to use ......................................................................................178 21.1.1 Limitations of the automatic meshing ...........................................................................................179 21.1.2 Viewing the finite element mesh ..................................................................................................... 180 21.1.3 Improving the mesh .............................................................................................................................. 180 21.1.4 Selectively refining the mesh ........................................................................................................................................182 Using point and line supports to refine the mesh .................................................................... 183 21.2.1
Chapter 22: Manually Drawing the Finite Elements ................................................................185 22.1 22.2 22.3 22.4 22.5 22.6
22.7 22.8 22.9 22.10 22.11 22.12 22.13 22.14
RAM Concept
Using the Element layer .................................................................................................................................................. 185 About column elements and wall elements ............................................................................................................185 Column element properties ...........................................................................................................................................185 Drawing column elements ............................................................................................................................................. 186 To draw a column element .................................................................................................................186 22.4.1 To copy columns from below to above ......................................................................................... 186 22.4.2 Wall element properties ................................................................................................................................................. 187 Drawing wall elements ....................................................................................................................................................187 To draw wall elements on slab elements ..................................................................................... 187 22.6.1 To draw wall elements where there are no slab elements ...................................................188 22.6.2 To copy walls from below to above ................................................................................................ 188 22.6.3 About point and line supports ......................................................................................................................................188 Point support properties ................................................................................................................................................ 188 Drawing point supports .................................................................................................................................................. 189 Line support properties .................................................................................................................................................. 189 Drawing line supports ..................................................................................................................................................... 189 About springs .......................................................................................................................................................................189 Point spring properties ................................................................................................................................................... 190 Drawing point springs ..................................................................................................................................................... 190
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22.15 22.16 22.17 22.18 22.19 22.20 22.21
22.22
Line spring properties ..................................................................................................................................................... 190 Drawing line springs ........................................................................................................................................................ 191 Area spring properties .................................................................................................................................................... 191 Drawing area springs ....................................................................................................................................................... 191 About floor areas ................................................................................................................................................................191 Slab element properties ..................................................................................................................................................192 Drawing the slab elements ............................................................................................................................................ 193 To draw a rectangular slab mesh area .......................................................................................... 193 22.21.1 To draw a polygon slab mesh area ................................................................................................. 193 22.21.2 To draw a single mesh element ........................................................................................................193 22.21.3 A few final words ............................................................................................................................................................... 194
Chapter 23: Drawing Loads ................................................................................................... 195 23.1 23.2 23.3 23.4 23.5 23.6 23.7 23.8 23.9 23.10 23.11 23.12 23.13
About self-weight ...............................................................................................................................................................195 About superposition of loads ........................................................................................................................................195 Point load properties ....................................................................................................................................................... 196 Drawing point loads ......................................................................................................................................................... 196 Line load properties ..........................................................................................................................................................196 Drawing line loads .............................................................................................................................................................197 Standard line load .................................................................................................................................. 197 23.6.1 Perimeter line load ................................................................................................................................ 198 23.6.2 Area load properties .........................................................................................................................................................198 Drawing area loads ........................................................................................................................................................... 199 Copying loads ...................................................................................................................................................................... 199 Temperature Area Load properties ............................................................................................................................200 Drawing temperature area loads ................................................................................................................................. 200 Shrinkage Area Load Properties .................................................................................................................................. 201 Drawing shrinkage area loads .......................................................................................................................................201
Chapter 24: Creating Pattern Loading ....................................................................................203 24.1 24.2 24.3
Deciding how many load patterns to use ................................................................................................................ 203 Drawing load patterns ..................................................................................................................................................... 204 Load pattern filtering ....................................................................................................................................................... 205 Effect of mesh on load pattern ..........................................................................................................205 24.3.1
Chapter 25: Defining Design Strips ........................................................................................ 211 25.1 25.2 25.3 25.4 25.5 25.6 25.7 25.8 25.9
RAM Concept
Definition of a design strip .............................................................................................................................................211 Design strip terminology ................................................................................................................................................211 Understanding how a design strip works ............................................................................................................... 212 The design strip process .................................................................................................................................................213 Span segment properties ................................................................................................................................................214 Creating span segments .................................................................................................................................................. 224 Generating span segments automatically .................................................................................... 225 25.6.1 Drawing span segments manually .................................................................................................. 225 25.6.2 Creating span segment strips (design strips) .........................................................................................................226 To generate span segment strips .....................................................................................................226 25.7.1 To generate some span segment strips .........................................................................................226 25.7.2 Defining span segment widths and strip widths manually ............................................................................. 227 Defining span segment boundaries manually ............................................................................227 25.8.1 Defining strip boundaries manually ...............................................................................................228 25.8.2 Cross Section Trimming ..................................................................................................................................................233
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25.10 25.11 25.12
25.13 25.14
About cross section trimming ........................................................................................................... 233 25.9.1 About shear core .....................................................................................................................................234 25.9.2 Shear core in slabs ................................................................................................................................. 236 25.9.3 Viewing a perspective of design strip cross sections ..............................................................236 25.9.4 Single Cross Section Trimming .........................................................................................................237 25.9.5 Selecting cross section trimming .....................................................................................................240 25.9.6 Inter Cross Section Slope Limit Trimming .................................................................................. 240 25.9.7 Improving the mesh ..........................................................................................................................................................242 Additional design strip information .......................................................................................................................... 242 Irregular column layouts ................................................................................................................................................ 243 Design Strip Skew Angles ....................................................................................................................243 25.12.1 Effect of tendon components on design strip cross sections ...............................................247 25.12.2 Examples of irregular grids ................................................................................................................249 25.12.3 Drawing design strips near walls ..................................................................................................... 263 25.12.4 Changing from PT to RC design ........................................................................................................ 264 25.12.5 Miscellaneous tips ............................................................................................................................................................. 264 A final word on design strips ........................................................................................................................................ 265
Chapter 26: Defining Design Sections .................................................................................... 266 26.1 26.2 26.3 26.4
26.5
Using design sections ....................................................................................................................................................... 266 Design section properties ................................................................................................................................................266 Drawing design sections .................................................................................................................................................269 About ignore depths ......................................................................................................................................................... 270 When to use ignore depths .................................................................................................................270 26.4.1 Examples of concrete form that should use ignore depth .................................................... 270 26.4.2 Effect of ignore depth on reinforcement location .................................................................... 273 26.4.3 A final word on design sections ...................................................................................................................................273
Chapter 27: Defining Punching Shear Checks .........................................................................274 27.1 27.2
27.3 27.4
About punching shear checks .......................................................................................................................................274 Punching shear check properties and options ......................................................................................................274 General ........................................................................................................................................................ 274 27.2.1 Ancon Shearfix Parameters ................................................................................................................277 27.2.2 AS3600 specific options .......................................................................................................................277 27.2.3 BS 8110/EC2 specific options ...........................................................................................................277 27.2.4 Drawing punching shear checks ................................................................................................................................. 278 A final word on punching shear checks ................................................................................................................... 278
Chapter 28: Drawing Reinforcement Bars ............................................................................. 279 28.1 28.2 28.3 28.4 28.5 28.6
RAM Concept
Reinforcement bar definitions ..................................................................................................................................... 279 About User and Program Reinforcement .....................................................................................279 28.1.1 Reinforcement object types ................................................................................................................ 279 28.1.2 Reinforcement properties ..............................................................................................................................................280 Transverse Reinforcement properties ...................................................................................................................... 282 About drawing reinforcement ......................................................................................................................................284 Expected workflows ..............................................................................................................................284 28.4.1 Drawing concentrated reinforcement ...................................................................................................................... 284 Drawing concentrated reinforcement ...........................................................................................284 28.5.1 Drawing concentrated reinforcement in two directions .......................................................285 28.5.2 Drawing distributed reinforcement .......................................................................................................................... 285 Drawing distributed reinforcement ............................................................................................... 285 28.6.1
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28.7 28.8 28.9 28.10
28.11 28.12
28.13
Drawing transverse reinforcement .............................................................................................................................286 Drawing transverse reinforcement ................................................................................................. 286 28.7.1 Concentrated and distributed reinforcement drawing examples ................................................................ 286 Transverse reinforcement drawing examples ....................................................................................................... 291 Other reinforcement plan tools ................................................................................................................................... 293 The Orient Reinforcement tool .........................................................................................................293 28.10.1 The Skew Reinforcement Extent tool ............................................................................................ 294 28.10.2 Auto Hook tool ......................................................................................................................................... 294 28.10.3 Layout and Detailing Parameters ............................................................................................................................... 298 Reinforcement Text Formatting ...................................................................................................................................299 Concentrated and distributed reinforcement callouts ...........................................................299 28.12.1 Transverse reinforcement callouts ..................................................................................................300 28.12.2 SSR Callout .................................................................................................................................................301 28.12.3 Examples of reinforcement text formatting ................................................................................302 28.12.4 About SSR callouts and SSR rails: ............................................................................................................................... 302
Chapter 29: Defining Tendons ............................................................................................... 303 29.1 29.2
29.3 29.4 29.5
29.6 29.7 29.8
29.9
29.10 29.11 29.12
RAM Concept
Tendon definitions ............................................................................................................................................................ 303 Post-Tensioning terminology and definitions ........................................................................... 303 29.1.1 Using the latitude and longitude prestressing folders ........................................................... 304 29.1.2 Tendon Parameters Layer ............................................................................................................................................. 304 Tendon Parameters object types .....................................................................................................304 29.2.1 Banded Tendon Polyline and Distributed Tendon Quadrilateral Properties ...............305 29.2.2 Distributed Tendon Overlap and Tendon Void Properties .................................................. 308 29.2.3 Profile Polyline Properties ................................................................................................................. 308 29.2.4 Jack Region Properties .......................................................................................................................... 309 29.2.5 Tendon Parameters Group ............................................................................................................................................. 310 Viewing the Tendon Parameters Group ........................................................................................ 310 29.3.1 Manual Tendon Layer ....................................................................................................................................................... 310 Tendon properties ................................................................................................................................. 311 29.4.1 About creating tendons ...................................................................................................................................................312 All tendon definition done on the tendon parameters layers ............................................. 313 29.5.1 Most tendon definition done on the tendon parameters layers ........................................ 313 29.5.2 All work done on manual tendon layers .......................................................................................313 29.5.3 Drawing banded tendon polylines ............................................................................................................................. 313 Drawing distributed tendon quadrilaterals ........................................................................................................... 314 Defining profiles for banded tendon polylines and distributed tendon quadrilaterals ......................314 Drawing Profile Polylines ................................................................................................................... 315 29.8.1 Defining profile polylines using the Generate Profile Polylines tool ............................... 315 29.8.2 Defining span polylines using the Generate Span Polylines tool .......................................316 29.8.3 Other tendon parameter plan objects and tools ...................................................................................................317 Drawing Tendon Voids .........................................................................................................................317 29.9.1 Drawing Jack Regions ............................................................................................................................ 317 29.9.2 Split banded tendon polyline tool ................................................................................................... 317 29.9.3 Split profile polyline tool ......................................................................................................................318 29.9.4 Generate program tendons tool ....................................................................................................... 318 29.9.5 Tendon parameter drawing examples ..................................................................................................................... 318 Tendon parameter drawing and text formatting .................................................................................................319 Banded tendon polyline formatting options ...............................................................................319 29.11.1 Distributed tendon quadrilateral formatting options ............................................................ 320 29.11.2 Optimization parameters for tendons ....................................................................................................................... 321
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29.13 29.14
29.15 29.16 29.17 29.18 29.19
About drawing individual tendons ............................................................................................................................ 322 Drawing single tendons .................................................................................................................................................. 322 Drawing a half-span tendon ...............................................................................................................323 29.14.1 Drawing a full-span tendon ................................................................................................................323 29.14.2 Drawing a multi-span tendon with the tendon polyline ....................................................... 323 29.14.3 Drawing multiple tendons ............................................................................................................................................. 323 Tendon panel layout options .............................................................................................................324 29.15.1 Editing tendons ...................................................................................................................................................................328 Calc profile tool ........................................................................................................................................328 29.16.1 Change profiles tool ...............................................................................................................................328 29.16.2 About jacks ........................................................................................................................................................................... 329 Jack properties .................................................................................................................................................................... 329 Drawing the jacks .............................................................................................................................................................. 330
Chapter 30: Designing and Optimizing Post-tensioning ........................................................... 331 30.1 30.2 30.3 30.4
30.5
30.6
What does RAM Concept’s optimization achieve? ................................................................................................331 What doesn’t RAM Concept’s optimization achieve? .......................................................................................... 331 How does the optimization work? ...............................................................................................................................332 Optimizable Objects ...........................................................................................................................................................332 Banded Tendon Polyline ...................................................................................................................... 332 30.4.1 Distributed Tendon Quadrilateral ....................................................................................................333 30.4.2 Profile Polylines ....................................................................................................................................... 334 30.4.3 Optimization Regions .............................................................................................................................335 30.4.4 The Optimization Process ............................................................................................................................................... 337 Defining Tendons and Profile Polylines .........................................................................................337 30.5.1 Setting Optimizable Properties ......................................................................................................... 338 30.5.2 Defining Optimization Regions ..........................................................................................................338 30.5.3 Starting an Optimization ...................................................................................................................... 339 30.5.4 Saving Optimization Data .....................................................................................................................340 30.5.5 Monitoring a Running Optimization ................................................................................................341 30.5.6 How Optimization Achieves Better Designs ............................................................................................................344 Slab Thickness Comparison Analysis ..............................................................................................344 30.6.1
Chapter 31: Using Live Load Reduction ................................................................................. 346 31.1 31.2 31.3 31.4 31.5 31.6 31.7
About Live Load Reduction ........................................................................................................................................... 346 Live Load Reduction Options ........................................................................................................................................346 Setting the Live Load Reduction Code ...................................................................................................................... 346 Live Loading Types ........................................................................................................................................................... 347 Live Load Reduction Parameters ................................................................................................................................348 Specifying Live Load Reduction Parameters ......................................................................................................... 348 Implementation of Live Load Reduction ................................................................................................................. 349
Chapter 32: Calculating Results ............................................................................................. 350 32.1
RAM Concept
Calculating the results ..................................................................................................................................................... 350 Calculating all of the results ...............................................................................................................350 32.1.1 Partially calculating the results ........................................................................................................350 32.1.2 Calculation options ................................................................................................................................ 351 32.1.3 General options ....................................................................................................................................... 352 32.1.4 Code options ............................................................................................................................................. 353 32.1.5 Zero tension iteration options .......................................................................................................... 353 32.1.6 Reinforcement layout and detailing parameters ......................................................................354 32.1.7
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32.2 32.3 32.4 32.5 32.6
32.7
Load History / ECR tab ..........................................................................................................................354 32.1.8 Vibration options .....................................................................................................................................357 32.1.9 About analysis errors .......................................................................................................................................................360 Recalculating ........................................................................................................................................................................360 Calculating load history deflections ...........................................................................................................................360 Calculating vibration analysis ...................................................................................................................................... 361 Reviewing the calc log ..................................................................................................................................................... 361 To open the Calc Log ............................................................................................................................. 361 32.6.1 To open the Load History Calc Log ................................................................................................. 361 32.6.2 To open the Vibration Calc Log ........................................................................................................ 361 32.6.3 Decreasing calculation time .......................................................................................................................................... 361
Chapter 33: Viewing the Results ........................................................................................... 363 33.1 33.2
33.3
33.4
33.5
Type of results .....................................................................................................................................................................363 Viewing frequently used results ..................................................................................................................................363 Viewing reinforcement results ......................................................................................................... 364 33.2.1 Viewing status ..........................................................................................................................................364 33.2.2 Viewing deflections ............................................................................................................................... 365 33.2.3 Viewing support reactions ................................................................................................................. 365 33.2.4 Viewing post-tensioning precompression (P/A) ......................................................................366 33.2.5 Viewing balanced load percentages ............................................................................................... 366 33.2.6 Viewing bending moment contours ............................................................................................... 367 33.2.7 Viewing section stresses ..................................................................................................................... 367 33.2.8 Viewing punching shear results .......................................................................................................367 33.2.9 Viewing live load reduction results ................................................................................................ 368 33.2.10 Viewing soil bearing pressures ........................................................................................................ 368 33.2.11 Viewing other results ....................................................................................................................................................... 369 Changing which result objects are visible ................................................................................... 369 33.3.1 Changing which results plot .............................................................................................................. 369 33.3.2 Creating new result plans ................................................................................................................... 370 33.3.3 Section distribution plots ............................................................................................................................................... 372 Distribution plot values ....................................................................................................................... 372 33.4.1 Moment distribution plots ..................................................................................................................372 33.4.2 Shear distribution plots ....................................................................................................................... 373 33.4.3 Axial force distribution plots .............................................................................................................374 33.4.4 Selected distribution plots ..................................................................................................................374 33.4.5 Effects of averaging ................................................................................................................................374 33.4.6 Summary .................................................................................................................................................... 375 33.4.7 Miscellaneous results information .............................................................................................................................375 Top and bottom longitudinal reinforcement ..............................................................................375 33.5.1 Reinforcement bar lengths .................................................................................................................376 33.5.2 Orientation of reinforcement ............................................................................................................ 376 33.5.3 Shear reinforcement ............................................................................................................................. 377 33.5.4 Punching Shear Results ........................................................................................................................377 33.5.5
Chapter 34: Plotting Results ..................................................................................................379 34.1 34.2 34.3
RAM Concept
Setting the plotted results ..............................................................................................................................................379 Slab ...........................................................................................................................................................................................379 About slab plotting contexts .............................................................................................................. 380 34.2.1 Max and Min context slab plot limitations ...................................................................................381 34.2.2 Reaction ................................................................................................................................................................................. 382
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34.4 34.5 34.6 34.7 34.8 34.9 34.10
Strip ...........................................................................................................................................................................................386 Section Analysis ..................................................................................................................................................................388 Section Design ..................................................................................................................................................................... 389 About section design “context” plots ............................................................................................. 390 34.6.1 About skyline plots ................................................................................................................................ 391 34.6.2 Punching Analysis ..............................................................................................................................................................392 Punching Shear Results ........................................................................................................................393 34.7.1 Vibration Analysis ............................................................................................................................................................. 394 Vibration Results .................................................................................................................................... 394 34.8.1 Plot Animation Controls ...................................................................................................................................................395 Playing the Animation ........................................................................................................................... 396 34.9.1 Difference Plot Controls ..................................................................................................................................................396
Chapter 35: Using the Auditor ...............................................................................................398 35.1 35.2 35.3 35.4 35.5 35.6 35.7
How the Auditor can assist the design process .................................................................................................... 398 About the three design steps ........................................................................................................................................ 398 About the information displayed by the Auditor .................................................................................................399 Using the Auditor ............................................................................................................................................................... 401 To use the Auditor for the design summary ............................................................................... 401 35.4.1 Using the Auditor for guidance on post-tensioning ............................................................................................401 About the information displayed by the Punching Check Auditor ...............................................................402 Using the Punching Check Auditor .............................................................................................................................403 To use the Auditor for the design summary ............................................................................... 403 35.7.1
Chapter 36: Using the Report Viewer .................................................................................... 404 36.1 36.2 36.3 36.4 36.5 36.6
Using the Report Viewer .................................................................................................................................................404 Collapsing Sections ............................................................................................................................................................404 Searching for Text ..............................................................................................................................................................404 Saving Reports .................................................................................................................................................................... 405 Saving One Report ...................................................................................................................................405 36.4.1 Saving All Reports .................................................................................................................................. 405 36.4.2 Opening Previously Saved Reports ............................................................................................................................ 405 Printing Reports ................................................................................................................................................................. 406
Chapter 37: Using the estimate ............................................................................................. 407 37.1 37.2 37.3 37.4
Viewing the estimate ........................................................................................................................................................407 What the estimate calculates ........................................................................................................................................ 407 Editing the unit costs ........................................................................................................................................................407 About unit costs ..................................................................................................................................................................408
Chapter 38: Printing ..............................................................................................................409 38.1 38.2
38.3
RAM Concept
Basic printing instructions ............................................................................................................................................ 409 To print the report ................................................................................................................................. 409 38.1.1 General printing options .................................................................................................................................................410 Printer selection ......................................................................................................................................410 38.2.1 Page range ................................................................................................................................................. 410 38.2.2 Number of copies ....................................................................................................................................410 38.2.3 Printing to PDF ........................................................................................................................................ 410 38.2.4 Select and Configure Printer options ........................................................................................................................ 410 To change the print setup options .................................................................................................. 411 38.3.1 Printer selection ......................................................................................................................................411 38.3.2
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38.4
38.5 38.6
38.7 38.8
Paper size and source ........................................................................................................................... 411 38.3.3 Default orientation .................................................................................................................................411 38.3.4 Margin size ................................................................................................................................................ 411 38.3.5 Determining the fit of plans ...........................................................................................................................................412 To specify the print scale .................................................................................................................... 412 38.4.1 To specify the printed area on the plan ........................................................................................ 412 38.4.2 To specify the printed area with coordinates ............................................................................ 412 38.4.3 Printing the desired perspective viewpoint ...........................................................................................................412 To show the set print viewpoint on screen .................................................................................413 38.5.1 Previewing the print job ................................................................................................................................................. 413 To preview the active window print job ...................................................................................... 413 38.6.1 To preview the report print job ....................................................................................................... 413 38.6.2 Zooming ...................................................................................................................................................... 414 38.6.3 Viewing multiple pages at once ........................................................................................................414 38.6.4 Paging through the print job ..............................................................................................................414 38.6.5 Printing optimizations .....................................................................................................................................................414 Customizing page orientation ........................................................................................................... 414 38.7.1 Customizing the printed appearance of plans and perspectives .......................................415 38.7.2 Changing the report contents .......................................................................................................................................415 Including items in the report .............................................................................................................416 38.8.1 Reordering report items ......................................................................................................................418 38.8.2
Chapter 39: Exporting Plans and Tables ................................................................................ 419 39.1 39.2
Exporting a plan ................................................................................................................................................................. 419 Selecting the text size ............................................................................................................................419 39.1.1 Exporting a table ................................................................................................................................................................ 419
Chapter 40: Exporting a Database to the RAM Structural System .......................................... 421 40.1
40.2
About the export of reactions .......................................................................................................................................421 Special handling of the Self-Dead Loading and the Balance Loading during export .421 40.1.1 Special handling of the Partition Loading during export ....................................................... 422 40.1.2 The export of reactions process .......................................................................................................422 40.1.3 About export reactions access and consistency checking .................................................... 423 40.1.4 Checks performed before choosing export stories .................................................................. 423 40.1.5 Checks performed after choosing export stories ......................................................................424 40.1.6 Using RAM Concept reactions in RAM Concrete ....................................................................... 424 40.1.7 How the RAM Structural System - RAM Concept link works ...............................................424 40.1.8 About the export of geometry ...................................................................................................................................... 425 About errors and ambiguities ........................................................................................................... 427 40.2.1
Chapter 41: Using Strip Wizard ............................................................................................. 428 41.1 41.2 41.3
41.4 41.5
RAM Concept
Starting Strip Wizard ........................................................................................................................................................428 Specifying general parameters .................................................................................................................................... 428 Entering span data ............................................................................................................................................................ 429 One-way and two-way systems ........................................................................................................429 41.3.1 Beam systems ...........................................................................................................................................430 41.3.2 Joist systems ............................................................................................................................................. 430 41.3.3 Entering support data ......................................................................................................................................................430 Support (above and below) properties .........................................................................................431 41.4.1 Adding drop caps and drop panels .............................................................................................................................431 Drop cap and drop panel properties ..............................................................................................431 41.5.1
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41.6 41.7
41.8
41.9 41.10 41.11
Entering the loads ..............................................................................................................................................................431 Load properties ....................................................................................................................................... 432 41.6.1 Specifying the post-tensioning .....................................................................................................................................432 General PT information ....................................................................................................................... 432 41.7.1 Balance load ..............................................................................................................................................432 41.7.2 Profiling ...................................................................................................................................................... 433 41.7.3 Specifying reinforcement ............................................................................................................................................... 433 Reinforcing bar ........................................................................................................................................ 433 41.8.1 Reinforcement clear cover ................................................................................................................. 433 41.8.2 Punching shear checks ......................................................................................................................... 434 41.8.3 Completing Strip Wizard ................................................................................................................................................ 434 Generating the mesh and calculating results .........................................................................................................434 Loading and saving Strip Wizard settings ...............................................................................................................434 To load strip wizard settings .............................................................................................................435 41.11.1 To save Strip Wizard settings ............................................................................................................435 41.11.2
Chapter 42: General Tips .......................................................................................................436 42.1 42.2
42.3 42.4
Beams ......................................................................................................................................................................................436 Walls ........................................................................................................................................................................................ 437 Drawing connecting walls ...................................................................................................................437 42.2.1 Walls above ................................................................................................................................................ 437 42.2.2 The difference between walls above and upstand beams of similar proportions ..... 438 42.2.3 Restraint ................................................................................................................................................................................ 438 Miscellaneous ...................................................................................................................................................................... 439 Templates .................................................................................................................................................. 439 42.4.1 Adding plans ............................................................................................................................................. 439 42.4.2 Copying and moving objects ..............................................................................................................439 42.4.3 Expanding tool buttons ........................................................................................................................439 42.4.4 The Utility tool ......................................................................................................................................... 440 42.4.5 Left Wall and Right Wall tools ...........................................................................................................440 42.4.6 Changing multiple tendon profile points ..................................................................................... 440 42.4.7 Plotting Results ........................................................................................................................................440 42.4.8 Reducing the information shown on plans ................................................................................. 440 42.4.9 Load balancing .........................................................................................................................................440 42.4.10 The Auditor ............................................................................................................................................... 441 42.4.11
Chapter 43: Frequently Asked Questions .............................................................................. 442 43.1 43.2 43.3 43.4 43.5 43.6 43.7
43.8 43.9
RAM Concept
Capabilities and Modeling ..............................................................................................................................................442 Files ..........................................................................................................................................................................................443 Plans and perspectives .................................................................................................................................................... 444 Units .........................................................................................................................................................................................445 Codes ....................................................................................................................................................................................... 445 Sign Conventions ................................................................................................................................................................446 Structure ................................................................................................................................................................................ 446 Mesh Input layer ..................................................................................................................................... 446 43.7.1 Element layer ........................................................................................................................................... 447 43.7.2 Columns ...................................................................................................................................................... 447 43.7.3 Walls .............................................................................................................................................................447 43.7.4 Mats (rafts) ................................................................................................................................................448 43.7.5 Tendons ..................................................................................................................................................................................449 Loadings .................................................................................................................................................................................452
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43.10 43.11 43.12
43.13
Lateral Self Equilibrium Example .....................................................................................................452 43.9.1 Analysis .................................................................................................................................................................................. 454 Design Issues ....................................................................................................................................................................... 454 Results .................................................................................................................................................................................... 454 Reactions .................................................................................................................................................... 455 43.12.1 Plots ..............................................................................................................................................................455 43.12.2 Torsion ........................................................................................................................................................ 457 43.12.3 Envelopes ...................................................................................................................................................457 43.12.4 Reinforcement ......................................................................................................................................... 457 43.12.5 AS3600 specific reinforcement questions ................................................................................... 458 43.12.6 BS8110 / TR43 specific reinforcement questions ................................................................... 459 43.12.7 Punching Shear ........................................................................................................................................460 43.12.8 Shear reinforcement (one-way) .......................................................................................................462 43.12.9 Deflection ................................................................................................................................................... 463 43.12.10 Soil bearing ................................................................................................................................................463 43.12.11 Performance .........................................................................................................................................................................464
Chapter 44: Warnings and Errors ........................................................................................... 465 44.1 44.2
44.3
44.4
RAM Concept
To show an object number ............................................................................................................................................ 465 Meshing ................................................................................................................................................................................... 465 Two or more slab areas or beams with the same priority overlap at (x,y) ...................465 44.2.1 Two or more beam areas overlap with conflicting stiffnesses at (x,y) ............................ 466 44.2.2 Vertical gaps in beam elevation at (x,y) .........................................................................................466 44.2.3 Different concrete mixes specified at (x,y) ...................................................................................466 44.2.4 Line is too short at (x,y) ....................................................................................................................... 466 44.2.5 Feature eliminated at (x,y) ................................................................................................................. 467 44.2.6 Recursion too deep ................................................................................................................................ 467 44.2.7 An error has been found. Two column elements below the slab are at the same 44.2.8 location. Delete column element #a or #b. ..................................................................................467 An error has been found. A column element below the slab is not attached to the slab. 44.2.9 Revise column element #a (below the slab) ...............................................................................467 It is good modeling practice to connect wall centerlines. Click on the Fix button to 44.2.10 move wall endpoints to a nearby centerline .............................................................................. 468 Loads ....................................................................................................................................................................................... 468 An error has occurred while assembling the load vector. A point load is not on the 44.3.1 slab. Revise point load #a. .................................................................................................................. 468 An error has occurred while assembling the load vector. A line load is not totally on 44.3.2 the slab. Revise line load #a. ..............................................................................................................468 An error has occurred while assembling the load vector. A tendon is not totally on the 44.3.3 slab. Revise the tendon at #a. .............................................................................................................468 An error has occurred while assembling the load vector. An area load is not on the 44.3.4 slab. Revise area load #a. ..................................................................................................................... 469 Tendons ..................................................................................................................................................................................469 Tendon #a has a radius (b) that is less than the minimum allowable (c). .....................469 44.4.1 Tendon #a is harped, and hence violates the minimum allowable radius (b) .............469 44.4.2 Tendon #a is a simple parabola, and hence violates the minimum allowable radius (b) 470 44.4.3 Cannot auto-position profile point at (x,y) due to profile point value ............................ 470 44.4.4 Cannot auto-position the profile elevation for tendon (a) at (b) because the tendon 44.4.5 represents a partial half span .............................................................................................................470 An error has occurred while trying to calculate a profile. A profile point is not on the 44.4.6 slab. Click on the Fix button to correct the profile point at (x,y). ...................................... 470
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Tendon is not on slab at (a). ................................................................................................................470 Tendon elevation conflict at (a) (Profile Point above slab soffit step?) ...........................471 An error has occurred while trying to calculate a profile. A profile point is not within the slab (vertically). Adjust the profile at (x,y). .........................................................................471 An error has occurred while trying to calculate the tendon profiles. A tendon is out of 44.4.10 the slab at (x,y). ....................................................................................................................................... 471 An error has occurred while trying to calculate the tendon effective stresses. A tendon 44.4.11 has a different number of strands than an adjacent tendon. Investigate tendon #a. 471 An error has occurred while trying to calculate the tendon effective stresses. Two 44.4.12 connected tendons have inconsistent half span ratios. Revise tendon #a. ................... 471 An error has occurred while trying to calculate the tendon effective stresses. Two 44.4.13 connected tendons have different post-tensioning systems. Revise tendon #a. ......... 472 An error has occurred while trying to calculate the tendon effective stresses. A tendon 44.4.14 is not connected to any jacks. Investigate tendon #a. [If any tendons are stressed then all tendons must be stressed.] .......................................................................................................... 472 An error has occurred while trying to calculate the tendon effective stresses. A tendon 44.4.15 is stressed by two jacks with different wobble friction coefficients/with different angular friction coefficients/with different long-term losses. .............................................472 An error has occurred while trying to calculate the tendon effective stresses. A tendon 44.4.16 is connected with other tendons in a circular fashion. Revise tendon (a) ......................472 An error has occurred while trying to calculate the tendon effective stresses. A tendon 44.4.17 is jacked to a stress higher than its yield stress. Revise the jack connected to tendon #a .................................................................................................................................................................... 473 An error has occurred while trying to stress a tendon. There are no tendons at a jack/ 44.4.18 There are multiple tendons at a jack. Investigate jack #a ......................................................473 Load History Deflections ................................................................................................................................................ 473 An error has been found while calculating load history deflections. The floor may have 44.5.1 incomplete design strip/cross section coverage to accurately calculate load history deflections. The slab coverages are a and b in orthogonal directions .............................473 Optimization ......................................................................................................................................................................... 473 Miscellaneous ...................................................................................................................................................................... 475 An error has occurred while triangularizing the stiffness matrix. The structure is 44.7.1 unstable at (a). Revise the structure. ............................................................................................. 475 An error has occurred: (a) has horizontal loads, but the structure is automatically 44.7.2 stabilized in the X and Y directions ..................................................................................................475 The code rules selected in Rule Set “Service” (Sustained Service / Max Service) do not 44.7.3 appear compatible with the load factors in the load combinations using the rule set. This is likely an error. ........................................................................................................................... 475 Load Combination “Service” (Sustained Service / Max Service) has unusual balance 44.7.4 and / or hyperstatic load factors. This is likely an error. ......................................................476 Rule Set “Strength Design” is being used by load combinations that appear to have 44.7.5 load factors set for different purposes. This is likely an error. ...........................................476 The mat / raft is likely unstable. There is less that 25% contact area. ........................... 476 44.7.6 Punching Check #a is not located at a column ...........................................................................477 44.7.7 Too many slab shapes intersecting the column shape at (x,y) ........................................... 477 44.7.8 An error has been found. The cross section trimming for strip ab-c has caused there to 44.7.9 be no concrete remaining at one or more locations. ...............................................................477 An error has been found. [Design strip] ab-c has reinforcing bars with too much cover 44.7.10 (the bottom bar is closer to the top than the top bar). ...........................................................477 A cross section in design strip ab-c has no shear core ............................................................ 477 44.7.11 A cross section in design strip ab-c has a very small shear core ........................................ 478 44.7.12 44.4.7 44.4.8 44.4.9
44.5
44.6 44.7
RAM Concept
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44.7.13 44.7.14 44.7.15
ab-c contains user transverse reinforcement but has multiple shear cores. Shear/ torsion calculations may be approximate .....................................................................................478 ab-c contains user reinforcement that is not within the primary (largest) shear core. This transverse reinforcement will be ignored ..........................................................................478 An error has been found. ab-c contains multiple user transverse rebar regions ........478
Chapter 45: Warnings and Errors Management Tool .............................................................. 479 45.1 45.2 45.3 45.4
To launch the warnings and errors management tool ....................................................................................... 479 Using the warning and error tool to find and resolve problems ....................................................................480 Hiding and Unhiding Individual Warnings or Errors ..........................................................................................481 Filtering Warnings and Errors by Type .................................................................................................................... 481
Chapter 46: Simple RC Slab Tutorial ...................................................................................... 482 46.1
46.2 46.3
46.4 46.5
46.6
Defining the structure ......................................................................................................................................................482 Define the column locations and properties ...............................................................................482 46.1.1 Draw the slab area ................................................................................................................................. 483 46.1.2 Hatch the slab area .................................................................................................................................484 46.1.3 Generate the mesh ................................................................................................................................. 484 46.1.4 View the mesh ..........................................................................................................................................484 46.1.5 View the structure ..................................................................................................................................485 46.1.6 Drawing the loads ..............................................................................................................................................................486 Defining the design strips .............................................................................................................................................. 487 Draw latitude design strips ................................................................................................................ 487 46.3.1 Draw longitude design strips ............................................................................................................ 489 46.3.2 Regenerate the mesh .............................................................................................................................490 46.3.3 Drawing punching shear checks ................................................................................................................................. 490 Calculate and view the results ......................................................................................................................................491 Design status ..............................................................................................................................................491 46.5.1 Design reinforcement ........................................................................................................................... 494 46.5.2 Design reinforcement plots ................................................................................................................498 46.5.3 Punching shear ........................................................................................................................................ 500 46.5.4 Deflection ................................................................................................................................................... 502 46.5.5 Bending Moments ...................................................................................................................................506 46.5.6 Drawing reinforcement ...................................................................................................................................................507 Drawing a bottom reinforcement mat ...........................................................................................508 46.6.1
Chapter 47: PT Flat Plate Tutorial: ACI 318-08 ....................................................................... 511 47.2 47.3
47.4
RAM Concept
Import the CAD drawing .................................................................................................................................................511 Define the structure ..........................................................................................................................................................511 Show the drawing on the mesh input layer ................................................................................ 511 47.3.1 Draw the slab area ................................................................................................................................. 512 47.3.2 Draw the balcony slab area ................................................................................................................ 513 47.3.3 Draw the drop caps ................................................................................................................................514 47.3.4 Draw the opening ................................................................................................................................... 515 47.3.5 Hatch the slab areas .............................................................................................................................. 516 47.3.6 Define the column locations and properties ...............................................................................517 47.3.7 Define the wall location and properties ....................................................................................... 517 47.3.8 Generate the mesh ................................................................................................................................. 518 47.3.9 View the mesh ..........................................................................................................................................519 47.3.10 View the structure ..................................................................................................................................519 47.3.11 Define the loads .................................................................................................................................................................. 520
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47.5
47.6
47.7 47.8
Define the typical live load ................................................................................................................. 520 47.4.1 Define the balcony live load ............................................................................................................... 520 47.4.2 Define the other dead loading ...........................................................................................................521 47.4.3 Define the post-tensioning .............................................................................................................................................522 Define the manual latitude tendons Pt. 1 .....................................................................................522 47.5.1 Define the manual latitude tendons Pt. 2 .....................................................................................523 47.5.2 Define the manual latitude tendons Pt. 3 .....................................................................................524 47.5.3 Define the manual latitude tendons Pt. 4 .....................................................................................524 47.5.4 Define a latitude tendon polyline .................................................................................................... 525 47.5.5 Define the latitude profile polylines ...............................................................................................526 47.5.6 Define the manual longitude tendons Pt. 1 ................................................................................. 527 47.5.7 Define the manual longitude tendons Pt. 2 ................................................................................. 528 47.5.8 Define the manual longitude tendons Pt. 3 ................................................................................. 529 47.5.9 Define the manual longitude tendons Pt. 4 ................................................................................. 530 47.5.10 Define the manual longitude tendons Pt. 5 ................................................................................. 531 47.5.11 Replace some manual longitude tendons with a distributed tendon quadrilateral ..532 47.5.12 Define the longitude profile polylines Pt. 1 .................................................................................532 47.5.13 Define the longitude profile polylines Pt. 2 .................................................................................533 47.5.14 Define the longitude profile polylines Pt. 3 .................................................................................533 47.5.15 Create the design strips ...................................................................................................................................................534 Generate the latitude spans ............................................................................................................... 535 47.6.1 Generate the latitude strips ............................................................................................................... 535 47.6.2 Hatch the strips ....................................................................................................................................... 536 47.6.3 Straighten a span segment ................................................................................................................. 536 47.6.4 Edit the span cross section orientation .........................................................................................537 47.6.5 Draw a Span Boundary Polyline .......................................................................................................537 47.6.6 Regenerate the latitude span strips ................................................................................................537 47.6.7 Generate the longitude spans ............................................................................................................538 47.6.8 Straighten a span segment ................................................................................................................. 539 47.6.9 Delete the span segment over the wall ......................................................................................... 539 47.6.10 Edit the span cross section orientation .........................................................................................539 47.6.11 Generate the longitude strips ............................................................................................................540 47.6.12 Check for punching shear ................................................................................................................... 540 47.6.13 Regenerate the mesh ........................................................................................................................................................541 Calculate and view the results ......................................................................................................................................542 Review Calc Options ..............................................................................................................................542 47.8.1 Calculate ..................................................................................................................................................... 542 47.8.2 View the design strips with tendons ..............................................................................................542 47.8.3 Edit span segment 6-2 .......................................................................................................................... 543 47.8.4 Recalculate ................................................................................................................................................ 543 47.8.5 Design status ............................................................................................................................................ 544 47.8.6 Design reinforcement ........................................................................................................................... 545 47.8.7 Concrete stresses ....................................................................................................................................548 47.8.8 Deflection ................................................................................................................................................... 549 47.8.9 Bending Moments ...................................................................................................................................552 47.8.10
Chapter 48: PT Flat Plate Tutorial: AS3600-2001 ....................................................................554 48.2 48.3
RAM Concept
Import the CAD drawing .................................................................................................................................................554 Define the structure ..........................................................................................................................................................554 Show the drawing on the mesh input layer ................................................................................ 555 48.3.1 Draw the slab area ................................................................................................................................. 555 48.3.2
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48.4
48.5
48.6
48.7 48.8
RAM Concept
Draw the balcony slab area ................................................................................................................ 556 48.3.3 Draw the drop caps ................................................................................................................................557 48.3.4 Draw the opening ................................................................................................................................... 558 48.3.5 Hatch the slab areas .............................................................................................................................. 559 48.3.6 Define the column locations and properties ...............................................................................560 48.3.7 Define the wall location and properties ....................................................................................... 560 48.3.8 Generate the mesh ................................................................................................................................. 561 48.3.9 View the mesh ..........................................................................................................................................562 48.3.10 View the structure ..................................................................................................................................562 48.3.11 Define the loads .................................................................................................................................................................. 563 Define the typical live load ................................................................................................................. 563 48.4.1 Define the balcony live load ............................................................................................................... 563 48.4.2 Define the other dead loading ...........................................................................................................564 48.4.3 Define the post-tensioning .............................................................................................................................................565 Define the manual latitude tendons Pt. 1 ...................................................................................... 565 48.5.1 Define the manual latitude tendons Pt. 2 .....................................................................................566 48.5.2 Define the manual latitude tendons Pt. 3 .....................................................................................567 48.5.3 Define the manual latitude tendons Pt. 4 ...................................................................................... 568 48.5.4 Define the manual latitude tendons Pt. 5 ...................................................................................... 568 48.5.5 Define the manual latitude tendons Pt. 6 ...................................................................................... 569 48.5.6 Define the longitude tendons Pt. 1 ................................................................................................... 570 48.5.7 Define the longitude tendons Pt. 2 ..................................................................................................571 48.5.8 Define the longitude tendons Pt. 3 ..................................................................................................571 48.5.9 Define the longitude tendons Pt. 4 ..................................................................................................572 48.5.10 Define the longitude tendons Pt. 5 ..................................................................................................573 48.5.11 Define the longitude tendons Pt. 6 ................................................................................................... 574 48.5.12 Create the design strips ...................................................................................................................................................574 Generate the latitude spans ............................................................................................................... 575 48.6.1 Generate the latitude strips ............................................................................................................... 575 48.6.2 Hatch the strips ....................................................................................................................................... 576 48.6.3 Straighten a span segment ................................................................................................................. 576 48.6.4 Edit the span cross section orientation .........................................................................................577 48.6.5 Draw a Span Boundary Polyline .......................................................................................................577 48.6.6 Regenerate the latitude span strips ................................................................................................578 48.6.7 Draw a Span Boundary Polyline .......................................................................................................578 48.6.8 Generate the longitude spans ............................................................................................................579 48.6.9 Straighten a span segment ................................................................................................................. 580 48.6.10 Delete the span segment over the wall ......................................................................................... 580 48.6.11 Generate the longitude strips ............................................................................................................580 48.6.12 Edit span segment with Span Boundaries and Strip Boundaries ...................................... 581 48.6.13 Edit the span cross section orientation .........................................................................................582 48.6.14 Check for punching shear ................................................................................................................... 582 48.6.15 Regenerate the mesh ........................................................................................................................................................583 Calculate and view the results ......................................................................................................................................583 Review Calc Options ..............................................................................................................................584 48.8.1 Calculate ..................................................................................................................................................... 584 48.8.2 View the design strips with tendons ..............................................................................................584 48.8.3 Edit span segment 6-2 .......................................................................................................................... 585 48.8.4 Edit span segment 2-3 .......................................................................................................................... 585 48.8.5 Recalculate ..................................................................................................................................................586 48.8.6 Design status ............................................................................................................................................ 586 48.8.7
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48.8.8 48.8.9 48.8.10
Design reinforcement ........................................................................................................................... 587 Deflection ................................................................................................................................................... 588 Bending Moments ...................................................................................................................................590
Chapter 49: PT Flat Plate Tutorial: BS8110 / TR43 ................................................................. 592 49.2 49.3
49.4
49.5
49.6
49.7 49.8
RAM Concept
Import the CAD drawing .................................................................................................................................................592 Define the structure ..........................................................................................................................................................592 Show the drawing on the mesh input layer ................................................................................ 593 49.3.1 Draw the slab area ................................................................................................................................. 593 49.3.2 Draw the balcony slab area ................................................................................................................ 594 49.3.3 Draw the drop caps ................................................................................................................................595 49.3.4 Draw the opening ................................................................................................................................... 596 49.3.5 Hatch the slab areas .............................................................................................................................. 597 49.3.6 Define the column locations and properties ...............................................................................598 49.3.7 Define the wall location and properties ....................................................................................... 598 49.3.8 Generate the mesh ................................................................................................................................. 599 49.3.9 View the mesh ..........................................................................................................................................600 49.3.10 View the structure ..................................................................................................................................600 49.3.11 Define the loads .................................................................................................................................................................. 601 Define the typical live load ................................................................................................................. 601 49.4.1 Define the balcony live load ............................................................................................................... 601 49.4.2 Define the other dead loading ...........................................................................................................602 49.4.3 Define the post-tensioning .............................................................................................................................................603 Define the latitude tendons Pt. 1 .......................................................................................................603 49.5.1 Define the latitude tendons Pt. 2 .......................................................................................................604 49.5.2 Define the latitude tendons Pt. 3 .......................................................................................................605 49.5.3 Define the latitude tendons Pt. 4 .......................................................................................................605 49.5.4 Define the latitude tendons Pt. 5 ......................................................................................................606 49.5.5 Define the longitude tendons Pt. 1 ................................................................................................... 607 49.5.6 Define the longitude tendons Pt. 2 ................................................................................................... 607 49.5.7 Define the longitude tendons Pt. 3 ................................................................................................... 608 49.5.8 Define the longitude tendons Pt. 4 ................................................................................................... 609 49.5.9 Define the longitude tendons Pt. 5 ................................................................................................... 610 49.5.10 Define the longitude tendons Pt. 6 ................................................................................................... 610 49.5.11 Create the design strips ...................................................................................................................................................611 Generate the latitude spans ............................................................................................................... 611 49.6.1 Generate the latitude strips ............................................................................................................... 612 49.6.2 Hatch the strips ....................................................................................................................................... 613 49.6.3 Straighten a span segment ................................................................................................................. 613 49.6.4 Edit the span cross section orientation .........................................................................................614 49.6.5 Draw a Span Boundary Polyline .......................................................................................................614 49.6.6 Regenerate the latitude span strips ................................................................................................614 49.6.7 Generate the longitude spans ............................................................................................................615 49.6.8 Straighten a span segment ................................................................................................................. 616 49.6.9 Delete the span segment over the wall ......................................................................................... 616 49.6.10 Edit the span cross section orientation ..........................................................................................616 49.6.11 Generate the longitude strips ............................................................................................................616 49.6.12 Check for punching shear ................................................................................................................... 617 49.6.13 Regenerate the mesh ........................................................................................................................................................618 Calculate and view the results ......................................................................................................................................619 Review Calc Options ..............................................................................................................................619 49.8.1
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49.8.2 49.8.3 49.8.4 49.8.5 49.8.6 49.8.7 49.8.8 49.8.9 49.8.10
Calculate ..................................................................................................................................................... 619 View the design strips with tendons ..............................................................................................619 Edit span segment 6-2 .......................................................................................................................... 620 Recalculate ................................................................................................................................................ 620 Design status ............................................................................................................................................ 621 Design reinforcement ........................................................................................................................... 622 Concrete stresses ....................................................................................................................................623 Deflection ................................................................................................................................................... 624 Bending Moments ...................................................................................................................................626
Chapter 50: PT Flat Plate Tutorial: EC2 / TR43 ....................................................................... 628 50.2 50.3
50.4
50.5
50.6
RAM Concept
Import the CAD drawing .................................................................................................................................................628 Define the structure ..........................................................................................................................................................628 Show the drawing on the mesh input layer ................................................................................ 629 50.3.1 Draw the slab area ................................................................................................................................. 629 50.3.2 Draw the balcony slab area ................................................................................................................ 630 50.3.3 Draw the drop caps ................................................................................................................................631 50.3.4 Draw the opening ................................................................................................................................... 632 50.3.5 Hatch the slab areas .............................................................................................................................. 633 50.3.6 Define the column locations and properties ...............................................................................634 50.3.7 Define the wall location and properties ....................................................................................... 634 50.3.8 Generate the mesh ................................................................................................................................. 635 50.3.9 View the mesh ..........................................................................................................................................636 50.3.10 View the structure ..................................................................................................................................636 50.3.11 Define the loads .................................................................................................................................................................. 637 Define the typical live load .................................................................................................................. 637 50.4.1 Define the balcony live load ............................................................................................................... 637 50.4.2 Define the other dead loading ...........................................................................................................638 50.4.3 Define the post-tensioning .............................................................................................................................................639 Define the latitude tendons Pt. 1 .......................................................................................................639 50.5.1 Define the latitude tendons Pt. 2 .......................................................................................................640 50.5.2 Define the latitude tendons Pt. 3 .......................................................................................................641 50.5.3 Define the latitude tendons Pt. 4 .......................................................................................................641 50.5.4 Define the latitude tendons Pt. 5 .......................................................................................................642 50.5.5 Define the longitude tendons Pt. 1 ................................................................................................... 643 50.5.6 Define the longitude tendons Pt. 2 ................................................................................................... 643 50.5.7 Define the longitude tendons Pt. 3 ................................................................................................... 644 50.5.8 Define the longitude tendons Pt. 4 ................................................................................................... 645 50.5.9 Define the longitude tendons Pt. 5 ................................................................................................... 646 50.5.10 Define the longitude tendons Pt. 6 ................................................................................................... 646 50.5.11 Create the design strips ...................................................................................................................................................647 Generate the latitude spans ............................................................................................................... 647 50.6.1 Generate the latitude strips ............................................................................................................... 648 50.6.2 Hatch the strips ....................................................................................................................................... 649 50.6.3 Straighten a span segment ................................................................................................................. 649 50.6.4 Edit the span cross section orientation .........................................................................................650 50.6.5 Draw a Span Boundary Polyline .......................................................................................................650 50.6.6 Regenerate the latitude span strips ................................................................................................650 50.6.7 Generate the longitude spans ............................................................................................................651 50.6.8 Straighten a span segment ................................................................................................................. 652 50.6.9 Delete the span segment over the wall ......................................................................................... 652 50.6.10
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50.7 50.8
Edit the span cross section orientation .........................................................................................652 50.6.11 Generate the longitude strips ............................................................................................................652 50.6.12 Check for punching shear ................................................................................................................... 653 50.6.13 Regenerate the mesh ........................................................................................................................................................654 Calculate and view the results ......................................................................................................................................655 Review Calc Options ............................................................................................................................... 655 50.8.1 Calculate ..................................................................................................................................................... 655 50.8.2 View the design strips with tendons ..............................................................................................655 50.8.3 Edit span segment 6-2 .......................................................................................................................... 656 50.8.4 Recalculate ................................................................................................................................................ 656 50.8.5 Design status ............................................................................................................................................ 657 50.8.6 Stress and Crack Width Designs .......................................................................................................658 50.8.7 Design reinforcement ........................................................................................................................... 661 50.8.8 Concrete stresses ....................................................................................................................................663 50.8.9 Deflection ................................................................................................................................................... 665 50.8.10 Bending Moments ...................................................................................................................................668 50.8.11
Chapter 51: PT Flat Plate Tutorial: IS 456 : 2000 .................................................................... 672 51.2 51.3
51.4
51.5
51.6
RAM Concept
Import the CAD drawing .................................................................................................................................................672 Define the structure ..........................................................................................................................................................672 Show the drawing on the mesh input layer ................................................................................ 673 51.3.1 Draw the slab area ................................................................................................................................. 673 51.3.2 Draw the balcony slab area ................................................................................................................ 674 51.3.3 Draw the drop caps ................................................................................................................................675 51.3.4 Draw the opening ................................................................................................................................... 676 51.3.5 Hatch the slab areas .............................................................................................................................. 677 51.3.6 Define the column locations and properties ...............................................................................678 51.3.7 Define the wall location and properties ....................................................................................... 678 51.3.8 Generate the mesh ................................................................................................................................. 679 51.3.9 View the mesh ..........................................................................................................................................680 51.3.10 View the structure ..................................................................................................................................680 51.3.11 Define the loads .................................................................................................................................................................. 681 Define the typical live load ................................................................................................................. 681 51.4.1 Define the balcony live load ............................................................................................................... 681 51.4.2 Define the other dead loading ...........................................................................................................682 51.4.3 Define the post-tensioning .............................................................................................................................................683 Define the latitude tendons Pt. 1 .......................................................................................................683 51.5.1 Define the latitude tendons Pt. 2 .......................................................................................................684 51.5.2 Define the latitude tendons Pt. 3 .......................................................................................................685 51.5.3 Define the latitude tendons Pt. 4 .......................................................................................................686 51.5.4 Define the latitude tendons Pt. 5 .......................................................................................................686 51.5.5 Define the latitude tendons Pt. 6 .......................................................................................................687 51.5.6 Define the latitude tendons Pt. 7 .......................................................................................................687 51.5.7 Define the longitude tendons Pt. 1 ................................................................................................... 688 51.5.8 Define the longitude tendons Pt. 2 ................................................................................................... 688 51.5.9 Define the longitude tendons Pt. 3 ................................................................................................... 689 51.5.10 Define the longitude tendons Pt. 4 ................................................................................................... 690 51.5.11 Define the longitude tendons Pt. 5 ................................................................................................... 691 51.5.12 Define the longitude tendons Pt. 6 ................................................................................................... 692 51.5.13 Create the design strips ...................................................................................................................................................692 Generate the latitude spans ............................................................................................................... 693 51.6.1
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User Manual
51.7 51.8
Generate the latitude strips ............................................................................................................... 694 51.6.2 Hatch the strips ....................................................................................................................................... 694 51.6.3 Straighten a span segment ...................................................................................................................694 51.6.4 Edit the span cross section orientation .........................................................................................695 51.6.5 Draw a Span Boundary Polyline ........................................................................................................696 51.6.6 Regenerate the latitude span strips ................................................................................................696 51.6.7 Draw a Span Boundary Polyline .......................................................................................................697 51.6.8 Generate the longitude spans ............................................................................................................697 51.6.9 Straighten a span segment ................................................................................................................. 698 51.6.10 Delete the span segment over the wall ......................................................................................... 698 51.6.11 Generate the longitude strips ............................................................................................................698 51.6.12 Edit span segment with Span Boundaries and Strip Boundaries ...................................... 699 51.6.13 Edit the span cross section orientation .........................................................................................700 51.6.14 Check for punching shear ................................................................................................................... 700 51.6.15 Regenerate the mesh ........................................................................................................................................................701 Calculate and view the results ......................................................................................................................................701 Review Calc Options ..............................................................................................................................702 51.8.1 Calculate ..................................................................................................................................................... 702 51.8.2 View the design strips with tendons ...............................................................................................702 51.8.3 Edit span segment 6-2 .......................................................................................................................... 703 51.8.4 Edit span segment 2-3 .......................................................................................................................... 703 51.8.5 Recalculate ................................................................................................................................................ 703 51.8.6 Design Status ............................................................................................................................................ 704 51.8.7 Design reinforcement ........................................................................................................................... 705 51.8.8 Deflection ................................................................................................................................................... 706 51.8.9 Bending Moments ...................................................................................................................................708 51.8.10
Chapter 52: PT Flat Plate Tutorial: CSA A23.3-04 ................................................................... 710 52.2 52.3
52.4
52.5
RAM Concept
Import the CAD drawing .................................................................................................................................................710 Define the structure ..........................................................................................................................................................710 Show the drawing on the mesh input layer ................................................................................ 711 52.3.1 Draw the slab area ................................................................................................................................. 711 52.3.2 Draw the balcony slab area ................................................................................................................ 712 52.3.3 Draw the drop caps ................................................................................................................................713 52.3.4 Draw the opening ................................................................................................................................... 714 52.3.5 Hatch the slab areas .............................................................................................................................. 715 52.3.6 Define the column locations and properties ...............................................................................716 52.3.7 Define the wall location and properties ....................................................................................... 716 52.3.8 Generate the mesh ................................................................................................................................. 717 52.3.9 View the mesh ..........................................................................................................................................718 52.3.10 View the structure ..................................................................................................................................718 52.3.11 Define the loads .................................................................................................................................................................. 719 Define the typical live load ................................................................................................................. 719 52.4.1 Define the balcony live load ............................................................................................................... 719 52.4.2 Define the other dead loading ...........................................................................................................720 52.4.3 Define the post-tensioning .............................................................................................................................................721 Define the latitude tendons Pt. 1 .......................................................................................................721 52.5.1 Define the latitude tendons Pt. 2 .......................................................................................................722 52.5.2 Define the latitude tendons Pt. 3 .......................................................................................................723 52.5.3 Define the latitude tendons Pt. 4 .......................................................................................................723 52.5.4 Define the latitude tendons Pt. 5 .......................................................................................................724 52.5.5
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User Manual
52.6
52.7 52.8
Define the longitude tendons Pt. 1 ................................................................................................... 724 52.5.6 Define the longitude tendons Pt. 2 ................................................................................................... 725 52.5.7 Define the longitude tendons Pt. 3 ................................................................................................... 726 52.5.8 Define the longitude tendons Pt. 4 ................................................................................................... 727 52.5.9 Define the longitude tendons Pt. 5 ................................................................................................... 728 52.5.10 Define the longitude tendons Pt. 6 ................................................................................................... 728 52.5.11 Create the design strips ...................................................................................................................................................729 Generate the latitude spans ............................................................................................................... 729 52.6.1 Generate the latitude strips ............................................................................................................... 730 52.6.2 Hatch the strips ....................................................................................................................................... 731 52.6.3 Straighten a span segment ................................................................................................................. 731 52.6.4 Edit the span cross section orientation .........................................................................................731 52.6.5 Draw a Span Boundary Polyline .......................................................................................................732 52.6.6 Regenerate the latitude span strips ................................................................................................732 52.6.7 Generate the longitude spans ............................................................................................................732 52.6.8 Straighten a span segment ................................................................................................................. 733 52.6.9 Delete the span segment over the wall ......................................................................................... 734 52.6.10 Edit the span cross section orientation .........................................................................................734 52.6.11 Generate the longitude strips ............................................................................................................734 52.6.12 Check for punching shear ................................................................................................................... 734 52.6.13 Regenerate the mesh ........................................................................................................................................................735 Calculate and view the results ......................................................................................................................................736 Review Calc Options ..............................................................................................................................736 52.8.1 Calculate ..................................................................................................................................................... 736 52.8.2 View the design strips with tendons ..............................................................................................737 52.8.3 Edit span segment 6-2 .......................................................................................................................... 737 52.8.4 Recalculate ................................................................................................................................................ 738 52.8.5 Design status ............................................................................................................................................ 738 52.8.6 Design reinforcement ........................................................................................................................... 740 52.8.7 Concrete stresses ....................................................................................................................................742 52.8.8 Deflection ................................................................................................................................................... 745 52.8.9 Bending Moments ...................................................................................................................................747 52.8.10
Chapter 53: Mat Foundation Tutorial .................................................................................... 751 53.1 53.2
53.3
53.4
RAM Concept
Import the CAD drawing .................................................................................................................................................751 Define the structure ..........................................................................................................................................................751 Show the drawing on the mesh input layer ................................................................................ 751 53.2.1 Draw the slab area ................................................................................................................................. 752 53.2.2 Define the column locations and properties ...............................................................................752 53.2.3 Define the wall location and properties ....................................................................................... 752 53.2.4 Define the area spring location and properties .........................................................................753 53.2.5 Generate the mesh ................................................................................................................................. 753 53.2.6 View the mesh ..........................................................................................................................................753 53.2.7 View the structure ..................................................................................................................................753 53.2.8 Define the loads .................................................................................................................................................................. 757 Define the other dead loading ...........................................................................................................757 53.3.1 Copy to the live (reducible) loading layer ................................................................................... 757 53.3.2 Define the ultimate seismic east loading ......................................................................................758 53.3.3 Create the design strips ...................................................................................................................................................760 Draw latitude design strips ................................................................................................................ 760 53.4.1 Generate the latitude strips ............................................................................................................... 762 53.4.2
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User Manual
53.5 53.6
Hatch the strips ....................................................................................................................................... 762 53.4.3 Edit the cross section orientation ................................................................................................... 763 53.4.4 Regenerate the latitude span strips ................................................................................................763 53.4.5 Draw longitude design strips ............................................................................................................ 764 53.4.6 Generate the longitude strips ............................................................................................................766 53.4.7 Edit the cross section orientation ................................................................................................... 766 53.4.8 Regenerate the longitude span strips ............................................................................................767 53.4.9 Check for punching shear ................................................................................................................... 767 53.4.10 Regenerate the mesh ........................................................................................................................................................768 Calculate and view the results ......................................................................................................................................768 Review Calc Options ..............................................................................................................................769 53.6.1 Calculate ..................................................................................................................................................... 769 53.6.2 Look at reinforcement and design status .....................................................................................769 53.6.3 View Specific Reinforcement .............................................................................................................770 53.6.4 Bearing stresses ...................................................................................................................................... 771 53.6.5
Chapter 54: Strip Wizard Tutorial .......................................................................................... 773 54.1 54.2 54.3 54.4 54.5 54.6 54.7 54.8 54.9 54.10 54.11 54.12
Start Strip Wizard .............................................................................................................................................................. 773 Set the general parameters ............................................................................................................................................773 Enter the span data ........................................................................................................................................................... 774 Create the supports below .............................................................................................................................................775 Add drop caps ......................................................................................................................................................................776 Specify the loads .................................................................................................................................................................776 Define the post-tensioning .............................................................................................................................................776 Specify the reinforcement parameters .....................................................................................................................777 Complete the Strip Wizard .............................................................................................................................................777 Proceed with RAM Concept ........................................................................................................................................... 777 Comparison with PT Flat Plate Tutorial .................................................................................................................. 778 Conclusion .............................................................................................................................................................................778
Chapter 55: Analysis Notes ................................................................................................... 780 55.1
55.2
55.3 55.4
55.5
RAM Concept
Review of plate behavior ................................................................................................................................................ 780 In-plane and out-of-plane behavior ................................................................................................780 55.1.1 In-plane behavior ................................................................................................................................... 781 55.1.2 Out-of-plane behavior .......................................................................................................................... 782 55.1.3 Interaction of in-plane and out-of-plane behavior .................................................................. 784 55.1.4 RAM Concept plotting and relevant axes ..................................................................................... 785 55.1.5 Finite element analysis ....................................................................................................................................................785 About finite element analysis ............................................................................................................785 55.2.1 Finite element formulation used in RAM Concept ................................................................... 786 55.2.2 Slab element general properties ......................................................................................................786 55.2.3 Orthotropic behavior ....................................................................................................................................................... 786 K Factors and Instability ..................................................................................................................... 786 55.3.1 Interaction of in-plane and out-of-plane stiffnesses ............................................................... 787 55.3.2 Deep beam considerations ............................................................................................................................................ 787 Analysis of slab and beam elements ...............................................................................................787 55.4.1 Analysis and design of deep beams for bending moment and shear ...............................790 55.4.2 Analysis and design of deep beams with transverse bending moments ........................791 55.4.3 Analysis of deep beams with torsion ............................................................................................. 793 55.4.4 Analysis and design of moment transfer through step-beams ...........................................795 55.4.5 Wall behavior ...................................................................................................................................................................... 796
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User Manual
55.6 55.7
55.8
55.9
Walls above slab ......................................................................................................................................796 55.5.1 Post-tensioning loadings ................................................................................................................................................ 797 Hyperstatic loading ................................................................................................................................797 55.6.1 Self-equilibrium analysis ................................................................................................................................................ 797 About self-equilibrium analysis ....................................................................................................... 798 55.7.1 Uses of Self-Equilibrium Analyses ...................................................................................................798 55.7.2 Using Self-Equilibrium Analyses ......................................................................................................798 55.7.3 Self-Equilibrium Analyses Details ................................................................................................... 799 55.7.4 Design strip and design section forces ..................................................................................................................... 800 Design section axes and sign convention .....................................................................................800 55.8.1 Design strip segment axes and sign convention ....................................................................... 800 55.8.2 Design centroids ..................................................................................................................................... 800 55.8.3 Calculating the forces on the cross section ................................................................................. 801 55.8.4 Calculating the balanced load percentages ................................................................................. 801 55.8.5 Using the “Don't Reduce Integrated M and V due to Sign Change” option .................... 802 55.8.6 Result categories in RAM Concept ..............................................................................................................................803 Standard results ...................................................................................................................................... 803 55.9.1 Envelope results ......................................................................................................................................804 55.9.2 How RAM Concept calculates envelope results .........................................................................804 55.9.3
Chapter 56: Section Design Notes ......................................................................................... 806 56.1
General Design Approach ...............................................................................................................................................806 Strip and Section Design – A 3 Step Process ...............................................................................806 56.1.1 Non-prestressed Reinforcement Stress-Strain Curves .......................................................... 806 56.1.2 Post-tensioning Material Stress-Strain Curves ..........................................................................806 56.1.3 Relationship of Bonded Post-tensioning Strains to Cross-Section Strains ....................807 56.1.4 Unbonded Post-tensioning Stress-Strain Curves – General Theory .................................808 56.1.5 Unbonded Post-tensioning Stress-Strain Curves – Program Implementation ............ 809 56.1.6 Tendons – External Load or Internal Force? .............................................................................. 809 56.1.7 Tendons – inclusion of force vector on a cross section ..........................................................810 56.1.8 Tendons – calculation of number of ducts ...................................................................................810 56.1.9 Concrete Stress-Strain Curves .......................................................................................................... 810 56.1.10 Creep and Shrinkage Effects .............................................................................................................. 811 56.1.11 Cracked Section Analyses ................................................................................................................... 811 56.1.12 Branson’s Stress Ratio ..........................................................................................................................812 56.1.13 Calculation of Effective Curvature Ratio ...................................................................................... 813 56.1.14 Use of ECR ..................................................................................................................................................813 56.1.15 Crack Width Predictions ......................................................................................................................814 56.1.16 “Cracking Moment” Used in Design Calculations ......................................................................815 56.1.17 Concrete “Core” Determination ........................................................................................................816 56.1.18 Torsion Considerations ........................................................................................................................816 56.1.19 Wood-Armer Torsion Design ............................................................................................................ 817 56.1.20
Chapter 57: Live Load Reduction Notes ................................................................................. 818 57.1 57.2 57.3 57.4
RAM Concept
Live Load Reduction for Loadings, Load Combinations and Rule Sets .......................................................818 Loadings ..................................................................................................................................................... 818 57.1.1 Load Combinations and Rule Sets ................................................................................................... 818 57.1.2 Tributary Area Calculations .......................................................................................................................................... 819 Influence Area Calculations ...........................................................................................................................................819 Example of Influence Areas ................................................................................................................820 57.3.1 ASCE-7 2002 Live Load Reduction .............................................................................................................................824
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User Manual
57.5 57.6 57.7 57.8 57.9 57.10 57.11 57.12 57.13 57.14 57.15 57.16 57.17 57.18 57.19
ASCE-7 2010 Live Load Reduction .............................................................................................................................825 ASCE-7 2016 Live Load Reduction ..............................................................................................................................825 IBC 2003 Live Load Reduction .....................................................................................................................................825 IBC 2006 Live Load Reduction .....................................................................................................................................826 IBC 2009 Live Load Reduction .....................................................................................................................................826 IBC 2012 Live Load Reduction ......................................................................................................................................827 IBC 2015 Live Load Reduction ......................................................................................................................................827 UBC 1997 Live Load Reduction ................................................................................................................................... 827 AS/NZS 1170.1-2002 Live Load Reduction ............................................................................................................828 BS 6399-1:1996 Live Load Reduction ...................................................................................................................... 828 IS 875 (Part 2) - 1987 Live Load Reduction ...........................................................................................................828 Eurocode 1-2002 (UK Annex) Live Load Reduction ...........................................................................................829 National Building Code of Canada 2005 Live Load Reduction .......................................................................829 Mat Foundations ................................................................................................................................................................ 829 Special Member Considerations ..................................................................................................................................829 Columns Above the Slab ...................................................................................................................... 830 57.19.1 Columns Above and Below the Slab ............................................................................................... 830 57.19.2
Chapter 58: Reinforcement Notes ......................................................................................... 831 58.1
58.2
58.3 58.4 58.5 58.6
Span detailing ...................................................................................................................................................................... 831 About Concept’s detailing calculations ......................................................................................... 832 58.1.1 Span detailing assumptions ............................................................................................................... 833 58.1.2 ACI 318-99, 318-02, 318-05, 318-08, 318-11 Code Span Detailing Rules .....................834 58.1.3 AS 3600 - 2001 Code Span Detailing Rules ................................................................................. 834 58.1.4 AS 3600 - 2009 Code Span Detailing Rules ................................................................................. 834 58.1.5 AS 3600 - 2018 Code Span Detailing Rules ................................................................................. 834 58.1.6 BS 8110 - 1997 Code Span Detailing Rules ................................................................................. 834 58.1.7 CSA A23.3-04 Code Span Detailing Rules ......................................................................................835 58.1.8 IS 456 - 2000 Code Span Detailing Rules ..................................................................................... 835 58.1.9 EC2 Code Span Detailing Rules .........................................................................................................835 58.1.10 Development lengths / anchorage ............................................................................................................................. 835 ACI 318-99, 318-02, 318-05, 318-08, 318-11 Development Lengths ............................. 837 58.2.1 ACI 318-14 Development Lengths ................................................................................................... 838 58.2.2 AS 3600-2001 and AS 3600-2009 Development Lengths ..................................................... 839 58.2.3 AS 3600-2018 Development Lengths ............................................................................................. 841 58.2.4 BS 8110-1997 Development Lengths ............................................................................................ 842 58.2.5 IS 456-2000 Development Lengths ................................................................................................ 843 58.2.6 EC2 Development Lengths ................................................................................................................. 844 58.2.7 CSA A23.3-04 Development Lengths .............................................................................................. 845 58.2.8 How RAM Concept lays out longitudinal program reinforcement ...............................................................846 How RAM Concept details longitudinal user and program reinforcement .............................................. 847 How Concept treats transverse user and program reinforcement and individual transverse bars 849 Example 1: reinforcement results .............................................................................................................................. 849 Strength (only) calculations ...............................................................................................................850 58.6.1 Code Minimum and Strength calculations ...................................................................................855 58.6.2
Chapter 59: ACI 318-99 Design .............................................................................................. 861 59.1 59.2
RAM Concept
ACI 318-99 default loadings ..........................................................................................................................................861 Temporary Construction (At Stressing) Loading ..................................................................... 861 59.1.1 ACI 318-99 default load combinations .....................................................................................................................861 All Dead LC ................................................................................................................................................ 862 59.2.1
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User Manual
59.3 59.4
59.5
59.6
RAM Concept
Initial Service LC ..................................................................................................................................... 862 59.2.2 Service LC: D + L + Lr ............................................................................................................................ 862 59.2.3 Service LC: D + L + S .............................................................................................................................. 862 59.2.4 Sustained Service LC ............................................................................................................................. 863 59.2.5 DL + 0.25LL LC .........................................................................................................................................863 59.2.6 Factored LC: 1.4D + 1.7L + 1.7S ........................................................................................................863 59.2.7 Service Wind LC: D + L + Lr + W .......................................................................................................864 59.2.8 Service Wind LC: D + L + S + W .........................................................................................................864 59.2.9 Service Wind LC: 0.6D + W ................................................................................................................. 864 59.2.10 Service Seismic LC: D + L + Lr + 0.7E ............................................................................................. 864 59.2.11 Service Seismic LC: D + L + S + 0.7E ............................................................................................... 865 59.2.12 Service Seismic LC: 0.6D + 0.7E ........................................................................................................865 59.2.13 Factored Wind LC: 1.05D + 1.28L + 1.28S + 1.6W ....................................................................865 59.2.14 Factored Seismic LC: 1.2D + f1L + 0.7S + E ..................................................................................866 59.2.15 ACI 318-99 / ASCE-7 / IBC 2003 live load factors .............................................................................................. 866 ACI 318-99 Material Behaviors .....................................................................................................................................866 Concrete Behavior ..................................................................................................................................867 59.4.1 (Non-prestressed) Reinforcement Behavior ..............................................................................867 59.4.2 Bonded Prestressed Reinforcement Behavior ...........................................................................867 59.4.3 Unbonded Prestressed Reinforcement Behavior ..................................................................... 868 59.4.4 ACI 318-99 code rule selection .................................................................................................................................... 868 Code Minimum Reinforcement .........................................................................................................868 59.5.1 User Minimum Reinforcement .......................................................................................................... 869 59.5.2 Initial Service ............................................................................................................................................870 59.5.3 Service ......................................................................................................................................................... 870 59.5.4 Sustained Service ....................................................................................................................................871 59.5.5 Strength ...................................................................................................................................................... 871 59.5.6 Ductility ...................................................................................................................................................... 872 59.5.7 UBC DL + 0.25 LL .................................................................................................................................... 872 59.5.8 ACI 318-99 code implementation ...............................................................................................................................873 Section 7.12 Shrinkage and Temperature Reinforcement ................................................... 873 59.6.1 Section 10.2 Factored Moment Resistance (Non prestressed) ...........................................873 59.6.2 Section 10.3.3 Ductility (Non prestressed) ................................................................................. 874 59.6.3 Section 10.5.1 Minimum Reinforcement of Flexural Members (Non Prestressed) ...874 59.6.4 Section 10.6.4 Minimum Reinforcement of Flexural Members (Non Prestressed) ...875 59.6.5 Section 11.3 Shear Resistance of Beams (Non Prestressed) ............................................... 875 59.6.6 Section 11.4 Shear Resistance of Beams (Prestressed) ......................................................... 875 59.6.7 Section 11.6 Beam Torsion .................................................................................................................876 59.6.8 Chapter 13 (Two-way slab systems) ..............................................................................................877 59.6.9 Section 18.4.1a Initial (at stressing) Compressive Stress Limit .........................................877 59.6.10 Section 18.4.1b Initial (at stressing) Tensile Stress Limit .................................................... 877 59.6.11 Section 18.4.2a Sustained Compressive Stress Limit ..............................................................877 59.6.12 Section 18.4.2b Service Compressive Stress Limit .................................................................. 878 59.6.13 Section 18.4.2c Service Tensile Stress Limit ...............................................................................878 59.6.14 Section 18.7 Design Flexural Resistance (Prestressed) .........................................................878 59.6.15 Section 18.8.1 Ductility (Prestressed) ...........................................................................................879 59.6.16 Section 18.8.3 Cracking Moment ..................................................................................................... 879 59.6.17 Section 18.9.2 Minimum Reinforcement - One Way ............................................................... 879 59.6.18 Section 18.9.3.2 Midspan Two Way Minimum Reinforcement .......................................... 880 59.6.19 Section 18.9.3.3 Support Two Way Minimum Reinforcement ............................................880 59.6.20 Punching Shear Design .........................................................................................................................881 59.6.21
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Chapter 60: ACI 318-02 Design .............................................................................................. 882 60.1 60.2
60.3 60.4
60.5
60.6
RAM Concept
ACI 318-02 default loadings ..........................................................................................................................................882 Temporary Construction (At Stressing) Loading ..................................................................... 882 60.1.1 ACI 318-02 default load combinations .....................................................................................................................882 All Dead LC ................................................................................................................................................ 883 60.2.1 Initial Service LC ..................................................................................................................................... 883 60.2.2 Service LC: D + L + Lr ............................................................................................................................ 883 60.2.3 Service LC: D + L + S .............................................................................................................................. 884 60.2.4 Sustained Service LC ............................................................................................................................. 884 60.2.5 Factored LC: 1.4D ................................................................................................................................... 884 60.2.6 Factored LC: 1.2D + 1.6L + 0.5Lr ......................................................................................................884 60.2.7 Factored LC: 1.2D + f1L+ 1.6Lr ......................................................................................................... 885 60.2.8 Factored LC: 1.2D + 1.6L + 0.5S ........................................................................................................885 60.2.9 Factored LC: 1.2D + f1L+ 1.6S ........................................................................................................... 886 60.2.10 Service Wind LC: D + L + Lr + W .......................................................................................................886 60.2.11 Service Wind LC: D + L + S + W .........................................................................................................886 60.2.12 Service Wind LC: 0.6D + W ................................................................................................................. 887 60.2.13 Service Seismic LC: D + L + Lr + 0.7E ............................................................................................. 887 60.2.14 Service Seismic LC: D + L + S + 0.7E ............................................................................................... 887 60.2.15 Service Seismic LC: 0.6D + 0.7E ........................................................................................................887 60.2.16 Factored Wind LC: 1.2D + f1L+ 0.5Lr + 1.6W .............................................................................888 60.2.17 Factored Wind LC: 1.2D + f1L+ 0.5S + 1.6W ............................................................................... 888 60.2.18 Factored Wind LC: 1.2D + 1.6Lr + 0.8W ....................................................................................... 889 60.2.19 Factored Wind LC: 1.2D + 1.6S + 0.8W ..........................................................................................889 60.2.20 Factored Seismic LC: 1.2D + f1L+ f2S + E .....................................................................................889 60.2.21 ACI318-02 / ASCE-7 / IBC 2003 live load factors ............................................................................................... 889 ACI 318-02 Material Behaviors .....................................................................................................................................890 Concrete Behavior ..................................................................................................................................890 60.4.1 (Non-prestressed) Reinforcement Behavior ..............................................................................890 60.4.2 Bonded Prestressed Reinforcement Behavior ...........................................................................891 60.4.3 Unbonded Prestressed Reinforcement Behavior ..................................................................... 891 60.4.4 ACI 318-02 code rule selection .................................................................................................................................... 891 Code Minimum Reinforcement .........................................................................................................891 60.5.1 User Minimum Reinforcement .......................................................................................................... 892 60.5.2 Initial Service ............................................................................................................................................893 60.5.3 Service ......................................................................................................................................................... 894 60.5.4 Sustained Service ....................................................................................................................................894 60.5.5 Strength ...................................................................................................................................................... 895 60.5.6 Ductility ...................................................................................................................................................... 895 60.5.7 ACI 318-02 code implementation ...............................................................................................................................896 Section 7.12 Shrinkage and Temperature Reinforcement ................................................... 896 60.6.1 Section 10.2 Factored Moment Resistance (Non prestressed) ...........................................897 60.6.2 Section 10.3.5 Ductility (Non prestressed) ................................................................................. 897 60.6.3 Section 10.5.1 Minimum Reinforcement of Flexural Members (Non Prestressed) ...898 60.6.4 Section 10.6.4 Minimum Reinforcement of Flexural Members (Non Prestressed) ...898 60.6.5 Section 11.3 Shear Resistance of Beams (Non Prestressed) ............................................... 899 60.6.6 Section 11.4 Shear Resistance of Beams (Prestressed) ......................................................... 899 60.6.7 Section 11.6 Beam Torsion .................................................................................................................900 60.6.8 Chapter 13 (Two-way slab systems) ..............................................................................................901 60.6.9 Section 18.3.3 Service Tensile Stress Limit .................................................................................901 60.6.10 Section 18.4.1a Initial (at stressing) Compressive Stress Limit .........................................902 60.6.11
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60.6.12 60.6.13 60.6.14 60.6.15 60.6.16 60.6.17 60.6.18 60.6.19 60.6.20 60.6.21
Section 18.4.1b Initial (at stressing) Tensile Stress Limit .................................................... 902 Section 18.4.2a Sustained Compressive Stress Limit ..............................................................903 Section 18.4.2b Service Compressive Stress Limit .................................................................. 903 Section 18.4.4 Reinforcement Spacing Limits for Class C Members ................................ 903 Section 18.7 Design Flexural Resistance (Prestressed) .........................................................904 Section 18.8.2 Cracking Moment ..................................................................................................... 904 Section 18.9.2 Minimum Reinforcement - One Way ............................................................... 905 Section 18.9.3.2 Midspan Two Way Minimum Reinforcement .......................................... 905 Section 18.9.3.3 Support Two Way Minimum Reinforcement ............................................906 Punching Shear Design .........................................................................................................................906
Chapter 61: ACI 318-05 Design .............................................................................................. 907 61.1 61.2
61.3 61.4
61.5
RAM Concept
ACI 318-05 default loadings ..........................................................................................................................................907 Temporary Construction (At Stressing) Loading ..................................................................... 907 61.1.1 ACI 318-05 default load combinations .....................................................................................................................907 All Dead LC ................................................................................................................................................ 908 61.2.1 Initial Service LC ..................................................................................................................................... 908 61.2.2 Service LC: D + L ......................................................................................................................................908 61.2.3 Service LC: D + Lr ....................................................................................................................................909 61.2.4 Service LC: D + S ......................................................................................................................................909 61.2.5 Service LC: D + 0.75L + 0.75Lr .......................................................................................................... 909 61.2.6 Service LC: D + 0.75L + 0.75S ............................................................................................................ 909 61.2.7 Sustained Service LC ............................................................................................................................. 910 61.2.8 Factored LC: 1.4D ................................................................................................................................... 910 61.2.9 Factored LC: 1.2D + 1.6L + 0.5Lr ......................................................................................................910 61.2.10 Factored LC: 1.2D + f1L+ 1.6Lr ......................................................................................................... 910 61.2.11 Factored LC: 1.2D + 1.6L + 0.5S ........................................................................................................911 61.2.12 Factored LC: 1.2D + f1L+ 1.6S ........................................................................................................... 911 61.2.13 Service Wind LC: D + W ....................................................................................................................... 911 61.2.14 Service Wind LC: D + 0.75L + 0.75Lr + 0.75W ........................................................................... 912 61.2.15 Service Wind LC: D + 0.75L + 0.75S + 0.75W ............................................................................. 912 61.2.16 Service Wind LC: 0.6D + W ................................................................................................................. 912 61.2.17 Service Seismic LC: D + 0.7E .............................................................................................................. 913 61.2.18 Service Seismic LC: D + 0.75L + 0.75Lr + 0.525E ......................................................................913 61.2.19 Service Seismic LC: D + 0.75L + 0.75S + 0.525E ........................................................................913 61.2.20 Service Seismic LC: 0.6D + 0.7E ........................................................................................................913 61.2.21 Factored Wind LC: 1.2D + f1L+ 0.5Lr + 1.6W .............................................................................914 61.2.22 Factored Wind LC: 1.2D + f1L+ 0.5S + 1.6W ............................................................................... 914 61.2.23 Factored Wind LC: 1.2D + 1.6Lr + 0.8W ....................................................................................... 914 61.2.24 Factored Wind LC: 1.2D + 1.6S + 0.8W ..........................................................................................915 61.2.25 Factored Seismic LC: 1.2D + f1L+ f2S + E .....................................................................................915 61.2.26 ACI318-05 / ASCE-7 / IBC 2006 live load factors ............................................................................................... 915 ACI 318-05 Material Behaviors .....................................................................................................................................916 Concrete Behavior ..................................................................................................................................916 61.4.1 (Non-prestressed) Reinforcement Behavior ..............................................................................916 61.4.2 Bonded Prestressed Reinforcement Behavior ...........................................................................917 61.4.3 Unbonded Prestressed Reinforcement Behavior ..................................................................... 917 61.4.4 ACI 318-05 code rule selection .................................................................................................................................... 917 Code Minimum Reinforcement .........................................................................................................917 61.5.1 User Minimum Reinforcement ......................................................................................................... 918 61.5.2 Initial Service ............................................................................................................................................919 61.5.3
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61.6
Service ......................................................................................................................................................... 920 61.5.4 Sustained Service ....................................................................................................................................920 61.5.5 Strength ...................................................................................................................................................... 921 61.5.6 Ductility ...................................................................................................................................................... 921 61.5.7 ACI 318-05 code implementation ...............................................................................................................................922 Section 7.12 Shrinkage and Temperature Reinforcement ................................................... 922 61.6.1 Section 10.2 Factored Moment Resistance (Non prestressed) ...........................................922 61.6.2 Section 10.3.5 Ductility (Non prestressed) ................................................................................. 923 61.6.3 Section 10.5.1 Minimum Reinforcement of Flexural Members (Non Prestressed) ...924 61.6.4 Section 10.6.4 Minimum Reinforcement of Flexural Members (Non Prestressed) ...924 61.6.5 Section 11.3 Shear Resistance of Beams (Non Prestressed) ............................................... 924 61.6.6 Section 11.4 Shear Resistance of Beams (Prestressed) ......................................................... 925 61.6.7 Section 11.6 Beam Torsion .................................................................................................................926 61.6.8 Chapter 13 (Two-way slab systems) ..............................................................................................927 61.6.9 Section 18.3.3 Service Tensile Stress Limit .................................................................................927 61.6.10 Section 18.4.1a Initial (at stressing) Compressive Stress Limit .........................................928 61.6.11 Section 18.4.1b Initial (at stressing) Tensile Stress Limit .................................................... 928 61.6.12 Section 18.4.2a Sustained Compressive Stress Limit ..............................................................928 61.6.13 Section 18.4.2b Service Compressive Stress Limit .................................................................. 929 61.6.14 Section 18.4.4 Reinforcement Spacing Limits for Class C Members ................................ 929 61.6.15 Section 18.7 Design Flexural Resistance (Prestressed) .........................................................929 61.6.16 Section 18.8.2 Cracking Moment ..................................................................................................... 930 61.6.17 Section 18.9.2 Minimum Reinforcement - One Way ............................................................... 930 61.6.18 Section 18.9.3.2 Midspan Two Way Minimum Reinforcement .......................................... 931 61.6.19 Section 18.9.3.3 Support Two Way Minimum Reinforcement ............................................931 61.6.20 Punching Shear Design .........................................................................................................................932 61.6.21
Chapter 62: ACI 318-08 Design .............................................................................................. 933 62.1 62.2
RAM Concept
ACI 318-08 default loadings ..........................................................................................................................................933 Temporary Construction (At Stressing) Loading ..................................................................... 933 62.1.1 ACI 318-08 default load combinations .....................................................................................................................933 All Dead LC ................................................................................................................................................ 934 62.2.1 Initial Service LC ..................................................................................................................................... 934 62.2.2 Service LC: D + L ......................................................................................................................................934 62.2.3 Service LC: D + Lr ....................................................................................................................................935 62.2.4 Service LC: D + S ......................................................................................................................................935 62.2.5 Service LC: D + 0.75L + 0.75Lr .......................................................................................................... 935 62.2.6 Service LC: D + 0.75L + 0.75S ............................................................................................................ 935 62.2.7 Sustained Service LC ............................................................................................................................. 936 62.2.8 Factored LC: 1.4D ................................................................................................................................... 936 62.2.9 Factored LC: 1.2D + 1.6L + 0.5Lr ......................................................................................................936 62.2.10 Factored LC: 1.2D + f1L+ 1.6Lr ......................................................................................................... 936 62.2.11 Factored LC: 1.2D + 1.6L + 0.5S ........................................................................................................937 62.2.12 Factored LC: 1.2D + f1L+ 1.6S ........................................................................................................... 937 62.2.13 Service Wind LC: D + W ....................................................................................................................... 937 62.2.14 Service Wind LC: D + 0.75L + 0.75Lr + 0.75W ........................................................................... 938 62.2.15 Service Wind LC: D + 0.75L + 0.75S + 0.75W ............................................................................. 938 62.2.16 Service Wind LC: 0.6D + W ................................................................................................................. 938 62.2.17 Service Seismic LC: D + 0.7E .............................................................................................................. 939 62.2.18 Service Seismic LC: D + 0.75L + 0.75Lr + 0.525E ......................................................................939 62.2.19 Service Seismic LC: D + 0.75L + 0.75S + 0.525E ........................................................................939 62.2.20
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62.3 62.4
62.5
62.6
Service Seismic LC: 0.6D + 0.7E ........................................................................................................939 62.2.21 Factored Wind LC: 1.2D + f1L+ 0.5Lr + 1.6W .............................................................................940 62.2.22 Factored Wind LC: 1.2D + f1L+ 0.5S + 1.6W ............................................................................... 940 62.2.23 Factored Wind LC: 1.2D + 1.6Lr + 0.8W ....................................................................................... 940 62.2.24 Factored Wind LC: 1.2D + 1.6S + 0.8W ..........................................................................................941 62.2.25 Factored Seismic LC: 1.2D + f1L+ f2S + E .....................................................................................941 62.2.26 Factored Seismic LC: 0.9D + E ...........................................................................................................941 62.2.27 ACI318-08 / ASCE-7 / IBC 2009 live load factors ............................................................................................... 942 ACI 318-08 Material Behaviors .....................................................................................................................................942 Concrete Behavior ..................................................................................................................................942 62.4.1 (Non-prestressed) Reinforcement Behavior ..............................................................................943 62.4.2 Bonded Prestressed Reinforcement Behavior ...........................................................................943 62.4.3 Unbonded Prestressed Reinforcement Behavior ..................................................................... 943 62.4.4 ACI 318-08 code rule selection .................................................................................................................................... 943 Code Minimum Reinforcement .........................................................................................................943 62.5.1 User Minimum Reinforcement ......................................................................................................... 944 62.5.2 Initial Service ............................................................................................................................................945 62.5.3 Service ......................................................................................................................................................... 946 62.5.4 Sustained Service ....................................................................................................................................946 62.5.5 Strength ...................................................................................................................................................... 947 62.5.6 Ductility ...................................................................................................................................................... 947 62.5.7 ACI 318-08 code implementation ...............................................................................................................................948 Section 7.12 Shrinkage and Temperature Reinforcement ................................................... 948 62.6.1 Section 10.2 Factored Moment Resistance (Non prestressed) ...........................................949 62.6.2 Section 10.3.5 Ductility (Non prestressed) ................................................................................. 950 62.6.3 Section 10.5.1 Minimum Reinforcement of Flexural Members (Non Prestressed) ...950 62.6.4 Section 10.6.4 Minimum Reinforcement of Flexural Members (Non Prestressed) ...950 62.6.5 Section 11.2 Shear Resistance of Beams (Non Prestressed) ............................................... 951 62.6.6 Section 11.3 Shear Resistance of Beams (Prestressed) ......................................................... 951 62.6.7 Section 11.5 Beam Torsion .................................................................................................................952 62.6.8 Chapter 13 (Two-way slab systems) ..............................................................................................953 62.6.9 Section 18.3.3 Service Tensile Stress Limit .................................................................................953 62.6.10 Section 18.4.1a Initial (at stressing) Compressive Stress Limit .........................................954 62.6.11 Section 18.4.1c Initial (at stressing) Tensile Stress Limit ......................................................954 62.6.12 Section 18.4.2a Sustained Compressive Stress Limit ..............................................................955 62.6.13 Section 18.4.2b Service Compressive Stress Limit .................................................................. 955 62.6.14 Section 18.4.4 Reinforcement Spacing Limits for Class C Members ................................ 955 62.6.15 Section 18.7 Design Flexural Resistance (Prestressed) .........................................................956 62.6.16 Section 18.8.2 Cracking Moment ..................................................................................................... 956 62.6.17 Section 18.9.2 Minimum Reinforcement - One Way ............................................................... 957 62.6.18 Section 18.9.3.2 Midspan Two Way Minimum Reinforcement .......................................... 957 62.6.19 Section 18.9.3.3 Support Two Way Minimum Reinforcement ............................................958 62.6.20 Punching Shear Design .........................................................................................................................958 62.6.21
Chapter 63: ACI 318-11 Design ............................................................................................... 959 63.1 63.2
RAM Concept
ACI 318-11 default loadings ..........................................................................................................................................959 Temporary Construction (At Stressing) Loading ..................................................................... 959 63.1.1 ACI 318-11 default load combinations .....................................................................................................................959 All Dead LC ................................................................................................................................................ 960 63.2.1 Initial Service LC ..................................................................................................................................... 960 63.2.2 Service LC: D + L ......................................................................................................................................960 63.2.3
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User Manual
63.3 63.4
63.5
63.6
RAM Concept
Service LC: D + Lr ....................................................................................................................................961 63.2.4 Service LC: D + S ......................................................................................................................................961 63.2.5 Service LC: D + 0.75L + 0.75Lr .......................................................................................................... 961 63.2.6 Service LC: D + 0.75L + 0.75S ............................................................................................................ 961 63.2.7 Sustained Service LC ............................................................................................................................. 962 63.2.8 Factored LC: 1.4D ................................................................................................................................... 962 63.2.9 Factored LC: 1.2D + 1.6L + 0.5Lr ......................................................................................................962 63.2.10 Factored LC: 1.2D + f1L+ 1.6Lr ......................................................................................................... 962 63.2.11 Factored LC: 1.2D + 1.6L + 0.5S ........................................................................................................963 63.2.12 Factored LC: 1.2D + f1L+ 1.6S ........................................................................................................... 963 63.2.13 Service Wind LC: D + 0.6W ................................................................................................................. 963 63.2.14 Service Wind LC: D + 0.75L + 0.75Lr + 0.45W ........................................................................... 964 63.2.15 Service Wind LC: D + 0.75L + 0.75S + 0.45W ............................................................................. 964 63.2.16 Service Wind LC: 0.6D + 0.6W ...........................................................................................................964 63.2.17 Service Seismic LC: D + 0.7E .............................................................................................................. 965 63.2.18 Service Seismic LC: D + 0.75L + 0.75S + 0.525E ........................................................................965 63.2.19 Service Seismic LC: 0.6D + 0.7E ........................................................................................................965 63.2.20 Factored Wind LC: 1.2D + f1L+ 0.5Lr + W ................................................................................... 965 63.2.21 Factored Wind LC: 1.2D + f1L+ 0.5S + W ..................................................................................... 966 63.2.22 Factored Wind LC: 1.2D + 1.6Lr + 0.5W ....................................................................................... 966 63.2.23 Factored Wind LC: 1.2D + 1.6S + 0.5W ..........................................................................................966 63.2.24 Factored Seismic LC: 1.2D + f1L+ f2S + E .....................................................................................967 63.2.25 Factored Seismic LC: 0.9D + E ...........................................................................................................967 63.2.26 ACI318-11 / ASCE-7 / live load factors ....................................................................................................................967 ACI 318-11 Material Behaviors .....................................................................................................................................967 Concrete Behavior ..................................................................................................................................968 63.4.1 (Non-prestressed) Reinforcement Behavior ..............................................................................968 63.4.2 Bonded Prestressed Reinforcement Behavior ...........................................................................968 63.4.3 Unbonded Prestressed Reinforcement Behavior ..................................................................... 969 63.4.4 ACI 318-11 code rule selection .................................................................................................................................... 969 Code Minimum Reinforcement .........................................................................................................969 63.5.1 User Minimum Reinforcement ......................................................................................................... 970 63.5.2 Initial Service ............................................................................................................................................971 63.5.3 Service ......................................................................................................................................................... 971 63.5.4 Sustained Service ....................................................................................................................................972 63.5.5 Strength ...................................................................................................................................................... 973 63.5.6 Ductility ...................................................................................................................................................... 973 63.5.7 ACI 318-11 code implementation ...............................................................................................................................974 Section 7.12 Shrinkage and Temperature Reinforcement ................................................... 974 63.6.1 Section 10.2 Factored Moment Resistance (Non prestressed) ...........................................974 63.6.2 Section 10.3.5 Ductility (Non prestressed) ................................................................................. 975 63.6.3 Section 10.5.1 Minimum Reinforcement of Flexural Members (Non Prestressed) ...975 63.6.4 Section 10.6.4 Minimum Reinforcement of Flexural Members (Non Prestressed) ...976 63.6.5 Section 11.2 Shear Resistance of Beams (Non Prestressed) ............................................... 976 63.6.6 Section 11.3 Shear Resistance of Beams (Prestressed) ......................................................... 977 63.6.7 Section 11.5 Beam Torsion .................................................................................................................978 63.6.8 Chapter 13 (Two-way slab systems) ..............................................................................................979 63.6.9 Section 18.3.3 Service Tensile Stress Limit .................................................................................979 63.6.10 Section 18.4.1a Initial (at stressing) Compressive Stress Limit .........................................980 63.6.11 Section 18.4.1c Initial (at stressing) Tensile Stress Limit .....................................................980 63.6.12 Section 18.4.2a Sustained Compressive Stress Limit ..............................................................980 63.6.13
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63.6.14 63.6.15 63.6.16 63.6.17 63.6.18 63.6.19 63.6.20 63.6.21
Section 18.4.2b Service Compressive Stress Limit .................................................................. 981 Section 18.4.4 Reinforcement Spacing Limits for Class C Members ................................ 981 Section 18.7 Design Flexural Resistance (Prestressed) .........................................................981 Section 18.8.2 Cracking Moment ..................................................................................................... 982 Section 18.9.2 Minimum Reinforcement - One Way ............................................................... 982 Section 18.9.3.2 Midspan Two Way Minimum Reinforcement .......................................... 983 Section 18.9.3.3 Support Two Way Minimum Reinforcement ............................................983 Punching Shear Design .........................................................................................................................984
Chapter 64: ACI 318-14 Design ............................................................................................... 985 64.1 64.2
64.3 64.4 64.5
64.6
RAM Concept
ACI 318-14 default loadings ..........................................................................................................................................985 Temporary Construction (At Stressing) Loading ..................................................................... 985 64.1.1 ACI 318-14 default load combinations .....................................................................................................................985 All Dead LC ................................................................................................................................................ 986 64.2.1 Initial Service LC ..................................................................................................................................... 986 64.2.2 Service LC: D + L ......................................................................................................................................986 64.2.3 Service LC: D + Lr ....................................................................................................................................987 64.2.4 Service LC: D + S ......................................................................................................................................987 64.2.5 Service LC: D + 0.75L + 0.75Lr .......................................................................................................... 987 64.2.6 Service LC: D + 0.75L + 0.75S ............................................................................................................ 987 64.2.7 Sustained Service LC ............................................................................................................................. 988 64.2.8 Factored LC: 1.4D ................................................................................................................................... 988 64.2.9 Factored LC: 1.2D + 1.6L + 0.5Lr ......................................................................................................988 64.2.10 Factored LC: 1.2D + f1L+ 1.6Lr ......................................................................................................... 988 64.2.11 Factored LC: 1.2D + 1.6L + 0.5S ........................................................................................................989 64.2.12 Factored LC: 1.2D + f1L+ 1.6S ........................................................................................................... 989 64.2.13 Service Wind LC: D + 0.6W ................................................................................................................. 989 64.2.14 Service Wind LC: D + 0.75L + 0.75Lr + 0.45W ........................................................................... 990 64.2.15 Service Wind LC: D + 0.75L + 0.75S + 0.45W ............................................................................. 990 64.2.16 Service Wind LC: 0.6D + 0.6W ...........................................................................................................990 64.2.17 Service Seismic LC: D + 0.7E .............................................................................................................. 991 64.2.18 Service Seismic LC: D + 0.75L + 0.75S + 0.525E ........................................................................991 64.2.19 Service Seismic LC: 0.6D + 0.7E ........................................................................................................991 64.2.20 Factored Wind LC: 1.2D + f1L+ 0.5Lr + W ................................................................................... 991 64.2.21 Factored Wind LC: 1.2D + f1L+ 0.5S + W ..................................................................................... 992 64.2.22 Factored Wind LC: 1.2D + 1.6Lr + 0.5W ....................................................................................... 992 64.2.23 Factored Wind LC: 1.2D + 1.6S + 0.5W ..........................................................................................992 64.2.24 Factored Seismic LC: 1.2D + f1L+ f2S + E .....................................................................................993 64.2.25 Factored Seismic LC: 0.9D + E ...........................................................................................................993 64.2.26 ACI318-14 / ASCE-7 / live load factors ....................................................................................................................993 ACI 318-14 Material Behaviors .....................................................................................................................................993 ACI 318-14 code rule selection .................................................................................................................................... 995 Code Minimum Reinforcement .........................................................................................................995 64.5.1 User Minimum Reinforcement ......................................................................................................... 996 64.5.2 Initial Service ............................................................................................................................................997 64.5.3 Service ......................................................................................................................................................... 997 64.5.4 Sustained Service ....................................................................................................................................998 64.5.5 Strength ...................................................................................................................................................... 998 64.5.6 Ductility ...................................................................................................................................................... 999 64.5.7 ACI 318-14 code implementation ...............................................................................................................................999 Section 7.6.1.1 and 8.6.1.1 Minimum Flexural Reinforcement ............................................ 999 64.6.1
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64.6.2 64.6.3 64.6.4 64.6.5 64.6.6 64.6.7 64.6.8 64.6.9 64.6.10 64.6.11 64.6.12 64.6.13 64.6.14 64.6.15 64.6.16 64.6.17 64.6.18 64.6.19 64.6.20 64.6.21
Sections 7.5.2, 8.5.2 and 9.5.2 Factored Moment Resistance (Non prestressed) .....1000 Sections 7.3.3.1, 8.3.3.1, and 9.3.3.1 Ductility (Non prestressed) ...................................1001 Sections 9.6.1.1 and 9.6.1.2 Minimum Reinforcement of Flexural Members (Non Prestressed) ........................................................................................................................................... 1001 Sections 7.7.2.2 and 9.7.2.2 Minimum Reinforcement of Flexural Members (Non Prestressed) ............................................................................................................................................ 1002 Sections 7.5.3, 8.5.3 and 9.5.3 Shear Resistance (Non Prestressed) ..............................1002 Sections 7.5.3, 8.5.3 and 9.5.3 Shear Resistance of Beams (Prestressed) ................... 1003 Section 9.5.4 Beam Torsion ............................................................................................................. 1003 Chapter 8 (Two-way slab systems) ..............................................................................................1004 Section 24.5.2.1 Service Tensile Stress Limit .......................................................................... 1005 Section 24.5.3.1 Initial (at stressing) Compressive Stress Limit .....................................1005 Section 24.5.3.2 Initial (at stressing) Tensile Stress Limit .................................................1006 Section 24.5.4.1 Sustained Compressive Stress Limit ..........................................................1006 Section 24.5.4.1 Service Compressive Stress Limit ...............................................................1006 Sections 7.7.2.2 and 9.7.2.2 Reinforcement Spacing Limits for Class C Members ...1007 Section 7.5.2, 8.5.2 and 9.5.2 Design Flexural Resistance (Prestressed) .....................1007 Sections 7.6.2.1, 8.6.2.2 and 9.6.2.1 Cracking Moment ........................................................1008 Sections 7.6.2.3 and 9.6.2.3 Minimum Reinforcement - One Way ..................................1008 Section 8.6.2.3 Midspan Two Way Minimum Reinforcement .......................................... 1008 Section 8.6.2.3 Support Two Way Minimum Reinforcement ............................................1009 Punching Shear Design ......................................................................................................................1009
Chapter 65: AS 3600-2001 Design ........................................................................................1011 65.1 65.2
65.3
65.4
RAM Concept
AS 3600-2001 default loadings .................................................................................................................................1011 Temporary Construction (At Stressing) Loading ...................................................................1011 65.1.1 Snow Loading ........................................................................................................................................ 1011 65.1.2 AS 3600-2001 default load combinations ............................................................................................................ 1012 All Dead LC ..............................................................................................................................................1012 65.2.1 Initial Service LC ...................................................................................................................................1012 65.2.2 Service LC: D + ψ L .............................................................................................................................. 1012 65.2.3 Service LC: D + ψ L + S ....................................................................................................................... 1013 65.2.4 Max Service LC: D + L ......................................................................................................................... 1013 65.2.5 Ultimate LC: 1.35D ...............................................................................................................................1013 65.2.6 Ultimate LC: 1.2D + 1.5L ................................................................................................................... 1013 65.2.7 Ultimate LC: 1.2D + ψ L + S ..............................................................................................................1014 65.2.8 Service Wind LC: D + ψ L + W .........................................................................................................1014 65.2.9 Service Seismic LC: D + ψ L + E ......................................................................................................1014 65.2.10 Ultimate Wind LC: 1.2D + ψ L + W ................................................................................................1015 65.2.11 Ultimate Seismic LC: D + ψ L + E ................................................................................................... 1015 65.2.12 Sustained Service LC ...........................................................................................................................1015 65.2.13 AS3600 / AS/NZS 1170.1 live load factors ...............................................................................1016 65.2.14 AS 3600-2001 Material Behaviors ............................................................................................................................1016 Concrete Behavior ............................................................................................................................... 1016 65.3.1 (Non-prestressed) Reinforcement Behavior ........................................................................... 1017 65.3.2 Bonded Prestressed Reinforcement Behavior ........................................................................ 1017 65.3.3 Unbonded Prestressed Reinforcement Behavior .................................................................. 1017 65.3.4 AS 3600-2001 code rule selection ........................................................................................................................... 1017 Code Minimum Reinforcement ......................................................................................................1018 65.4.1 User Minimum Reinforcement .......................................................................................................1018 65.4.2 Initial Service ......................................................................................................................................... 1019 65.4.3
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65.5
Service ...................................................................................................................................................... 1020 65.4.4 Max Service .............................................................................................................................................1020 65.4.5 Strength ....................................................................................................................................................1021 65.4.6 Ductility ....................................................................................................................................................1021 65.4.7 AS 3600-2001 code implementation ......................................................................................................................1022 Concrete Modulus of Elasticity ...................................................................................................... 1022 65.5.1 Concrete Flexural Tensile Strength ..............................................................................................1022 65.5.2 Unbonded Post-Tensioning Stress-Strain Curves ..................................................................1022 65.5.3 Section 8.1 Strength of Beams in Bending ................................................................................ 1023 65.5.4 8.1.4 Minimum Flexural Strength ................................................................................................. 1023 65.5.5 8.1.4.2 Transfer Compressive Stress Limits .............................................................................1023 65.5.6 Section 8.1.3 Ductility of Beams in Bending .............................................................................1024 65.5.7 Section 8.2 Shear Design ...................................................................................................................1024 65.5.8 Section 8.3 Beam Torsion Design ................................................................................................. 1025 65.5.9 Section 8.6.1 RC Beam Crack Control ..........................................................................................1025 65.5.10 Section 8.6.2 PT Beam Crack Control ..........................................................................................1026 65.5.11 Section 9.1 Strength of Slabs in Bending ................................................................................... 1027 65.5.12 Section 9.4.1 RC Slab Crack Control .............................................................................................1027 65.5.13 Section 9.4.2 PT Slab Crack Control .............................................................................................1028 65.5.14 Section 9.4.3.2 Shrinkage and Temperature ............................................................................ 1028 65.5.15 Punching Shear Design ......................................................................................................................1029 65.5.16
Chapter 66: AS 3600-2009 Design ........................................................................................1030 66.1 66.2
66.3 66.4
66.5
RAM Concept
AS 3600-2009 default loadings .................................................................................................................................1030 Temporary Construction (At Stressing) Loading ...................................................................1030 66.1.1 Snow Loading ........................................................................................................................................ 1030 66.1.2 AS 3600-2009 default load combinations ............................................................................................................ 1031 All Dead LC ..............................................................................................................................................1031 66.2.1 Initial Service LC ...................................................................................................................................1031 66.2.2 Service LC: D + ψ L .............................................................................................................................. 1031 66.2.3 Service LC: D + ψ L + S ....................................................................................................................... 1032 66.2.4 Max Service LC: D + L ......................................................................................................................... 1032 66.2.5 Ultimate LC: 1.35D ...............................................................................................................................1032 66.2.6 Ultimate LC: 1.2D + 1.5L ................................................................................................................... 1033 66.2.7 Ultimate LC: 1.2D + ψ L + S ..............................................................................................................1033 66.2.8 Service Wind LC: D + ψ L + W .........................................................................................................1033 66.2.9 Service Seismic LC: D + ψ L + E ......................................................................................................1033 66.2.10 Ultimate Wind LC: 1.2D + ψ L + W ................................................................................................1034 66.2.11 Ultimate Seismic LC: D + ψ L + E ................................................................................................... 1034 66.2.12 Sustained Service LC ...........................................................................................................................1035 66.2.13 AS3600 / AS/NZS 1170.1 live load factors .......................................................................................................... 1035 AS 3600-2009 Material Behaviors ............................................................................................................................1035 Concrete Behavior ............................................................................................................................... 1035 66.4.1 (Non-prestressed) Reinforcement Behavior ........................................................................... 1036 66.4.2 Bonded Prestressed Reinforcement Behavior ........................................................................ 1036 66.4.3 Unbonded Prestressed Reinforcement Behavior .................................................................. 1036 66.4.4 AS 3600-2009 code rule selection ........................................................................................................................... 1036 Code Minimum Reinforcement ......................................................................................................1037 66.5.1 User Minimum Reinforcement .......................................................................................................1037 66.5.2 Initial Service ......................................................................................................................................... 1039 66.5.3 Service ...................................................................................................................................................... 1039 66.5.4
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66.6
Max Service .............................................................................................................................................1040 66.5.5 Strength ....................................................................................................................................................1040 66.5.6 Ductility ....................................................................................................................................................1041 66.5.7 AS 3600-2009 code implementation ......................................................................................................................1041 Concrete Modulus of Elasticity ...................................................................................................... 1041 66.6.1 Concrete Flexural Tensile Strength ..............................................................................................1041 66.6.2 Unbonded Post-Tensioning Stress-Strain Curves ..................................................................1042 66.6.3 Section 8.1 Strength of Beams in Bending ................................................................................ 1042 66.6.4 8.1.6 Minimum Flexural Strength ................................................................................................. 1043 66.6.5 8.1.6.2 Transfer Compressive Stress Limits .............................................................................1043 66.6.6 Section 8.1.5 Ductility of Beams in Bending .............................................................................1043 66.6.7 Section 8.2 Shear Design ...................................................................................................................1043 66.6.8 Section 8.3 Beam Torsion Design ................................................................................................. 1044 66.6.9 Section 8.6.1 RC Beam Crack Control ..........................................................................................1045 66.6.10 Section 8.6.2 PT Beam Crack Control ..........................................................................................1045 66.6.11 Section 9.1 Strength of Slabs in Bending ................................................................................... 1046 66.6.12 Section 9.4.1 RC Slab Crack Control .............................................................................................1046 66.6.13 Section 9.4.2 PT Slab Crack Control .............................................................................................1047 66.6.14 Section 9.4.3.2 Shrinkage and Temperature ............................................................................ 1047 66.6.15 Punching Shear Design ......................................................................................................................1048 66.6.16
Chapter 67: AS 3600-2018 Design ........................................................................................1049 67.1 67.2 67.3 67.4 67.5
67.6
RAM Concept
AS 3600-2018 default loadings .................................................................................................................................1049 AS 3600-2018 default load combinations ............................................................................................................ 1049 AS3600 / AS/NZS 1170.1 live load factors .......................................................................................................... 1053 AS 3600-2018 Material Behaviors ............................................................................................................................1054 AS 3600-2018 code rule selection ........................................................................................................................... 1055 Code Minimum Reinforcement ......................................................................................................1055 67.5.1 User Minimum Reinforcement .......................................................................................................1056 67.5.2 Initial Service ......................................................................................................................................... 1057 67.5.3 Service ...................................................................................................................................................... 1057 67.5.4 Max Service .............................................................................................................................................1058 67.5.5 Strength ....................................................................................................................................................1059 67.5.6 Ductility ....................................................................................................................................................1059 67.5.7 AS 3600-2018 code implementation ......................................................................................................................1059 Concrete Modulus of Elasticity ...................................................................................................... 1060 67.6.1 Concrete Flexural Tensile Strength ..............................................................................................1060 67.6.2 Unbonded Post-Tensioning Stress-Strain Curves ..................................................................1060 67.6.3 Section 8.1 Strength of Beams in Bending ................................................................................ 1060 67.6.4 8.1.6 Minimum Flexural Strength ................................................................................................. 1062 67.6.5 8.1.6.2 Transfer Compressive Stress Limits .............................................................................1062 67.6.6 Section 8.1.5 Ductility of Beams in Bending .............................................................................1062 67.6.7 Section 8.2 Shear Design ...................................................................................................................1063 67.6.8 Section 8.3 Beam Torsion Design ................................................................................................. 1063 67.6.9 Section 9.1 Strength of Slabs in Bending ................................................................................... 1064 67.6.10 Section 8.6.1/9.5.1 Crack Control .................................................................................................. 1064 67.6.11 Section 8.6.2.2/9.5.2.2 Assessment of Crack Widths for RC Beams and Slabs Without 67.6.12 Direct Calculation (Tables) ............................................................................................................... 1065 Section 8.6.3/9.5.2.3 Crack Control for PT Beams and Slabs Without Direct Calculation 67.6.13 (Tables) .................................................................................................................................................... 1066 Section 8.6.3/9.5.2.3 Crack Control with Direct Crack Width Calculation ...................1067 67.6.14
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67.6.15 67.6.16
Section 9.5.3.2 Minimum Shrinkage and Temperature Reinforcement in Primary Direction ................................................................................................................................................... 1068 Punching Shear Design ......................................................................................................................1069
Chapter 68: BS 8110: 1997 Design ....................................................................................... 1070 68.1 68.2
68.3 68.4
68.5
68.6
RAM Concept
BS 8110 / TR 43 default loadings ............................................................................................................................ 1070 Default Pattern Loading Factors ................................................................................................... 1070 68.1.1 Temporary Construction (At Stressing) Loading ...................................................................1070 68.1.2 BS 8110 / TR 43 Default Load Combinations ..................................................................................................... 1071 All Dead LC ..............................................................................................................................................1071 68.2.1 Initial Service LC ...................................................................................................................................1071 68.2.2 Service LC: D + L + S ............................................................................................................................1072 68.2.3 Ultimate LC: 1.4D + 1.6L + 1.6S ......................................................................................................1072 68.2.4 Service Wind LC: D + L + S + W ...................................................................................................... 1072 68.2.5 Service Wind LC: D + W .....................................................................................................................1072 68.2.6 Ultimate Wind LC: 1.2D + 1.2L + 1.2S + 1.2W ..........................................................................1073 68.2.7 Ultimate Wind LC: D + 1.4W ............................................................................................................1073 68.2.8 Accident LC ............................................................................................................................................. 1073 68.2.9 Sustained Service LC ...........................................................................................................................1073 68.2.10 BS 8110 / BS 6399-1 live load factors ................................................................................................................... 1074 BS 8110/TR43 Material Behaviors .......................................................................................................................... 1074 Concrete Behavior ............................................................................................................................... 1074 68.4.1 (Untensioned) Reinforcement Behavior ....................................................................................1076 68.4.2 Bonded Prestressed Reinforcement Behavior ........................................................................ 1077 68.4.3 Unbonded Prestressed Reinforcement Behavior .................................................................. 1077 68.4.4 BS 8110 / TR 43 code rule selection .......................................................................................................................1078 Code Minimum Reinforcement ......................................................................................................1078 68.5.1 User Minimum Reinforcement .......................................................................................................1079 68.5.2 Initial Service (“Transfer”) ...............................................................................................................1080 68.5.3 Service ...................................................................................................................................................... 1081 68.5.4 Strength ....................................................................................................................................................1081 68.5.5 Ductility ....................................................................................................................................................1082 68.5.6 Accident ................................................................................................................................................... 1082 68.5.7 BS8110 / TR43 code implementation ....................................................................................................................1083 Section 3.2.2.1 Redistribution of moments (Ductility Check) .......................................... 1083 68.6.1 Section 3.4.4 Design resistance moment of beams ............................................................... 1084 68.6.2 Section 3.4.5 Design shear resistance of beams ..................................................................... 1084 68.6.3 Section 3.4.5.13 Torsion ................................................................................................................... 1085 68.6.4 Section 3.5.4 Resistance moment of solid slabs ..................................................................... 1086 68.6.5 Section 3.5.5 Shear resistance of solid slabs ............................................................................ 1086 68.6.6 Section 3.12.5 Minimum areas of reinforcement in members .........................................1086 68.6.7 Section 3.12.11.2.1 Bar spacing ..................................................................................................... 1087 68.6.8 Section 3.12.11.2.4 Beam Bar spacing ........................................................................................ 1087 68.6.9 Section 3.12.11.2.7 Slab Bar spacing ........................................................................................... 1087 68.6.10 Section 4.2.3.1 Redistribution of Moments (Ductility Check) .......................................... 1088 68.6.11 Section 4.3.4.2 Compressive stresses in concrete ................................................................. 1088 68.6.12 Section 4.3.4.3 Flexural tension stresses in concrete ...........................................................1088 68.6.13 Determination of Bonded vs. Unbonded Cross Sections .................................................... 1089 68.6.14 Calculation of Supplemental Untensioned Reinforcement ................................................1090 68.6.15 Calculation of Supplemental Reinforcement Per 4.3.4.3(c) .............................................. 1090 68.6.16 Calculation of Supplemental Reinforcement Per TR 43, 6.10.5 .......................................1090 68.6.17
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68.6.18 68.6.19 68.6.20 68.6.21 68.6.22 68.6.23 68.6.24 68.6.25 68.6.26 68.6.27
Section 4.3.5.1 Design compressive stresses (Transfer) .................................................... 1091 Section 4.3.5.2 Design tensile stresses in flexure (Transfer) ............................................1091 Section 4.3.7 Ultimate limit state for beams in flexure ....................................................... 1092 Section 4.3.8 Design shear resistance of beams ..................................................................... 1092 Section 4.3.9 Torsion ..........................................................................................................................1094 Section 4.4.1 / 4.3.8 Slabs (shear) ................................................................................................ 1094 Section 4.12.2 Limitation on area of prestressing tendons ............................................... 1094 Part 2, Section 3.8.3 Assessment of Crack Widths .................................................................1094 TR 43 / Section 6.10.6 Minimum un-tensioned reinforcement .......................................1095 Punching shear design .......................................................................................................................1096
Chapter 69: IS 456 : 2000 / IS 1343 : 1980 Design ................................................................ 1097 69.1 69.2
69.3 69.4
69.5
69.6
69.7
RAM Concept
IS 456 / IS 1343 default loadings ............................................................................................................................. 1097 Temporary Construction (At Stressing) Loading ...................................................................1097 69.1.1 IS 456 Default Load Combinations ........................................................................................................................... 1097 All Dead LC ..............................................................................................................................................1098 69.2.1 Initial Service LC ...................................................................................................................................1098 69.2.2 Service LC: D + L + S ............................................................................................................................1098 69.2.3 Ultimate LC: 1.5D + 1.5L + 1.5S ......................................................................................................1098 69.2.4 Service Wind LC: D + 0.8L + 0.8S + 0.8W ...................................................................................1099 69.2.5 Service Wind LC: D + W .....................................................................................................................1099 69.2.6 Ultimate Wind LC: 1.2D + 1.2L + 1.2S + 1.2W ..........................................................................1099 69.2.7 Ultimate Wind LC: 0.9D + 1.5W ..................................................................................................... 1099 69.2.8 Service Seismic LC: D + 0.8L + 0.2S + 0.8E ................................................................................ 1100 69.2.9 Service Seismic LC: D + E ..................................................................................................................1100 69.2.10 Ultimate Seismic LC: 1.2D + 1.2L + 0.3S + 1.2E .......................................................................1100 69.2.11 Ultimate Seismic LC: 0.9D + 1.5E .................................................................................................. 1101 69.2.12 Sustained Service LC ...........................................................................................................................1101 69.2.13 IS 875 (Part 2) live load factors ................................................................................................................................ 1102 IS 456 Material Behaviors ............................................................................................................................................ 1102 Concrete Behavior ............................................................................................................................... 1102 69.4.1 (Untensioned) Reinforcement Behavior ....................................................................................1104 69.4.2 Bonded Prestressed Reinforcement Behavior ........................................................................ 1105 69.4.3 Unbonded Prestressed Reinforcement Behavior .................................................................. 1105 69.4.4 IS 456 code rule selection ............................................................................................................................................1105 Code Minimum Reinforcement ......................................................................................................1106 69.5.1 User Minimum Reinforcement .......................................................................................................1106 69.5.2 Initial Service (“Transfer”) ...............................................................................................................1107 69.5.3 Service ...................................................................................................................................................... 1108 69.5.4 Strength ....................................................................................................................................................1109 69.5.5 Ductility ....................................................................................................................................................1110 69.5.6 IS 456 code implementation ...................................................................................................................................... 1110 Section 26.5.1.1 .....................................................................................................................................1111 69.6.1 Section 26.5.2.1 .....................................................................................................................................1111 69.6.2 Section 31.7.1 ........................................................................................................................................ 1111 69.6.3 Section 37 / 38 Redistribution of moments (Ductility Check) .........................................1112 69.6.4 Section 38 Design resistance moment of beams .................................................................... 1112 69.6.5 Section 40 Design shear resistance ..............................................................................................1113 69.6.6 Section 41 Torsion ...............................................................................................................................1114 69.6.7 Annex F Assessment of Crack Widths .........................................................................................1114 69.6.8 IS 1343 code implementation ....................................................................................................................................1115
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69.7.1 69.7.2 69.7.3 69.7.4 69.7.5 69.7.6 69.7.7 69.7.8 69.7.9 69.7.10 69.7.11 69.7.12 69.7.13
Section 18.6.3.2c Minimum transverse reinforcement ....................................................... 1115 Section 18.6.3.3 Minimum longitudinal reinforcement ...................................................... 1116 Section 18.6.3.3 Limitation on area of prestressing tendons ........................................... 1116 Section 21.1.1 Redistribution of moments (Ductility Check) ........................................... 1116 Section 22.1 Ultimate limit state for beams in flexure ........................................................ 1116 Section 22.4 Design shear resistance of beams ...................................................................... 1117 Section 22.5 Torsion ...........................................................................................................................1118 Section 22.7.1 Flexural tension stresses in concrete ............................................................1119 Determination of Bonded vs. Unbonded Cross Sections .................................................... 1119 Calculation of Supplemental Untensioned Reinforcement ................................................1119 Section 22.8.1 Design compressive stresses ............................................................................ 1120 Section 22.8.2 Design compressive stresses (Transfer) ..................................................... 1120 Punching Shear Design ......................................................................................................................1120
Chapter 70: EN 1992-1-1: 2004 (Eurocode 2) With TR43 Design ........................................... 1121 70.1
70.2
70.3
70.4
RAM Concept
EC2 default loadings ...................................................................................................................................................... 1123 Temporary Construction (At Stressing) Loading ...................................................................1123 70.1.1 Snow Loading ........................................................................................................................................ 1123 70.1.2 Live (Parking) Loading ...................................................................................................................... 1123 70.1.3 EC2 Default Load Combinations ............................................................................................................................... 1123 All Dead LC ..............................................................................................................................................1124 70.2.1 Dead + Balance LC ............................................................................................................................... 1124 70.2.2 Initial Service LC ...................................................................................................................................1124 70.2.3 Characteristic Service LC: D + L + 0.5S ....................................................................................... 1124 70.2.4 Characteristic Service Snow LC: D + ψ0L + S ...........................................................................1125 70.2.5 Frequent Service LC: D + ψ 1 L ...................................................................................................... 1125 70.2.6 Frequent Service Snow LC: D + ψ2L + 0.2S .............................................................................. 1126 70.2.7 Quasi-Permanent Service LC: D + ψ2L ....................................................................................... 1126 70.2.8 Ultimate LC: 1.35D + 0.9H + 1.5ψ0L + 0.75S ............................................................................1126 70.2.9 Ultimate LC: 1.35ξ D + 0.9H + 1.5ψ0L + 1.5S ........................................................................... 1127 70.2.10 Ultimate LC: 1.35ξ D + 0.9H + 1.5L + 0.75S ...............................................................................1127 70.2.11 Accident LC ............................................................................................................................................. 1128 70.2.12 Characteristic Service Wind LC: D + ψ0L + 0.5S + W ........................................................... 1128 70.2.13 Characteristic Service Wind LC: D + ψ0L + S + ψ0W ............................................................1128 70.2.14 Characteristic Service Wind LC: D + L + 0.5S + ψ0W ........................................................... 1129 70.2.15 Frequent Service Wind LC: D + ψ2L + 0.2W ............................................................................ 1129 70.2.16 Ultimate Wind LC: 1.35D + 0.9H + 1.5ψ0L + 0.75S + 1.5ψ0W ......................................... 1130 70.2.17 Ultimate Wind LC: 1.35ξ D + 0.9H + 1.5L + 0.75S + 1.5ψ0W ............................................ 1130 70.2.18 Ultimate Wind LC: 1.35ξ D + 0.9H + 1.5ψ0 L + 1.5S + 1.5ψ0W ........................................1131 70.2.19 Ultimate Wind LC: 1.35ξ D + 0.9H + 1.5ψ0 L + 0.75S + 1.5W ........................................... 1131 70.2.20 Equilibrium Wind LC: 0.9D + 1.5W .............................................................................................. 1132 70.2.21 Eurocode 1 Part 1-1 (UK National Annex) Live Load Reduction .................................... 1132 70.2.22 EC2 Material behaviors ................................................................................................................................................ 1132 Concrete Behavior ............................................................................................................................... 1132 70.3.1 (Untensioned) Reinforcement Behavior ....................................................................................1133 70.3.2 Bonded Prestressed Reinforcement Behavior ........................................................................ 1133 70.3.3 Unbonded Prestressed Reinforcement Behavior .................................................................. 1134 70.3.4 EC2 code rule selection .................................................................................................................................................1135 Code Minimum Reinforcement ......................................................................................................1135 70.4.1 User Minimum Reinforcement .......................................................................................................1136 70.4.2 Initial Service (“Transfer”) ...............................................................................................................1137 70.4.3
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Characteristic Service ........................................................................................................................ 1137 70.4.4 Frequent Service .................................................................................................................................. 1138 70.4.5 Quasi-Permanent Service ................................................................................................................. 1139 70.4.6 Strength .....................................................................................................................................................1140 70.4.7 Ductility ....................................................................................................................................................1141 70.4.8 Accident ................................................................................................................................................... 1141 70.4.9 EC2 code implementation ........................................................................................................................................... 1141 Section 5.5 Redistribution of moments (Ductility Check) ..................................................1142 70.5.1 Section 5.10.2.2 Limitation of Concrete Stress (Transfer) .................................................1142 70.5.2 Section 6.1 Design resistance moment .......................................................................................1142 70.5.3 Section 6.2 Design shear resistance .............................................................................................1143 70.5.4 Section 6.3 Torsion ..............................................................................................................................1144 70.5.5 7.2 Stress Limitation ...........................................................................................................................1145 70.5.6 7.3.1 Assessment of Crack Widths ................................................................................................1145 70.5.7 Section 9.2.1.1 Beam Minimum Reinforcement ..................................................................... 1147 70.5.8 Section 9.3.1.1 RC Slab Minimum Reinforcement ..................................................................1147 70.5.9 Section 9.10 Tying Systems for Accidental Design Situations ..........................................1148 70.5.10 Determination of Bonded vs. Unbonded Cross Sections .................................................... 1149 70.5.11 TR-43 5.8.1 PT Service Stresses (UK National Annex only) .............................................. 1149 70.5.12 TR-43 5.8.2 PT Initial Service (transfer) Stresses (UK National Annex Only) .......... 1151 70.5.13 TR-43 5.8.3 PT Crack Control (UK National Annex Only) .................................................. 1152 70.5.14 TR-43 5.8.5 PT Ultimate Limit State ............................................................................................ 1152 70.5.15 TR-43 5.8.7 PT Un-tensioned Reinforcement (UK National Annex Only) ...................1152 70.5.16 TR-43 5.8.8 PT Minimum Reinforcement (UK National Annex Only) ...........................1152 70.5.17 TR-43 5.9 Shear Strength ................................................................................................................. 1153 70.5.18
Chapter 71: CSA A23.3-04 Design ........................................................................................ 1154 71.1 71.2
71.3 71.4
RAM Concept
CSA A23.3-04 default loadings .................................................................................................................................. 1154 Temporary Construction (At Stressing) Loading ...................................................................1154 71.1.1 Snow Loading ........................................................................................................................................ 1154 71.1.2 CSA A23.3-04 default load combinations ............................................................................................................. 1155 All Dead LC ..............................................................................................................................................1155 71.2.1 Initial Service LC ...................................................................................................................................1155 71.2.2 Service LC: D + L + 0.45S ...................................................................................................................1155 71.2.3 Service Snow LC: D + 0.5L + 0.9S .................................................................................................. 1156 71.2.4 Service Wind LC: D + 0.5L + 0.45S + 0.75W ............................................................................. 1156 71.2.5 Service Wind LC: D + L + 0.45S + 0.3W .......................................................................................1156 71.2.6 Service Wind LC: D + 0.5L + 0.9S + 0.3W ...................................................................................1157 71.2.7 Sustained Service LC ...........................................................................................................................1157 71.2.8 Factored LC: 1.4D .................................................................................................................................1157 71.2.9 Factored LC: 1.25D + 1.5L + 0.5S .................................................................................................. 1158 71.2.10 Factored LC: 1.25D + 0.5L + 1.5S .................................................................................................. 1158 71.2.11 Factored Wind LC: 1.25D + 0.5L+ 0.5S + 1.4W ....................................................................... 1158 71.2.12 Factored Wind LC: 1.25D + 1.5L + 0.5S + 0.4W ...................................................................... 1159 71.2.13 Factored Wind LC: 1.25D + 0.5L+ 1.5S + 0.4W ....................................................................... 1159 71.2.14 Factored Seismic LC: D + 0.5L+ 0.25S + E ................................................................................. 1160 71.2.15 CSA A23.3-04/NBC 2005 live load factors ........................................................................................................... 1160 CSA A23.3-04 Material Behaviors ............................................................................................................................. 1160 Concrete Behavior ............................................................................................................................... 1160 71.4.1 (Non-prestressed) Reinforcement Behavior ........................................................................... 1161 71.4.2 Bonded Prestressed Reinforcement Behavior ........................................................................ 1161 71.4.3
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71.5
71.6
Unbonded Prestressed Reinforcement Behavior .................................................................. 1161 71.4.4 CSA A23.3-04 code rule selection ............................................................................................................................ 1162 Code Minimum Reinforcement ......................................................................................................1162 71.5.1 User Minimum Reinforcement .......................................................................................................1162 71.5.2 Initial Service ......................................................................................................................................... 1164 71.5.3 Service ...................................................................................................................................................... 1164 71.5.4 Sustained Service ................................................................................................................................. 1165 71.5.5 Strength ....................................................................................................................................................1165 71.5.6 Ductility ....................................................................................................................................................1166 71.5.7 CSA A23.3-04 code implementation ....................................................................................................................... 1166 Section 7.8 Minimum Reinforcement in Slabs .........................................................................1166 71.6.1 Section 10.1 Factored Moment Resistance ...............................................................................1167 71.6.2 Section 10.5.1 Minimum Reinforcement in Beams (Non prestressed) ........................ 1168 71.6.3 Section 10.5.2 Redistribution of Moments - Ductility Check (Non prestressed) ..... 1168 71.6.4 Section 10.6.1 Beams and One-way Slabs - Crack Control .................................................1168 71.6.5 Section 10.5.1 Minimum Reinforcement of Flexural Members (Non Prestressed) 1169 71.6.6 Section 10.6.1 Minimum Reinforcement of Flexural Members (Non Prestressed) 1169 71.6.7 Section 11.3 Shear and Torsion Tension ................................................................................... 1169 71.6.8 Section 11.3 Shear Resistance of Beams ....................................................................................1170 71.6.9 Section 11.3 Torsion Design ............................................................................................................1170 71.6.10 Chapter 13 (Two-way slab systems) ...........................................................................................1171 71.6.11 Section 18.3.1.1a Initial (at stressing) Compressive Stress Limit .................................. 1172 71.6.12 Section 18.3.1.1b Initial (at stressing) Tensile Stress Limit ..............................................1172 71.6.13 Section 18.3.2a Sustained Compressive Stress Limit ...........................................................1172 71.6.14 Section 18.3.2b Service Compressive Stress Limit ................................................................1172 71.6.15 Section 18.7 Cracking Moment ...................................................................................................... 1173 71.6.16 Section 18.8.2 Minimum Bonded Reinforcement .................................................................. 1173 71.6.17 Section 18.8.3 Minimum Reinforcement of Flexural Members (Prestressed) ..........1174 71.6.18 Punching Shear Design ......................................................................................................................1175 71.6.19
Chapter 72: Load History Deflections .................................................................................. 1176 72.1 72.2 72.3
72.4 72.5 72.6 72.7
About RAM Concept’s load history deflection calculations .......................................................................... 1176 The load history deflection calculation process ................................................................................................ 1178 Load history calculations on the cross section ...................................................................................................1178 Material Stress Strain Curves ......................................................................................................... 1179 72.3.1 Creep ......................................................................................................................................................... 1179 72.3.2 Shrinkage .................................................................................................................................................1179 72.3.3 Creep and Shrinkage Models ........................................................................................................... 1180 72.3.4 Cracking/Tension Stiffening ............................................................................................................ 1183 72.3.5 Load History ...........................................................................................................................................1185 72.3.6 Element stiffness adjustments .................................................................................................................................. 1186 Why are load history deflection results different from Long Term Deflection results plotted for the strip? ..................................................................................................................................................................................... 1186 Advice on drawing cross sections ............................................................................................................................1187 A final word of caution ..................................................................................................................................................1187
Chapter 73: Punching Shear Design Notes ........................................................................... 1188 73.1
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Punching shear overview ............................................................................................................................................ 1188 What is a “punching shear” failure? .............................................................................................1188 73.1.1 How are forces really transferred in a punching zone? ...................................................... 1188 73.1.2 How do the building codes handle punching shear? ............................................................1188 73.1.3
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73.3 73.4 73.5
73.6 73.7 73.8 73.9 73.10 73.11
How does RAM Concept handle punching shear? .............................................................................................1189 Step 1: Determine the force envelopes to be checked ......................................................... 1189 73.2.1 Step 2: Determine the “column” critical sections ...................................................................1190 73.2.2 Step 3: Determine the code-model stresses on the column sections ............................ 1191 73.2.3 Step 4: Determine the code-allowable stresses on the column sections .....................1191 73.2.4 Step 5: Design stud shear reinforcement (SSR) if necessary ............................................ 1191 73.2.5 Step 6: Summarize the Results .......................................................................................................1192 73.2.6 Using RAM Concept's results to specify stud shear reinforcement (SSR) systems ............................ 1192 Column connection type .............................................................................................................................................. 1193 About Connection Type ......................................................................................................................1193 73.4.1 ACI 318/CSA A23.3 Punching Shear Design ........................................................................................................1195 Critical Section Properties and Equations for Actual Stress .............................................. 1195 73.5.1 ACI 318 Specific Provisions .............................................................................................................. 1197 73.5.2 CSA A23.3 Specific Provisions ......................................................................................................... 1199 73.5.3 AS 3600 Punching Shear Design ...............................................................................................................................1200 EN 1992-2004 Punching Shear Design ..................................................................................................................1203 Calculation of punching resistance for the unreinforced section ................................... 1204 73.7.2 Sign convention ................................................................................................................................................................1208 Advice on the selection of punching check properties ................................................................................... 1209 Miscellaneous information ......................................................................................................................................... 1210 Some final words of advice ......................................................................................................................................... 1210
Chapter 74: Vibration Analysis Notes .................................................................................. 1211 74.1
74.2
74.3 74.4
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Dynamic Characteristics of Structures .................................................................................................................. 1211 Free Vibration ....................................................................................................................................... 1211 74.1.1 Damping ...................................................................................................................................................1212 74.1.2 Resonant vs. Impulsive Response .................................................................................................1213 74.1.3 Resonant Footfall Response ....................................................................................................................................... 1213 Resonant Simplified (fast) Analysis .............................................................................................1214 74.2.1 Resonant Modal Analysis ................................................................................................................. 1215 74.2.2 RMS Values for Resonant Response ............................................................................................ 1215 74.2.3 Calculation of Response Factor ......................................................................................................1215 74.2.4 Impulsive Footfall Response ...................................................................................................................................... 1216 RMS Values for Impulsive Response ........................................................................................... 1216 74.3.1 Calculation of Response Factor ......................................................................................................1216 74.3.2 Evaluating Vibration Performance and Interpreting Results ...................................................................... 1216 Excitation and Response Node Options ..................................................................................... 1216 74.4.1 Recommendations for Analysis Options ....................................................................................1217 74.4.2 Mode Data Text Table ......................................................................................................................... 1218 74.4.3 Velocity and Acceleration Contour Plots ................................................................................... 1218 74.4.4 Evaluation of Response Factor Plots ........................................................................................... 1218 74.4.5
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Introduction RAM Concept is an analysis and design program that uses the finite element method for elevated concrete floor systems, or mat foundations. The floors or mats can be post-tensioned concrete (PT), reinforced concrete (RC), or hybrid (a mixture of PT and RC). RAM Concept is extremely powerful and allows you to design an entire floor in one model, or design individual strips or beams. In this context, the term “design” means that: • You (the user) define the following: structural geometry, loads, load combinations, and post-tensioning layout (if applicable). • RAM Concept calculates (for any number of load combinations): the required amount of reinforcement for flexure and one-way shear according to relevant code requirements; the stud shear reinforcement (SSR) for punching shear, stresses for flexure, and deflections. • RAM Concept has a post-tensioning optimization feature that allows to select better and economic tendon designs analyzing many alternatives using cloud computing to get a fast optimization process. A model consists of anything from a single simply supported beam or slab to an entire floor. All models are three-dimensional (even those developed with Strip Wizard). RAM Concept does not generally use strip methods other than to replicate the intent of concrete code rules, and with the Strip Wizard interface. Note: The Equivalent Frame method is not used.
1.1 Comparing with “traditional” methods Historically, the vast majority of concrete floors have been analyzed by approximating a region of a slab as a frame (or design strip), and then analyzing the frame/strip using variations of conventional frame or moment distribution analysis techniques. There are two limitations to this approach. First, in irregular structures, the approximation of the real structure into a frame model could be grossly inaccurate and designing with the analysis results might not even satisfy equilibrium requirements in the real structure. The second limitation is that even in regular structures with regular loadings, the frame analysis approximates the slab/column interaction and provides no information regarding the distribution of forces across the design strip. RAM Concept enables you to design post-tensioned and reinforced concrete slabs by using a finite element model of the entire slab. RAM Concept can predict the elastic behavior of a slab much more accurately than frame models. In addition, the finite element method guarantees that the analysis satisfies all equilibrium requirements, regardless of a structure’s irregularities.
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Introduction RAM Concept options
1.2 RAM Concept options RAM Concept is available in the core configuration which is suitable for the analysis and design of reinforced concrete mat foundations (rafts) of any size and shape as well as reinforced concrete floor systems of any size and shape. Increase RAM Concept’s analysis and design capabilities by adding the post-tension option: • RAM Concept PT option (post-tensioned option) Analysis and design of post-tensioned floors or mats in conjunction with reinforced concrete.
1.2.1 Manage License Restrictions Bentley's Open Access licensing scheme does not prevent the use of the post-tensioning option when a license has not been purchased. Use of this feature is permitted, but can result in additional usage fees. To prevent the inadvertent use of the post-tensioning option, a dialog opens when RAM Concept is started which allows you to restrict the use of post-tensioning features. In the event a post-tensioning feature is selected with this restriction option set, a message dialog opens to provide you the option of changing your license restriction settings, or to cancel the operation. Select Help > Manage License Restrictions to change these settings at any time.
1.3 Strip Wizard Strip Wizard uses text input to generate a model. This allows the designer to perform quick preliminary design in 2-D, or final design of straightforward structures. Strips generated by Strip Wizard are three-dimensional, but boundary conditions are automatically introduced which effectively model 2-D behavior. All models use the finite element method. You can use Strip Wizard to design a beam or one-way slab without many mouse clicks. It can provide an initial design of tendons and profiles, negating the need for the designer to start with a guess.
1.4 Structural systems You can use RAM Concept for models that contain any combination of the following: • one-way slab systems • two-way slab systems • beams
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Introduction Learning RAM Concept • • • • • •
girders “wide shallow” beams (that behave similarly to slabs) ribs (joists) waffles (two-way rib systems) mats (rafts) openings
There may be steps and changes in thickness and elevations for all of these items. RAM Concept is not effective, or you cannot use it directly, for the following: • • • •
deep beams using the strut and tie method I-shaped sections ramps concrete sections with internal voids or cells
In most cases, you could model ramps with a large number of steps. The authors do not recommend that you do this for evaluating post-tensioning behavior, as it is not particularly relevant.
1.5 Learning RAM Concept The RAM Concept design process could be considered to comprise six stages: 1. 2. 3. 4. 5. 6.
Defining the concrete form (**) Drawing loads (*) Defining design strips (*****) Defining tendons (if used) (***) Interpreting results (****) Optimization of tendons (only for post-tensioning with cloud computing services) (****)
The (**) rating is meant to indicate relative degree of difficulty, or relative time you would expect to spend on the stage. You should not use RAM Concept for final design without a sufficient grounding in concrete design, or adequate understanding of the program. The manual contains a large amount of information. Ideally, you should read it all, but this may not be practical. We recommend that you do the tutorials and read critical chapters.
1.5.1 Tutorials We recommend that you start by doing the tutorials: • Chapter 41, “Simple RC Slab Tutorial”. • One of the following PT Tutorial Chapters: 42, 43, 44,45 46, or 46.
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Introduction Learning RAM Concept Note: Even if you do not have access to the PT version, it is advisable to do one of these tutorials as a thicker RC slab. • For Mat (Raft Users): Chapter 48, “Mat Foundation Tutorial”. The tutorials introduce you to the “philosophy” of the program. They quickly give you experience in some basic modeling and many of the tools. The descriptions are not exhaustive, and you should reference the actual tool description in the appropriate chapter for further information. This should prove useful for real projects. It is recommended that you redo the tutorials. The completed tutorial files are available from the program directory, so you don’t have to start from scratch. For example, you could open the ACI 318-02 PT Tutorial, delete the design strips, and then start with the design strips input.
1.5.2 Critical Chapters We consider that you should at least read the following chapters, together with the tips in this chapter before starting your first design. • • • • •
Introduction (on page 45) Looking at the Workspace (on page 50) Understanding Layers (on page 55) Using Plans and Perspectives (on page 59) Drawing and Editing Objects (on page 68) Note: Chapter 5 describes snapping. Nearly all meshing problems are due to the user’s failure to use snapping properly.
• • • • • • •
Defining the Structure (on page 160) Defining Design Strips (on page 211) General Tips (on page 436) Frequently Asked Questions (on page 442) Warnings and Errors (on page 465) Load History Deflections (on page 1176) The appropriate code chapter. See the section below: “Know your building code”.
1.5.3 Know your building code RAM Concept does not replace the code. It implements some, but not all, of the code. Using the program does not absolve you of knowing your building code. You should review the appropriate code chapter: • • • • •
ACI 318-14 Design (on page 985) AS 3600-2018 Design (on page 1049) BS 8110: 1997 Design (on page 1070) IS 456 : 2000 / IS 1343 : 1980 Design (on page 1097) EN 1992-1-1: 2004 (Eurocode 2) With TR43 Design (on page 1121)
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Introduction Technical support • CSA A23.3-04 Design (on page 1154) These chapters discuss the following code specific issues: • • • • • •
default loadings default load combinations live load reduction assumptions on material behavior rule selection rule implementation
In particular, you should review what rules are used and how the authors interpret and implement the rules.
Rules not considered Specifically, Concept does not consider the following: • • • •
ACI 318-99, ACI 318-02, ACI 318-05, ACI 318-08, ACI 318-11: Rule 13.5.3 ACI 318-14: Rule 8.4.2.3.1 AS3600-2001/2009 Rules 9.1.2 (detailing bars for 25% of the negative moment) and 9.1.3 BS8110: 1997 Rule 3.7.3.1
1.5.4 Upgrading Old Files Recommendations for Old Files We do not recommend that you upgrade old files that contain models that have been fully designed or are nearing final design. We recommend that you upgrade files that contain partially designed slabs.
1.6 Technical support Bentley Systems want you to get the maximum benefit from your purchase of RAM Concept. If you have any questions that are not answered in this manual, please contact us. For customer support, please contact: www.bentley.com/serviceticketmanager
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2
Looking at the Workspace This chapter provides a basic orientation to the RAM Concept interface.
2.1 About the workspace When you create a new file, RAM Concept generates layers, plans and perspectives for you to begin design. As you open windows in the workspace, RAM Concept activates the relevant toolbars. Workspace with a plan open:
Figure 1: A. Standard toolbar for general operations. B. Menu Bar contains the set of menus for the program. Includes the File, Edit, Criteria, Layers, Tools, Process, Report, View, Window, and Help menus. C. Action Tools for manipulating the current view. D. Snap toolbar for setting coordinate snaps for the active plan. E. General Tools for editing the active plan window. F. Layer Specific Tools for editing the active plan window. G. Report Contents Window for viewing, opening, and reordering report sections. H. The active window. I. Status Bar for program status information. J. Command Prompt for displaying tool relative instructions and the current cursor location in plan coordinates.
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Looking at the Workspace Creating and opening files
2.2 Creating and opening files When you start RAM Concept, you can create a new file or open an existing file. You can also create a new file based on a template.
2.2.1 Starting a new file When creating a new file, you make basic decisions about your model in the New File dialog, which appears when you choose File > New. You specify the type of slab, code and units to use. You can copy an existing RAM Concept file or template by clicking Copy File on the New File dialog.
To start a new file 1. Start RAM Concept and choose File > New. 2. Specify options in the New File dialog box and then click OK. Related Links • About templates (on page 53)
To start a new file from a template 1. Start RAM Concept, and choose File > New. 2. Click Copy File in the New File dialog. 3. Select the file or template you want to copy.
2.2.2 Opening an existing file Use File > Open to open an existing RAM Concept file. For quick access, RAM Concept keeps track of the last ten files you opened and lists them at the bottom of the File menu. 1. Choose File > Open. 2. Select the RAM Concept file you want to open. Note: See “Upgrading Old Files” for discussion on using files from an earlier version. Related Links • Upgrading Old Files (on page 49)
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Looking at the Workspace Saving a file
2.3 Saving a file Save your files often. When you save, you ensure that the file is stored on your computer even in the event of a power failure or system crash.
2.3.1 To save and name a file for the first time 1. Choose File > Save As (since the file has not yet been saved, you could also choose File > Save). 2. Select the folder in which to save the file. 3. Type a name for your file and click Save. RAM Concept adds the filename extension .cpt if not provided.
2.3.2 To save any open file 1. Choose File > Save (if you have not yet saved the file, and the Save As dialog box appears, follow the previous steps for saving for the first time).
2.3.3 To save a file as a template 1. Choose File > Save Template. 2. Click Continue on the warning message box. 3. Type a name for the template and click Save. RAM Concept adds the filename extension .cpttmp (if not provided) and saves the file without the objects. Related Links • About templates (on page 53)
2.3.4 Saving a copy of a file with a new name or location Use the Save As command to create a copy of a file and change its name or location. The original file and the copy are completely separate and any work you do on one file does not affect the other.
2.3.5 Reverting to a backup copy For version control, RAM Concept creates a copy of your last save every time you save your file to allow you to go back to an older version if necessary. RAM Concept creates the file with the filename extension .cpt.bak1. If you need to revert to an older version of a file, use the backup copy created by RAM Concept.
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Looking at the Workspace About templates
2.3.6 Restoring an auto-save file As a safety net, RAM Concept automatically saves a copy of your working file in the same folder as the original and with the filename extension .autosave. RAM Concept updates the auto-save file approximately every 2 minutes if you have made changes to your original file. Once you save your file, RAM Concept deletes the autosave file since your saved version is up to date. We recommend that you save often to prevent loss of work. If a computer malfunction or loss of power occurs while you are using RAM Concept, when you restart RAM Concept it detects the last auto-save file and open it automatically. If you open a second copy of RAM Concept while one is running, the second copy may detect the auto-save file of the first and open it. In this case, just close the auto-save file and continue.
2.4 About templates A template file contains everything a normal file includes (such as specification settings, plans, etc.) but has no objects. You can create a template from any RAM Concept file by choosing File > Save Template. RAM Concept saves a copy of your file without any objects and with the .cpttmp filename extension. For details on how to save a template, see “To save a file as a template:”. Copy an existing template file by choosing File > New and clicking Copy File to create a new file based on the template. For more information on starting a new file from a template, see “Starting a new file”. Related Links • To save a file as a template (on page 52) • To start a new file (on page 51)
2.5 Expanding tool buttons Some tool button icons have a small triangle in the lower right corner ( ). This indicates that there are other similar tools available for this button. Press down on the left mouse button for one second over the tool button to reveal a pop-up menu. Select a tool from the menu. The selected tool becomes the new tool for that button. Expanding tool button with pop-up:
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Looking at the Workspace Rearranging toolbars
Figure 2: Pressing down on the left mouse button for one second over the Selection tool reveals a pop-up menu.
2.6 Rearranging toolbars You can move the toolbars in RAM Concept to suit your particular work habits. To move a tool bar, click on the handle of the toolbar and drag the toolbar to its new location. The toolbar handle is two lines on the right edge of horizontal toolbars or at the top edge of vertical toolbars. The toolbars snap to the edges of the application window or can remain floating in the workspace.
2.7 Using the right mouse button RAM Concept provides some of the commands available from the menus or toolbars in a special contextsensitive pop-up menu that appears when you click the right mouse button. The contents of the menu vary depending on where you click, what window is active, and whether there is a current selection.
2.8 Undoing changes RAM Concept provides multiple levels of undo to correct mistakes or reverse actions you have taken. RAM Concept limits the amount of memory used to record undo information. RAM Concept is therefore able to undo more small operations (deleting 10 objects) than large operations (deleting 1000 objects). Choose Edit > Undo to reverse the last action taken. To redo a command that has been undone, choose Edit > Redo. Note: The Undo command cannot reverse the Generate Mesh and Calc All commands. All changes you have made are committed once you perform one of these operations.
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3
Understanding Layers In RAM Concept, objects (such as walls, columns, slab areas, springs, loads, tendons, design strips, etc.) make up the structural model. Since there are so many objects involved in modeling a structure, RAM Concept uses layers to organize these objects. A layer is a collection of related objects and each object in RAM Concept resides on one and only one layer. You can handle all of the objects on a single layer as a group or individually.
3.1 Modeling with objects Since objects make up the structural model, they are more than a combination of points and lines. Each object is an individual entity with properties. Column object properties, for example, include concrete mix, height, width, depth, and more. You draw some objects on plans, and RAM Concept creates some objects automatically when you generate the finite element mesh or run an analysis calculation. If you have wall, column, and slab area objects on the Mesh Input layer, RAM Concept creates corresponding wall element, column element, and slab element objects on the Element layer when you generate the finite element mesh. If you want to create or edit objects on a layer, use the plans on that layer. When you draw columns on the Standard Plan of the Mesh Input layer, you are creating objects on the Mesh Input layer. These objects belong to the layer and not the plan. They are editable by any plan on the Mesh Input layer, but not by plans on any other layer. Each object is an individual entity so you can manipulate it both separately and together with other objects on the same layer.
3.2 Managing layers RAM Concept performs most of the layer management automatically. Almost all of the layers you need to design a structure are already in place when you start a new file. RAM Concept adds appropriate layers when you create new Loadings, Load Combinations, and Rule Set Designs. Note: You can create and edit a separate group of Line Objects, Dimension Objects, and Text Note Objects on every layer. Drawing Import Layer
RAM Concept
This layer contains all the imported CAD drawing information. RAM Concept automatically stores any imported drawings on this layer.
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Understanding Layers Managing layers Mesh Input Layer
This layer contains the objects that define the geometry of the structure. RAM Concept uses these objects to generate corresponding finite element objects on the Element Layer. Layer-Specific Objects: Column, Wall, Slab Area, Slab Opening, Beam, Point Support, Line Support, Point Spring, Line Spring, Area Spring.
Element Layer
This layer contains the finite element objects. These objects can be generated by RAM Concept based on the information on the Mesh Input Layer, or can be created by hand. Layer-Specific Objects:Column Element, Wall Element, Slab Element, Point Support, Line Support, Point Spring, Line Spring, Area Spring.
Loading Layers (Self-dead, Balance, Hyperstatic, Temporary Construction (at Stressing), Other Dead, Live (Reducible), Live (Unreducible), Live (Storage), Live (Roof) and User-defined)
These layers contain all the information that defines the loads on the structure. In RAM Concept, a loading is a set of loads applied as a group, such as the live loads. The loading layers also contain the loading analysis results. RAM Concept provides the self-dead, balance, and hyperstatic loading layers by default and you cannot delete them. You can define an unlimited number of loadings and RAM Concept creates a corresponding layer for each. Layer-Specific Objects:Point Loads, Line Loads, Area Loads. Note: You cannot edit the load objects on the Self-Dead Loading Layer, Balance Loading Layer, and Hyperstatic Loading Layer.
Pattern Layer
This layer contains the load patterns for the structure. Layer-Specific Objects:Load Patterns.
Design Strip Layer
This layer contains the design strips, design sections and punching checks for the structure. Layer-Specific Objects:Span Segments, Span Boundaries, Strip Boundaries, Design Sections, Punching Checks.
Tendon Parameters Layers (Latitude and Longitude)
These layers contain high level post-tensioning objects. Although there are two tendon layers, Latitude and Longitude, there is no requirement to use both layers. You can draw tendon parameters on the tendon parameters layers in whatever manner you wish. Layer-Specific Objects:Banded Tendon Polyline, Distributed Tendon Quadrilateral, Tendon Void, Profile Polyline.
Manual Tendon Layers (Latitude and Longitude)
These layers contain the layout of post-tensioning tendons and jacks for the structure. Although there are two tendon layers, Latitude and Longitude, there is no requirement to use both layers. You can draw tendons on the tendon layers in whatever manner you wish. Layer-Specific Objects:Tendon, Jack.
Load Combination Layers These layers contain the load combination analysis results. (All Dead, Dead and Note: The load combinations listed are for ACI318. Other codes use some Balance, Initial Service, Service, Sustained Service, different terminology.
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Understanding Layers Managing layers Factored and Userdefined) Rule Set Design Layers These layers contain the rule set design analysis and design results. (Code Minimum, User Minimum, Initial Service, Note: The rule set designs listed are for ACI318, other codes use some different Service, Sustained Service, terminology. Strength, Ductility) Load History Deflection Layers
These layers contain the results of the load history analyses.
Additional Mass Loading Layer
This layer contains loads that are converted to mass for the vibration analysis.
Vibration Analysis Layer
This layer contains vibration related analysis results.
Layer-Specific Objects: Point Loads, Line Loads, Area Loads. Layer-Specific Objects: Excitation Areas.
Design Status Layer
This layer contains the summary of all the design results. The summary information is automatically created by RAM Concept when you Calc All. You cannot create, edit, or delete the objects on this layer but you can view them.
Optimization Layer
This layer contains the definition of all Optimization Regions. See the Optimization Chapter for further details.
3.2.1 Determining which plans contain objects Some layer icons next to a layer name in the contents window have a dot on the top “sheet”. This indicates that there is at least one object resident on that layer. In other words, the dot means there exists at least one object that belongs to that layer. This is different to any visible objects on one of the layers’ plans, which may or may not belong to that layer. Note: There may be a lag time (such as 10 seconds) for this to happen after the first item on the layer is drawn. Note: This feature is added in response to the frustration of having to search every layer in support files to see if they contained any items. Note: Dots do not typically appear on Load Combination layers as these layers have no items drawn on them. This does NOT mean the load combo is not used in the design.
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Understanding Layers Managing layers
Figure 3: Layer icons indicating that there are objects on the following layers: Drawing Import, Mesh Input, Element, Design Strip, Reinforcement, Design Status
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Using Plans and Perspectives Plan windows are used to create, view, and edit objects in two dimensions while perspective windows provide a three dimensional view of those objects.
4.1 Using plans A plan is a view of the geometric model and results. You can view any object on any plan. You can only create and edit an object on a plan belonging to the object’s layer. For example, an other dead load can only be edited on a plan belonging to the Other Dead Loading layer. Objects are drawn and edited with tools located in Layer-Specific toolbars, and the Tools menu. The available tools are dependent on which plan is the active window in the workspace. Once you draw an object on a plan, the object belongs to that plan’s layer. Note: For information on drawing and editing objects, see the following chapter.
4.2 Creating new plans Create new plans when you need additional ones to those provided by default. 1. Choose Layers > New Plan. 2. Enter a name for the plan. (RAM Concept automatically prepends the layer name and appends the word “Plan”). 3. Select the layer on which you want the plan and click OK.
4.3 Viewing perspectives Perspectives provide a three dimensional view of the model. You can view the model from any angle by rotating the perspective about the x-, y-, and z-axes. The model can be viewed in parallel projection or perspective projection and can be modeled as a solid or wire structure.
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Using Plans and Perspectives Creating new perspectives
4.3.1 Setting the projection You can render the model in either parallel or perspective projection. In parallel projection, lines that are parallel in the original model are also drawn parallel in the three dimensional image. In perspective projection, near objects appear larger than far objects of the same size. The Parallel Projection ( ) and Perspective Projection ( ) toggles control which way the image is rendered. One, and only one, of these toggles is always set.
4.3.2 Selecting the modeling The Wire Frame Modeling ( ) and Solid Modeling ( ) toggles control how the image is rendered. The wire frame is made of only the edges of the visible objects whereas the solid model shows the visible objects’ surfaces. The solid model is more realistic, however the wire frame image is often useful since it allows you to see through the model. One, and only one, of these toggles is always set.
4.3.3 Rotating the model Use the Rotate about x- and y-axes tool ( the screen’s x-, y-, and z-axes.
) and the Rotate about z-axis tool (
) to rotate the model about
1.
) or the Rotate about z-axis tool ( ). Select the Rotate about x- and y-axes tool ( 2. Click once on the perspective window to begin and move the cursor until you position the model as desired. 3. Click on the perspective again to set the view.
4.4 Creating new perspectives Create new perspectives when you need additional ones to those provided by default. 1. Choose Layers > New Perspective. 2. Enter a name for the perspective. (RAM Concept automatically prepends the layer name and appends the word “Perspective”). 3. Select the layer on which you want the plan and click OK.
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Using Plans and Perspectives Controlling views
4.5 Controlling views You can manipulate the plan and perspective windows to show the desired view or information. Zooming and panning allow you to change what portion of the model you are viewing. RAM Concept usually regenerates the view automatically. It is sometimes necessary, however, to use the Redraw command ( ) to update the image on the screen. Plans and perspectives represent unique views of the model. You control which object types are visible and their colors, font, and line type for each plan and perspective.
4.5.1 Zooming to magnify or diminish Use zooming to magnify or diminish the plan or perspective view. If you have a mouse with a wheel button, roll the wheel to zoom in and out at the cursor location. Zoom In ( Zoom Out ( (
) and Zoom Rectangle (
) magnify the view.
) diminishes the view. You can set the view to encompass the entire model by using Zoom Extent
).
To magnify or diminish the view with the mouse wheel button 1. Place the cursor on a location over the active plan or perspective window. This is the zoom center point. 2. Roll the mouse wheel button away from you to zoom in, and toward you to zoom out.
To magnify a specific area in the view 1.
Select the Zoom Rectangle tool ( ). 2. Fence the area you want to magnify.
4.5.2 Panning to reposition Panning allows you to reposition the view in the plan or perspective window. If you have a mouse with a wheel button, press down on the wheel over the view and pan. You can use the Pan tool ( ) to move the view as well. In addition, plans have scroll bars along the bottom and right side of the window that you can use to reposition the view.
To reposition the view with the mouse wheel button 1. Press down on the mouse wheel button over the active plan or perspective window. 2. Pan the view into position and release the wheel button.
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To reposition the view with a tool 1.
Select the Pan tool ( ). 2. Click once on the plan to begin panning, click again when the view is in the desired position.
4.5.3 View History The View Previous (
) and View Next (
) tools implement a history of your views.
The view history operates much like the forward and backward buttons in a web browser. Each zoom or pan action is added to the view history. The View Previous (
) button steps back through previous views and the
View Next button ( ) steps forward through the views. The buttons are disabled if there are no views in that direction. If you step back to a previous view and perform a zoom or pan action, the new view will replace the entire next view history. The View History is implemented for plans and perspectives. Each plan or perspective’s view history is maintained separately. Switching from one plan or perspective to another does not affect the view history for either plan. All zoom, extent, pan, and rotation view changes are recorded in the view history. Some consecutive view changes of the same type are compressed into one view history item to prevent the history from getting cluttered with many similar views. For example, consecutive Zoom In actions -- whether by the Zoom In tool or by mouse wheel movements -- add only one new view to the history.
4.5.4 Regenerating Regenerating the view is necessary when anything occurs that invalidates the current view. When you generate the mesh, analyze the model or change the settings, the open windows may need updating. In most cases, RAM Concept automatically regenerates for you. If you find that the view is not up to date, click Redraw ( ) to regenerate the view in the active window.
4.5.5 Setting the visible objects Use the Visible Objects dialog box to set which objects types are visible on a plan or perspective. Plans and perspectives can show objects from any layer, but you can only edit objects on a plan from the object’s layer.
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Figure 4: Visible Objects dialog box (Mesh Input tab)
To show or hide objects on a plan or perspective To show or hide objects on a plan or perspective 1. Make the plan or perspective the active window. 2. Choose View > Visible Objects ( ). 3. Click on the tab for the object’s layer. The plan or perspective’s layer is the one initially selected. 4. Check boxes to show objects and uncheck to hide objects, then click OK. Note: You can also right click to see a popup menu that includes the Visible Objects command.
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4.5.6 Changing colors, font, and line type Each plan and perspective has an associated appearance scheme that dictates the colors, font, and line type used for the objects shown. When a plan or perspective is the active window, you can select and modify its appearance scheme using the Appearance dialog. If you change the settings of an appearance scheme, it affects all the plans and perspectives that use that scheme. You can create as many appearance schemes as you need to customize the look of your plans and perspectives. When you create a new plan or perspective, the window initially uses the default scheme.
Figure 5: Appearance dialog
To set the appearance scheme for a plan or perspective 1. Make the plan or perspective the active window. 2. Choose View > Appearance ( ). 3. Select the scheme from the list of schemes on the left side of the Appearance dialog and click OK.
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Using Plans and Perspectives Controlling views Note: You can also right click to see a popup menu that includes the Appearance command.
To create a new appearance scheme 1.
Choose View > Appearance ( ). 2. Click New below the list of schemes in the Appearance dialog. 3. Type a name for the new scheme and select the base scheme. The settings from the base scheme initialize the new scheme.
To delete an appearance scheme 1.
Choose View > Appearance ( ). 2. Select the scheme you want to delete from the list of schemes in the Appearance dialog. 3. Click Delete below the list of schemes to delete the highlighted scheme.
To set a new default scheme 1.
Choose View > Appearance ( ). 2. Select the scheme you want to make the new default scheme from the list of schemes in the Appearance dialog. 3. Click Set As Default below the list of schemes to make the highlighted scheme the new default scheme. RAM Concept uses this scheme to initialize newly created plans and perspectives. You can select the color of every drawn object type for each appearance scheme. You can also set the background, grid and highlight colors. If an object type has no color selected ( ), RAM Concept uses the color setting for the object’s layer. For example, you can set the Tendon object color to no selection, and then set the Latitude Tendon layer to red and Longitude Tendon layer color to blue. RAM Concept uses the foreground color in the case that you have selected neither the object type color nor the layer default color.
To change the colors in an appearance scheme 1.
Choose View > Appearance ( ). 2. Select the appearance scheme (if a plan or perspective is the active window, the selection is already the scheme set for that window). 3. Select the item from the drop-down list (if changing plotting colors skip this step). 4. Click on the color selection box for the item and choose a color. Lines of drawn objects can be set to solid, dashed, or dotted. Reference lines have Line Type and Line Width properties that are independent of the appearance scheme setting. The transparency of all Strip Plots in both 2-D and 3-D are controlled via the Transp. % control in the Appearance Settings dialog. This setting is used to modify the transparency already set in the default strip plot colors defined.
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Using Plans and Perspectives Setting up the grid
4.5.7 Changing font size You can change the font size in two ways. In the appearance schemes, you can select the font size for all text other then text notes. With the font buttons, you can temporarily change the font size. 1.
Click Enlarge Fonts (
) or Shrink Fonts (
).
Note: The temporary font size change only affects the active window and RAM Concept discards the change when the window is closed.
4.5.8 Changing font scale You can select the font scale so that the font size either changes or stays unchanged as you zoom in and out on a plan. 1.
Choose View > Appearance ( ). 2. Select the appearance scheme (if a plan or perspective is the active window, the selection is already the scheme set for that window). 3. Enter the font scale and click OK. Note: A font scale of zero causes the font to stay a constant size regardless of the plan scale. A non-zero value scales the font to be the same relative size as you zoom in and out
4.6 Setting up the grid A grid can be set up to help you draw objects accurately by providing snap points at a designated spacing. The Plan Grid Setup dialog allows you to make the grid visible and to change the spacing, origin, and rotation angle of the grid. You can change the grid setting for the active plan window or all plan windows at once.
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Using Plans and Perspectives Setting up the grid
Figure 6: Plan grid dialog box
4.6.1 To make the grid visible for a plan 1. Make the plan the active window. 2. Choose View > Grid. 3. Check Show Grid and click OK. Note: If you want the grid to be visible on all plans then check Set for all Plans. Note: You can also right click to see a popup menu that includes the Grid.
4.6.2 To change the grid settings for a plan 1. Make the plan the active window. 2. Choose View > Grid. 3. Enter values in the Plan Grid Setup dialog box and click OK. Note: If you want the grid settings to apply to all plan windows then check Set for all Plans.
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Drawing and Editing Objects Drawing objects is the cornerstone of using RAM Concept. There are many tools available to make this as straightforward as possible. To create or edit objects on a layer, use the plans on that layer. You draw and edit objects on plans using the tools from the Layer-Specific toolbar.
5.1 Precision drawing with snaps RAM Concept provides drawing tools and settings to help you work precisely. Snap tools allow you to snap the cursor to precise points on objects or locations on the screen. Using snaps is a quick way to specify an exact location on an object without drawing construction lines or knowing the exact coordinate. Whenever you move your cursor over an object, RAM Concept identifies snap points based on what snaps are active. To turn on a snap, click on its button. Click on the button again to turn off the snap. ) snaps to the intersection of any two lines including polygon vertices.
Snap to Intersection ( Snap to Point ( polygon.
) snaps to any defined point such as the center of a column, end point of a line, or vertex of a
Snap to End Point ( Snap to Mid Point (
) snaps to the end points of lines (including vertices of polygons). ) snaps to the mid points of lines.
Snap Nearest Snapable Point (
) snaps to the point on a drawn object nearest to the cursor.
Snap Orthogonal ( ) snaps orthogonally in the direction of the grid’s local x- or y-axis. This need not be parallel with the global x- and y-axes. Snap to Perpendicular ( Snap to Center ( Snap to Grid (
) snaps perpendicularly from the last click to a line.
) snaps the center of polygons and columns. ) snaps to the grid.
Snap Extension ( snap settings.
) does not create a snapping mode by itself, but it affects the behavior of some of the other
In general, the snap extension setting causes the other snap calculations to behave as if the line segments displayed extended to be infinitely long lines. The specific changes to the other snap settings are: • Intersection: intersections between infinite lines (defined by visible line segments) are snappable points.
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Drawing and Editing Objects Drawing objects • • • • • • • •
Point: no effect. End Point: no effect. Mid Point: no effect. Nearest: nearby infinite lines (defined by visible line segments) are snappable. Orthogonal: no effect. Perpendicular: perpendicular point on infinite lines (defined by visible line segments) are snappable. Center: no effect. Grid: no effect.
5.2 Drawing objects To draw objects on a plan, first select a drawing tool by clicking on it or choosing it from the Tools menu. The selected tool will be the active drawing tool for the plan until you select a new tool. Follow the command prompts for points to enter. For example, with a Mesh Input layer plan open, and the Column tool selected, the command prompt will read “Enter column center point:”. If you are drawing with a tool and wish to cancel what you have drawn, click the right mouse button, or press the key. If you need to reposition or magnify the view while you are drawing and do not want to cancel the work you are doing, use the mouse wheel button to pan or zoom. See “Controlling views” for more information on how to use the mouse wheel button.
5.3 Entering coordinate points Each point on a plan is a location represented by coordinates. Many tools require you to locate one or more points on a plan. With a tool selected, you can enter points by clicking at a location on the plan, entering the coordinates in the command line, entering the relative coordinates in the command line, or by using snaps. 1. With the appropriate tool selected, type the x- and y-coordinates separated by a comma (e.g. 10, 5).
5.4 Using relative coordinates Relative coordinates locate a point on a plan by referencing it to the last point entered. They can be very useful for moving and copying objects a set distance. To enter relative coordinates 1. With the appropriate tool selected, type the letter “r” followed by the x- and y-coordinates separated by a comma (e.g. r10, 5).
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Drawing and Editing Objects Selecting objects
5.5 Selecting objects Before you can edit objects on a plan, you must select them. Use the Selection tool ( ) or the Utility tool ( ) to select objects on a plan. You select visible objects by fencing the area in which they are located. For example, if you have a slab opening (on the Mesh Input layer) in the middle of a slab, fencing the opening selects both the opening and the slab area because the rectangle crosses the slab area and surrounds the opening. If you want to select just the opening, double click on it. You can select any single object by double clicking on it. To add objects to the current selection, hold the key down as you select.
5.5.1 To select an object or group of objects 1.
Choose the Selection tool ( ) or the Utility tool ( ). 2. Click at opposite corners of a rectangle. This selects objects within and crossing the rectangular selection area. (Hold down the Shift key on the first click to add objects to the current selection.)
5.5.2 To select only a single object 1.
Choose the Selection tool ( ) or the Utility tool ( ). 2. Double click on the object you wish to select (Hold down the key as you click to add the object to the current selection). When you are selecting, RAM Concept interprets a very small rectangle as a double click.
5.6 Deselecting objects You can deselect objects from the current selection by holding the key while you select objects to remove from the selection.
5.6.1 To deselect an object or group of objects from a selection 1.
Choose the Selection tool ( ) or the Utility tool ( ). 2. Hold down the key as you fence the objects in the selection you want to deselect. This deselects the selected objects within and crossing the rectangular area, and selects any objects in the rectangular area not previously selected.
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Drawing and Editing Objects Filtering selected objects
5.6.2 To deselect only a single object from a selection 1.
Choose the Selection tool ( ) or the Utility tool ( ). 2. Hold down the key as you double click on the object in the selection you wish to deselect. When you are deselecting, RAM Concept interprets a very small rectangle as a double click.
5.7 Filtering selected objects You can deselect objects from the current selection set by choosing the Selection Filter tool ( ). This tool will invoke a dialog that lists all of the currently selected objects grouped by object type. All of the objects of a particular type can be removed from the selection set by unselecting the objects in the list.
5.8 Cutting, copying, and pasting objects To cut or copy objects, first select the objects then choose the appropriate command from the Edit menu. RAM Concept places objects that you cut or copy on the Windows clipboard. The coordinate locations of objects pasted from the clipboard are the same as the coordinate location from where you copied or cut them. RAM Concept makes the pasted objects the current selection, so you can reposition them after you paste.
5.8.1 To cut objects 1. Select the object or group of objects you want to cut. 2. Choose Edit > Cut (or right-click and choose Cut from the popup menu that appears).
5.8.2 To copy objects 1. Select the object or group of objects you want to copy. 2. Choose Edit > Copy (or right-click and choose Copy from the popup menu that appears).
5.8.3 To paste objects from the clipboard 1. Choose Edit > Paste (or right-click and choose Paste from the popup menu that appears).
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Drawing and Editing Objects Copying and pasting objects by layer You can also copy and move, rotate, stretch or mirror an object in one step by pressing the key while you use the Move tool ( ), Stretch tool ( ), Rotate tool ( ) or Mirror tool ( ). See “Moving, rotating, stretching, and mirroring objects” for more information.
5.9 Copying and pasting objects by layer The “layer” clipboard mode simplifies the process of copying data from multiple layers of one Concept file to another Concept file. Clipboard data is built up from multiple objects on different layers. Each object added to the clipboard data is tagged with its source layer. When the layer clipboard data is pasted into a plan, only data that originated from the same layer as the destination plan will be pasted into the plan.
5.9.1 To append objects to the layer clipboard 1. Select the object or group of objects you want to copy. 2. Choose Edit > Append (or right-click and choose Append from the popup menu that appears). 3. Repeat for each layer. When objects are appended from a layer, they completely replace the objects for that layer. Other layers are not affected.
5.9.2 To paste objects from the layer clipboard 1. Choose Edit > Paste (or right-click and choose Paste from the popup menu that appears). 2. Repeat for each layer. When the clipboard contains layer data, the Paste menu item is only enabled when the clipboard contains data for the current plan's layer. The contents of the layer data cannot be viewed directly, but the enabled Paste menu item is an indication that the clipboard contains data from the current layer. The layer clipboard data is stored in the system clipboard selection. This means that the layer clipboard data is cleared any time another Copy operation is performed, by Concept or by any other application on the system. The selection is also lost if the system is shut down or restarted.
5.10 Editing polygon objects Nodes can be added or removed from polygonal objects with the Add Node ( (
) and the Delete Node tools
).
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Drawing and Editing Objects Moving, rotating, stretching, and mirroring objects
5.10.1 To add a node to a polygonal object 1. Select the object or group of objects to edit. 2. Select the Add Node tool ( ). 3. Click on any edge of a polygonal object. Nodes must be added to an edge of a polygonal object. It is possible to enter the new node coordinates, but it will be ignored if the new location is not exactly on an edge. It is better to add the node at an approximate location, then stretch the node to the final position. The exact location can be specfied as coordinates or by snapping with the Stretch tool.
5.10.2 To delete a node from a polygonal object 1. Select the object or group of objects to edit. 2. Select the Delete Node tool ( ). 3. Click on any node of a polygonal object. A node cannot be deleted if it would create a misshapened polygon (less than 3 points, or all points colinear). Some polygonal objects may define a varying property, e.g. the force constant of an Area Spring. The varying property is defined by seed values of the first 3 nodes of the polygon. Therefore, the first 3 nodes cannot be colinear when the varying property is defined. Adding or deleting nodes does not change the value of the varying property. However, the start of the polygon may have to be shifted to a new node, so that the first 3 nodes are not colinear. The seed values will be adjusted accordingly for the new locations.
5.11 Moving, rotating, stretching, and mirroring objects An object or group of objects must be selected before using the Move tool ( ), Stretch tool ( ), Rotate tool ( ) or Mirror tool ( ) (See “Selecting objects”). If you hold down the key on the first click of a move, rotate, or mirror, the operation will be performed on a copy of the selection rather then the selection itself.
5.11.1 To move a selection 1. 2. 3. 4.
Select the object or group of objects to move. Choose the Move tool ( ). Enter the point from which to move (hold down the key as you click to move a copy of the selection). Click on the point to where you want the object, or group of objects, to move.
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Drawing and Editing Objects Using the Utility tool to move and stretch
5.11.2 To stretch the selection 1. 2. 3. 4.
Select the object or group of objects to stretch. Choose the Stretch tool ( ). Snap to the point you want to stretch on the selection (limited to highlighted control points). Click on the point to where you want the object, or group of objects, to stretch.
5.11.3 To rotate a selection 1. 2. 3. 4. 5.
Select the object or group of objects to rotate. Choose the Rotate tool ( ). Enter the rotation center point (hold down the key as you click to rotate a copy of the selection). Enter the rotation start angle or a point to create a line to rotate. Click on the new end point of the rotation line or enter an end angle.
5.11.4 To mirror the selection 1. Select the object or group of objects to mirror. 2. Choose the Mirror tool ( ). 3. Enter the two points that create the line across which you would like to mirror the selected object(s). (Hold down the key as you click to mirror a copy of the selection.)
5.12 Using the Utility tool to move and stretch The Utility tool ( ) is a multi-purpose tool used for selecting, moving, and stretching objects. See “Selecting objects” for information on how to select objects with the Utility tool. Once you have selected an object or group of objects, you can move or stretch a grip point by snapping to it on the selection.
5.12.1 To move an object by one of its grips 1. Choose the Utility tool ( ). 2. Select an object or group of objects. 3. Snap to a grip point and position the cursor in the top half of the snap area until you see the move cross cursor (
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Drawing and Editing Objects Manipulating the model as a whole 4. Click on the point to where you want the object, or group of objects, to move.
5.12.2 To stretch an object by one of its grips 1. Choose the Utility tool ( ). 2. Select an object or group of objects. 3. Snap to a grip point and position the cursor in the bottom half of the snap area until you see the stretch ) then click. cursor ( 4. Click on the point to where you want the object, or group of objects, to stretch.
5.13 Manipulating the model as a whole The Move Model tool ( ), Mirror Model tool ( ), and Rotate Model tool ( ) work just like the Move tool ( ), Mirror tool ( ), and Rotate tool ( ) except they affect the whole model (all layers). You can also scale the entire model with the Scale Model tool (
).
5.13.1 To move the entire model 1.
Choose the Move Model tool ( 2. Enter the start point. 3. Enter the move point.
).
5.13.2 To rotate the entire model 1.
Choose the Rotate Model tool ( ). 2. Enter the rotation center point (hold down the key as you click to rotate a copy of the model). 3. Enter the rotation start angle or a point to create a line to rotate. 4. Click on the new end point of the rotation line or enter an end angle.
5.13.3 To mirror the entire model 1.
Choose the Mirror Model tool (
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Drawing and Editing Objects Editing object properties 2. Enter the two points that create the line across which you would like to mirror the model (hold down the key as you click to mirror a copy of the model).
5.13.4 To scale the entire model 1.
Choose the Scale Model tool ( ). 2. Enter a scale center point. 3. In the Scale Model dialog box, enter the relative scale factors and click OK.
5.14 Editing object properties The properties of an object define its individual characteristics. For example, the properties of a Line object include the Line Type and Line Width. Some objects’ properties can be edited together as a group. Specifically, you can always modify objects of the same type together, and you can often modify objects of different types but with similar properties together. For example, you can edit the Concrete Mix and Height properties of Column and Wall objects together. To change the properties of an object or group of objects 1. Select the object or group of objects. 2. Choose Edit > Selection Properties, or right-click and choose Selection Properties. 3. Specify the property values in the Properties dialog and click OK.
5.15 Setting default properties It is useful to set the default properties of object drawing tools so that when you use the tool the drawn object has the desired properties. This is valuable when many objects will have the same properties. To set the default properties for an object drawing tool 1. Double click on the drawing tool or with the tool selected, choose Tools > Current Tool Properties. 2. Specify default property values in the Properties dialog and click OK. When you now use the tool, it will draw objects with the specified default properties. Note: Changing the default properties of an object drawing tool does not change the properties of such objects already drawn.
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Drawing and Editing Objects Adding reference lines, dimensions, and text notes
5.16 Adding reference lines, dimensions, and text notes The Line tool ( ), Dimension tool ( ), and Text tool ( ) are all used to add information to plans. These objects are not part of the structural model and RAM Concept does not consider them when generating the mesh or calculating results. As for all objects, the lines, dimensions and text objects belong to the layer on which they are drawn.
5.16.1 To draw a line 1.
). Choose the Line tool ( 2. Click at the line start point (or enter the coordinates in the command line). 3. Click at the line end point (or enter the coordinates in the command line).
5.16.2 To draw a dimension line 1.
Choose the Dimension tool ( ). 2. Click at the start point. 3. Click at the end point. 4. Click at the offset point where the dimension line will be located.
5.16.3 To draw text 1.
Choose the Text tool ( ). 2. Click at a point (or enter the coordinates in the command line). 3. Right click and choose Selection Properties. 4. Enter the text and its properties.
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Viewing Objects in Text Tables A text table shows all the objects of a particular type on a specific layer. Tables provide a customizable textual view of each objects’ properties. You can access text tables from the Tables folder of any layer. 1. Go to the Tables folder of the object type’s layer. 2. Open the appropriate text table from the folder. For example, the text table for Walls Below on the Mesh Input layer can be opened by choosing Layers > Mesh Input > Tables > Walls Below.
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Viewing Objects in Text Tables Customizing tables
Figure 7: Mesh Input: Walls Below Table
6.1 Customizing tables You can choose which columns and rows are visible in the table, and the column widths. You can also sort the rows based on a particular column’s values in ascending or descending order.
6.1.1 Choosing which rows and columns to show Customize the table columns and rows by clicking on the Customize button above the table. In the Customize dialog box, you can select which rows and columns are visible in the table. Check the columns you want to see and uncheck the columns you want hidden. To make a table column visible or hidden 1. Click on the Customize button above the table.
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Viewing Objects in Text Tables Customizing tables 2. In the Customize dialog box, to make a column visible, check the checkbox. To hide the column, uncheck the checkbox. 3. Click OK.
6.1.2 Sizing table columns You can resize columns by changing the width of the column header. To resize the width of the column 1. Place your cursor on the line between two columns on the table header and press down on the left mouse button. 2. Drag the table header to its new width and release the left mouse button. The table will print as seen on screen so the column widths you set will appear the same way on paper.
6.1.3 Sorting table rows To sort the table rows according to the values in a column, click on the column header once for ascending order. Click on the column header again to sort in the descending order.
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Choosing Units RAM Concept allows you to work with three unit systems: US, SI and MKS. Some designers refer to the US units system as “US customary units”, and others call it “Imperial”. SI and MKS are metric unit systems, with MKS using mass rather than weight. It is up to you which system you use but local practice should dictate your choice. The choice of actual units is more subjective. For example, after choosing the US system, one designer might use the default area load units of pounds per square feet, and another might change the selection to kips per square feet.
7.1 About units Internally, RAM Concept performs all calculations with the SI unit system. It converts all property values into an equivalent SI unit prior to calculation. Once complete, it converts the values back into the selected units for reporting. It is possible to mix unit systems (e.g. pounds and meters) but this is not advisable.
7.2 Selecting units A new file has default units that you can change at any time.
7.2.1 Selecting the default units The default units depend on how you created the file. When you use a template or an existing file, the default units are those of the source. When you create a file using the New command, you only have a choice of default units for ACI 318 (US or SI). For all other codes, the default units are SI.
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Choosing Units Specifying report as zero
7.2.2 Changing the units You can change either the unit system or individual units. 1. Choose Criteria > Units. 2. Do one of the following: Select each unit by accessing the appropriate drop down box. or Select a unit system by clicking on US, SI, or MKS at the top of the window. Note: There is often a long list of choices for the units. Scroll down the drop down menu to view the options.
Figure 8: Units Window
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Choosing Units Specifying report as zero
7.3 Specifying report as zero RAM Concept allows you to filter out trivial results with the Report as Zero option. For example, column reactions have components for Fr, Fs, Fz, Mr and Ms. Some of these values, such as Fr and Fs, may be very small and hence not important. Filtering small values from plan plots can make the results easier to read. Note: Using this feature could result in human error, as you might later assume zeroed values are exactly equal to zero. You specify Report as Zero in the Units window. 1. Choose Criteria > Units. 2. Enter one or more Report as Zero values. Note: You can also turn off plotted values such as Fr and Fs with the plot menu. See “Setting the plotted results”.
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Choosing Sign Convention RAM Concept allows you to choose the sign convention for loads, analysis and reactions. RAM Concept uses the Cartesian coordinate system with the following sign convention for axes:
Z Y X You cannot change the sign of the coordinates’ axes. Sign convention dictates how you input parameters and how RAM Concept displays results. For example, the sign convention of an applied load dictates whether the input value is positive or negative. Note that changing a sign setting does not change the real value of any previously specified data. For example if a +10 kips downward load was specified when RAM Concept had a downward-positive load sign convention and then the load sign convention was changed to upward-positive, the load value would now be reported as -10 kip, but the load would still be a 10 kip downward load. Similarly, a change in sign convention does not affect the true value of results. When you add loads after a change in sign convention, you must observe the new sign convention.
8.1 Selecting sign convention A new file has a default sign convention that you can change at any time.
8.1.1 Default sign convention The default sign convention depends on how you created the file. If you use a template or an existing file then the default sign convention is that of the source. When you create a file (not from a template), the sign convention is as follows:
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Choosing Sign Convention Selecting sign convention
Figure 9: Left to right: Fx, Fy, Fz, Mx, My. Fx In the positive x-direction (see coordinate axes). Fy In the positive y-direction (see coordinate axes). Fz In the negative z-direction (see coordinate axes). Mx (moment about the X-axis) Per right-hand-rule. My (moment about the Y-axis) Per right-hand-rule. Mz (moment about the Z-axis) Per right-hand-rule.
Figure 10: Top row, left to right: Vertical Element Shear, Element Bending, Element Axial, Vertical Deflection. Bottom row, left to right: Horizontal Shear, Twist, Lateral Deflection, Angular Deflection. Vertical element shear Positive z-shear on the positive x- and y-faces. Element bending Tension bottom face. Element axial Tension. Vertical deflection In negative z-direction (down). Horizontal shear Positive y-shear on Positive x-face (equivalent to Positive x-shear on Positive y-face). Twist Positive x-axis moment on positive x-face (equivalent to negative y-axis moment on positive y-face). Lateral deflection Positive in x- and y-axes directions. Angular deflection Per right-hand-rule about x- and y-axes.
Figure 11: Left to right: Fx, Fy, Fz, Coordinate Axis, Mx, My, Mz. Fx In the positive x-direction (see coordinate axes). Fy In the positive y-direction (see coordinate axes). Fz In the positive z-direction (see coordinate axes).
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Choosing Sign Convention About plot sign convention Mx (moment about the x-axis) Per right-hand-rule. My (moment about the y-axis) Per right-hand-rule. Mz (moment about the z-axis) Per right-hand-rule. Note: The only difference in defaults between Positive Loads and Positive Reactions is Fz. This is because point loads are usually down if positive, and vertical reactions are usually up if positive.
8.1.2 Changing the sign convention You can change the sign convention for any loads or results, but only one at a time. 1. Choose Criteria > Signs. 2. Change each positive sign by clicking the appropriate graphic. The direction changes.
Figure 12: Signs Window
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Choosing Sign Convention About plot sign convention
8.2 About plot sign convention With the exception of vertical deflection, line plots show positive results plotted above the axis line. This ensures that plots do not appear upside down. For axis lines that are parallel to the y-axis (and hence have no “above the axis line” direction), line plots show positive results to the left of the axis line. Note: Line plots show positive vertical deflection below the axis line. Perspectives are plotted with positive results in the global z-direction (what is considered positive is dependent upon the sign convention of the Value Plotted). For example, a perspective of deflection shows positive deflection up. You cannot change the sign of the coordinates’ axes.
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Specifying Material Properties RAM Concept uses materials as part of the input and the results. You specify concrete mixes and post-tensioning systems as part of the input and RAM Concept reports reinforcement bar requirements as part of the results. You can use the materials provided or create your own. For example, you might want to redesign the floor with the actual tested strength of the concrete poured on site. In this case, you would create a new concrete mix defined with that strength. You can delete any of the materials that you find are unnecessary.
9.1 Viewing the available materials The Materials window shows the names and properties of concrete mixes, PT systems and reinforcing bars. 1. Choose Criteria > Materials.
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Specifying Material Properties Material properties
Figure 13: The Materials window.
9.2 Material properties The following is a list of Material properties:
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Specifying Material Properties Material properties
9.2.1 Concrete Mix Mix Name
The label used to identify a concrete mix. The mix name is not necessarily the concrete strength. Each column, wall, slab and beam has a concrete mix property.
Density
The concrete mass density used to calculate various stiffness properties for Concrete.
Density for Loads
The concrete mass density used to calculate self weight.
f’ci
The characteristic cylinder strength of the concrete mix at the time of applying prestress (also known as initial strength).
f’c
The characteristic cylinder strength of the concrete mix. Note: f’ci and f’c are used for all codes except BS8110.
fcui
The characteristic cube strength of the concrete mix at the time of applying prestress (also known as initial strength).
fcu
The characteristic cube strength of the concrete mix. Note: fcui and fcu are only used for BS8110 and IS456.
Poisson’s Ratio
The negative of the ratio of lateral strains to axial strains for an axially loaded material. This is usually 0.2 for concrete.
Coefficient of Thermal Expansion
The concrete coefficient of thermal expansion used to calculate temperature strains.
Ec
Calc The method used to calculate Young’s Modulus (for both initial characteristic strength and characteristic strength). This can be according to the active code rules or a specified value.
User Eci
The user-defined Young’s Modulus used for initial cross section analysis.
User Ec
The user-defined Young’s Modulus used for global analysis, service cross section analysis and strength design.
9.2.2 PT Systems System Name The label used to identify a PT system. It usually describes the system, such as strand size and bonding. Type Whether the system has unbonded or bonded strand. Aps The cross sectional area of one strand. Since strand is usually comprised of seven wires then the area is more complicated than πd2/4. Eps The Young’s Modulus of the strand at zero strain. fse The assumed effective stress in the strand after all losses. Using jacks overrides this assumption. See “About jacks” for further information.
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Specifying Material Properties Material properties fpy The yield stress of the strand. fpu The ultimate stress of the strand. Duct Width The width or diameter of bonded tendon duct. Max Strands Per Duct The maximum number of strands in a bonded tendon (use 1 for unbonded tendons). Minimum Radius The minimum vertical radius that allows satisfactory placement of tendons in the field. You should consult with a local PT supplier. A value of zero disables radius checking for this PT system. Jacking Stress / Anchor Friction / Wobble Friction / Angular Friction / Seating Distance / Long-Term Losses Friction loss calculations use these properties. They have no effect unless tendon jacks are used. See “Jack properties” in Chapter 26, “Defining Tendons” for further information. Related Links • About jacks (on page 329)
9.2.3 Reinforcing Bars Bar Name The label used to identify a reinforcing bar. It usually refers to the bar’s diameter. As Cross sectional area of the bar. Es The Young’s Modulus of the bar. Fy The yield stress of the bar. Coating The coating type of the bar (epoxy coating) Straight Ld/Db The development length of straight bars, calculated either by “Code” or a user specified multiple of bar diameter. 90 Hook Ld/Db The development length of 90 degree hook bars, calculated either by “Code” or a user specified multiple of bar diameter. 180 Hook Ld/Db The development length of straight bars, calculated either by “Code” or a user specified multiple of bar diameter.
9.2.4 SSR Systems SSR System Name The label used to identify a SSR (stud shear reinforcement) system. It usually describes the system, such as stud size. Stud Area Cross sectional area of the stud stem that is used in strength calculations Head Area The area of the stud head, generally about 10 times the stem area. RAM Concept uses this to calculate the head diameter for clear spacing calculations. Min Head Spacing The minimum clear spacing between stud heads along the length of a rail. The design will not succeed if this value is too large.
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Specifying Material Properties Adding and deleting materials Specified Stud Spacing The desired stud spacing for the SSR design. If set to “none”, RAM Concept automatically designs the stud spacing. Fy The yield stress of the SSR reinforcement. Stud Spacing Rounding Increment Specifies an increment to which all stud designs are rounded down. For example, specifying a larger number forces a larger number of designs to have the same spacing, creating the potential for “grouping” of designs at different columns. Min Studs Per Rail Specifies the minimum number of studs that RAM Concept designs on any rail. This can be useful in a number of situations. For example, if one face of a column has a small overhang for which the designer does not want SSR reinforcement, this minimum stud number can be increased to prevent the design of rails on that face. System Type The type of system to use in the SSR design.
9.3 Adding and deleting materials You can add materials to define properties of concrete mixes, PT systems and reinforcing bars. You can delete materials as long as at least one material of each type remains.
9.3.1 To add materials 1. Choose Criteria > Materials. 2. Click Add Concrete Mix, or Add PT System, or Add Reinforcing Bar, or Add SSR System. 3. In the dialog box that appears, enter a name for the new material and click OK. A new row appears at the bottom of the appropriate table. 4. Enter the property value for each cell in the new row.
9.3.2 To delete materials 1. Choose Criteria > Materials. 2. Click Delete Concrete Mix, Delete PT System, or Delete Reinforcing Bar, or Delete SSR System. A dialog box appears with a list of the available materials. 3. Choose the material to delete and click OK.
9.4 About post-tensioning systems There are two types of systems considered in RAM Concept. • Unbonded systems: greased strand encased in plastic sheathing. • Bonded systems: bare strand within grouted ducts.
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Specifying Material Properties About post-tensioning systems Strands are typically comprised of seven wires spirally wound. There are two dominant strand sizes used in building construction: • 0.5 inch diameter (12.7 mm) • 0.6 inch diameter (15.2 mm) For further discussion on post-tensioning systems, see Chapter 26, “Defining Tendons”.
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Specifying loadings A loading is a set of point, line and area loads applied as a group. You define loading properties in the loadings window. You draw the actual loads on the loading plans. Loadings can be added (e.g. seismic, snow, soil and wind). Loadings can be deleted (other than those of a special type, as described in “About loading types” below). RAM Concept can perform pattern (or skip) loading and you define the factors that control this process in the loading window.
10.1 About default loadings RAM Concept provides default loadings for self-weight, post-tensioning and gravity loads. For mat files, RAM Concept provides additional default loadings for wind and seismic. Self-Dead Loading This is the self-weight of the concrete. All other dead loading is superimposed. Balance Loading Post-tensioning tendons and anchors apply internal loads to the concrete structure. We call this set of loads the Balance Loading because you normally design the post-tensioning to balance or offset the other loadings applied to the slab. Hyperstatic Loading The hyperstatic loading is a theoretical loading that considers the restraining effect of the supports on the structure as it tries to deform due to the application of post-tensioning. Many people use the term “secondary” in place of “hyperstatic”. The loading is not necessarily secondary in nature. RAM Concept calculates the effects of the hyperstatic loading for all objects (elements, springs, supports, design sections, design strip segments and punching checks) as described in “Post-tensioning loadings”. Temporary Construction (At Stressing) Loading This set of superimposed loads is present during construction when the contractor stresses the tendons. This loading is rarely used, and you need not consider it for RC structures. Other Dead Loading This set of superimposed dead loads applies to PT structures after stressing of posttensioning tendons. It is simply the superimposed dead loads for RC structures. Live (Reducible) Loading Live (Unreducible) Loading Live (Storage) Loading Live (Parking) Loading Live (Roof) Loading
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Specifying loadings Viewing the loadings Different sets of live loads. See About loading types (on page 96) for further description. Snow Loading The snow loads on the structure. Service Wind North Loading The set of wind loads in the north-south direction (for mat defaults only). Service Wind East Loading The set of wind loads in the east-west direction (for mat defaults only). Ultimate Seismic North Loading The set of seismic loads in the north-south direction (for mat defaults only). Ultimate Seismic East Loading The set of seismic loads in the east-west direction (for mat defaults only).
10.2 Viewing the loadings The Loading window lists the different loadings and their type and pattern factors. 1. Choose Criteria > Loadings. 2. If there are many loadings, scroll down to view them all.
Figure 14: Loadings Window
10.3 Loading properties Loadings have the following properties: Loading Name The label used to identify the loading. Loading Type See “About loading types” for more information.
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Specifying loadings About loading types Analysis The type of analysis, which can be Normal, Hyperstatic or Lateral SE. A Hyperstatic analysis is used for only the Hyperstatic Loading described in “About default loadings”. For information on Lateral SE, see “Self-equilibrium analysis” in Chapter 50, “Analysis Notes”. On-Pattern Factor The factor that applies to loads that are located within the loading pattern when performing pattern-loading calculations. See “About load pattern” for more information. Off-Pattern Factor The factor that applies to loads that are not located within the loading pattern when performing pattern-loading calculations. Note: Concept ignores the pattern factors if both factors are the same value. Setting both factors to 2.0 is identical to setting both factors to 1.0
10.4 About loading types Every loading in RAM Concept has a loading type. RAM Concept uses loading type to generate the appropriate load combinations from the defined set of loadings, and to apply appropriate live load reductions. See “Rebuilding load combinations” for information on how RAM Concept generates load combinations. Related Links • Rebuilding load combinations (on page 105)
10.5 Available loading types The available loading types are: Self-Weight
The structure’s concrete self-weight loads are always generated with this loading type. There is always one and only one loading of this type.
Balance
As described in “About default loadings”. There is always one and only one loading of this type.
Hyperstatic
As described in “About default loadings”. There is always one and only one loading of this type.
Stressing Dead
Loadings of this type contain superimposed loads applied before stressing of posttensioning tendons. This loading type is rarely used and is generally not considered for other loading conditions. You need not consider it for RC structures.
Dead
Loadings of this type contain permanent dead loads other than those from the self-weight type.
Live (Reducible)
Loadings of this type contain typical floor live loads that are reducible. See Chapter 52, “Live Load Reduction Notes” for detailed information regarding how each live load reduction code handles loadings of this type.
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Specifying loadings Available loading types Live (Unreducible) Loadings of this type contain typical floor live loads that are not reducible (typically assembly loadings - see “About assembly loads”). Live (Storage)
Loadings of this type contain typical floor live loads that are reducible using special storage loading reduction rules.
Live (Parking)
Loadings of this type contain typical loads for parking garages or car parks.
Live (Roof)
Loadings of this type contain typical roof live loads - except snow - that are reducible. RAM Concept never reduces these loads (the RAM Structural System may reduce these loads).
Snow
Loadings of this type contain typical snow loads. They generally do not consider drift or exceptional circmstances, and they may be characteristic or design loads. See the specific code chapters for further details.
Other
Loadings of this type contain loads of an unspecified nature. RAM Concept never considers these loadings except in manually created or edited load combinations (or load combinations created in previous files). All loading from Floor versions 2.3 and before, and RAM Concept versions 1.3 and before (except self-dead, balance and hyperstatic) are given this type; it is often useful to change the loading types of these loadings from earlier program versions.
Service Wind
Loadings of these types contain wind loads at service force levels. Service Wind Loading N is assumed to correspond to Ultimate Wind Loading N (if it exists).
Ultimate Wind
Loadings of these types contain wind loads at ultimate force levels. Ultimate Wind Loading N is assumed to correspond to Service Wind Loading N (if it exists).
Service Seismic
Loadings of these types contain seismic loads at service force levels. Service Seismic Loading N is assumed to correspond to Ultimate Seismic Loading N (if it exists).
Ultimate Seismic
Loadings of these types contain seismic loads at ultimate force levels. Ultimate Seismic Loading N is assumed to correspond to Service Seismic Loading N (if it exists).
Temperature
Loadings of this type account for axial strains or element curvature induced by temperature changes.
Shrinkage
Loadings of this type account for axial strains and or element curvatures. These loadings behave similar to temperature loadings but are not dependent on temperature changes or thermal material properties.
Most of these loading types are also available in a “transfer” variation. See About Transfer Loading Types (on page 98) for more information. Notes: • All loading types except self-weight, balance and hyperstatic may be used for more than one loading. • Temperature and shrinkage loadings are not included in default load combinations.
10.5.1 About assembly loads Assembly loadings deserve special consideration
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Specifying loadings Changing Loading Types Assembly loads It is recommended that, in order to get the appropriate factors, you define assembly loads on a Live (Unreducible) layer. Refer to the applicable live load reduction section for detailed information regarding how a specific code handles loadings of this type:
10.5.2 About Transfer Loading Types Almost all of the loading types previously discussed are available with a “transfer” variation. The transfer variations represent loads transferred from the structure above onto the level under consideration (via columns or walls). A few loading types are not available with a transfer variation, or have a somewhat different meaning with a transfer variation. These are: Self-Weight
There is no transfer variation of this loading type.
Balance
The transfer variation of this loading type is for loads generated by the tendons in the structure above the level under consideration. Unlike the non-transfer balance type: multiple loadings of this type may exist; the loadings do not contain loads generated from the tendons; and the loadings of this type are user-editable. Loadings of this type are considered in the calculation of hyperstatic effects.
Hyperstatic
There is no transfer variation of this loading type.
Stressing Dead There is no transfer variation of this loading type. Temperature
There is no transfer variation of this loading type.
Shrinkage
There is no transfer variation of this loading type.
10.6 Changing Loading Types 1. Choose Criteria > Loadings. 2. Click the loading type of the loading name. A drop down menu appears. 3. Select the new loading type. Notes: Loading types for self-weight loading cannot be changed. Loading types for balance, hyperstatic, temperature, and shrinkage loading cannot be changed since they are not compatible with other loading types.
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Specifying loadings Adding and deleting loadings
10.7 Changing Analysis The analysis of any loading (except Self-Dead, Balance, Hyperstatic, Temperature, and Shrinkage) may be changed in the Loadings window. 1. Choose Criteria > Loadings. 2. Click the analysis of the loading name. A drop down menu appears. 3. Select the new analysis.
10.8 Adding and deleting loadings At times, you may wish to add loadings such as seismic or temperature loadings. Conversely, you may choose to delete loadings such as Temporary Construction (At Stressing) Loading.
10.8.1 To add a loading 1. Choose Criteria > Loadings. 2. Click Add Loading. 3. In the Add Loading dialog box, do the following: a. Type a name for the new loading. b. Select the loading type (standard, temperature, or shrinkage). c. Click OK. The new loading appears in a row at the bottom of the table. 4. Enter the Loading Type and Analysis for the new loading. (standard loadings only) 5. Enter the On-Pattern Factor and Off-Pattern Factor for the new loading. (standard loadings only)
10.8.2 To delete a loading 1. Choose Criteria > Loadings. 2. Click Delete Loading. A dialog box appears with a list of the current loadings. 3. Choose the loading to delete and click OK.
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Specifying loadings About load pattern
10.9 About load pattern In structural engineering, pattern loading refers to a load arrangement that ignores or reduces loads on selected spans for the purpose of maximizing moments, shears or reactions. In 2D analysis, it is not difficult to create an algorithm that determines the important patterns, but this is extremely difficult for a 3D program, especially for irregular column layouts and panels. To handle pattern loading, RAM Concept uses the concept of load patterns. Note: Some refer to pattern loading as skip loading.
10.9.1 How load patterns work A load pattern creates a (invisible) pattern loading that contains only filtered loads for each standard loading. The On-Pattern and Off-Pattern factors control the filtering. The inclusion and exclusion of loads within the pattern area defines the pattern loading. RAM Concept multiplies loads inside the pattern area by the on-pattern factor and multiplies loads outside the pattern area by the offpattern factor. The actual pattern area is dependent upon the finite element mesh. See Creating Pattern Loading (on page 203), for further explanation. On-Pattern areas (shaded) for 6-panel slab:
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Specifying loadings About load pattern
For the figures above, if the live load is 100 psf, the on-pattern factor is 0.8 and the off-pattern factor is 0.1 then two pattern loadings are created with a load of 80 psf on the hatched areas and a load of 10 psf on the remainder of the slab. RAM Concept uses the load patterns for a loading - along with the full loading - to determine the design force envelopes for design strip segments, design sections and punching checks.
10.9.2 When to use load pattern Whether you use pattern loading is a matter of which code you are using and your engineering judgment. Some codes allow you to ignore pattern loading for certain types of structures and magnitudes of live loading. Common sense should lead you to logical load patterns that produce very close to the maximum moments, shears and reactions. In most circumstances, you only pattern the live loading. There could be circumstances where you pattern other loadings. For patterned loads, the on-pattern factor often has a value of 0.75 and the off-pattern factor often has a value of zero.
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Specifying loadings About load pattern For non-patterned loads, both factors should be 1.0. In special circumstances, the on-pattern factor can exceed a value of 1.0. When in doubt, all on-pattern and off-pattern factors should be 1.0. This results in no pattern loading. See Chapter 21, “Creating Pattern Loading”, for further discussion.
10.9.3 How load pattern can approximate moving loads You can approximate moving loads by using load patterns. 1. Specify an on-pattern factor of 10 and an off-pattern factor of zero. 2. Specify load factors (in the load combinations window) for the “moving” loading of one-tenth their actual values. 3. Define the movement using the load patterns. 4. Draw the load once in each pattern. Note: Concept still analyses a load combination with all the loads present that is included in the envelope. This is the reason for scaling the on-pattern, off-pattern and load factors - it diminishes the effect of the “all the loads” load combination.
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Specifying Load Combinations A load combination is a factored linear combination of loadings. Strictly speaking, we should call it “loading combination”, but we have adopted the commonly used terminology.
11.1 About default load combinations Codes generally specify which loadings you need to consider in the design of a structure and how you should combine these loadings. RAM Concept's default load combinations depend on how you created the file. When you use a template or an existing file then the default load combinations are those of the source. When you create a file using the New command the default load combinations depend on the code selected. These load combinations are usually appropriate for the selected code, but there may be times when you need to modify the load factors and add loadings. For example, temperature and shrinkage loadings are not included in the default load combinations. The default load combinations for each code are described in detail in the relevant chapter: • • • • • •
ACI 318-14 Design (on page 985) AS 3600-2018 Design (on page 1049) BS 8110: 1997 Design (on page 1070) IS 456 : 2000 / IS 1343 : 1980 Design (on page 1097) EN 1992-1-1: 2004 (Eurocode 2) With TR43 Design (on page 1121) CSA A23.3-04 Design (on page 1154)
11.2 Viewing the load combinations The Load Combinations window lists the different load combinations and their design criteria and load factors. 1. Choose Criteria > Load Combinations. 2. If there are many load combinations, scroll down to view them all.
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Specifying Load Combinations Viewing the load combinations
Figure 15: Load Combination Window
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Specifying Load Combinations Rebuilding load combinations
11.3 Rebuilding load combinations At times, you may wish to rebuild an existing load combination that includes a new or revised loading. For example, if a loading’s type changes, it affects the load factors and live load reduction process. You can account for these changes by using the rebuild command. RAM Concept will not automatically update load factors when a loading's loading type changes. RAM Concept only sets the load factors when rebuilding load combinations. 1. Choose Criteria > Rebuild Load Combos Another dialog box appears that requires you to specify if the load combinations are for an elevated slab or mat foundation. 2. Select elevated slab or mat foundation 3. Select Rebuild
11.4 Adding and deleting load combinations At times, you may wish to add load combinations such as seismic plus dead or snow plus dead. Conversely, you might choose to delete load combinations such as Temporary Construction (At Stressing) LC.
11.4.1 To add a load combination 1. Choose Criteria > Load Combinations. 2. Click Add Load Combination. 3. In the dialog box that appears, enter a name for the new load combination and click OK. Another dialog box appears that requires you to specify the plans that you want RAM Concept to create (Slab Stress, Slab Deflection and Slab Force). These plans appear in the new load combination’s folder. 4. Choose the plans that you want created and click OK. The new load combination appears at the bottom of the window. 5. Select the active rule sets. 6. Enter the load factors and the alternative load factors for each loading in the load combination.
11.4.2 To delete a load combination 1. Choose Criteria > Load Combinations. 2. Click Delete Load Combination. A dialog box opens with a list of the current load combinations. 3. Choose the load combination to delete and click OK.
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Specifying Load Combinations Load combination properties
11.5 Load combination properties Load Combination Name The label used to identify the load combination. Combo Type The choices are: • Single: this is the standard type. • Lateral Group: this is used for a floor that is part of the lateral force resisting system [especially mat foundations (rafts)]. Note: The primary purpose of Load Combination types is to reduce the number of lateral load combinations. A secondary purpose is to provide easy enveloping for results such as soil bearing pressure. Analysis Type The choices are: • Linear: this is the standard type. • Zero-Tension: these load combinations do NOT have alternate load factors and never consider pattern loading. Active Rule Sets These control which rule sets are used for design calculations. Up to six active rule sets can be associated with each load combination. See Chapter 12, “Selecting Design Rules” for further explanation. Load Factor The factor applied to a particular loading in the load combination. Alternate Envelope Factor You should only use these if you fully understand the principle involved. Do not set these factors to zero without understanding their use. If you are unsure then set them to equal the corresponding load factors. See “About alternate envelope factors”.
11.6 About group load combinations A group load combination has load factors for every non-lateral loading and for one single lateral loading type. Effectively, a group load combination's results are the envelope of all the results from N invisible single load combinations, where N is the number of loadings for the given lateral loading type. A linear group load combination has a standard and alternate load factor for every non-lateral loading, and a standard and alternate load factor for the selected lateral loading type. It never has zero tension iterations. A zero-tension group load combination has a single load factor for every non-lateral loading, and a single load factor for the selected lateral loading type. It has zero-tension iterations as necessary for invisible (internal) component load combo, and will be the envelope of all of the component load combos combined. It never considers pattern loading. The following figure is intended to explain the ramifications of load combination type selection.
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Specifying Load Combinations About alternate envelope factors
Load Combination TYPE
Single
Lateral
All loadings are listed Each loading has load factors Linear Load Combinations have an Alternate Envelope Factor Zero-Tension Load Combinations do not have Alternate Envelope Factors
All non-lateral loads are listed One –and only one– key loading type can be used (per load combination) All N loadings within the Key Loading Type are used to generate N load combinations
Figure 16: Ramifications of Load Combination Type Refer to Summary of load combination types (on page 108) for more information.
11.7 About alternate envelope factors There can be situations where the application of a loading has an unconservative effect on the results. For example • a retaining wall loading that applies compression to a floor. • a cantilever live loading that reduces the internal span moment. In such circumstances, it is desirable to analyze the structure both with and without the full loading. While you could do this by creating an additional load combination, RAM Concept provides a much simpler solution Alternate Envelope Factors (AEF).
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Specifying Load Combinations Summary of load combination types
Figure 17: This beam supports dead loads (not shown) and live loads (shown). The live loading reduces the positive span moment. By using an AEF less than the corresponding load factor, you create a load combination with a reduced live loading. Note that the AEF affects the entire live loading, not just the live load on the cantilever. Conceptually, RAM Concept considers alternate envelope factors by analyzing the load combination 2L times (where L is the number of loadings) - once for every permutation of load factors and alternate envelope factors for all of the loadings. RAM Concept then envelopes the design strip forces, design section forces and punching shear reactions for all of the load combination analyses. RAM Concept uses these force envelopes later for design purposes. You can also plot the force envelopes or view them in tables. RAM Concept fully considers any pattern loading effects while considering the load factors. Note that the general analysis forces that are not used as design forces by RAM Concept - such as standard slab bending moments and deflections - are only stored for the load combination considering the standard load factors. As stated above, you should only use alternate envelope factors if you fully understand the principle involved. Do not set them to zero without understanding their use. If you are unsure then set them to equal the corresponding load factors.
11.7.1 Example of Alternate Load Factors The following figure shows the suggested way to use the factors for a strength design of the ACI318-05 Factored LC.
Figure 18: Factored LC load factors and alternate envelope factors.
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11.8 Summary of load combination types The effects of using different load combination types and analysis types are summarized in the following table. Table 1: Load Combination Summary Linear
Zero-tension
Single
• Standard and Alternate load factors for every loading • No zero-tension iterations • Considers pattern loading
• Standard load factor for every loading • Zero-tension iterations as necessary • Ignores pattern loading
Group
• Standard and Alternate load factors for every non-lateral loading • Standard and Alternate load factors for the selected lateral loading type • No zero-tension iterations • Considers pattern loading • No results for point springs, line springs, point supports, line supports, walls. • No “Standard” results for any quantity • See the second figure in this chapter for more information.
• Standard load factor for every non-lateral loading • Standard load factor for the selected lateral loading type • Zero-tension iterations as necessary • Ignores pattern loading • No results for point springs, line springs, point supports, line supports, walls. • No “Standard” results for any quantity • See the second figure in this chapter for more information.
ACI 318-05 Elevated floor file with lateral loadings added To simplify the example, four loadings have been deleted from the standard file.
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Specifying Load Combinations Summary of load combination types
Figure 19: Loading table for ACI 318-05 Elevated Floor - six wind loadings have been added (and one stressing dead and three live loadings have been deleted) After adding and deleting some loadings, the load combinations have been rebuilt. See “Rebuilding load combinations”. The Rebuild operation adds the load combination “Factored Wind LC: 1.2D + f1L+ 0.5Lr + 1.6W”, as shown in the following figure.
Figure 20: Rebuilt load combination: Factored Wind LC: 1.2D + f1L+ 0.5Lr + 1.6W RAM Concept now expands this load combination and calculates the following load combinations: 1. 1.2 Self-dead + 1.0 Hyperstatic + 1.2 Other dead + 0.5 Live (reducible) + 1.6 North Wind + 1.6 North Wind (transfer) 2. 1.2 Self-dead + 1.0 Hyperstatic + 1.2 Other dead + 0.5 Live (reducible) - 1.6 North Wind - 1.6 North Wind (transfer) 3. 1.2 Self-dead + 1.0 Hyperstatic + 1.2 Other dead + 0.5 Live (reducible) + 1.6 East Wind 4. 1.2 Self-dead + 1.0 Hyperstatic + 1.2 Other dead + 0.5 Live (reducible) - 1.6 East Wind
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Specifying Load Combinations Summary of load combination types 5. 1.2 Self-dead + 1.0 Hyperstatic + 1.2 Other dead + 0.5 Live (reducible) + 1.6 Trade Wind + 1.6 Sirocco Wind + 1.6 Zephyr Wind 6. 1.2 Self-dead + 1.0 Hyperstatic + 1.2 Other dead + 0.5 Live (reducible) - 1.6 Trade Wind - 1.6 Sirocco Wind 1.6 Zephyr Wind
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Selecting Design Rules You design concrete floors manually by calculating the resultants (moments, shears and axial forces) of a load combination and applying the appropriate code rules and formula. You select code rules based upon the type of member (reinforced slab, post-tensioned beam, etc.) and the type of load combinations. For example, codes intend some load combinations are for strength design and others for serviceability design. RAM Concept uses a similar method. It sorts code rules into sets of rules and applies them to the resultant envelopes of load combinations. Thus, a rule set design is one or more code rules applied to the resultant envelope of one or more load combinations. For example, the set of code formula for bending and shear strength is the strength rule set. RAM Concept applies this rule set to the envelope of all “factored” (or ultimate) load combinations. The strength rule set does not apply to service load combinations. You design most floors or members for more than one rule set. For example, a post-tensioned floor is usually checked for initial service stresses, service stresses and strength, all with different load combinations.
12.1 Using rule set designs RAM Concept uses the concept of a design strip to link finite element analysis with concrete code rules (see Chapter 22, “Defining Design Strips”). Each design strip’s properties include design system (beam / one-way slab / two-way slab) and the “considered as post-tensioned” option. Design strips contain design cross sections. You assign each load combination active rule set designs in the load combinations window. How RAM Concept utilizes rule set designs: 1. Load combinations generate envelopes for resultants (moments, shears, axial forces and torsions). 2. All load combination envelopes with the same rule set design are in turn enveloped. This is a rule set design envelope. 3. For each rule set design envelope, design strips generate rule set design force envelopes. 4. Each design strip determines which code rules are appropriate for each rule set design. Design strip properties impact which particular rules are used. 5. Design and checking rules are applied to the rule set design section envelopes. 6. A design summary envelopes the reinforcement requirements and section status for all rule set design section envelopes. Example: The following example describes how RAM Concept selects the ACI 318-02 design rules for a post-tensioned beam with live and wind loadings.
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Selecting Design Rules Rule set design properties
Figure 21: Example of load combinations and rule sets RAM Concept’s process is as follows: • The two load combinations generate envelopes for resultants. • The five active rule set designs (service design, code minimum design, user minimum design, strength design and ductility design) each create envelopes from the load combinations. • Each rule set design envelope creates a rule set design section envelope. • The design strip properties of “Structural system: beam” and “consider as post-tensioned” determines the following rules from ACI 318-02 are applicable: • Strength Design: rules 18.7.2 (flexural strength) and 11.4 and 11.5 (shear strength) are used with the beam clauses. • Minimum Design: rule 18.9.2. • Service Design: rules 18.3.3 and 18.4.2 (b). • These rules are applied to the rule set design section envelopes. • The reinforcement requirements and section status for all rule set design section envelopes are in turn enveloped for a design summary.
12.2 Rule set design properties The following is a list of rule set design properties: Name This relates to the rule set design. It most cases it is the same as the active rules, but there can be exceptions (see adding rule set designs - below). Active Rules This describes the set of rules applied by this rule set.
12.3 Types of active rules The available ACI 318-02 active rules are:
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Selecting Design Rules Adding and deleting rule set designs Code Minimum Design
Rules for minimum reinforcement (shrinkage, detailing, etc.) based upon geometry rather than stress or moment level. Does not include shear reinforcement.
User Minimum Design
Reinforcement based on user defined reinforcement ratio. See the design strip property description in chapter 22.
Initial Service Design Checks of PT floor stresses just after application of prestress (when dead load is minimal). Service Design
Checks of PT floor stresses due to service loads. Rules for reinforcement bar based upon bar stress levels.
Sustained Service Design
Checks of PT floor compression stresses due to sustained loads.
Strength Design
Rules to ensure section has sufficient strength in bending and shear for factored (or ultimate) moments, and minimum shear reinforcement.
Ductility Design
Rules intended to produce ductile behavior.
Soil Bearing
This is used in mat foundation (raft) files to facilitate the enveloping of soil bearing pressure. It does not use any active rules.
12.4 Adding and deleting rule set designs Adding a duplicate rule set design allows you to separate the results for different load combinations with the same active rules. For example, if a strength design is required for three different load combinations (1. Dead and Live; 2. Dead, Reduced Live and Snow; 3. Seismic) then you could keep the results separate by creating two new rule set designs with names such as “Snow” and “Seismic” which both use the code strength rules. This way you can view the strength reinforcement requirements separately. You can delete non-applicable rule set designs to simplify the file. For example, in ACI 318-02, initial service design, and sustained service design are not required for floors without post-tensioning. Another example is DL + 0.25LL Design is not required if the UBC is not used.
12.4.1 To add a rule set design 1. Choose Criteria > Design Rules. 2. Click Add Rule Set Design. 3. Type a name for the new Rule Set Design in the Add Rule Set Design dialog box and click OK. A dialog box appears that requires you to specify the plans that you want created (Top and Bottom Reinforcement, Shear Reinforcement and Punching). 4. Choose the plans that you want created and click OK. The new rule set design appears at the bottom of the window. 5. Select the active rules.
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Selecting Design Rules Adding and deleting rule set designs
12.4.2 To delete a rule set 1. Choose Criteria > Design Rules. 2. Click Delete Rule Set Design. A dialog box appears with a list of the current rule set designs. 3. Choose the rule set design to delete and click OK.
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Using a CAD Drawing You can define the model’s geometry quickly if there is a CAD file (with .dwg or .dxf filename extension) available to use as a background. You trace the CAD drawing with object tools to facilitate the finite element mesh generation. You can also use the CAD drawing to locate other objects such as loads. Snap tools make tracing the imported CAD drawing easier. Note: RAM Concept itself does not recognize the meaning of actual drawing lines. It is not necessary, however, to use a CAD file. If the floor is straightforward, or there is no drawing available, you should skip this chapter. For strip-like models that do not warrant the use of a CAD file, it may be better to use Strip Wizard.
13.1 Importing, verifying and viewing a drawing To use a background drawing you import the drawing and then verify that it is at the correct scale.
13.1.1 Importing a CAD file You can import a drawing at any time. An imported drawing overwrites any previously imported drawing. RAM Concept can work with either a .dwg or a .dxf file. It is typically best to use a .dwg file. 1. Choose File > Import Drawing. 2. Select the CAD drawing file you want to import. If Concept cannot determine the units of CAD file, the File Units dialog box will appear with a list of units. The units relate to the CAD file, not the RAM Concept file. 3. Select the appropriate units and click OK. Note: It is possible to import a CAD drawing with one set of units into a model with another set of units.
13.1.2 Checking the imported information When you import the drawing file, it will be visible on the Standard Plan of the Drawing Import Layer. You should verify that the plan scale is correct.
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Using a CAD Drawing Importing, verifying and viewing a drawing To check that the imported drawing is at the correct scale 1. Choose Layers > Drawing Import > Standard Plan. 2. Click Zoom Extent ( ) to ensure that you are viewing the entire CAD plan. 3. Select the Dimension tool ( ) and draw a dimension line between two snapable points that are a known distance apart. The distance between the two points will appear as a dimension. If this dimension is not as expected then the imported file may be in the wrong scale. Consider importing the drawing with different units to fix this problem.
13.1.3 Making the drawing visible on other plans You can make the imported drawing visible on any plan through the Visible Objects dialog box. Usually you want to make it visible on the Mesh Input Standard Plan (for defining the floor geometry), and perhaps on some loading plans (for locations of line and point loads). You may choose to turn off some CAD layers if they clutter the drawing. If you happened to bring in an architectural drawing, it is probably a good idea to turn off the furniture. See “Controlling views” for more information on making objects visible or hidden.
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Importing a Database from the RAM Structural System Note: In many places in this chapter the RAM Structural System is referred to as “RSS”. RAM Concept can import concrete structure information and loads from the RAM Structural System (Version 9.01 or higher) into a RAM Concept file. RAM Concept can also export support member forces back to RSS.
14.1 What can be imported from the RAM Structural System RAM Concept allows the selective import of concrete members (slabs, beams, openings, columns and walls), applied loads and member loads from one story of a RAM Structural System database. Member loads can be from gravity and / or lateral analyses.
14.2 Controlling which concrete members are imported A story defined in the RAM Structural System can have two types of floors: elevated or mat foundation. The floor type designation determines which concrete members in the story are imported. The following figure and table show the relationship between the selected story, the import slab type and the slab area imported. Note that mats are below the designated story. For example, the 2nd story mat is the mat that supports the second story elevated floor. 2nd Story
1st Story
B
A
D
C
Figure 22: The slab areas shown above (A,B,C,D) will be imported based upon the selections shown below.
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Importing a Database from the RAM Structural System About load importation Table 2: Relationship between the selected story, the import slab type, and the slab area imported. Story
Import Type Elevated
Mat Foundation
1st
A
C
2nd
B
D
14.2.1 Definition of the “import perimeter” The selected slab areas define the import perimeter. Only RAM Structural System support members within the import perimeter will be imported. For example, in the figure in “Controlling which concrete members are imported”, if the 1st story elevated slab is imported with the “columns above” setting, the two furthermost right columns between the 1st story and 2nd story will not be imported as they are not within the slab perimeter of the 1st story elevated slab. The following structural members can be imported: 1. Slabs • All slabs of the selected slab type. 2. Beams • All concrete beams from the selected story. 3. Openings and Penetrations • All openings and penetrations within the import perimeter. 4. Columns • Any column (below and / or above) whose center point lies inside the import perimeter. 5. Walls • Any wall (below and / or above) whose center line is contained by or crosses any part of the import perimeter. 6. Grids • All orthogonal and radial grids. Note: All structural members are imported into RAM Concept’s Mesh Input layer. Grids are imported into the Drawing Import layer.
14.3 About load importation RAM Concept imports applied loads and analyzed member forces from the selected member group.
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Importing a Database from the RAM Structural System About load importation Certain components of member loads are ignored when importing. The components that are ignored depend on the slab type and whether the member forces are from gravity and lateral loads. The following table summarizes the force components that are imported onto a mat foundation and an elevated slab. Table 3: Relationship between the slab type, member loading type, and imported force components for a slab. Slab Type
Loading Type
Forces Imported
Mat
Transfer Gravity
Fz, Mx, My
Mat
Transfer Lateral
Fx, Fy, Fz, Mx, My
Elevated
Transfer Gravity
Fz
Elevated
Transfer Lateral
Fz, Mx, My
Wall forces are resolved into a statically equivalent linearly varying force applied along the length of the wall. The following loads can be imported 1. Direct gravity loads • Point, line and area gravity loads applied directly to the imported slabs. The following table shows how RSS load cases are mapped to RAM Concept loading layers. Table 4: Mapping of RSS load cases RSS Load Case
RAM Concept Loading Layer
Dead
Dead Load
Live
Ignored (imported as 4 individual live loadings)
Live Reducible
Live Reducible
Live Unreducible
Live Unreducible
Live Storage
Live Storage
Live Roof
Live Load Roof
Partition
Partition (imported as “Live Unreducible” type)
Construction Dead
Construction Dead Load
Construction Live
Ignored
Mass Dead
Ignored
2. Transfer gravity loads
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Importing a Database from the RAM Structural System Importing a database • RAM Concept imports transferred gravity loads from RSS members above the import slabs. The loads include member self-weight with the transferred gravity loads. The loads are imported as point loads and line loads into separate RAM Concept loading layers. • A new RAM Concept transfer gravity loading layer is created for each RSS Load Case, as in Table 14-3, but with the string “(transfer)” appended to the name. For example, transfer loads from the RSS Dead load case are imported into the Concept “Dead Load (transfer)” loading layer. The Concept “(transfer)” loading layers are not created if the Transfer Gravity Loads are not imported. • 3. Lateral Member Loads • Lateral member forces (such as wind and seismic) from members above and below the imported slab are imported as point loads. The member loads are imported into a new loading layer for each analyzed load case in RSS. RAM Concept creates the name for the new loading layer from the user's label and the RSS load type. • For example, the name could be “mySeismic(EQ_UBC97_X_+E_F)”. Note: Mat foundation loads imported from the RAM Structural System will always be reduced during the import. For this reason you should always choose the live load reduction code of “None” in these files.
14.4 Importing a database You can import from the RAM Structural System at anytime. An import overwrites some or all previously imported time. An import overwrites some or all previously imported data, and may overwrite information you have directly input to RAM Concept. Note: RAM Concept may not be able to import data correctly if the RSS file does not pass the “Data Check” operation in the RAM Modeler module. It is strongly recommended that your RSS file have no errors before attempting to import it into RAM Concept. 1. Select the RAM Structural System file to import: a. Select File > Import RAM Structural System. b. If there is no open RAM Concept file the Open RAM Structural System Database dialog opens. Browse and select a RSS database (. RSS) file and click OK. When a valid RSS database file is selected, the RAM Structural System Import dialog opens. The RSS filename selected appears after File: at the top of the window. c. (Optional) Click Browse at the top of the dialog to select a different file with the file browser. Note: If you select a file with a version prior to 9.0, an error will be displayed and you will be returned to the file browser. Clicking the Cancel button cancels the import operation. Note: If you are using RSS version 9, select RSS database files with the .RAM extension.
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Importing a Database from the RAM Structural System Importing a database
Figure 23: RSS import dialog box 2. Select the story label from the Choose story drop-down list and then select the Slab Type. 3. Select the RSS Structure options to import:, select the structural members from the check boxes. a. Check the individual structure elements (e.g., Slab/Mat Areas, Beams, etc.) to import for the selected story. Note: For Mat Foundations, the Columns Below Slab, Walls Below Slab, Beams and Openings and Penetrations objects are disabled.
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Importing a Database from the RAM Structural System Importing a database b. (Optional) Select the Use RAM Structural System crack factors for member stiffness if you want to use the cracked factors of the imported members as calculated by RSS. If this option is not selected, then the crack factors for slab areas, beams, and columns are set to 1.0. When this option is selected, the stiffness values are set according to the following table. Object
Concept
RAM Structural System
Slab
kMr, kMs, kMrs
Bending Cracked Factor
kFr, kFs, kVrs
Diaphragm Cracked Factor
kMs
Cracked Factor
kMrs
Torsion Factor
kFr
Axial Factor
kMr, kFs, kVrs
1.0
IFactor
Axial Factor
Beam
Column
4. Select the load types to import from the check boxes in the Loading group. Note: For Mat Foundations, the Direct Gravity Loads option is disabled. 5. Click OK. After an RSS file is imported, the RAM Import Status opens with a summary and any warnings.
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Importing a Database from the RAM Structural System Reimporting a database
Figure 24: Example of an import summary with warnings The RSS geometry definitions and loads are now imported into RAM Concept. You can now generate the finite element mesh. See Generating the Mesh (on page 178). Note: If you are re-importing, there could be additional dialogs that appear with more warnings. Note: Importing lateral analysis loads from RSS models which contain a large number of lateral load cases will cause RAM Concept to create a corresponding large number of load combinations. This will result in sluggish performance in RAM Concept.
14.5 Reimporting a database If the information in the RAM Structural System database changes, the RAM Concept model will not be automatically updated. You can, however, reimport the changed information.
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Importing a Database from the RAM Structural System Reimporting a database Changes to structural members and loads made in RAM Concept can be lost when importing an RSS file, so care should be taken to avoid losing information.
14.5.1 Resolving loading conflicts If the RAM Concept file has existing loadings that do not match the RSS loadings to be imported, a dialog box like that in the following figure asks if you want to keep or delete the existing loadings. If you have already specified (drawn) loads in the loadings that RAM Concept has proposed to delete, then you should keep the loadings that RAM Concept offers to remove. If you want to export the reactions from these preexisting loads to RSS, you need to copy the loads from the original loadings to the corresponding RSS loadings that are being imported (after which you should manually delete the non-RSS loadings). Note: If you have used the Export Geometry to RAM Structural System feature (section 36.2) prior to importing, then you always see this warning. The recommended workflow is to either draw the loads in RSS or draw the loads in Concept after importing from RSS; with either of these workflows, you can safely allow the loadings proposed for removal to be deleted.
Figure 25: Choices for dealing with new loadings RAM Concept will also prompt you to determine if you require rebuilding of the load combinations and design rules, as shown in the following figure. You have three choices: • Rebuild: load combinations and design rules in the RAM Concept file are rebuilt • Don’t Rebuild: the new load cases are added to the RAM Concept file, but not included in the load combinations. • Cancel: RAM Concept returns you to the file browser.
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Importing a Database from the RAM Structural System Reimporting a database
Note: When reimporting a particular member type, e.g. beams, all entities of that category are removed from the RAM Concept file before importing. For example, if beams are imported, all beams in the RAM Concept file are removed first. Any beams you have added manually in RAM Concept will be lost. If beams are not selected for import, then beams in the RAM Concept file will not be affected when the file is reimported. Note: If any loading categories are selected, then ALL loads in reimported loading layers are removed. Any loads you have added manually on a loading layer being reimported will be lost.You have the option whether to regenerate load combinations or not. RAM Concept always asks you to confirm a reimport operation, because it may lead to loss of information. It warns you if the data to be reimported would be significantly different from the previously imported data, or if significant information will be lost. For example, RAM Concept warns you when reimporting a mat foundation after previously importing an elevated slab, or vice versa.
14.5.2 To reimport from the RAM Structural System 1. Select File > Import RSS. A file dialog box will open with the name of the last RSS file you imported into this RAM Concept file. 2. Select the RSS file and click OK. The file can be a different RSS file which may have a significant (and possibly negative) effect on the RAM Concept model. The RAM Structural System Import dialog box will appear with a list of options. The default options will be the story and slab type from the last import. 3. Select the story, slab type, structure and loading and click OK. A New Loadings confirmation box may appear that describes loadings in the RSS file that are not in the current RAM Concept file. Click Replace, Add, or Cancel. Figure 26: Examples of warnings for an import operation with different levels and structure type
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Importing a Database from the RAM Structural System Limitations, Defaults and Assumptions
A confirmation box appears that warns about differences from previously imported data. 4. Click Replace or Cancel. A RSS Import Status dialog box will appear with a summary and any warnings. 5. Click OK.
14.6 Limitations, Defaults and Assumptions 14.6.1 Limitations • Not all information stored in a RAM Structural System database can be transferred into RAM Concept. • RAM Concept models RAM Structural System data using one of the following building codes: ACI 318-99, ACI 318-02, ACI 318-05, ACI 318-08, ACI 318-11, ACI 318-14, AS 3600:2001, AS 3600:2009, Eurocode 2:2004, CAN/CSA A23.3-04, or BS 8110:1997. A RAM Structural System database that has live load reduction set to China GB or Hong Kong will be imported using the BS 8110: 1997 building code; a live load reduction setting of NBC of Canada will be imported using the CAN/CSA A23.3-04 standard; otherwise the building code set in RAM Concrete is used to set the RAM Concept code. The building code can be changed, if necessary after the importation is complete. • RAM Concept does not model beam fixity. • RAM Concept models a column end as fixed if the RAM Structural System column is fixed along either its major or minor axis. • RAM Concept only models walls of constant height. RAM Concept will create a wall with the average height of the RAM Structural System wall. • The lateral loads applied to the structure in RAM Frame Analysis are not imported. • RAM Concept ignores holes in walls modeled in RAM Structural System version 10.
14.6.2 Defaults RAM Concept uses the following defaults for properties that are not defined in the RAM Structural System. Beams
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Importing a Database from the RAM Structural System Limitations, Defaults and Assumptions • Surface elevation is 0.0. Columns • Compressible is true. • Roller is false, except above mat foundations. • Columns above mat foundations are pinned at the top regardless of the setting in the RAM database. Walls • • • •
Neither the top nor the bottom is fixed. Modeled as a Shear Wall. Modeled as compressible. The RAM Structural System “cracked section factor” is ignored.
14.6.3 Assumptions • All loads are applied to the surface of the slab. • Wall forces are applied as a linearly varying force along the length of the wall that is statically equivalent to the wall forces and moments. Refer to the following tables for mapping of RAM load cases and types to RAM Concept’s loadings and force levels. Table 5: RAM Modeler Force Level Assumptions RSS Load Type
RAM Concept Loading
RAM Concept Loading Force Level (Limit State)
Wind
Wind
Service *
Seismic
Seismic
Ultimate *
Other
Seismic
Ultimate *
Virtual
Ignored
Note: * denotes assumed Table 6: RAM Frame Load Cases RSS Load Case Type
Sub-Type
RAM Concept Loading
RAM Concept Loading Force Level (Limit State)
Wind
User defined story forces
Wind
Service *
Wind
all others
Wind
Service
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Importing a Database from the RAM Structural System Tight integration with the RAM Structural System
RSS Load Case Type
Sub-Type
RAM Concept Loading
RAM Concept Loading Force Level (Limit State)
Seismic
User defined story forces
Seismic
Ultimate *
Seismic
UBC 94
Seismic
Service
Seismic
all others
Seismic
Ultimate
Dynamic
Eigen solution
Ignored
Dynamic
all others
Ignored
User defined story forces
Seismic
Center of rigidity
Ignored
Virtual Work
Ignored
Ultimate *
Note: * denotes assumed
14.7 Tight integration with the RAM Structural System Starting with version 14.5, the RAM Structural System can be used to control the model data exported, run Concept, and manage the Concept data file as part of the RSS model file. Selection of the data to be imported into Concept is very similar to that described here. For more information, refer to the RSS Structural System documentation. Concept executes in a restricted mode when it is run from RAM Manager. The following operations are disabled: • • • • • • • • •
New Open Close Save As Save Template Strip Wizard Sync ISM / New from Repository All Sync RSS Operations All Sync STAAD Operations
These restrictions are in place primarily to maintain the integrity of the Concept files when they are imbedded in the RSS model file.
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Data Transfer from STAAD The STAAD analysis and design program can transfer structure geometry and loading information to RAM Concept.
15.1 STAAD Interface In STAAD, you can select slabs elements, wall elements, column elements and beams for export into RAM Concept. You can also select STAAD load cases for export and associate them with RAM Concept loading types. The STAAD interface allows you to either run RAM Concept immediately with the exported data or to save the data to a GCFF file for later import into RAM Concept. If the STAAD file changes (perhaps loads or column sizes change), you can update the RAM Concept file by reexporting the STAAD information. Please see the STAAD manuals for more information on the STAAD interface.
15.2 RAM Concept Interface 15.2.1 Data Transfer Paths RAM Concept can import STAAD information in four ways: 1. 2. 3. 4.
RAM Concept is started by STAAD to create a new file. RAM Concept is started by STAAD to update a previously created file. The RAM Concept File menu item New From STAAD GCFF file is chosen to create a new file. The RAM Concept File menu item Update from STAAD GCFF file is chosen to update an already opened RAM Concept file.
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Data Transfer from STAAD RAM Concept Interface
15.2.2 New file options in RAM Concept When creating a new file from STAAD information - either via the New from STAAD GCFF file menu item or by STAAD starting RAM Concept, the dialog box shown in the following figure opens.
Figure 27: File options dialog box
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Data Transfer from STAAD RAM Concept Interface The options at the top of the dialog window are the same as for creating any new RAM Concept file and are not discussed further here. The checkboxes at the bottom of the window allow you to import one or more of the following classes of information: slabs (including beams), walls, columns and loads.
15.2.3 Update file options in RAM Concept When updating a ConceptRAM Concept file with new STAAD information - either via the Update From STAAD GCFF file menu item or by STAAD starting RAM Concept, the following dialog box opens.
Figure 28: Update file options dialog box The options in the window are the same as those discussed in “New file options in RAM Concept,” but behave slightly differently due to the operation being an “update”. For example if “Columns” is selected, all existing columns will be removed and new columns defined by the STAAD information. If “Columns” is not selected, no changes will be made to the columns in the RAM Concept file.
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Data Transfer from ISM RAM Concept can exchange structure information with Bentley’s Integrated Structural Model (ISM) technology.
16.1 What is ISM? Bentley’s Integrated Structural Model (ISM) is a technology for sharing structural engineering project information among structural modeling, analysis, design, drafting and detailing applications. ISM is similar to Building Information Modeling (BIM), but focuses on the information that is important in the design, construction and modification of the load bearing components of buildings, bridges and other structures.
16.1.1 Purpose There are two related purposes for ISM: • The transfer of structural information between applications. • The coordination of structural information between applications. To provide for transferring information, ISM provides a means of defining, storing, reading and querying ISM models. To provide for coordination of information, ISM can detect differences between ISM models, allowing you to selectively update either an ISM repository or an application’s data. This gives you control over the consistency between the two data sets.
16.1.2 ISM and Application Data ISM is not intended to store all of the information that all of its client applications contain. Rather, it is intended to store and communicate a consensus view of data that is common to two or more of its client applications, such as RAM Concept. RAM Concept continues to hold and maintain its own private copy of project data. Some of RAM Concept’s data will duplicate that of the associated ISM repository. RAM Concept’s data may even conflict with that in the ISM repository. RAM Concept (or you as its user) may decide that maintaining conflicting data is best for RAM Concept’s and ISM’s different uses.
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Data Transfer from ISM ISM Sync Tools Overview
16.2 ISM Sync Tools Overview RAM Concept can send structural data to and from an ISM repository through a set of ISM synchronization tools. These tools allow you to both create and update RAM Concept models as well as ISM repositories. These flexible tools also allow you to create models and move data as your workflow dictates. There are four ISM operations: • Create ISM repository: creates a new ISM repository from the model currently open in RAM Concept. • Create RAM Concept file: creates a new RAM Concept model from an existing ISM repository. • Update ISM repository: transfers changes made to the current RAM Concept model into an existing ISM repository, and allows you to accept some or all of those changes. • Update RAM Concept model: transfers changes made to the ISM repository into the current RAM Concept model, and allows you to accept some or all of those changes. When the Update operations are executed, the Structural Synchronizer update dialog opens to coordinate which changes are to be reflected in the models and repository.
16.2.1 Create ISM Repository To create an ISM repository from a RAM Concept model: 1. Select File > Sync ISM > Create repository. 2. Select the repository file and click OK. The Export Story dialog opens, as in the following figure.
Figure 29: ISM Export Dialog 3. Type a story Name and Elevation (in the indicated units), and click OK. The story name and elevation are both required. 4. (Optional) Type a Substructure name, if wanted. If included, the substructure is created –if it does not already exist– and all ISM objects exported by RAM Concept are made members of this substructure.
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Data Transfer from ISM ISM Sync Tools Overview 5. (Optional) Set the Open Structural Synchronizer checkbox to open the Structural Synchronizer update dialog next. Use this window for manual inspection and filtering of the items to be exported. 6. Click OK.
16.2.2 Create RAM Concept File To create a RAM Concept File from one story defined in an ISM repository: 1. Select File > Sync ISM > New from repository. 2. Select the ISM repository file and click OK. The New File dialog opens, as in the following figure.
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Data Transfer from ISM ISM Sync Tools Overview
3. 4. 5. 6.
Figure 30: New File (from ISM) dialog Select the file's Structure Type. Select an option for the Code and Units. Select the story to be imported from the Story drop-down list. The Substructure drop-down list is populated with the names of substructures defined in the ISM repository. Either:
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Data Transfer from ISM Import and Export Details Selection
Result
select a substructure name
only the members within that substructure will be imported in the model
select No Substructure
no substructure filtering is applied to the selected story
7. (Optional) Set the Recompute nodes for support members. Nodes determine which walls and columns will be imported and the height RAM Concept models for them. If the nodes in the import model are incomplete, some support members will not be imported. This option recomputes the import model's nodes for internal use only. The new nodes are not added to the model. 8. (Optional) Set the Open Structural Synchronizer checkbox to open the Structural Synchronizer update dialog next. Use this window for manual inspection and filtering of the items to be imported. 9. Click OK. Related Links • ISM Options dialog (on page 149)
16.2.3 Update ISM Repository To update the ISM repository with changes made to the RAM Concept file, select File > Sync ISM > Update repository. The Structural Synchronizer update dialog opens, giving you control over each change to the repository. If the ISM repository cannot be found, you are given the opportunity to select its new location or cancel the operation.
16.2.4 Update RAM Concept Model To update the RAM Concept File with changes made to the ISM repository, select File > Sync ISM > Update from repository. The Structural Synchronizer update dialog opens, giving you control over each change to the RAM Concept file.
16.3 Import and Export Details It is useful to describe here the differences between the ISM and RAM Concept models, the conversion process, and how the RAM Concept model is modified to make the conversion process smoother.
16.3.1 Filtering The ISM model is very general. It can represent diverse structure types, such as buildings and bridges, and material types like steel, wood, and concrete. RAM Concept filters out any part of the ISM repository that it does not model or is not relevant. The Update operations use the filtered model to determine the context of the changes to be applied.
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Data Transfer from ISM Import and Export Details For example, RAM Concept filters out all steel members. When RAM Concept updates the ISM repository, it does not need to replicate steel members in the model. The Change Management deduces that RAM Concept is not deleting the steel members because it never read them in. The RAM Concept filter retains only the following objects from the ISM model: • • • • • • • • •
The imported story information Concrete slabs, footings and beams on the imported story Concrete walls and columns that are connected to the slabs or beams retained Static load cases and their loads that are applied to the slabs or beams retained Concrete materials and curve member sections that are used by the members retained Concentrated and area surface rebar in slabs Layer parallel rebar inside and parallel to a beam Rebar materials used by imported rebar Straight, rectangular tie, and open U tie perpendicular rebar in slabs or inside and parallel to a beam
RAM Concept ignores the following ISM objects: • • • • • • • • • •
Non-planar slabs, walls, and surface loads Sloped slabs Modifiers and openings in walls Beams, columns, and curve loads with geometry not equivalent to a single line segment Beams and columns that do not have the Orientation, Section, and SectionPlacementPoint properties set Beams with a non-vertical Orientation Duplicate load cases that correspond to fixed RAM Concept loadings Hyperstatic load case cause Rebar in walls or columns Non-horizontal rebar
RAM Concept and ISM use slightly different terminology for structural members and loading types. The following table is a cross-reference of RAM Concept and ISM type names. Table 7: Concept and ISM Type Name Cross-Reference RAM Concept Name
ISM Type(/Use)
N/A
Story
Concrete Mix
Concrete
Slab Area
Surface Member/Slab or Surface Member Modifier
Slab Opening
Surface Opening
Beam
Curve Member/Beam
Column
Curve Member/Column
Wall
Surface Member/Wall
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ISM Type(/Use)
Loading
Load Case
Point Load
Point Load
Line Load
Curve Load
Area Load
Surface Load
N/A
Section
Rebar
Rebar Material
Concentrated Rebar
Concentrated Surface Rebar
Distributed Rebar
Area Surface Rebar
Transverse Rebar
Perpendicular Rebar
16.3.2 The ISM Model ISM structure models consist of multiple stories. Each slab or beam is “on” exactly one story. Wall and column members may extend through multiple stories and are connected to slab and beam members. Load Cases contain point, line and area loads that are applied to exactly one member.
16.3.3 Slabs and Openings ISM and RAM Concept model slab areas differently. It is instructive to describe the differences in detail here to explain how the import and export operations are affected. RAM Concept slabs are defined by a collection of slab areas and openings with arbitrary overlapping polygonal boundaries. Each slab area defines material, thickness and surface elevation properties. An integer priority determines which slab area or opening takes precedence where two or more slab areas overlap. ISM slabs are defined by a collection of surface members with polygonal boundaries. Each surface member may contain any number of surface member modifiers. The surface member and its modifiers define the slab material, thickness and surface position properties. Modifier boundaries must lie inside the parent surface member's boundary. Modifier boundaries may overlap, so modifiers have an integer priority to determine precedence in overlapping areas. Modifiers always take precedence over the parent surface member. Normal practice is for modifier priorities to be sequential, starting at 1. A surface member may also contain any number of surface member openings. Like modifier boundaries, opening boundaries must lie within the parent surface member's boundary and may overlap. However, openings always take precedence over the surface member and its modifiers. In effect, surface members have an infinitely low priority, surface member modifiers have an explicit integer priority, and openings have an infinitely high priority.
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Data Transfer from ISM Import and Export Details Note: We use the term effective shape to mean the surface member boundary minus all of its openings. This shape is not necessarily polygonal. Although not common, it may have holes and islands. The effective shape may also be disjoint if surface member openings split it into pieces. We also use the term outer boundary of an arbitrary shape. This is the shape with all interior holes filled. It may consist of more than one disjoint shapes, but each shape will be polygonal. Therefore, ISM surface member boundaries may overlap, as long as there is no overlap between the surface member effective shapes.
Importing ISM Slabs to RAM Concept Importing a single ISM surface member as a set of RAM Concept slab areas and openings is straightforward. The surface members and surface member modifiers are imported as RAM Concept slab areas. The openings are imported as RAM Concept openings. The slab area created from the surface member is assigned a priority of 0. The openings are assigned a priority of 90. The slab areas created from the surface member modifiers are assigned priorities in the range 10-89, with an increment of at least 2. Modifier priorities are compressed where possible (e.g., where two non-overlapping modifiers may be set to the same priority). A surface member that overflows this range (i.e., it contains modifiers in a configuration that requires more than 45 distinct modifier priorities) should be very rare. In this case, some of the modifiers will have duplicate priorities. You will need to fix this model in the RAM Concept modeler and then update the ISM repository. The priority mapping is applied to each surface member on the story. If the boundaries of surface members overlap, it should only be in the opening of one surface member. The priorities of the slab areas and openings of the overlapping surface member are offset by a multiple of 100 to make the RAM Concept model unambiguous.
Exporting RAM Concept slabs to ISM Exporting overlapping RAM Concept slab areas and openings to ISM objects is more complicated. The ISM repository creation and update operations will be less error-prone and less confusing if the RAM Concept slabs and openings map directly to ISM objects. The RAM Concept slab area and opening geometries and priorities will sometimes be modified before the export operation so that they will map directly to ISM objects. The lowest priority RAM Concept slab area is expanded to contain overlapping slab areas and is then exported as a parent ISM surface member. Overlapping slab areas are exported as surface modifiers of the parent surface member. RAM Concept slabs that do not overlap are exported as separate ISM surface members. Any RAM Concept slab that does not have any effect on the slabs it overlaps is not exported. ISM surface openings effectively have an infinite priority. In order to model ISM surface openings, any RAM Concept slab openings that are obscured by higher-priority slab areas are first trimmed to their effective shape. New slab openings are added to the RAM Concept model if the trimming operation splits an opening into two or more pieces. Openings that are completely obscured by higher-priority slab areas are not added to the ISM model. The slab areas and slab opening priorities are compressed and reassigned as described for importing ISM surface members. You will be notified when the shape or priority of a RAM Concept slab area or opening is changed or when openings are added or removed. You can stop the export operation at any point and the RAM Concept model will not be changed.
Small Features Changing the shape of a slab can sometimes introduce small features that are not detected until the model is meshed. For example, the corner of a drop cap might extend slightly past the edge of the lowest priority slab. When the lowest priority slab is extended to contain the drop cap, it may have a very small (< 50 mm) edge. The
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Data Transfer from ISM Import and Export Details “Line too short” (39.1.2) or “Feature eliminated” (39.1.3) warnings will be generated when meshing the model. Removing these features will generally not hurt anything, but it is best to fix them manually in RAM Concept and update the ISM repository to eliminate future warnings.
Slab Modeling Guidelines Almost any RAM Concept slab model can be converted to an equivalent ISM model. Following these modeling guidelines in RAM Concept will reduce the chance of problems in model consistency. • Drop Caps and Panels, on the interior or exterior, should not be modeled by adding openings to a slab and filling them with other slabs. Instead, increase the priority on the drop panel slabs so that they override the base slab. • Slab area islands can be handled properly if modeled with care. A slab area island is completely contained within, and higher priority than, a slab opening. The slab opening is contained within or on the edge of, and higher priority than, another slab area. If the island slab area does not overlap the outer slab area's effective shape, it will converted into a separate ISM surface member. The preferred ISM model is a surface member with an opening and a modifier. This can be accomplished by splitting the opening so that it surrounds the island slab without covering the larger slab. If the RAM Concept slab is constructed with openings whose priorities are larger than all of the slab areas, then it will map correctly to the ISM surface member.
16.3.4 Support Members ISM wall and column definitions are much more flexible than those in RAM Concept. However, because most building structures have regular features such as vertical columns, this normally won’t be a significant issue. An ISM repository models an entire building. Support members may extend through all stories of the building and be connected to members on each story. ISM walls are surface members; they may be as complex as slabs, with openings, arbitrary shapes and thickness variations. Walls and columns can also be sloped. On the other hand, RAM Concept only models vertical support members, and their height is assumed to extend just to the next slab above or below. RAM Concept walls are rectangular and openings are not supported.
Importing ISM Support Members to RAM Concept RAM Concept imports only ISM support members that are connected to a slab or beam that is on the story imported. RAM Concept creates one or two support members above and below the imported slab. RAM Concept models the support member height from the imported story to the next connected slab or beam above (or below), or to the end of the member if it is not connected to another story above (or below). If the ISM support member ends at the imported story or the next connected story, RAM Concept models the complete support height to that end. If the support member does not terminate on one of these stories, the RAM Concept member height is modeled from the elevation midpoint of all slabs and beams connected to it on that story. RAM Concept will not create support members shorter than 500 mm for cases where the member extends only a short distance past the import story. If the ISM support member is sloped, RAM Concept models the sloped length of the member, not the difference in elevation of ends (i.e. the modeled height will be greater than the elevation difference). For example, consider a column that is connected to a slab on the imported story and stories above and below, and ends on the stories above and below. The column heights will be computed relative to the elevation midpoint of the imported slab. If a drop cap or deep beam is added to the imported slab and connected to the column in the ISM repository, the elevation midpoint imported slab will shift downward. When the RAM Concept
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Data Transfer from ISM Import and Export Details model is updated, the RAM Concept column height above will increase and the column height below will decrease by equal amounts.
Exporting Concept Support Members to ISM When exporting support members to ISM, pairs of matching support members at the same location are merged to create a single ISM support member. Two support members are merged only if all of their properties match (e.g., concrete mix, thickness, etc.), and either they were imported from the same ISM support member, or they are both new in RAM Concept. If a pair of support members at a location cannot be merged, then two ISM support members are exported. The support member exported by RAM Concept extends only to the ends of the heights modeled in RAM Concept, relative to the center of the slab or beam the support member passes through. Dealing with this geometry approximation requires some care when updating RAM Concept or ISM. When updating RAM Concept from ISM, the RAM Concept model may have shortened support members. In general, the ISM geometry can be accepted to capture changes made to the repository, and RAM Concept will just create a new approximation. There are times when you should reject changes to the RAM Concept support member geometry. For example, when the RAM Concept support member geometry has been adjusted to compensate for a problem in the RAM Concept approximation. In those cases, the Reject setting in the Structural Synchronizer update dialog will prevent the RAM Concept geometry from changing. It is usually not desirable to update the ISM repository with the approximate RAM Concept support member geometry. For this reason, updating the ISM repository support member is disabled by default. See 16.3.10 for information on enabling updates to support members. If updating support members is enabled, you can decide which properties should be changed. The support member geometry—defined by the Location or Boundary properties—can be updated for simple one or two story support members. Changes to concrete mixes, dimensions or column orientation can also be updated.
16.3.5 ISM Section Shapes ISM supports a wide array of section shapes, including parametric sections, custom section shapes, composite sections, and linearly varying sections. RAM Concept supports only two section shapes: solid rectangles for beams and solid rectangles or circles for columns. RAM Concept must therefore create a rectangular or circular approximation for any non-rectangular or non-circular ISM section shape. ISM Parametric Sections use a small number of parameters to define the most common section shapes. For column members, RAM Concept maps solid and hollow circular ISM parametric section shapes to solid circles. All other parametric shapes for beams and columns are approximated by rectangles. The following table shows the width and height the RAM Concept rectangular section approximations for each ISM Parametric Section Type: Table 8: Rectangular Section Approximations to ISM Parametric Section Shapes ISM Parametric Section Type
RAM Concept Width
RAM Concept Height
Solid Rectangle
Width
Height
Hollow Rectangle
Width
Height
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ISM Parametric Section Type
RAM Concept Width
RAM Concept Height
Solid Circle
Outer Diameter
Outer Diameter
Hollow Circle
Diameter
Diameter
I
Web Thickness
Depth
T
Web Thickness
Depth
L
Thickness
Depth
C
Web Thickness
Depth
Double L
2×Thickness
Depth
Double T
2×Web Thickness
Depth
ISM also defines Custom, Built Up and Varying section shapes. ISM Custom sections are defined by an arbitrary geometric shape. RAM Concept approximates Custom sections by a square of the same area. ISM Built Up sections are composites of other parametric or custom sections. RAM Concept approximates Built Up sections by a square with the area of the sum of the areas of the section's components. ISM Varying sections vary shape linearly along a member. RAM Concept approximates a Varying section shape by applying the rules for constant sections to the start of the first varying section segment. When updating an ISM repository, RAM Concept section approximations will appear as changes in the Structural Synchronizer update dialog. The Change action on these changes can be set to Always Reject to prevent the ISM sections from being replaced.
16.3.6 ISM Load Cases and Loads ISM Load Case objects and their Load Cause property are analogous to RAM Concept Loadings and their Loading Type property. The following table gives the RAM Concept Loading Type imported for each ISM Dead Load Cause. Table 9: Concept Dead Loading Types Imported Ism Load Cause
RAM Concept Loading Type
DeadConstruction
Stressing Dead
DeadStructure
Other Dead
DeadSuperimposed
Other Dead
DeadUnspecified
Other Dead
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Data Transfer from ISM Import and Export Details The following table gives the RAM Concept Loading Type imported for each ISM Floor Load Cause. Table 10: Concept Floor Loading Types Imported Ism Load Cause
RAM Concept Loading Type
FloorAssembly
Live Unreducible
FloorOffice
Live Reducible
FloorResidential
Live Reducible
FloorRetail
Live Reducible
FloorStorage
Live Storage
FloorUnspecified
Live Reducible
ParkingHeavy
Live Parking
ParkingLight
Live Parking
ParkingUnspecified
Live Parking
The following table gives the RAM Concept Loading Type imported for each ISM Roof Load Cause Table 11: Concept Roof Loading Types Imported Ism Load Cause
RAM Concept Loading Type
RoofAccess
Live Roof
RoofRain
Live Roof
RoofSnowDrift
Snow
RoofSnowUniform
Snow
RoofSnowUnspecified
Snow
RoofUnspecified
Live Roof
The following table gives the RAM Concept Loading Type imported for each ISM Lateral Load Cause.
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Data Transfer from ISM Import and Export Details Table 12: Concept Lateral Loading Types Imported Ism Load Cause
RAM Concept Loading Type
SeismicService
Seismic Service
SeismicUltimate
Seismic Ultimate
SeismicUnspecified
Seismic Ultimate
WindService
Wind Service
WindUltimate
Wind Ultimate
WindUnspecified
Wind Service
The following table gives the RAM Concept Loading Type imported for each ISM Other Load Cause. Table 13: Concept Other Loading Types Imported Ism Load Cause
RAM Concept Loading Type
EarthPressureService
Other
EarthPressureUltimate
Other
EarthPressureUnspecified
Other
FloorConstruction
Other
FluidContained
Other
FluidUncontained
Other
FluidUnspecified
Other
GroundWaterPressure
Other
Hydrodynamic
Other
Hydrostatic
Other
Ice
Other
Other
Other
PostTensioning
Balance
Settlement
Other
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Ism Load Cause
RAM Concept Loading Type
Shrinkage
Other
Thermal
Other
The following table defines the ISM Load Cause exported for each RAM Concept Loading Type. Table 14: ISM Load Cases Exported RAM Concept Loading Type
Ism Load Cause
Balance
PostTensioning
Stressing Dead
DeadConstruction
Other Dead
DeadSuperimposed
Live Reducible
FloorUnspecified
Live Unreducible
FloorAssembly
Live Storage
FloorStorage
Live Parking
ParkingUnspecified
Live Roof
RoofAccess
Snow
RoofSnowUnspecified
Other
Other
Wind Service
WindService
Wind Ultimate
WindUltimate
Seismic Service
SeismicService
Seismic Ultimate
SeismicUltimate
The Balance loading is not exported to ISM by default. It is not always useful to other programs, and it may significantly increase the size of the ISM repository. See the Options section below for information on enabling Balance loading export.
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16.3.7 Member Loading RAM Concept loads are applied to the highest priority slab or beam they intersect. ISM loads are applied to a single ISM member. When exporting loads to ISM, RAM Concept must determine which single ISM member the load should be applied to. RAM Concept may have to split line or area loads that straddle more than one ISM member. A RAM Concept Point Load is applied to an ISM beam if it lies on the beam centerline. Otherwise, it is applied to the surface member whose effective shape contains the point. A RAM Concept Line Load that is completely contained in the beam centerline is applied to that beam. Otherwise, the line load is trimmed to the effective shape of each ISM surface member it intersects. If the line load intersects more than one surface member or has a disjoint intersection with a single surface member, it is split into shorter line loads and applied to the surface members they overlap. RAM Concept area loads are trimmed to the outer boundary of the effective shapes of all ISM surface members that they intersect. If the intersection is disjoint, the RAM Concept area load is split into smaller polygonal area loads and applied to the surface members they overlap. It is possible to create a RAM Concept model in a way that makes it impossible for RAM Concept to maintain the accuracy of both the RAM Concept and ISM models. For example, consider a RAM Concept slab containing an opening and a second slab inside the hole (an island). RAM Concept maintains the user's intentions by creating an ISM surface member for each slab. If there is an area load covering both slabs, RAM Concept must create an additional area load for the island slab. However, the larger RAM Concept area load will still cover the island slab, so the next Update operation would create yet another area load on the island slab. Instead, RAM Concept does not create a new area load for the island slab and will leave the ISM surface member unloaded. The preferred method for modeling this configuration is to split up the larger area load so that it does not overlap the island slab.
16.3.8 Rebar Exporting RAM Concept Rebar to ISM RAM Concept exports three types of rebar to ISM.
User Concentrated Rebar RAM Concept User Concentrated rebar are exported as ISM Concentrated Surface Rebar. When the RAM Concept rebar is entirely contained within a beam and is parallel to the beam centerline, it is exported as ISM Layer Parallel Rebar. Plain, anchor, 90 degree, and 180 degree hook types are exported.
User Distributed Rebar RAM Concept User Distributed Rebar are exported as ISM Area Surface Rebar. Plain, anchor, 90 degree, and 180 degree hook types are exported.
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User Transverse Rebar RAM Concept User Transverse Rebar are exported as ISM Straight Perpendicular, Rectangular Tie, and Open U Tie rebar. ISM does not directly support shear rebar with 3 or more legs. A RAM Concept User Transverse Rebar with 3 or more legs will be exported as a Rectangular or Open U Tie rebar and one or more Straight rebar for the interior legs. The RAM Concept User Transverse Rebar object is intended to be used in areas of uniform slab geometry. ISM Perpendicular rebar are completely uniform with respect to the width, depth, and spacing of the bars. A RAM Concept User Transverse Rebar that crosses nonuniform regions slab geometry will be exported as end-to-end groups of ISM Perpendicular rebar. The actual width, depth, and spacing properties of the RAM Concept shear rebar are only determined after analyzing the RAM Concept model and generating individual shear rebar. Also, no individual shear rebar will be generated for a RAM Concept User Transverse Rebar if it is not required structurally. Therefore, a RAM Concept User Transverse Rebar is not exported at all if individual shear rebar have not been generated for it.
Importing ISM Rebar into Concept RAM Concept imports only rebar that reinforces slabs or beams that are also being imported. RAM Concept does not import non-horizontal ISM rebar. It also does not import any incompletely defined ISM rebar type. Rebar Type
Required Properties
ISM Concentrated Surface rebar
BarDirection BarSpacing BarCount BarLength LayoutDirection LayoutPoint HookLocalAxes
ISM Area Surface rebar
BarDirection BarSpacing LayoutBoundary HookLocalAxes
ISM Layer Parallel rebar
LayoutPath
ISM Perpendicular rebar
LayoutPath
ISM Anchor, Hook90, Hook180 and None (straight) rebar end types are supported. An Unset or Other hook type is imported as straight. Hook135 is imported as a 90 degree hook. LapSplice, OffsetLapSplice, MechanicalSplice and WeldedSplice are imported as anchors.
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Data Transfer from ISM Import and Export Details RAM Concept imports ISM Concentrated Surface Rebar and ISM Area Surface Rebar into RAM Concept as User Concentrated and User Distributed rebar. ISM Layer Parallel Rebar that are in an imported beam are imported as User Concentrated rebar.
Importing ISM Perpindicular Rebar When importing ISM Perpendicular Rebar, RAM Concept first clusters together groups of ISM Perpendicular to define stirrups of 3 or more. Any Straight Perpendicular rebar that starts and ends on the first and last stirrup bar of a Rectangular Tie or Open U Tie rebar is considered an interior leg of the stirrup. The Straight Perpendicular rebars do not have to be spaced uniformly or parallel to the Rectangular Tie or Open U Tie rebar. The groups of ISM Perpendicular rebar are considered User Transverse Rebar candidates, with the Rectangular Tie or Open U layout path. The intersection of each candidate's path with each beam or slab generates a separate RAM Concept User Transverse Rebar. Priority is given to beam intersections where the candidate path intersects both. It may be the case that a single RAM Concept User Transverse Rebar—drawn across nonuniform slab geometry —will be exported as several groups of ISM Perpendicular rebar. When the RAM Concept model is updated from ISM, the original User Transverse Rebar object's geometry will be changed, and new User Transverse Rebar objects will be added for the additional ISM Perpendicular rebar.
16.3.9 ISM Options dialog This dialog is used to set options controlling the ISM operations. Select File > Sync ISM > Options to open this dialog.
Figure 31: ISM Options dialog Recompute nodes for support members
This option is stored in the model and is initially set by the Recompute nodes for support members option in the ISM import dialog. This option is used when updating the RAM Concept model from ISM and when updating the ISM model from RAM Concept if the Update Support Members in ISM Repository option is also enabled. Nodes determine which walls and columns are connected to the import story and their heights. If the nodes in the import model are incomplete, some support members will not be imported. This option recomputes the import model's nodes for internal use only. The new nodes are not added to the model.
Update Support Members in ISM Repository
Walls and columns in the ISM repository are updated only when this option is enabled. This option is stored in the file; by default, support members are not updated. Support members
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Data Transfer from ISM Import and Export Details are always imported from the ISM repository to create or update the RAM Concept model and are always exported when creating an ISM repository. Export Balance Loading
the Balance loading is exported to ISM only when this option is enabled. This option is stored in the file. It is off by default, so the Balance loading is not exported
Related Links • Create RAM Concept File (on page 135)
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Data Transfer from API RAM Concept includes a Python scripting API that allows you to automate routine RAM Concept tasks such as creating models, running analyses, and accessing the results. More information on the scripting API can be found in the Scripting API Documentation (Help > Scripting API), including: • • • •
Instructions for installing the API Getting started guides Detailed documentation Sample scripts
The scripting API permits RAM Concept to be run “headless” (from command lines without the graphical interface). RAM Concept and/or RAM Concept Post Tension licenses are consumed when running the program in this mode. Normal license rules and restrictions still apply.
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Bentley iTwin Services Features RAM Concept can integrate with Bentley's iTwin Services, including the iTwins Design Review feature. More information on iTwin Services can be found in the iTwin Analytical Services wiki (iTwin Services > iTwin Analytical Services Wiki
This feature is included as a Technical Preview. Please use this feature now in your Technical Preview: normal business environment, evaluate its capabilities, and send us your feedback. As a Technology Preview, this feature is provided to you “as-is” without the benefit of any Bentley warranty, indemnity, or support obligation.
18.1 What is iTwin Design Review? Bentley iTwin Design Review is a collaborative service hosted on the web that allows two or more interested parties to communicate with one another in the context of a 3D model or, more accurately, an iTwin. The iTwin Services Add-in within the desktop application publishes the analysis model to an iTwinDesign Review session, and therefore into an intuitive point of collaboration that facilitates review of design work in progress The web-based interface (accessible with a web browser) of Design Review offers a set of commands for navigating, viewing from different perspectives, isolating key elements, and clipping views. Several review tools are included with the service: • Measurements, including distance, area, location, radius, and angle • Querying elements for physical information, such as dimensions, construction materials, and coordinates • Querying analytical information, such as member fixities, applied loads, and reactions
18.2 Applications of iTwins Design Review Many aspects of iTwin Design Review are particularly relevant to engineering analysis workflows. Project managers or other stakeholders in a project may not be skilled in, or have access to, the analytical software used by engineers to analyze and design a structure. These individuals may instead have a practice of reviewing a set of 2D drawings or a BIM model that is disconnected from the engineering analysis models. In this case, the reviewer may not have a complete understanding of the assumptions used by the designers. iTwin Design
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Bentley iTwin Services Features Starting an iTwin Design Review Session Review can therefore help project managers catch incorrect assumptions or errors during the design phase before it becomes a construction problem. Some of the practical applications of this technology to the traditional engineering review and collaboration process include: • Have a conversation with participants via chat in the context of a 3D model, annotating and marking up objects, and leaving questions, comments, and markups for specific stakeholders. • Include stakeholders, such as project managers and other engineering disciplines, that are not users of Engineering Simulation software, in this review process. All that is needed is a web browser and anyone invited can contribute to the review. • Resolve issues raised by team members directly in the desktop application. • Save a record of conversations (chats) in the review so that reasons for key decisions can be revisited at a later point if needed. • Create specific views of the structure, with objects of interest isolated and zoomed to, that collaborators and reviewers can see immediately without needing to recreate the view themselves.
18.3 Starting an iTwin Design Review Session To start a new iTwin Design Review session: Note: You must have a Bentley CONNECT account in order to use iTwin Design Review. 1. Either: Select iTwin Services > iTwin Services or
2. 3. 4. 5.
6.
Select the iTwin Services tool ( ) A web browser window opens the iTwin Services panel. In the iTwin Services panel, click Get Started. The iTwin Design Review information for the current model loads. Click Create Session. Your default web browser opens and prompts you to allow for the sharing of data. Click Allow. In the iTwin Services panel, enter data used to describe the design review session: a. Type a unique Session Name. b. (Optional) Type one or more Session Tags that may be helpful metadata for the model. Type the tag string and press to add a tag. c. In the Session Participants field, begin typing a participant's name. Account names will appear that match the partial name string. d. Select a participant's name from this list to add them. e. Repeat steps 5c and 5d to add more participants as needed. Click Next. Your design review session is created and opened in your web browser.
You may visit https://review.itwin.bentley.com/home to see all your current design review sessions.
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Bentley CONNECT Features 19.1 CONNECTED Project Association RAM Concept CONNECT Edition allows you associate a file with a CONNECTED Project. A CONNECTED project is a single definition of a project for your entire organization and represents a one-to-one relationship with the contracted work being done by your organization. Note: In order to utilize this feature in RAM Concept, you must: 1. Have the Bentley CONNECTION client running. The CONNECTION client is typically installed with RAM Concept. 2. Register with Bentley Cloud Services. 3. Sign in using your credentials with the CONNECTION client. For additional details on the benefits of using CONNECTED Projects, please visit http://www.bentley.com/ connect/.
19.1.1 To Associate a CONNECTED Project with Your File When you create a new file or open an existing file which is not associated with a project, use the following procedure to associate your file with a CONNECTED project. Note: You must be signed in using the CONNECTION client to associate a CONNECTED project with your file. Tip: If you want to change the CONNECTED project associated with your file, use the same following procedure. 1. Select Bentley Cloud Services > Associate Project. The Assign Project dialog opens.
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2. (Optional) If you want to register a new project, do the following: a. Click Register Project. The Register a Project page opens in your browser. Note: Only users with Admin/Co-admin roles can register a project. b. Type or select the required items (marked with an asterisk, “*”) c. Click Save. A list of registered projects within your organization opens. The newly created project is highlighted in green. Tip: Alternately, you can visit connect.bentley.com and select +New on the Recent Projects tile on your personal dashboard. 3. Select the desired project from the list. Tip: Use the View controls and Search tool to locate your project. 4. Click Associate. Related Links • Assign Project dialog (on page 156) • Starting an Optimization (on page 339)
19.1.2 To Disassociate a CONNECTED Project from a File When you need to disassociate a file from a CONNECTED project, use the following procedure.
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Bentley CONNECT Features CONNECTED Project Association Tip: If you want to change the CONNECTED project association to another CONNECTED project, this procedure is not necessary. 1. Select Bentley Cloud Services > Disassociate CONNECT Project The project association is removed from the file. Related Links • Assign Project dialog (on page 156)
19.1.3 Assign Project dialog Used to select a project to associate with your current file or model. Register Project
Opens the Register a Project page in your browser from where you can register a project.
Refresh
Refreshes the list of available ProjectWise Projects.
View
Allows you to choose the list of projects that you want to see in the list box. Following are the options:
Note: Only users with Admin/Co-admin roles can register a project.
• Favorites - Displays the projects that are marked as favorites. • Recent - Displays the recently used projects. • All - Displays all the projects. Search
Searches through the list of available projects.
List box
Displays the following columns: • Favorite - Allows you to favorite a project. Select the star icon in this column for the project that you want to mark as favorite. • Number - Displays the number of the project. • Name - Displays the name of the project. • Location - Displays the geographic location of the project. • Industry - Displays the industry of the project. • Asset Type - Displays the asset type of the project.
Related Links • To Disassociate a CONNECTED Project from a File (on page 155) • To Associate a CONNECTED Project with Your File (on page 154) • To Register a CONNECTED Project (on page 157)
19.1.4 Register a CONNECTED Project Organizations can enable CONNECTED Users to register and collaborate on CONNECTED Projects. These projects contain project information such as Project Name, Asset Industry, Asset Type, Location etc. While creating a file
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Bentley CONNECT Features CONNECTED Project Association in a CONNECT Edition product, you can associate it to a CONNECTED Project where the project information is included in the data files as properties. Note: Project files, such as DGN files and library files are not stored on the cloud. They can be stored locally, on a network, or in ProjectWise.
What is the CONNECTED Project Registration Utility? The Project Registration utility is an administrative interface for registering an Organization’s projects with Bentley. Registered projects are referred to as CONNECTED Projects. CONNECTED Projects provide information regarding the project themselves, as well as serving as a focal point for tying together other sources of project information. For example, user and product usage for reporting and access to services available for each project.
Who can register a CONNECTED Project? To register a CONNECTED Project a user must have Administrator or Co-administrator privileges associated with their Bentley account. These privileges are required because registered CONNECTED Projects are Organization-wide resources that represent real-world projects and are used in many different locations for information organization and reporting. Therefore, access is limited to those members of an Organization with sufficient privileges to ensure that only recognized and permitted CONNECTED Projects be registered on behalf of an Organization. Note: Users within the organization who were not designated as an Administrator or Co-Administrator who are requesting rights should contact their organizations Administrator. Bentley does not fulfill these requests.
To Register a CONNECTED Project The Project Registration utility is used to provide information about a project as well as manage previously registered projects. Note: Only users with Admin/Co-admin roles can register a project. From the Assign Project dialog: 1. Click Register Project. The Register a Project page opens in your browser. 2. Type or select the required items (marked with an asterisk, “*”): Number
Project ID officially used in Organization for tracking project internally (e.g., EAP id, like DMO-063 VP 778).
Name
Common name for project within an Organization (e.g. I-565 Interchange at County Line Road).
Asset industry An Industry is a group of like organizations with a common business function centered on a like set of infrastructure assets. Example, Electric Utility. Asset type
An Asset Type is a set of related Assets. Example, the Asset Class Electric Network is comprised of the following Assets: Distribution Network, Substation, and Transmission Network.
Location
Geographic location of the Project (Example, city/state/country, Latitude/longitude)
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Bentley CONNECT Features Bentley CONNECT Advisor Status
Project state, either Active meaning the project is open for participation or inactive, closed for participation.
3. Click Save. A list of registered projects within your organization opens. The newly created project is highlighted in green. Related Links • Assign Project dialog (on page 156) • Starting an Optimization (on page 339)
19.2 Bentley CONNECT Advisor The Bentley CONNECT Advisor is a unified interface that enables you to view a variety of Bentley content at one location, thereby eliminating the need to browse through various sources separately. As an end user, you get the ability to browse, search, view, and interact without having to leave the product (RAM Concept) that you are working on. The Bentley CONNECT Advisor scans through different sources such as Bentley Communities, Bentley LEARNserver, and Bentley YouTube channels to display relevant information with links to the web pages. For example, if you want to search for information on the Place SmartLine tool, you can enter the tool name in Bentley CONNECT Advisor dialog's Search field. You will get a list of relevant results from different locations such as forum posts, blogs and wiki posts on Bentley Communities, Bentley LEARNserver courses that discuss about the tool, and so on. You can also look out for other information such as news and announcements, upcoming events, and QuickStarts. The Bentley CONNECT Advisor performs the following functions: • Gathers information from the following sources: • Forum posts, wikis and blogs from Bentley Communities • Videos, Hands-on and Assessments from Bentley LEARNserver • Videos from Bentley YouTube channels • Bentley News and Announcements • Upcoming Bentley Events • Provides a unified interface that displays the above items gathered from their respective sites and locations • Searches information within all the available sources (Bentley Communities, Bentley LEARNserver, Bentley YouTube channels, Bentley News and Announcements, Bentley Events) • Filters information based on: • • • • • •
Product Generation Release Label Language Content type Tags, region, and so on
Note: To be able to access the Bentley CONNECT Advisor, you need to sign into the Bentley Cloud Services using the CONNECTION Client.
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Bentley CONNECT Features Automated Updates via the CONNECTION Client
19.3 Automated Updates via the CONNECTION Client You will be notified of updates to RAM Concept automatically in the Bentley CONNECTION Client application. This application is installed with RAM Concept CONNECT Edition and runs in the Windows system tray. You can manually check for updates by opening the CONNECTION Client and selecting the Applications tab.
19.4 Subscription Entitlement Service Subscription Entitlement Service is Bentley's process for product activation and usage tracking, improving our licensing capabilities with features such as: • License alert notifications when you are approaching a custom usage threshold • Replacing site activation keys with user validation, enhancing security around your Bentley licenses and subscriptions With traditional SELECT Licensing, product activation has been through an activation key that an Organization distributed to all users. With Subscription Entitlement Service, product activation is managed by user sign in through the CONNECTION Client, which is installed on each machine that uses Bentley applications. This offers a more secure and manageable system as it offers usage alerts, notifying your users when they are about to reach a certain usage limit set by the Administrator. Select Help > Licensing > Licensing Service for more information on using and managing Subscription Entitlement Service.
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Defining the Structure The easiest and recommended way to define the concrete structure is to use RAM Concept’s automatic meshing facility (otherwise known as the “Mesher”). This approach requires that you define supports, slabs (of varying thickness), beams and openings with objects that Mesher uses to generate the finite element model. You do this on the Mesh Input Layer’s Standard Plan.
20.1 Using the Mesh Input Layer There is no set order in which you must define objects. Some people choose to draw supports first, whereas others draw the slab outline first. You can edit whatever drawn objects later. If you have imported a CAD drawing, make it visible on the Mesh Input Plan before drawing the structure.
20.2 About columns and walls RAM Concept allows for single story models whereby you define columns and walls below and above the slab. Supports above the slab do not provide vertical support, only horizontal support and bending resistance.
20.3 Column properties RAM Concept column properties are separated into three categories: general, meshing, and live load reduction.
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Defining the Structure Column properties
20.3.1 General column properties
Figure 32: Column properties: general Concrete Mix Type of concrete used (defined in Materials Specification). Height Vertical distance from centroid of slab element to far end of column. Support Set Defines the column as below or above the floor. Width Measured along the column’s r-axis. Set to zero for round columns. Depth / Diameter Measured along the column’s s-axis. Angle Plan angle measured counterclockwise from the global x-axis. It determines the column’s r-axis (and is usually zero). Bending Stiffness Factor Used to modify the bending stiffness without changing the dimensions or height. For example, you may expect an edge column to crack and rotate more than an internal column and so you might consider setting this value to 0.5. You could use the BSF to increase a column’s stiffness, but this is an unlikely scenario. Roller at Far End Results in zero horizontal shear in column. Fixed Near Provides a moment connection (about x- and y-axes) between column and slab; otherwise pinned. Fixed Far Provides a moment connection (about x- and y-axes) at far end; otherwise pinned. Compressible Allows for column to elongate in the z-direction according to Hooke’s law; otherwise incompressible. Compressible columns usually produce results that are more accurate.
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Defining the Structure Drawing columns
20.3.2 Meshing column properties
Mesh Slab Support Region
When checked meshed elements are generated within and bounded by the column shape.
Slab Support Region Stiffness Factor
The entered multiplier is used to factor the flexural stiffness terms (KMr, KMs, and KMrs) for the meshed slab elements that are generated in the support region. The default value is 10, which will result in a nearly rigid zone over the column. Consideration of such a stiffened zone may be important for accurate deflection prediction.
20.3.3 Live load reduction column properties See “Specifying Live Load Reduction Parameters”. Related Links • Specifying Live Load Reduction Parameters (on page 348)
20.4 Drawing columns Each column is located with an x- and y-coordinate. Two columns cannot have the same coordinates unless one is above and one is below.
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Defining the Structure Wall properties Note: Ensure you are working on the Mesh Input layer, not the Element layer. Note: See “Setting default properties” for relevant information. Related Links • Setting default properties (on page 76)
20.4.1 To draw a column 1.
Choose the Column tool ( 2. Click at the column center.
).
20.4.2 To copy columns from below to above 1. Select the columns and choose Edit > Copy. 2. Choose Edit > Paste. This pastes the new column objects in the same location as the original column objects. The pasted columns are the active selection. 3. Change the Support Set property from “below” to “above” in the Column Properties dialog box. Note: If you do not change the Support Set designation then there are duplicated columns that do not allow the model to run properly. If you have copied a large number, it is tedious to delete the second column at each location (one by one).
20.5 Wall properties Wall properties are similar to column properties though instead of width, depth and angle there is thickness. The fixity settings are somewhat different, and there is no Bending Stiffness Factor.
20.5.1 General The following is a list of RAM Concept general wall properties: Concrete Mix Type of concrete used (defined in Materials Specification). Height
Vertical distance from centroid of slab element to far end of wall.
Support Set
Defines the wall as below or above the floor.
Thickness Shear wall
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“Locks” the wall to the slab horizontally and thus restrains it; otherwise, the slab can “slide” over the wall.
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Provides a moment connection between wall and slab about the wall’s r-axis; otherwise pinned.
Fixed Far
Provides a moment connection about the wall’s r-axis at far end; otherwise pinned.
Compressible Allows for the wall to elongate in the z-direction according to Hooke’s law; otherwise incompressible. Compressible walls usually produce results that are more accurate.
20.5.2 Meshing The following is a list of RAM Concept meshing wall properties: Mesh Slab Support Region
When checked meshed elements are generated within and bounded by the wall shape.
Slab Support Region Stiffness Factor
The entered multiplier is used to factor the flexural stiffness terms (KMr, KMs, and KMrs) for the meshed slab elements that are generated in the support region. The default value is 10, which will result in a nearly rigid zone over the wall. Consideration of such a stiffened zone may be important for accurate deflection prediction.
20.6 Drawing walls The wall tool is very similar to the column tool except that it uses a line rather than a point. A wall can pass through a column, or intersect another wall. Note: Ensure you are working on the Mesh Input layer, not the Element layer. Note: The Wall tool ( ), Right Wall tool ( toolbar. See “Expanding tool buttons”.
) & Left Wall tool (
) share the same button on the Layer Specific
20.6.1 To draw a wall 1.
Choose the Wall tool ( ). 2. Click at the wall end center points.
20.6.2 To copy walls from below to above 1. Select the walls and choose Edit > Copy. 2. Choose Edit > Paste. This pastes the new wall objects in the same location as the original wall objects. The pasted walls are the active selection. 3. Change the Support Set property from “below” to “above” in the Wall Properties dialog box.
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Defining the Structure About point and line supports
20.7 About point and line supports The result of defining a point support is a single support at a finite element node. The result of defining a line support is one or more line supports that are each located at a finite element edges. RAM Concept uses the thickness of the lowest numbered element in determining the support elevation. For this reason, it is not advisable to locate point supports or line supports at slab steps. All supports that have a horizontal rigidity should be placed at the mid-depth of the slab or they may cause an unintended arch action in addition to their horizontal rigidity (mid-depth placement is done by setting the “Elevation above slab soffit” to be one-half of the slab depth). Normally there is no need to use horizontal fixities in point and line supports, as RAM Concept automatically stabilizes the structure in the x- and y-directions (you can turn this automatic stabilization off in the General tab of the Calc Options dialog box). One situation where you might use a horizontal support is a structure braced against sidesway but modeled without bracing members (perhaps something other than a concrete wall provides the bracing). Be very careful about specifying anything but “Fixed in z-direction” for point supports and “Translation in zdirection fixed” for line supports. For point supports, fixing the point support in the r- or s-direction could result in arch / membrane action. For line supports, fixing the slab translation along or across the support could result in arch / membrane action.
20.8 Point support properties The following is a list of RAM Concept point support properties: Elevation above slab soffit Vertical distance between the point support and the soffit. Angle (r=x, s=y@0) Allows you to set the local axes. Fixed in r-direction Prevents movement along the local r-axis. Fixed in s-direction Prevents movement along the local s-axis. Fixed in z-direction Prevents movement along the global z-axis. Rotation about r-axis fixed Prevents rotation about the local r-axis. Rotation about s-axis fixed Prevents rotation about the local s-axis.
20.9 Drawing point supports Each point support is located with an x- and y-coordinate. Two point supports cannot have the same coordinates.
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Defining the Structure Line support properties
Note: The Point Support tool ( ) and Line Support tool ( toolbar. See “Expanding tool buttons”.
) share the same button on the Layer Specific
To draw a point support 1.
Choose the Point Support tool ( ). 2. Click at the point support location. Related Links • Expanding tool buttons (on page 53)
20.10 Line support properties The following is a list of RAM Concept line support properties: Elevation above slab soffit Vertical distance between the line support and the soffit. Translation along support fixed (OFF for line of symmetry) Prevents the slab from moving along the support axis. Translation across support fixed (ON for line of symmetry) Prevents the slab from moving across the support axis. Translation in z-direction fixed (OFF for line of symmetry) Prevents the slab from deflecting up or down at the support axis. Rotation about support axis fixed (ON for line of symmetry) Prevents rotation of the slab about the support’s longitudinal axis. Rotation about perp.-to-support fixed (OFF for line of sym) Prevents rotation of the slab about the support’s transverse axis.
20.11 Drawing line supports You can use line supports as an axis of symmetry. This is very useful if a floor is symmetrical and you wish to model only half of it. Be aware that line supports could prevent post-tensioning forces being applied to the floor. Note: The Point Support tool ( ) and Line Support tool ( toolbar. See “Expanding tool buttons”. 1.
Choose the Line Support tool ( 2. Click at the support end points.
) share the same button on the Layer Specific
).
Related Links • Expanding tool buttons (on page 53)
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Defining the Structure About springs
20.12 About springs The result of defining a point spring is a single spring at a finite element node. The result of defining a line spring is one or more line springs that are each located at a finite element edge. RAM Concept uses the thickness of the lowest numbered element in determining the spring elevation. For this reason, it is not advisable to locate springs at slab steps. All springs that have a horizontal stiffness should be placed at the mid-depth of the slab or they may cause an unintended arch action in addition to their horizontal stiffness (mid-depth placement is done by setting the “Elevation above slab soffit” to be one-half of the slab depth). For slabs with varying centroid elevations, it can be difficult to avoid adding a rotational restraint to the slab when using lateral springs and supports. Normally there is no need to use horizontal springs, as RAM Concept automatically stabilizes the structure in the x- and y-directions (you can turn this automatic stabilization off in the General tab of the Calc Options dialog box). One situation where you might use a horizontal spring is a structure braced against sidesway but modeled without bracing members (perhaps soil friction provides the bracing). Be very careful about specifying anything but a z-force constant. R- and s-force constants could result in membrane action.
20.13 Point spring properties The following is a list of RAM Concept point spring properties: Elevation above slab soffit Vertical distance between the point spring and the soffit. Spring Angle (r=x, s=y@0) Orientation of the local axes. The plan shows spring orientation. R-Force Constant Spring constant in the direction of the local r-axis. S-Force Constant Spring constant in the direction of the local s-axis. Z-Force Constant Spring constant in the direction of the global z-axis. R-Axis Moment Constant Angular spring constant about the local r-axis. S-Axis Moment Constant Angular spring constant about the local s-axis.
20.14 Drawing point springs Each point spring is located with an x- and y-coordinate. Two point springs cannot have the same coordinates. Note: The Point Spring tool ( ), Line Spring tool ( ), and Area Spring tool ( the Layer Specific toolbar. See “Expanding tool buttons”.
) share the same button on
To draw a point spring
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Defining the Structure Line spring properties 1.
Choose the Point Spring tool ( 2. Click at the spring location.
).
Related Links • Expanding tool buttons (on page 53)
20.15 Line spring properties The following is a list of RAM Concept line spring properties: Elevation above slab soffit Vertical distance between the line spring and the soffit. Spring Angle (R=X, S=Y@0) Orientation of the local axes. The plan shows spring orientation. R-Force Constant Spring constant in the direction of the local r-axis at each end. S-Force Constant Spring constant in the direction of the local s-axis at each end. Z-Force Constant Spring constant in the direction of the global z-axis at each end. R-Moment Constant Angular spring constant about the local r-axis at each end. S-Moment Constant Angular spring constant about the local s-axis at each end. Note: If the force constant (or moment constant) is uniform you need to enter only one value. Otherwise you need to enter two values separated by a comma (ends 1 and 2). This allows linear variation of the force constant (or moment constant).
20.16 Drawing line springs The line spring tool is very similar to the point spring tool except that it uses a line rather than a point. Note: The Point Spring tool ( ), Line Spring tool ( ), and Area Spring tool ( the Layer Specific toolbar. See “Expanding tool buttons”.
) share the same button on
To draw a line spring 1.
Choose the Line Spring tool ( ). 2. Click at the line spring end points. Related Links • Expanding tool buttons (on page 53)
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Defining the Structure Drawing area springs
20.17 Area spring properties The following is a list of RAM Concept area spring properties: Elevation above slab soffit Vertical distance between the area spring and the soffit. Spring Angle (R=X, S=Y@0) Orientation of the local axes. The plan shows spring orientation. R-Force Constant Spring constant in the direction of the r-axis. S-Force Constant Spring constant in the direction of the s-axis. Z-Force Constant Spring constant in the direction of the global z-axis. R-Moment Constant Angular spring constant about the local r-axis. S-Moment Constant Angular spring constant about the local s-axis. Note: If the force constant (or moment constant) is uniform you need to enter only one value. Note: The force constant (or moment constant) can linearly vary in any direction. Note: If the force constant (or moment constant) varies you need to enter three values, separated by commas (corners 1, 2 and 3). This allows linear variation of the force constant (or moment constant) in two directions. See the following figure. Note: If you use the Area Spring tool to specify a varying force constant (or moment constant), Concept calculates the unique value of the fourth corner (three points define a plane).
Figure 33: Area spring properties varying from 100 to 200 to 300 units at the first three corners. For quad areas, Concept calculates the fourth corner value.
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Defining the Structure About floor areas and members
20.18 Drawing area springs You use the Area Spring tool (
) to locate the spring area corners.
Note: The Point Spring tool ( ), Line Spring tool ( ), and Area Spring tool ( the Layer Specific toolbar. See “Expanding tool buttons”.
) share the same button on
To draw an area spring 1.
Choose the Area Spring tool ( ). 2. Click at the vertices of the area spring (or enter the coordinates in the command line). 3. Close the polygon by typing “c” in the command line or clicking at the first vertex. Note: An Area Spring object can be larger than the structure it supports. Related Links • Expanding tool buttons (on page 53)
20.19 About floor areas and members Objects representing slabs, beams and openings define floor areas and members. Often these objects overlap.
20.19.1 The priority method At any floor location, only one thickness (depth) is used, and the object with the highest priority defines that thickness. The thicknesses of overlapping objects do not add to define the thickness. For example, you would expect the overall thickness of a drop panel located at a column to take priority over the slab thickness. By assigning a Priority to each object, the automatic mesh generator understands how to generate the finite elements. The lowest Priority is 1. This is so that you can keep adding beams, thickenings and slab areas with higher priorities. There is no limit to the highest priority (other than your computer and text overflow). Note: Overlapping objects for slabs, beams and openings must have different priorities. Priority numbers need not be sequential.
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Defining the Structure About floor areas and members
20.19.2 Meshing beams as slabs Beam objects by default do not need to have priorities specified. However, beams have an option to be meshed “Mesh as Slab” using the priority method. Any beams using the priority method will be meshed first along with slab and opening areas. The remaining beams are meshed last and are merged with the elements that result from the mesh resulting from the priority method. Any “gaps” between the beams and other meshed surfaces are filled during the process, although this will result in a warning. Note: Supports do not have priorities.
Figure 34: Slab, beam and opening objects defined in the Mesh Input Standard Plan
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Defining the Structure Slab area properties
Figure 35: The Element Slab Summary Plan after mesh generation from the previous figure.
20.20 Slab area properties Slab area properties fall into two categories: general and behavior. The following is an explanation of RAM Concept slab area properties:
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Defining the Structure Slab area properties
Figure 36: Slab area properties - general Concrete Mix Type of concrete used (defined in Materials Specification). Thickness You define slab thickenings, such as drop caps and drop panels, by specifying an increased thickness. Surface Elevation It is customary to set the typical elevation as 0. Setting the elevation to a very large value (such as 100 feet or 30 m) may result in round off errors in the analysis. You create surface and soffit steps by using different surface elevations for different areas. Priority Generally, the typical slab thickness has a Priority of 1.
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Defining the Structure Drawing slab areas
Figure 37: Slab area properties - behavior R-Axis defines an orientation for the slab. If the slab is a two way slab with identical properties in all directions (“isotropic”), then the R-Axis is irrelevant, because there is no inherent orientation of the slab. However, if the slab is not isotropic, then this axis (defined as the counter-clockwise angle from 3 o'clock) defines the r-axis which is used along with the other slab area properties to define the behavior of the slab. The s-axis is always 90 degrees counter-clockwise from the r-axis. Behavior This defines the slab area’s behavior type. It has four possible designations: • Two-way slab The slab is isotropic and behaves in the same manner in all directions. • One-way slab The slab has normal bending stiffness along the r-axis and about the s-axis (Ms). The slab has only minimal bending stiffness in the perpendicular direction (Mr). The slab also has reduced torsional stiffness (Mrs). The in-plane stiffnesses are not affected by this setting. • No-torsion 2-way slab The slab behaves like a two-way slab, except that it has only minimal torsional stiffness (Mrs). • Custom All of the stiffnesses (relative to the isotropic slab stiffness) can be specified by the user. These values are called KMr, KMs, KMrs, KFr, KFs and KVrs. In general, we do not recommend using this option. Refer to “Orthotropic behavior” for further information on the use of Behavior properties.
20.21 Drawing slab areas Use the Slab Area tool ( ) to define the slab area by clicking on each consecutive point (vertex). To close the polygon, click on the first polygon point or type “c” and press . To draw a slab area 1.
Choose the Slab Area tool (
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Defining the Structure About beams 2. Click at each slab area vertex consecutively. 3. Snap to the first vertex and click to close the polygon (or type “c” and press ). Note: You can approximate curves by a series of straight edges.
20.22 About beams In RAM Concept, you model beams as thickened slabs with the beam tool. You can assign properties that differentiate beam behavior from slab behavior.
20.23 Beam properties Beam properties fall into two categories: general and behavior. The following is an explanation of RAM Concept beam properties:
Figure 38: Beam properties - general Concrete Mix Type of concrete used (defined in Materials Specification). Thickness is the same as beam depth. Surface Elevation It is customary to set the typical elevation as 0. Setting the elevation to a very large value (such as 100 feet or 30 m) may result in round off errors in the analysis. You create surface and soffit steps by using different surface elevations for different areas. Width The beam width automatically appears to scale. Priority Generally, beams have higher priorities than slabs.
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Defining the Structure Drawing beams Mesh As Slab If checked, this beam will be meshed identically to slabs using the priority method.
Figure 39: Beam properties - behavior The beam behavior properties are very similar to the slab area properties. The beam R-Axis is automatically set to the beam longitudinal axis. Behavior This defines the beam’s behavior type. It has four possible values: • Standard The beam is isotropic and behaves in the same manner in all directions. • No-torsion The beam behaves like a two-way slab, except that it has only minimal torsional stiffness (Mrs). • Custom All of the stiffnesses (relative to the isotropic slab stiffness) can be specified by the user. These values are called KMr, KMs, KMrs, KFr, KFs and KVrs. In general, we do not recommend using this option.
20.24 Drawing beams You draw a beam by clicking the start and end points of its centerline using the Beam tool ( ). Each beam has six control points. The four additional points are automatically located so that the beam-ends are perpendicular to the sides. You can stretch the corner grip points to define mitered corners. Note: The Beam tool ( ), Right Beam tool ( Specific toolbar. See “Expanding tool buttons”.
) & Left Beam tool (
) share the same button on the Layer
20.24.1 To draw a beam 1.
). Choose the Beam tool ( 2. Click at the each end of the beam centerline.
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Defining the Structure Slab opening properties
20.24.2 To define mitered corners on a beam 1. Select the beam and choose the Stretch tool ( ). 2. Snap to the beam corner grips and stretch them into position.
20.25 Slab opening properties There is only one slab opening property: Priority Generally, openings have the highest priorities in the floor.
20.26 Drawing slab openings The Slab Opening tool (
) defines an opening in the slab.
To draw a slab opening 1.
Choose the Slab Opening tool ( ). 2. Click at each slab-opening vertex consecutively. 3. Snap to the first vertex and click to close the polygon (or type “c” and press ). Note: You approximate curves with a series of straight edges.
20.27 Checking the structure definition After you have fully defined the structure’s geometry, you should check for obvious errors. RAM Concept flags illegal modeling when generating the mesh. A list of possible errors appears in Chapter 18, “Generating the Mesh”. Once you have drawn all the support and floor objects on the Mesh Input Plan, you must generate the actual finite element mesh. The structure does not exist until you generate the mesh.
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Generating the Mesh There are two ways to generate the finite element mesh in RAM Concept: • Using the automatic meshing facility that uses the mesh input objects described in Defining the Structure (on page 160). • Using the manual meshing tools. The first method is certainly easier and faster. It is the recommended method for nearly all models. The second method allows more control over mesh intensity. The mesh size can be more widely varied in different areas of the floor, but editing is more difficult. Instructions for the second (manual) method are in Manually Drawing the Finite Elements (on page 185).
21.1 Generating the mesh automatically Finite elements do not exist (and hence there is no structure) until the mesh has been generated. You need to have defined the mesh input objects (using the procedure described in the preceding chapter) before generating the mesh. It is preferable to generate the mesh as soon as possible, although it is possible to draw additional objects on other layers (such as loads) before generation.
21.1.1 Deciding what mesh element size to use When generating the mesh you need to decide what element size to use. The maximum is 32.8 feet (10 meters). To speed the analysis, it is useful to choose a coarse mesh for preliminary design and a fine mesh for final design. A coarse mesh might have an element size of span length / 6. A fine mesh might have an element size of span length / 12. If in doubt, you should investigate the effects of different mesh element sizes. 1.
Click Generate Mesh ( ). The following dialog box will appear.
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Generating the Mesh Generating the mesh automatically
Figure 40: Generate mesh dialog box 2. Specify the Element Size in the Generate Mesh dialog box. 3. Click Generate. The time taken to generate the mesh depends upon the size of the floor and the specified mesh element size. For most models, the mesh generates in less than 15 seconds. Note: Every time you generate a mesh, RAM Concept deletes any existing mesh and generates a new one.
21.1.2 Limitations of the automatic meshing The main automatic meshing limitation is that the minimum element size is 50 mm (0.164 feet). RAM Concept can usually overcome this limitation by adjusting the mesh input objects to generate a mesh. RAM Concept moves mesh input line objects (for example, walls, line supports) to accommodate point objects (for example, columns, point supports). RAM Concept automatically adjusts the mesh input objects if: • Two control points are closer than the minimum element size. • A control point is closer to a line than the minimum element size. Note: RAM Concept generates warnings during the meshing if it was necessary to make adjustments. You can stop the meshing and make corrections. If you continue, you should check the mesh to see if the adjustments are satisfactory. Note: RAM Concept generates a warning if two slab areas (or beams or openings) with the same priority overlap. You can stop the meshing and make corrections. If you continue you should check the mesh to see if the adjustments are satisfactory as the choice of which slab area (or beam) governs the elements is effectively random. Note: RAM Concept moves two columns to the same point that you draw closer than the minimum element size. A mesh generates but the model does not run properly if: • A column or point support is outside of the slab areas. • A wall or line support is partially outside the slab areas. • An area spring is completely outside the slab areas.
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Generating the Mesh Generating the mesh automatically • Two columns or walls of the same support set are duplicated (intersecting walls are allowed).
To avoid mesh warnings Do any one of the following: 1. Adjust objects on the Mesh Input plan so that the minimum element size dimension (or more) separates them. 2. Edit priorities so that slab areas, beams and openings with the same priorities do not overlap.
21.1.3 Viewing the finite element mesh You can view the finite element mesh on any plan, but the Standard Plan of the Element layer is the preferred plan to use. 1. Open Layers > Element > Standard Plan 2. The mesh generated at this stage appears to be somewhat random. This is normal and in fact, for sensible mesh sizes it produces highly satisfactory design results. At times, however, such a mesh (adversely) affects the contour plots.
21.1.4 Improving the mesh You can significantly improve the mesh once design strips are drawn. The following diagrams show the differences.
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Generating the Mesh Generating the mesh automatically
Figure 41: Mesh before Design Strips
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Generating the Mesh Selectively refining the mesh
Figure 42: Mesh after drawing Design Strips and Regenerating.
21.2 Selectively refining the mesh Although there is no setting that makes the mesh finer in some areas than others, you can employ a trick to achieve this.
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Generating the Mesh Selectively refining the mesh
21.2.1 Using point and line supports to refine the mesh You can draw “dummy” point or line supports to ensure that the mesh is finer in particular areas. You must ensure that all fixity boxes are unchecked, as shown in the two following figures. A refined mesh example is shown in the last figure.
Figure 43: Point support dialog with all fixity boxes unchecked
Figure 44: Line support dialog with all fixity boxes unchecked
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Generating the Mesh Selectively refining the mesh
Figure 45: Two slabs, identical in every way except for the implementation of line supports to refine the mesh.
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Manually Drawing the Finite Elements Note: In most cases, you do not need to draw the finite element mesh manually. If you have used the automatic method, there is no need to read this chapter There are two ways to generate the finite element mesh in RAM Concept: • Using the automatic meshing facility, described in Generating the Mesh (on page 178), that uses the mesh input objects, described in Defining the Structure (on page 160). • Using the manual meshing tools described in this chapter. The first method is certainly easier and faster. It is the recommended method for nearly all models. The second method allows more control over mesh intensity: the mesh size can be more widely varied in different areas of the floor. The method is, however, more prone to user error and editing is more difficult. Do not use the manual method to supplement a mesh made with the automatic meshing facility. This is because manual elements would be lost if you used the mesh generation facility. For example, if you added a column element above in the element layer it would be lost when you regenerated.
22.1 Using the Element layer There is no set order in which you must define objects. Most people choose to draw supports first. If you have imported a CAD drawing, make it visible on the Element Standard Plan before drawing the structure.
22.2 About column elements and wall elements RAM Concept allows for single story models whereby you define columns and walls below and above the slab. Supports above the slab do not provide vertical support, only horizontal support and bending resistance.
22.3 Column element properties The following is a list of RAM Concept column element properties: Concrete Mix Type of concrete used (defined in Materials Specification).
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Manually Drawing the Finite Elements Drawing column elements Height Vertical distance from centroid of slab element to far end of column. Support Set Defines the column as below or above the floor. Width Measured along the column’s r-axis. Set to zero for round columns. Depth / Diameter Measured along the column’s s-axis. Angle Plan angle measured counterclockwise from the global x-axis. It determines the column’s r-axis (and is usually zero). Bending Stiffness Factor Used to modify the bending stiffness without changing the dimensions or height. For example, you may expect an edge column to crack and rotate more than an internal column and so you might consider setting this value to 0.5. You could use the BSF to increase a column’s stiffness, but this is an unlikely scenario. Roller at Far End Results in zero horizontal shear in column. Fixed Near Provides a moment connection (about x- and y-axes) between column and slab; otherwise pinned. Fixed Far Provides a moment connection (about x- and y-axes) at far end; otherwise pinned. Compressible Allows for column to elongate in the z-direction according to Hooke’s law; otherwise incompressible. Compressible columns usually produce results that are more accurate.
22.4 Drawing column elements Each column is located with an x- and y-coordinate. Two columns cannot have the same coordinates unless one is above and one is below. Note: If slab elements are already drawn, you need to draw column elements at slab element nodes.
22.4.1 To draw a column element 1.
Choose the Column Element tool ( 2. Click at the column center.
).
22.4.2 To copy columns from below to above 1. Select the column elements and choose Edit > Copy. 2. Choose Edit > Paste. This pastes the new column elements in the same location as the original column elements. The pasted column elements are the active selection. 3. Change the Support Set property from “below” to “above” in the Column Element Properties dialog box.
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Manually Drawing the Finite Elements Wall element properties Note: If you do not change the Support Set designation then there are duplicated column elements that do not allow the model to run properly. If you have copied a large number, it is tedious to delete the second column element at each location (one by one).
22.5 Wall element properties Wall element properties are similar to column element properties though instead of width, depth and angle there is thickness. The fixity settings are somewhat different, and there is no Bending Stiffness Factor. The following is a list of RAM Concept wall element properties: Concrete Mix Type of concrete used (defined in Materials Specification). Height Vertical distance from centroid of slab element to far end of wall element. Support Set Defines the wall element as below or above the floor. Thickness Shear wall “Locks” the wall element to the slab horizontally and thus restrains it; otherwise, the slab can “slide” over the wall. Fixed Near Provides a moment connection between the wall element and the slab about the wall element’s raxis; otherwise pinned Fixed Far Provides a moment connection about the wall element’s r-axis at far end; otherwise pinned. Compressible Allows for wall element to elongate in the z-direction according to Hooke’s law; otherwise incompressible. Compressible walls usually produce results that are more accurate.
22.6 Drawing wall elements The wall element tool is very similar to the column tool except that it uses a line rather than a point. A wall element can pass through a column element, or intersect another wall element. Note: If slab elements are already drawn, you need to draw wall elements along the edge of the slab elements. The ends of the wall elements must be at slab element nodes. Wall elements cannot traverse a slab finite element.
22.6.1 To draw wall elements on slab elements 1.
). Choose the Wall Element tool ( 2. Click at the wall end center points.
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Manually Drawing the Finite Elements About point and line supports
22.6.2 To draw wall elements where there are no slab elements 1.
Choose the Wall Element tool ( ). 2. Click at the wall end center points. 3. Specify the number of elements in the Wall Element Tool dialog box and click OK.
22.6.3 To copy walls from below to above 1. Select the wall elements and choose Edit > Copy. 2. Choose Edit > Paste. This pastes the new wall elements in the same location as the original wall element objects. The pasted wall elements are the active selection. 3. Change the Support Set property from “below” to “above” in the Wall Element Properties dialog box.
22.7 About point and line supports The result of defining a point support is a single support at a finite element node. The result of defining a line support is one or more line supports that are each located at a finite element edge. RAM Concept uses the thickness of the lowest numbered element in determining the support elevation. For this reason, it is not advisable to locate point supports or line supports at slab steps. All supports that have a horizontal rigidity should be placed at the mid-depth of the slab or they may cause an unintended arch action in addition to their horizontal rigidity (mid-depth placement is done by setting the “Elevation above slab soffit” to be one-half of the slab depth). Normally there is no need to use horizontal fixities in point and line supports, as RAM Concept automatically stabilizes the structure in the x- and y-directions (you can turn this automatic stabilization off in the General tab of the Calc Options dialog box). One situation where you might use a horizontal support is a structure braced against sidesway but modeled without bracing members (perhaps something other than a concrete wall provides the bracing). Be very careful about specifying anything but “Fixed in z-direction” for point supports and “Translation in zdirection fixed” for line supports. For point supports, fixing the point support in the r- or s-direction could result in arch / membrane action. For line supports, fixing the slab translation along or across the support could result in arch / membrane action.
22.8 Point support properties See “Point support properties” for more information on point support properties.
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Manually Drawing the Finite Elements Drawing point supports
22.9 Drawing point supports You draw point supports by clicking at their location with the Point Support tool ( Note: The Point Support tool ( toolbar.
) and Line Support tool (
).
) share the same button on the Layer Specific
Note: If slab elements are already drawn, you need to draw point supports at slab element nodes. To draw a point support 1.
Choose the Point Support tool ( ). 2. Click at the point support location.
22.10 Line support properties See “Line support properties” for more information on line support properties.
22.11 Drawing line supports You can use line supports as an axis of symmetry. This is very useful if a floor is symmetrical and you wish to model only half of it. Be aware that line supports could prevent post-tensioning forces being applied to the floor. Note: The Point Support tool ( toolbar.
) and Line Support tool (
) share the same button on the Layer Specific
Note: If slab elements are already drawn, you need to draw line supports along the edge of the slab elements. The ends of the line supports must be at slab element nodes. Line supports cannot traverse a slab finite element. To drawing a line support on slab elements 1.
Choose the Line Support tool ( 2. Click at the support end points.
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Manually Drawing the Finite Elements Point spring properties
22.12 About springs The result of defining a point spring is a single spring at a finite element node. The result of defining a line spring is one or more line springs that are each located at a finite element edge. RAM Concept uses the thickness of the lowest numbered element in determining the spring elevation. For this reason, it is not advisable to locate springs at slab steps. All springs that have a horizontal stiffness should be placed at the mid-depth of the slab or they RAM Concept may cause an unintended arch action in addition to their horizontal stiffness (mid-depth placement is done by setting the “Elevation above slab soffit” to be one-half of the slab depth). For slabs with varying centroid elevations, it can be difficult to avoid adding a rotational restraint to the slab when using lateral springs and supports. Normally there is no need to use horizontal springs, as RAM Concept automatically stabilizes the structure in the x- and y-directions (you can turn this automatic stabilization off in the General tab of the Calc Options dialog box). One situation where you might use a horizontal spring is a structure braced against sidesway but modeled without bracing members (perhaps soil friction provides the bracing). Be very careful about specifying anything but a z-force constant. R- and s-force constants could result in membrane action.
22.13 Point spring properties See “Point spring properties” for more information on point spring properties.
22.14 Drawing point springs Each point spring is located with an x- and y-coordinate. Two point springs cannot have the same coordinates. Note: The Point Spring tool ( the Layer Specific toolbar.
), Line Spring tool (
), and Area Spring tool (
) share the same button on
Note: If slab elements are already drawn, you need to draw point springs at slab element nodes. To draw a point spring 1.
Choose the Point Spring tool ( 2. Click at the spring location.
).
22.15 Line spring properties See “Line spring properties” for more information on line spring properties.
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Manually Drawing the Finite Elements Drawing line springs
22.16 Drawing line springs The line spring tool is very similar to the point spring tool except that it uses a line rather than a point. Note: The Point Spring tool ( the Layer Specific toolbar.
), Line Spring tool (
), and Area Spring tool (
) share the same button on
Note: If slab elements are already drawn, you need to draw line springs along the edge of the slab elements. The ends of the line springs must be at slab element nodes. Line springs cannot traverse a slab finite element. To draw a line spring 1.
Choose the Line Spring tool ( ). 2. Click at the line spring end points.
22.17 Area spring properties See “Area spring properties” for more information on area spring properties.
22.18 Drawing area springs You use the Area Spring tool ( Note: The Point Spring tool ( the Layer Specific toolbar.
) and locate the spring area corners. ), Line Spring tool (
), and Area Spring tool (
) share the same button on
To draw an Area Spring 1.
). Choose the Area Spring tool ( 2. Click at the four corner point locations of the area spring. Note: An Area Spring object can be larger than the structure it supports.
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Manually Drawing the Finite Elements Slab element properties
22.19 About floor areas You define floor slabs and beams manually with the slab meshing tools. Drawing elements manually requires more thought on the drawing process. Poor decisions could require a significant amount of editing and duplication of work. Drawing elements manually also requires careful application of the tools to ensure that the side of each element is the same length as the adjacent element. In other words, each element node must be at the corner of any element that touches it. Elements cannot overlap. You model beam elements as thickened slab elements with the same slab element tools. You model openings as empty spaces in the mesh.
22.20 Slab element properties Slab area properties fall into two categories: general and behavior. The following is an explanation of RAM Concept slab area properties: Concrete Mix Type of concrete used (defined in Materials Specification). Thickness You define slab thickenings, such as drop caps and drop panels, by specifying an increased thickness. Surface Elevation It is customary to set the typical elevation as 0. Setting the elevation to a very large value (such as 100 feet or 30 m) may result in round off errors in the analysis. You create surface and soffit steps by using different surface elevations for different areas.
Figure 46: Slab element properties - behavior R-Axis defines an orientation for the slab. If the slab is a two way slab with identical properties in all directions (“isotropic”), then the R-Axis is irrelevant, because there is no inherent orientation of the slab. However, if the slab is not isotropic, then this axis (defined as the counter-clockwise angle from 3 o'clock) defines the r-axis
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Manually Drawing the Finite Elements Drawing the slab elements which is used along with the other slab area properties to define the behavior of the slab. The s-axis is always 90 degrees counter-clockwise from the r-axis. KMr, KMs, KMrs, KFr, KFs, KVrs Relative stiffnesses (compared to isotropic slab stiffness). Refer to “Orthotropic behavior” for further information on the use of Behavior properties.
22.21 Drawing the slab elements You can draw slab elements one or more at a time. Usually you would attempt to draw as many as practical in ) or the Poly Slab Mesh Elements tool ( one operation using the Rect Slab Mesh Elements tool ( would often mean drawing slab panels (with columns in the corners) in one operation. Note: The Rect Slab Mesh Elements tool ( the Element layer toolbar.
) and Poly Slab Mesh Elements tool (
). This
) share the same button on
Note: You can approximate curves by a series of straight edges.
22.21.1 To draw a rectangular slab mesh area 1.
Choose the Rect Slab Mesh Elements ( ) tool. 2. Click at two opposite corners of the rectangle. 3. Specify the element size in the Rect Mesh Tool dialog box and click OK.
22.21.2 To draw a polygon slab mesh area 1.
Choose the Poly Slab Mesh Elements ( ) tool. 2. Click at each slab panel vertex consecutively. 3. Snap to the first vertex and click to close the polygon (or type “c” and press ). 4. Specify the element size in the Poly Mesh Tool dialog box and click OK.
22.21.3 To draw a single mesh element 1.
Choose one of the single element tools ( ). 2. Click at each of the three (or four) slab panel vertices consecutively. 3. Snap to the first vertex and click to close the polygon (or type “c” and press ).
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Manually Drawing the Finite Elements A few final words
22.22 A few final words Do not click Generate Mesh ( have drawn.
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Drawing Loads RAM Concept allows you to draw point, line and area loads and moments on any loading plan. These loads can be in the directions of the global x-, y- and z-axes and the moments can be about the global x- and y-axes. Each load belongs to a loading layer, such as Live Loading. You define each loading in the loadings window, and draw the loads on plans. There is no limitation to the number of loads defined. Loads are independent of the finite element mesh and have no effect on the automatic mesh generation. This is satisfactory for most loads. For very heavy point or line loads (such as on a mat or transfer slab), however, the loads should correlate with the finite element mesh nodes. You can do this by drawing pinned columns and walls above the floor, and drawing the loads at these locations with the help of snaps. Alternatively, you can refine the mesh locally with the use of “dummy” slab objects. Refer to “ Selectively refining the mesh (on page 182)” for further information. Horizontal loads may cause applied moments depending upon the elevation above the slab surface of the loads. If a load is located at a slab surface step, RAM Concept uses the thickness of the lowest numbered slab element in determining the load elevation. For this reason, it is not advisable to locate point or line loads at steps. Tip: Importing a CAD drawing may assist you in drawing loads.
23.1 About self-weight RAM Concept automatically calculates the floor’s self-weight for the Self-Dead Loading.
23.2 About superposition of loads Point loads cannot be at the same location on the same loading layer. Line loads can intersect or overlap, but cannot have the exact same length and location on the same loading layer. With the exception of temperature and shrinkage loadings, area loads can overlap but cannot have the exact shape and location on the same loading layer. Overlapping area loads are additive.
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Drawing Loads Point load properties
23.3 Point load properties The following is a list of RAM Concept point load properties: Elevation above slab surface Vertical distance between the point load and the slab surface. Fx Point force in the direction of global x-axis (horizontal force). Fy Point force in the direction of global y-axis (horizontal force). Fz Point force in the direction of global z-axis (vertical force). Mx Point moment about the global x-axis. My Point moment about the global y-axis. Note: Although point loads need not be located at a finite element node, you should consider locating very large loads at nodes. Point loads must be located on finite elements; Concept issues a warning if you violate this rule. Note: Sign convention is defined in Criteria > Signs. See Chapter 8, “Choosing Sign Convention”. Note: Horizontal forces (Fx, Fy) cause applied moments unless the Elevation above slab surface is set to apply the load at the slab centroid.
23.4 Drawing point loads Each point load is located with an x- and y-coordinate. To draw a point load 1.
). Choose the Point Load tool ( 2. Click at the load location (or enter the coordinates in the command line).
23.5 Line load properties The following is a list of RAM Concept line load properties: Elevation above slab surface Vertical distance between the line load and the slab surface. Fx Line force in the direction of global x-axis (horizontal force). Fy Line force in the direction of global y-axis at each end (horizontal force). Fz Line force in the direction of global z-axis at each end (vertical force). Mx Line moment about the global x-axis at each end.
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Drawing Loads Drawing line loads My Line moment about the global y-axis at each end. Note: If the line force (or moment) is uniform you need to enter only one value. Otherwise you need to enter two values separated by a comma (ends 1 and 2). This allows linear variation of the line force (or moment). See the following figure. Note: Although line loads need not be located at a finite element node, you should consider locating very large loads at element edges. Line loads must be completely located on finite elements; Concept issues a warning if you violate this rule. Note: Sign convention is defined in Criteria > Signs. Note: Horizontal forces (Fx, Fy) cause applied moments unless the Elevation above slab surface is set to apply the load at the slab centroid.
Figure 47: Line load properties varying from 10 to 20 units.
23.6 Drawing line loads There are two line load tools.
23.6.1 Standard line load The line load tool is very similar to the point load tool except that it uses two points rather than one point. To draw a line load 1. Choose the Line Load tool (
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Drawing Loads Area load properties 2. Click at the load end points (or enter the coordinates in the command line).
23.6.2 Perimeter line load The perimeter line load tool facilitates the drawing of multiple line load objects around the perimeter, with or without an offset. To draw a perimeter line load 1. Choose the Perimeter Line Load tool ( ). 2. Click anywhere on the slab. 3. In the dialog box that appears, enter the Inset Distance, and click Apply.
23.7 Area load properties The following is a list of RAM Concept area load properties: Elevation above slab surface Vertical distance between the area load and the slab surface. Fx Area force in the direction of global x-axis (horizontal force). Fy Area force in the direction of global y-axis (horizontal force). Fz Area force in the direction of global z-axis (vertical force). Mx Area moment about the global x-axis. My Area moment about the global y-axis. Note: If the area force (or moment) is uniform you need to enter only one value per axis. Note: The area force (or moment) can linearly vary in any direction. The area force variation could be for snowdrift, or sloping soil. Note: If the area force (or moment) varies you need to enter three values, separated by commas (vertices 1, 2 and 3). This allows linear variation of the line force (or moment) in two directions. See the following figure. Note: If you use more than three vertices, Concept calculates the unique value at all vertices (three points define a plane). Note: Area loads must be at least partially located on finite elements; Concept issues a warning if you violate this rule. Concept ignores any part of an area load not on a finite element. Note: Sign convention is defined in Criteria > Signs. Note: Horizontal forces (Fx, Fy) cause applied moments unless the Elevation above slab surface is set to apply the load at the slab centroid.
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Drawing Loads Drawing area loads
Figure 48: Area load properties varying from 10 to 20 to 30 units at the first three vertices. Concept calculates the values at all other vertices.
23.8 Drawing area loads You use the Area Load tool (
) to locate the area load vertices.
While it is neater to draw area loads that match the floor, it is satisfactory to make the load oversize. RAM Concept ignores any part of an area load that is not on a floor element. Exaggerating the size too much affects the automatic printing and zooming bounds. To draw an area load 1. Choose the Area Load tool ( ). 2. Click at the vertices of the area load (or enter the coordinates in the command line). 3. Close the polygon by typing “c” in the command line or clicking at the first vertex.
23.9 Copying loads You can copy point, line, and area loads from one Loading plan to another using the following procedure. This is convenient since in practice most loads have values for more than one loading. 1. Select the load and choose Edit > Copy. 2. Open the loading plan to which you wish to paste. 3. Choose Edit > Paste. This pastes the new load in the same plan location as the original load. The pasted load is the active selection. 4. Edit the properties of the new load.
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Drawing Loads Temperature Area Load properties Note: You can copy, paste, and edit multiple loads simultaneously.
23.10 Temperature Area Load properties The following is a list of RAM Concept temperature area load properties: ΔT Top
Temperature change at the top of the slab.
ΔT Bot
Temperature change at the bottom of the slab.
The defined temperature change is converted to a strain by multiplying it by the coefficient of thermal expansion, which is a property of the concrete mix. Notes: • Positive temperature changes expand elements. Negative temperature changes contract elements. • When different values are input for ΔT Top and ΔT Bot, a curvature is induced in the elements. • The area temperature change cannot linearly vary. Only a single temperature change value can be input for ΔT Top and ΔT Bot. • Temperature area loads must be at least partially located on finite elements; Concept issues a warning if you violate this rule. Concept ignores any part of an area not on a finite element. • Units associated with the temperature changes are defined in Criteria > Units. • Overlapping temperature area loads are not permitted. • Where elements intersect multiple temperature area loads, the temperature area load covering the largest area of the element is used for the entire element.
23.11 Drawing temperature area loads You use the Area Temperature Load tool ( ) to locate the area vertices. While it is neater to draw area loads that match the floor, it is satisfactory to make the area oversize. RAM Concept ignores any part of an area load that is not on a floor element. Exaggerating the size too much affects the automatic printing and zooming bounds. 1. Select the Area Temperature Load tool.
2. Either: Click at the vertices of the area load or Type the coordinates in the command line 3. Close the polygon by either:
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Drawing Loads Shrinkage Area Load Properties clicking on the first vertex or typing in the command line
23.12 Shrinkage Area Load Properties The following is a list of RAM Concept shrinkage area load properties: Δε Top
Strain change at the top of the slab.
Δε Bot
Strain change at the bottom of the slab.
Notes: • Positive strain changes expand elements. Negative strain changes contract/shrink elements. • When different values are input for Δε Top and Δε Bot, a curvature is induced in the elements. • The area strain change cannot linearly vary. Only a single strain change value can be input for Δε Top and Δε Bot. • Shrinkage area loads must be at least partially located on finite elements; Concept issues a warning if you violate this rule. Concept ignores any part of an area not on a finite element. • Overlapping shrinkage area loads are not permitted. • Where elements intersect multiple shrinkage area loads, the shrinkage area load covering the larges are of the element is used for the entire element.
23.13 Drawing shrinkage area loads You use the Area Shrinkage Load tool ( ) to locate the area vertices. While it is neater to draw area loads that match the floor, it is satisfactory to make the area oversize. RAM Concept ignores any part of an area load that is not on a floor element. Exaggerating the size too much affects the automatic printing and zooming bounds. For multi-story structures, it is recommended to input the shrinkage strain that represents the relative shrinkage change between the level being analyzed and the restrained level below. Using a total shrinkage instead of a differential shrinkage will normally be overly conservative. 1. Select the Area Shrinkage Load tool.
2. Either: Click at the vertices of the area load or
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Drawing Loads Drawing shrinkage area loads Enter the coordinates in the command line 3. Close the polygon by either: Click the first vertex or Type in the command line
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Creating Pattern Loading RAM Concept generates pattern loadings based upon the load patterns that you draw. Refer to “ About load pattern (on page 99)” explains the principle of load pattern.
24.1 Deciding how many load patterns to use Mathematically, there could a large number of floor pattern loadings, which would all have different results. For practical reasons, the maximum number of load patterns is ten. This allows you to draw five load patterns in each direction. Typical pattern loading configurations are:
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Creating Pattern Loading Drawing load patterns
Figure 49: Beam Pattern Loadings. Note that these will not necessarily produce the maximum negative moments, but they will produce moments that are very close to the maximum and represent a practical solution in most situations.
24.2 Drawing load patterns You draw load patterns as part of the pattern loading process. 1. 2. 3. 4.
Choose Layers > Pattern. Open one of the load pattern plans (from Load Pattern 1 through Load Pattern 10). Double click the Pattern Load tool ( ). Specify which pattern number you wish to use (the number should correspond to the load pattern plan’s number). Draw the on-pattern areas with a polygon. 5. Click at each slab area vertex consecutively.
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Creating Pattern Loading Load pattern filtering 6. Snap to the first vertex and click to close the polygon (or type “c” and press ). 7. Repeat for all patterns. Note: Regardless of which load pattern plan you are using, the pattern number will be the last one specified. You will need to change this for each different pattern plan.
24.3 Load pattern filtering Internally, RAM Concept resolves a pattern loading by determining which slab and beam finite elements are partially or wholly within the related load pattern. The loads on these elements (the element loads) are multiplied by the on-pattern factor. For elements totally outside the pattern, the element loads are multiplied by the off-pattern factor. Thus, RAM Concept’s calculation pattern areas approximate the pattern areas that you draw. You should consider this when drawing load patterns and choosing mesh size as it will affect the actual pattern loadings generated.
24.3.1 Effect of mesh on load pattern The finite element mesh regularity and intensity has an effect on the load pattern process. The following example best explains the process. Load pattern for four-panel slab
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Creating Pattern Loading Load pattern filtering
Figure 50: To generate the maximum My at midspan you would use this load pattern. Actual pattern areas for an irregular coarse mesh
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Creating Pattern Loading Load pattern filtering
Figure 51: The point load and some additional area load will be included in the pattern loading. Actual pattern areas for an irregular fine mesh
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Creating Pattern Loading Load pattern filtering
Figure 52: With the finer mesh, the point load will not be included and there will be less additional area load in the pattern loading.
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Creating Pattern Loading Load pattern filtering Actual pattern areas for a regular coarse mesh
Figure 53: This mesh generates a pattern loading with an area that closely resembles the load pattern.
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Creating Pattern Loading Load pattern filtering Drawing design strips significantly improves the mesh. See Chapter 18, “Generating the Mesh” for more information on improving the mesh. Note: The mesh becomes more regular if you generate or regenerate after design strips are drawn.
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Defining Design Strips Note: Design strips are perhaps the most important tool in RAM Concept. It is highly recommended that the designer takes the time to fully understand what a design strip does, and how to use them. If you use design strips improperly then the results will be meaningless. Finite element analysis often produces high peak moments and stress concentrations which are inappropriate for calculation of reinforcement and evaluating performance. Code rules are generally intended for strip methods that assume an averaging (or “smearing”) of moment and shear across a designated width, such as a column strip. RAM Concept uses design strips and design sections to link finite element analysis with concrete code rules and concrete design.
25.1 Definition of a design strip A design strip is an object that: • contains a series of cross sections at specific locations • is usually the length of a span, or part of a span, but can in fact have any length within the structure • integrates resultants (moments, shears, axial forces, torsions) for all load combinations along each cross section (and, hence, across the design strip’s width) • applies appropriate code rules to the resultants A design strip is the same as a span segment strip.
25.2 Design strip terminology It is important to understand the different objects used to define design strips. Span segment A line segment-line entity that is intended to indicate a portion of a structural span or a whole structural span. The “at support” properties of the Span Segment indicate where the span starts and stops. Span One or more connected Span Segments that together make up a single structural span. Nearly all spans require only one Span Segment. Frame One or more Spans that are connected together to form a continuous line of spans. Span Segment Strip A set of cross sections associated with a Span Segment. The Span Segment can have up to three Span Segment Strips (left, center and right). These are known as design strips.
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Defining Design Strips Understanding how a design strip works See the following image for further explanation.
Figure 54: Design strips for a two-way flat plate.
25.3 Understanding how a design strip works RAM Concept generates design strips from span segments. A design strip is normally the length of a span with a logical width. RAM Concept subdivides each individual design strip segment according to the following parameters: • • • •
minimum number of divisions maximum division spacing support width changes in concrete section along the span
RAM Concept locates a design strip cross section at the start of each division, plus one at the end. The length of each cross section equals the width of the design strip at that location. RAM Concept modifies the geometrical properties of each design strip cross section according to the cross section trimming and inter cross section slope limit settings. RAM Concept integrates the resultants for each load combination along the length of each design strip cross section (and hence across the width of the design strip). RAM Concept uses some properties of each span segment to determine applicable code rules (beam or slab, posttensioned or reinforced) for the corresponding design strip. RAM Concept applies the code rules to the envelope of the load combination integrals within a rule set. Other span segment properties (reinforcement bar sizes, cover) facilitate the actual code rule calculations. See “Span segment properties” for more information.
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Defining Design Strips The design strip process RAM Concept separates design strips into two sets: latitude and longitude. The two sets are for convenience and recognize that concrete floors should be designed in two directions. Note: As with all plans, you can rename the Latitude Design Strip Plan and Longitude Design Strip Plan by choosing Layer > Rename.
Figure 55: Column strip and two middle strips belonging to one span with cross sections visible.
Figure 56: Moment about the y-axis (My) plotted across one cross section of three design strips.
25.4 The design strip process 1. Create the span segments. Specify the default span segment properties by either: Generate span segments (and supplement and adjust if necessary) or Draw span segments manually. These two methods can be used in conjunction. 2. Create span segment strips. You can create span segment strips from span segments with the Generate Strips tool. You cannot draw or directly edit span segment strips.
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Defining Design Strips Span segment properties 3. Review and modify span segment strips: a. Examine span segment strips. Check the Lock Generated Strips box of any Span Segment that has satisfactory strips. b. Edit span segment properties. Use the Strip Generation tab of the Span Segment properties dialog to modify the span segment strips. c. Edit span segments manually. Use the Span Boundary, Strip Boundary, and Orient Span Cross Section tools to control the strip generation. d. Set cross section trimming. This enables you to modify the concrete section used for shear and flexure calculations. 4. Continue by repeating steps 2 and 3 as necessary.
25.5 Span segment properties Span segment properties serve different purposes. RAM Concept uses properties to determine the following: • • • • •
design method (e.g. inclusion of axial force) design strip width and cross section geometry appropriate code design rules (e.g. beam or slab) reinforcement live load reduction
The following is an explanation of RAM Concept span segment properties:
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25.5.1 General tab
Figure 57: Span segment properties - General Span Set
Determines the set the span segment belongs to: latitude or longitude.
Environment
The environment setting affects which service rules RAM Concept selects in some codes. Refer to the appropriate code discussion chapter for more information: • See Service (on page 894) for relevance to ACI318-02. • See Service (on page 1020) for relevance to AS3600-2001, see Service (on page 1039) for relevance to AS3600-2009, and Service (on page 1057) for relevance to AS3600-2018. • See Service (on page 1081) for relevance to BS8110. • See Service (on page 1108) for relevance to IS 456. • See Characteristic Service (on page 1137) for relevance to EC2.
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• See Service (on page 1164) for relevance to CSA A23.3. Note: This setting has a significant effect on reinforcement quantities. Consider Axial Force Uses the net section axial force in bending design. in Strength Design This is a very important setting related to the effect of axial force resultants (not necessarily axial loads) in a cross section. If you select this option, RAM Concept includes the interaction of the axial force with the bending in the cross section strain calculations, similar to typical column design using strain compatibility. We generally recommend the consideration of axial forces in strength design. For sections with net axial compression this will tend to reduce the reinforcement demand while for sections with net axial tension it will typically increase the reinforcement demand. Consider as PostTensioned
Enables RAM Concept to decide which code rules are used. This determines if the design strip segment is checked for initial service design code rules (for the Initial Service LC) and whether RC or PT code rules are used (some codes do not make this distinction). Note: If consider as post-tensioned is not used then Concept ignores tendons in strength calculations.
Precompression Calc Determines how precompression is calculated and used to plot Section Analysis results on the User Minimum Layer. See also Creating a new precompression plan (on page 371). The choices are: • None: No precompression calculation is performed. This is the default setting. • Balance Loading: Precompression is calculated using the resultant axial force in the cross section divided by its area. This calculation includes the loss of precompression due to support restraints. • FseAps/Ac: Precompression is calculated using the effective tendon force multiplied by the perpendicular vector component of the tendon area intersecting the section divided by the cross section area. This calculation does not include the loss of precompression due to support restraint. Don’t reduce integrated M and V due to sign change
The intent of this option is to allow for safe, conservative designs where cross sections include regions of moment (or shear) with opposite signs that cause the moment (or shear) recorded for the cross section to be less than that for a shorter sub- cross section. When this option is selected, the design forces are always more conservative than when the option is not selected. This option should not be used without due consideration. See Using the Don't Reduce Integrated M and V due to Sign Change option (on page 802) for explanation.
Number of Stories for Accident Design
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This input will only be visible when the Eurocode 2-2004 (UK Annex) is the active Design Code. It is used to determine the number of stories that are used for accident rule set calculations for this span.
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25.5.2 Strip Generation tab
Figure 58: Span segment properties - Strip Generation Span Width Calc
This determines how RAM Concept calculates the span width. The choices are: • Automatic: this applies (sometimes fallible) logic to calculate the span width as the closest of:
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• the Span Boundaries (in the same latitude/longitude set as the Span Segment) • the slab edges • half-way to the nearby spans or walls • Manual: this overrides the automatic calculation and determines span widths by the closest Span Boundary items (in the same latitude/longitude set as the Span Segment). See “Drawing span segments manually” for further information. Note: When the Manual setting is used in a strip segment, all of the span boundaries for that strip segment must be defined. A strip segment generates a span width of zero when some of its length does not have any span boundaries defined. Column Strip Width Calc
This determines how the column strip width is determined. The term “column strip width” is used for more than flat slabs with column and middle strips. The choices are: • Full Width: this is typical for PT slabs designed to ACI318 and TR43. The column strip width is the same as the span width. • Code Slab: this is typical for two-way RC slabs, and two-way PT slabs designed to AS3600. The column strip width is the narrower of: • the span width • the Strip Boundaries (in the same latitude/longitude set as the Span Segment) • a fraction of the distance to the adjacent spans or supports (for all current codes this fraction is 0.25) • a fraction of the span length on each side of the span line (for all current codes this fraction is 0.25) • Code T-beam: the column strip width is the narrower of: • • • • •
the span width the Strip Boundaries (in the same latitude/longitude set as the Span Segment) the web width plus 8 times the flange thickness on either side (ACI codes only) 25% of the span length (ACI codes only) the web width plus 0.07 times the span length on either side (AS 3600 and BS 8110 only) • the web width plus 0.058 times the span length plus 3 times the flange thickness on either side (IS 456 only) • the web with plus 0.07 times the span length plus 0.2 times the overhanging flange width on either side, not to exceed 0.14 times the span length (EC2 only) • The web width plus 12 times the flange thickness on either side (CSA A23.3 codes only) • The web width plus 0.1 times the span length on either side (CSA A23.3 codes only) • % of Total Width: the column strip is the input column strip width % of the total strip width • Manual: the column strip width is the narrower of: • the span width • the Strip Boundaries (in the same latitude/longitude set as the Span Segment)
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Defining Design Strips Span segment properties Design Column This option instructs RAM Concept to combine the column and middle strip forces into a Strip for Column + single resultant at the centroid of the column strip cross section. The middle strip cross Middle Strip sections will still be generated, but the resulting forces in them will be zero. Resultants This can be useful, for example, when designing a beam with a column strip sized for the effective flange width and middle strips for the slab between the beam effective flanges. Using this option in this scenario will result in the beam cross section being designed for all forces in the entire bay. The middle strip cross sections will not have any design forces, but can still be designed for minimum reinforcement. Skew Angle
The angle between the design strip cross section and a line perpendicular to the span segment. The typical value is zero.
Min Number of Divisions
Determines how many design cross sections per span. For N divisions there are N+1 design cross sections. It is generally advisable to make N an even number. The upside of more divisions is greater design accuracy; RAM Concept’s ability to find critical design locations and length of reinforcement is a function of the number of divisions. The downside of more divisions is that calculating takes longer; for large models, you might consider using a small number of divisions (say, 4) and then increasing the number for final design (but you should consider the effect of the next property). There is no reason for all design strips to have the same number of divisions. Should you be designing a transfer beam within a flat plate it would probably make sense to have more divisions for the beam design strip.
Max Division Spacing
Overrides the Min Number of Divisions with an upper bound on division spacing.
Detect Supports and Edges Automatically (resets supports and widths below)
This detects: • the presence of supports at ends of span segments and overrides “Consider End as Support” and “Support Width”. • where the span spine is near the slab edge and “pulls back” the closest cross section by “x”, where x is the bar end cover plus 1 inch / 25 mm. • This is done by setting the support width to x. • If the spine end near the slab edge has detected a support, then the slab edge detection is NOT performed (and the regular support width calcs are used).
Critical Section Support Ratio
Places the first and last cross section in the design strip at a distance equal to the specified ratio times the distance from the support centerline to the support face. The default value is 1 for all design codes expect AS 3600 design codes, which uses a default value of 0.7 (refer to AS 3600-2018 6.2.3). A value of 1 places the first and last cross section in the design strip at the face of the support.
Consider End 1 as These checkboxes allow RAM Concept to determine your interpretation of “spans” in the Support structure. This determination of spans affects how RAM Concept applies code rules that are span-related, including determining support regions, span regions and areas used in live load reduction. Support Width at End 1
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The dimension of the support parallel to the design strip. The support width determines where the first and last design strip cross sections are located. Their locations are at half the support width (measured in the direction of the span) from the ends of the design
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25.5.3 Column Strip tab
Figure 59: Span segment properties - Column Strip Cross Section Trimming
Reduces design strip cross sections based on geometry. See About cross section trimming (on page 233) for more information.
Inter Cross Section Slope Limit
Reduces design strip cross sections based on slope limits. See Inter Cross Section Slope Limit Trimming (on page 240) for more information.
CS Top Bar
The label used to identify the top face reinforcing bar used for flexural design.
CS Bottom Bar
The label used to identify the bottom face reinforcing bar used for flexural design.
CS Shear Bar
The label used to identify the reinforcing bar used for one-way shear design.
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The label is not necessarily the bar size. Reinforcement bar labels (and their properties) are specified in the Criteria > Materials. It is possible for different design strips to have different bars. After completing the calculation process, RAM Concept reports design strip reinforcement requirements based upon the bars specified in the design strip properties. You can view the required reinforcement area in plots and tables. CS Top Cover
Clear cover to the top longitudinal bars.
CS Bottom Cover
Clear cover to the bottom longitudinal bars.
CS Legs in Shear Reinforcement
Determines the area of vertical shear reinforcement by multiplying the number of legs by the Shear Bar area.
CS Shear Effective Depth Calc
(ACI 318-02, ACI 318-05, ACI 318-08, ACI 318-11, and Eurocode2 only) The approach for determining the effective depth in shear calculations. The choices are: • All tension reinforcement: Uses all tension reinforcement in the cross section to calculate effective depth. • Maximize effective depth: Performs two calculations and utilizes the maximum result, one using all tension reinforcement in the cross section and the other utilizing only the reinforcement in the 1/4 depth of the cross section nearest the tension most face and ignoring post-tensioning. See the ACI 318-02, ACI 318-05, ACI 318-08, ACI 318-11, and Eurocode 2 code implementation chapters for additional information.
CS Min Shear Reinforcement Requirement
(AS 3600-2018 only). Controls design of minimum fitments. The choices are:
CS Torsion Design
The method used for torsion design.
Code: Designs minimum fitments for shear and/or torsion as required by code Shear: Designs open fitments per AS 3600-2018 8.2.1.7 even if not required otherwise Shear and Torsion: Designs closed fitments per AS 3600-2018 8.2.5.5 even if not required otherwise
See Torsion Considerations (on page 816) for further explanation. CS Design System
The design system (beam / one-way slab / two-way slab) for the design strip. Minimum reinforcement and other rules are dependent upon what type of system is in use in the span. For example, the minimum requirements for beam stirrups are different to those for a one-way slab.
CS Service Design Type (Eurocode 2 only) The service design type for members defined as PT for the design strip. The choices are: Stress: Perform a hypothetical stress limit design as prescribed in TR43. Crack Width: Perform a crack width design in accordance with Eurocode 2 clause 7.2/7.3. Stress & Crack Width: Perform both Stress and Crack Width design.
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Defining Design Strips Span segment properties CS Crack Control Design Type
(AS 3600-2018 only). Method used for crack control checks. The choices are:
CS Crack Width Limit
(Eurocode 2 only) The crack width limit wmax to use when designing for Eurocode 2 clause 7.3. When “Code” is selected the values in UK National Annex Table NA.4 are used.
Without Direct Calculation (Tables): Reinforcement stress is limited to the values in Tables 8.6.2.2(A) and (B) or Table 8.6.3 for beams or Tables 9.5.2.1(A) and (B) or Table 9.5.2.3 for slabs. Crack Width Calculation: Crack widths are calculated directly using the equations in 8.6.2.3
(Eurocode 2 and AS 3600-2018 only). For Eurocode 2, the crack width limit wmax to use when designing for Eurocode 2 clause 7.3. When Code is selected, the values in UK National Annex Table NA.4 are used. For AS 3600-2018, the crack width limit w'max to use when designing for AS 3600-2018 clause 8.6 or 9.5. When Code (Environment) is selected, the crack width limit is determined from the selected Environment option. See AS 3600-2018 Code Implementation chapter for details. CS Span Detailer
The detailing system used. See Span detailing (on page 831) . The choices are: • None • Code • User-defined
CS Min. Reinforcement Determines the face for minimum reinforcement. Location The choices are: • Elevated Slab: Some minimum tensile reinforcement code rules do not consider flexural stress conditions; they determine minimum reinforcement based solely on geometry and the “expected” tensile face. For example, ACI 318-99 Rule 18.9.3.3 stipulates that the minimum reinforcement at a column in an elevated slab should be in the top face. This setting ensures RAM Concept uses that face. • Mat Foundation: Similar to above, you would expect the minimum reinforcement at a column in a mat to be in the bottom face. • Tension Face: This setting details the minimum reinforcement on the tensile face, or the face with the least amount of compression. • Top: This setting details the minimum reinforcement on the top face, regardless of the concrete stresses. • Bottom: This setting details the minimum reinforcement on the bottom face, regardless of the concrete stresses. • None: No minimum reinforcement is detailed. CS Min. Top Reinforcement Ratio
The user-defined reinforcement ratio for the top face. RAM Concept multiplies the trimmed cross sectional area by this ratio.
CS Min. Bottom Reinforcement Ratio
The user-defined reinforcement ratio for the bottom face.
CS Min. Precompression
The user-defined minimum precompression limit.
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The user-defined maximum precompression limit.
25.5.4 Middle Strip tab
Figure 60: Span segment properties - Middle Strip Note: Middle strips have one additional property to column strips. The rest of the properties are the same, but can have different values to those of the column strips. Middle Strip uses Column Strip Properties
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Sets the middle strip properties to those of the column strip.
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25.5.5 Live Load Reduction tab
Figure 61: Span segment properties - Live Load Reduction Max live Load Reduction See Live Load Reduction Notes (on page 818) for information on RAM Concept’s implementation of live load reduction. User specified LLR parameters
See Live Load Reduction Notes (on page 818) for information on RAM Concept’s implementation of live load reduction.
25.6 Creating span segments You can create span segments in two ways: automatic and manual. For most models you use the automatic feature to generate span segments once in each orthogonal direction, and then make manual adjustments.
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25.6.1 Generating span segments automatically Unless you have a truly one-way concrete floor, it would be usual to first generate one set of span segments (and hence design strips) on the Latitude Design Spans Plan, and then an orthogonal set on the Longitude Design Spans Plan. 1.
Click the Generate Spans tool ( ), or choose Process > Generate Spans. The Generate Spans dialog box appears.
2. Set Spans to Generate to latitude. 3. Select other options and click OK. The span segments appear (with nominated orientation) on the Latitude Design Spans Plan. You should repeat this process for the longitude direction.
25.6.2 Drawing span segments manually You sometimes need to manually draw or adjust span segments for floors that are not rectilinear or have complications.
To draw a single span segment 1. Choose the Span Segment tool (
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Defining Design Strips Creating span segment strips (design strips) 2. Click at the span segment start point. 3. Click at the span segment end point. The two clicks define the span segment spine.
To draw multiple span segments 1. 2. 3. 4. 5. 6.
Choose the Span Segment Polyline tool ( ). Click at the first span segment start point. Click at the first span segment end point. Click at the second span segment end point. Continue to click segment end points until all related segments are drawn. Right click and select enter to close the operation.
Note: Start and end points are normally supports. There are, however, exceptions, such as a design strip used for a pour strip to discriminate between PT and RC areas, or used for a span with user-defined reinforcement in discrete locations.
25.7 Creating span segment strips (design strips) You generate span segment strips from span segments. This can be done for all strips (on both latitude and longitude plans) or just selected strips.
25.7.1 To generate span segment strips 1. Select either: the Generate Strips tool (
)
or Process > Generate Strips Note: The Generate Strips command does not generate strips for any span segment with the Lock Generated Strips checked. This is useful when you are satisfied with some, but not all, of the design strips. Note: Each span segment can generate up to 3 strips: a center (“column”) strip, a left (“middle”) strip and a right (“middle”) strip. Together, these three strips form the entire span strip.
25.7.2 To generate some span segment strips 1. Select one or more span segments 2. Choose the Generate Selected Strips tool (
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Defining Design Strips Defining span segment widths and strip widths manually RAM Concept recalculates the span segment strips for the selected span segments.
25.8 Defining span segment widths and strip widths manually RAM Concept often generates span segment widths and strips that require modification. This tendency becomes apparent once you have tried the span segment generation a few times. You should always examine the strip widths to determine that they are to your satisfaction.
25.8.1 Defining span segment boundaries manually You can manually define the span segment width when the automatic span width calculation has not provided a satisfactory result. To set the span segment width 1. 2. 3. 4. 5.
Choose the Span Boundary Polyline tool. Click at the span boundary start point. Click at the next span boundary point. Continue to click span boundary points until all are defined. Right click and select enter to close the operation.
Note: Boundaries with a span set of latitude (longitude) only affect latitude (longitude) span segment strips.
Figure 62: Slab with span segments.
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Figure 63: Strips generated from the span segments in previous figure. One span has some illogical design strips because the calculated span width is excessive.
Figure 64: Regenerated design strips after modification of span width with span boundaries (shown inside ellipses).
Figure 65: The same span segment strips with the cross sections oriented to ninety degrees. This did not require manual span boundaries.
25.8.2 Defining strip boundaries manually You can manually define the “column” strip boundaries when the Column Strip Width Calc has not provided a satisfactory result. To set the strip boundary
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Defining Design Strips Defining span segment widths and strip widths manually 1. 2. 3. 4.
Choose the Strip Boundary Polyline tool( ) Click at the strip boundary start point. Click at the next strip boundary point. Continue to click strip boundary points until all are defined.
Unequal spans are a source of varying column strip widths. You can choose to accept the column strip widths that RAM Concept calculates, or make some modifications.
BS8110 Clause 3.7.2.9 BS8110 Clause 3.7.2.9 states the following: “Columns strips between unlike panels: Where there is a support common to two panels of such dimensions that the strips in one panel do not match those in the other, the division of the panels over the region of the common support should be taken as that calculated for the panel giving the wider column strip.” The column strips in the following example are modified with logic derived from this clause. The following three figures show the use of strip boundaries to control the column strip width
Figure 66: Slab with span segments.
Figure 67: Strips generated from the span segments in the previous figure.
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Figure 68: Strip boundaries have made transitioning column strip widths Note: The short span segments in the preceding figure have Column Strip Width Calc set to Manual The following four figures show the use of strip boundaries to control the column strip width.
Figure 69: Slab with span segments
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Figure 70: Strips generated from the span segments in previous figure. One span (with gray shading) has illogical span width and column strip width.
Figure 71: Span boundaries have made a logical span width, but the column strip width is still a problem.
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Figure 72: Strip boundaries have made a logical column strip width. Short spans and cantilevers present problems for the design because RAM Concept will generate narrow column strips. Codes recommend that columns strips are no more than half the span in width. RAM Concept makes the (commonly used) assumption that the equivalent length of a cantilever is 2L. The cantilever column strip width is thus L. This can be quite narrow for short cantilevers.
Figure 73: Slab with span segments
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Defining Design Strips Cross Section Trimming
Figure 74: Strips generated from the span segments in previous figure.
Figure 75: Strip boundaries have made a logical column strip width.
25.9 Cross Section Trimming RAM Concept automatically trims cross sections in span segment strips according to the trimming settings in the associated span segments.
25.9.1 About cross section trimming True cross section shapes in a slab can be quite irregular due to slab steps and other forming or architectural considerations. While it is generally advised to model the geometry of the concrete as per the form in the constructed building, it is not advised to always use the true geometry in design. It is often better to modify cross sections considering both their own shape and that of the nearby concrete.
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Defining Design Strips Cross Section Trimming RAM Concept offers two types of cross section trimming: Single Cross Section Trimming and Inter Cross Section Slope Limits. Single Cross Section Trimming considers one cross-section at a time and modifies the cross-section based on the user-specified trimming type. Inter Cross Section Slope Limits trims the top and/or bottom of cross-sections based on the adjacent crosssections, their elevations, and the distance between the cross-sections. Inter Cross Section Slope Limit trimming always occurs after Single Cross Section Trimming.
25.9.2 About shear core It is important to understand “shear core” before using cross section trimming. RAM Concept defines the shear core as the parts of the trimmed cross section that include any vertical slices that extend from the top of the cross section to the bottom of the cross section, as shown in the following figure. RAM Concept bases one-way shear calculations on the entire shear force and shear core. For example, in a Tbeam the shear calculations are based on the cross-sectional area of the stem and the flange immediately above the stem. Cross-sections can have multiple separate cores. For example, in a double-T-beam, the core is the two stems and the flange areas above the two stems. RAM Concept typically considers this core to be the same as a single core with the same (total) width. Note: The shear core is modified for post-tensioning ducts as described in “Concrete “Core” Determination”.
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Figure 76: Shear core (shaded) for various cross sections
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Defining Design Strips Cross Section Trimming Some odd shaped cross-sections do not have a shear core. In such cases, RAM Concept cannot calculate some capacity values (such as shear capacity).
Figure 77: One cross section with a narrow shear core and one with zero shear core.
25.9.3 Shear core in slabs It is common for RAM Concept to report unexpected shear reinforcement in slabs with section changes when the trimming is not set appropriately. It is quite possible for a slab cross section with a small shear core to show large amounts of shear reinforcement or even design failure, even when the shear force is small. See Section 22.9.5 for trimming settings for rectification.
Figure 78: Slab depression showing shear core (right). Such narrow shear core “slivers” often result in shear reinforcement and design failure.
25.9.4 Viewing a perspective of design strip cross sections Viewing a perspective of the design strip cross sections is a useful way of checking the validity of the design strip cross section trimming settings. 1. Choose Layers > Design Strips > Latitude Cross Sections Perspective
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Figure 79: Design strip cross section perspective. Parts of the cross section not in the shear core are a different color.
25.9.5 Single Cross Section Trimming RAM Concept offers six different types of single cross section trimming: Max Rectangle The top and bottom of the cross section is trimmed, and other pieces may be removed to produce a cross section with a uniform top and bottom elevation, and a maximum area. The “rectangle” formed may actually be multiple separated rectangles with the same top and bottom elevations.
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Figure 80: Untrimmed slab showing cross-section (left) and shear core (right).
Figure 81: “Beam rectangle” trimming (left) and “Slab Rectangle trimming” (right) showing revised cross-sections. The shear core is now the same as the cross section. Beam Rectangle Vertical slices of the cross section are removed until the remaining portion is the maximum height rectangle possible. This rectangle can be multiple separated rectangles with the same top and bottom elevations. Slab Rectangle The top and bottom of the cross section is trimmed to produce a cross section with a uniform top and bottom elevation, and a maximum width. If multiple maximum-width rectangles are possible, the deepest on (maximum area) is used. The “rectangle” formed may actually be multiple separated rectangles with the same top and bottom elevations. T or L The top and bottom of the cross section is trimmed, and other pieces may be removed to produce a cross section with a uniform top elevation, and only two bottom elevations (flange bottom and web bottom). The Tees and Els formed can be joined (such as double-tees) or separated. Rectangles are considered the same as flangeless Tees.
Figure 82: Untrimmed beam showing cross-section (left) and shear core (right).
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Figure 83: “T or L” trimming showing revised section (left) and shear core (right). Inverted T or L Same as T or L, but with the flange on the bottom. Max Shear Core The top and/or bottom of the cross section is trimmed to produce a cross section with the maximum shear core area.
Figure 84: Untrimmed beam showing cross- section (left) and shear core (right).
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Figure 85: “Max Shear Core” trimming showing revised section (left) and shear core (right). None - No (single) cross section trimming is performed.
25.9.6 Selecting cross section trimming You must determine which cross section trimming is most appropriate, but the following is provided for guidance: Typical slabs with drop caps (but not The best trimming is usually Max Rectangle. drop panels): Slabs with drop panels (but not drop The best trimming is usually T or L. caps): Slabs with drop panels and drop caps:
The best trimming is usually T or L, but this assumes that the drop cap cross-sectional area is smaller than the drop panel cross sectional area.
Down-turned beams:
The best trimming is usually T or L.
Up-turned beams:
The best trimming is usually Inverted T or L.
After a Calc-All, you can view the actual cross-section perspectives. See “Viewing a perspective of design strip cross sections”. Related Links • Selecting cross section trimming (on page 240)
25.9.7 Inter Cross Section Slope Limit Trimming Once cross sections have been individually trimmed, they are trimmed relative to each other. This Inter Cross Section Slope Limit trimming effectively trims the top and bottom elevations of adjacent cross section to limit the slopes between them. This is done because compression and tension forces cannot “flow” at sharp angles from one cross-section to the next.
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Figure 86: Elevation of thickened slab. It would be unrealistic to use a design depth of t2 at cross-section A-A.
Figure 87: Elevation of effective design slab thickness using a slope limit of 0.25. A slope limit of 0.0 will not allow any change between adjacent cross sections’ top elevations and bottom elevations. This effectively trims all the cross sections in a span segment strip to have the same top and bottom elevation. In general, we do not recommend using a slope limit over 0.25.
Figure 88: Elevation of stepped slab. It would be unrealistic to use the full depth for all cross-section design
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Figure 89: Elevation of effective design slab thickness using a slope limit of 0.25.
25.10 Improving the mesh The presence of design strips can significantly improve the regularity of the finite element mesh. We recommend that once you have completed the design strips, you regenerate the mesh. See Chapter 18, “Generating the Mesh” for more information.
25.11 Additional design strip information RAM Concept automates a large percentage of the design strip process. It is relatively straightforward to rationalize the layout of design strips when the support arrangement is rectilinear. The more complicated the geometry the more you have to think about the design strip layout and make manual changes. If there is a lot of repetitive geometry in a floor then it should not be necessary to use design strips everywhere. You should only use as many as required to adequately design the floor. For example, if a floor has many beams of the same loading, tributary area, span and size then there is no need to use design strips for each similar beam. This is just as you would not perform hand calculations for each of twenty identical beams. Not withstanding, although slabs or beams may appear identical, continuity effects and other considerations may have a significant influence and the results could be different. It is better to define design strips properly in some critical areas than to cover the floor with unsuitable strips. When in doubt, draw a design strip, but keep in mind that the number of design strips affects the calculation time. Some engineering judgement is always a good thing. Keep in mind that any area without strips will not have the finite elements improved when you regenerate the mesh. In general, design strips for one span set (latitude or longitude) should not overlap. For beam and slab systems, you might consider placing design strips parallel and in between the beams. This is because the beam strips only collect the moments and shears over the width of the strip. If the beams are not significantly stiffer than the slab, there may be design reinforcement required for the slab. The following sections discuss some situations with irregular geometry.
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Defining Design Strips Irregular column layouts Note: See “Miscellaneous tips” for some more tips and hints.
25.12 Irregular column layouts Laying out design strips for irregular column layouts requires consideration of a number of issues. These include: 1. Skew angles: whether latitude and longitude design strips should be strictly orthogonal. 2. If tendons components from two directions are affecting the design strip. The following sections discuss these issues.
25.12.1 Design Strip Skew Angles It is intuitive that there would be a limit on the skew angle of design strips. One reference guideline is the Eurocode (EC2: 4.3.1.1 P(8)): “For slabs, deviations between the direction of the principal stress and the main reinforcement of less than 15 degrees may be ignored”. This suggests that flat slabs / flat plates should be designed for two directions that are between 75 and 105 degrees apart, which means the skew angle should not exceed fifteen degrees. The span segment property Skew Angle enables you to manipulate span segments such that design strip cross sections are normalized in each direction.
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Figure 90: Span segment 2-2 has an angle of 15 degrees. The skew angle is zero so the cross sections (shown in Figure ) are perpendicular to the span segment.
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Figure 91: Design strip cross-section
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Figure 92: Span segment 2-2 has an angle of 15 degrees. The skew angle is minus fifteen degrees so the cross sections (shown in the following figure) are parallel to those of adjacent spans
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Figure 93: Revised design strip cross sections.
25.12.2 Effect of tendon components on design strip cross sections In many instances the “latitude” and “longitude” tendons may be detailed and constructed in a non-orthogonal manner. This is often ignored in hand or strip calculations but it is a real issue that can affect design criteria such as service, strength and ductility. RAM Concept considers the force components of all tendons that cross a design strip cross section (or a design section). The following figures show an example.
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Figure 94: A skewed design strip with three design cross sections. The latitude tendons are not orthogonal to the longitude tendons.
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Figure 95: Perspective shows the central cross section is perpendicular to the latitude tendons which are at the low point. Due to the layout the strip collects a component of the longitude tendon which is at its high point. This configuration may cause design issues.
25.12.3 Examples of irregular grids The following examples show design strip layouts for non-rectilinear grids. Column and middle strips
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Figure 96: Irregular column layout
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Figure 97: Spans generated by Concept.
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Figure 98: Design strips generated by Concept. Span 3-2 has unsatisfactory design strips.
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Figure 99: Span 2-1, 3-2 and 4-1 deleted
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Figure 100: Manually drawn spans (2-1, 3-1, 4-1 and 5-1) after renumbering
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Figure 101: Regenerated design strips based on revised spans.
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Figure 102: Regenerated design strips after using the “Orient Span Cross Section” tool. Full panel design strips for an irregular grid (ACI318 and TR43 post-tension design)
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Figure 103: Irregular column layout
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Figure 104: Spans generated by Concept.
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Figure 105: Design strips generated by Concept. Span 3-2 has unsatisfactory design strips.
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Figure 106: Span 2-1, 3-2 and 4-1 deleted
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Figure 107: Manually drawn spans (2-1, 3-1, 4-1 and 5-1) after renumbering
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Figure 108: Regenerated design strips based on revised spans.
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Figure 109: Regenerated design strips after using the “Orient Span Cross Section” tool.
25.12.4 Drawing design strips near walls There are some considerations for drawing design strips near walls. Omission of design strips parallel to walls Since a wall is a continuous support, there is usually no need to design a floor over, and parallel to, a wall for strength. You may, however, be interested in the minimum reinforcement requirements and so a design strip could be warranted. Strips over or under walls will occasionally have unrealistic stress peaks as the forces and moments are continually transferred back and forth between the wall elements and the slab elements. For this reason, some designers eliminate span segments over and under walls.
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Figure 110: Column and middle strips with strip omitted over wall.
25.12.5 Changing from PT to RC design It is quite common for a floor to have a mixture of PT and RC areas. For example, a pour strip (an area with no post-tensioning that joins two post-tensioned slabs). For most codes, PT design rules are different from those for RC. As such, you should use multiple design strip segments in one span. The following figure shows two examples of a slab with tendons stopping either side of a pour strip (in gray). On the left, span segment 2-1 has been generated and extends from support to support. This means that the entire segment is designed according to the “Consider as Post-Tensioned” option. If the option is checked, then the pour strip design is wrong. On the right, span segments 1-1, 1-2(2) and 1-1 (3) have been drawn manually. The “Consider End x as Support” options have been unchecked, and support widths set to zero, where end “x” is at the pour strip. The “Consider as Post-Tensioned” option is checked for 1-1 and 1-1(3), but not 1-1(2). The pour strip is thus designed as reinforced, not post-tensioned, concrete. RAM Concept designs the PT span segments for service stress rules and checks initial stresses, but not the RC areas.
Figure 111: Multiple span segments used to model an RC pour strip. Note: You could define the pour strip to have orthotropic behavior such that it is very flexible in the Y direction. This is done in the Mesh Input Layer. See “Slab area properties” of Chapter 17, “Defining the Structure”.
25.13 Miscellaneous tips Middle strip support widths
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Defining Design Strips A final word on design strips Middle strip support widths are the same as those of the associated column strip. Should you require to use middle strips with a different support width (say, zero), you need to manually draw span segments for the column and middle strips and use the span boundary tool. Span segments that have no width A span segment has zero width if the Span Width Calc is set to “manual” and some of its length does not have any span boundaries defined. Design strips (span segment strips) with no cross sections You can specify a design strips’ minimum number of divisions as zero. Combined with a large maximum spacing, the number of cross sections could then be zero. This could be useful in affecting other span segments’ strip generation, without slowing down the calculations. (The overall number of cross sections has a significant effect on calculation time). For an example of this application, see steps 13 to 15 in Chapter 48, “Mat Foundation Tutorial”.
25.14 A final word on design strips Design strips are extremely powerful tools, but that is all they are: tools. It is important that you understand the calculations that these tools perform, so you can determine the appropriateness of the calculation for the situation under consideration, and so you can set the tools’ parameters correctly.
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Defining Design Sections A design section is the equivalent of one design strip cross section. You draw design sections manually to supplement design strips.
26.1 Using design sections There are situations where you may choose to use design sections rather than design strips. This would include: • In some areas, you may only require design information at one cross section rather than for an entire span. • A design strip may not provide sufficient design information. • A design strip may be inappropriate. For example, a slab step may not be orthogonal to the span (and design strip) and you want the reinforcement bars designed perpendicular to the step. In this case, you might draw a design section parallel to the step. • You find it is too difficult to define a design strip for an area with very complicated structural geometry.
26.2 Design section properties Design sections have similar properties to design strips. See Span segment properties (on page 214) for definitions and explanations. The following properties are unique to design sections:
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Figure 112: Design section properties - General Top Ignore Depth
The top concrete ignored in flexural and one-way shear design. See About ignore depths (on page 270) for more information on this important issue.
Bottom Ignore Depth
The bottom concrete ignored in flexural and one-way shear design. See About ignore depths (on page 270) for more information on this important issue.
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Figure 113: Design section properties - Design Parameters Span Length
Used to calculate the following: • Minimum reinforcement rules for some codes. • The upper bound on f ps for unbonded tendons based upon the selected code’s criteria (these criteria often include a span length parameter).
Tributary Length
This creates a zone over which the reinforcement required by the design section must be provided (development lengths, if required, are in addition to this zone). The zone length on the right side of the design section is the smaller of these two values: • TributaryLength/2.0 • (SpanRatio - 0.0) * SpanLength The zone length on the left side of the design section is the smaller of these two values: • TributaryLength/2.0 • (1.0 - SpanRatio) * SpanLength The intent of the span-ratio-based limit is to restrain the reinforcement zone to within the span, even if the design section is at the beginning or end of a span.
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Defining Design Sections Drawing design sections
Note: The Visible Objects dialog can be used to show the reinforced zone to be outlined and hatched. The region displayed also considers all the span ratio implications. The hatched region does not display before a calc-all. Span Ratio
Determines the location of the design section relative to supports and midspan.
Strip Type
(Eurocode 2 only) Determines the type of strip defined by this design section. The choices are: • Col. Strip (Full Width): Use design rules for full bay width cross sections (generally used without middle strips). • Col. Strip (w/ Mid. Strips): Use design rules for partial bay width column strips (generally used in conjunction with middle strips). • Middle Strip: Use design rules for partial bay width middle strips (generally used in conjunction with column strips).
CS Service Design Type
(Eurocode 2 only)The service design type for members defined as PT for the design strip. The choices are: • Stress: Perform a hypothetical stress limit design as prescribed in TR43. • Crack Width: Perform a crack width design in accordance with Eurocode 2 clause 7.2/7.3. • Stress & Crack Width: Perform both Stress and Crack Width design. See EN 1992-1-1: 2004 (Eurocode 2) With TR43 Design (on page 1121) for additional information.
CS Crack Width The crack width limit wmax to use when designing for Eurocode 2 clause 7.3. When “Code” is Limit (Eurocode selected the values in UK National Annex Table NA.4 are used. 2 only) Number of This input will only be visible when the Eurocode 2-2004 (UK Annex) is the active Design Stories for Code. It is used to determine the number of stories that are used for accident rule set Accident Design calculations for this span. (Eurocode 2 UK NA only)
26.3 Drawing design sections When using design sections it is advisable to draw one set on the Latitude Design Spans Plan, and the other on the Longitude Design Spans Plan. Design sections are located by a line that has a start point and an end point. 1. Choose the Design Section tool ( ). 2. Click at the design section start point. 3. Click at the design section end point.
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Defining Design Sections About ignore depths Note: You can use relative coordinates to define exact lengths. Alternatively, you can draw User Lines to provide snap points to define exact lengths.
26.4 About ignore depths Design sections use the full concrete section available unless overridden by “Top Ignore Depth” or “Bottom Ignore Depth”. In many instances, it is inappropriate to use the full concrete cross-section properties of a design section for flexural and one-way shear design since some concrete is not effective. Note: Design section “ignore depth” settings are the equivalent of design strip “cross section trimming” settings. See “Cross Section Trimming” in Chapter 22, “Defining Design Strips” for more information.
26.4.1 When to use ignore depths It is sometimes obvious when to use ignore depth. Often, however, engineering judgement is required to determine the use of ignore depth. You should decide if the concrete is effective based on code rules and a practical assessment of the situation. There are too many permutations of concrete form to lay down rules, and, as such, the following is for discussion purposes only.
26.4.2 Examples of concrete form that should use ignore depth The following are examples of when design sections should ignore part of the concrete cross-section.
Example 1 A two-way slab thickening that the building code deems does not comply as a drop panel. That is, a drop cap. You should ignore the incremental thickness of the drop cap below the slab. RAM Concept then only uses the drop cap for punching checks.
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Figure 114: Two-way slab with drop cap that should be ignored for flexure.
Example 2 A beam or slab that supports an upstand that is not an effective part of the concrete section. You should enter an appropriate Top Ignore Depth value.
Figure 115: Beam with upstand to be ignored.
Example 3 A beam or slab that deepens abruptly and the full depth of the concrete cannot be mobilized for flexure. You should enter an appropriate Bottom Ignore Depth value. The following figure shows bending moments in a slab perpendicular to a beam. For such an arrangement you need to decide if the slab should be designed for the bending moment at the face of the beam, or within the beam.
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Figure 116: Slab bending moments If the slab is to be designed for the bending moment at the face of beam, then it is a matter of locating a design section within the slab depth. If the slab is to be designed for the bending moment within the beam then you should consider the actual depth that can be mobilized for bending.
Figure 117: Slab supported by a beam that is effective for slab bending.
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Figure 118: Slab supported by a deep beam that is not fully effective for slab bending. Ignore depth should be used for the design sections to utilize a shallower section.
26.4.3 Effect of ignore depth on reinforcement location RAM Concept locates reinforcement based upon the covers and ignore depth settings. You should consider this to ensure that reinforcement bars are designed at the appropriate depth.
26.5 A final word on design sections Design sections are powerful tools, but that is all they are: tools. It is important that you understand the calculations that these tools perform, so you can determine the appropriateness of the calculation for the situation under consideration, and so you can set the tools’ parameters correctly.
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Defining Punching Shear Checks Punching shear is often a critical consideration when designing slabs, In particular, post-tensioned slabs are usually thinner than their reinforced counterparts and hence punching considerations are even more important.
27.1 About punching shear checks RAM Concept can calculate punching failure planes and the punching shear stresses due to column reactions (Fz, Mx, My). RAM Concept is not infallible in its determination of potentially critical sections. For unusual geometries, RAM Concept may not check the appropriate section and / or may check inappropriate sections that give higher than appropriate stress ratios. You should review RAM Concept’s selections of potentially critical sections and use engineering judgment to decide if RAM Concept’s selections and the application of the ACI 318 model are appropriate.
27.2 Punching shear check properties and options The following explains the general and code specific Punching Shear Check properties and options.
27.2.1 General Maximum Search Radius
The radius that defines the area RAM Concept searches for potential failure locations. The analysis is conservative when you set a very large radius, but this has two detrimental effects: RAM Concept will need to review a larger area of slab and hence take longer to check that punching location. More importantly, RAM Concept will consider slab openings that are far from the column in determining the potentially critical section that may result in a smaller critical section than is appropriate.
Cover to CGS
The distance that will be subtracted from the slab depth in each region to determine the “effective depth” for critical section calculations. For columns under, this is usually the distance from the top of the slab to the bottom of the top bar. RAM Concept subtracts this distance from the slab thickness to determine the “d” distance.
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If the depth in any region is smaller than the specified Cover to CGS, the region is treated as a hole. Angle
This is the angle of the first ray measured counter-clockwise from the global x-axis.
Number of Desired Sections per Zone
A zone can be envisioned as a region outside a column, drop cap, beam, etc. A column connection in a simple plate will have only one zone. A column connection with a drop cap will have multiple zones. This property enables RAM Concept to determine how many sections you want to generate in each of these “zones”. This property can be used to eliminate unwanted sections, but caution should be used when reducing the desired number of sections. The sections generated are based upon the minimum critical section cross-sectional area, and they are not actually analyzed until after they are generated. By setting this value to 1 you would be likely to get only the most critical section in each zone but this is not guaranteed.
Edge Treatment This determines how RAM Concept treats edges and openings. • An edge treatment of Sector Voids is always conservative. For columns near a slab edge, however, the Sector Voids setting stops the critical section before it reaches the slab edge (at a ray from the column center to the slab edge that has a length equal to the search radius). • An edge treatment of Failure Planes probably produces better results for critical sections at edge and corner locations. This setting, however, requires you to review the results more carefully to ensure that RAM Concept has checked all the appropriate sections. • An edge treatment of Ignore Edges is generally unconservative. You may want to try this setting to see if RAM Concept finds a critical section that it missed with the other settings. Connection Type
This determines which column classification RAM Concept uses for calculating allowable stresses. • • • •
A Corner type uses corner column rules. An Edge type uses edge column rules. An Interior type uses interior column rules. An Auto type determines if the column is corner, edge, or interior type based upon the number of calculated “sides” of a particular critical section.
See Column connection type (on page 1193) for more information. Note: See specific code sections in Punching Shear Design Notes (on page 1188) for rules regarding usage of post-tensioning allowable stress rules. SSR System
The stud shear reinforcement system used, if required, for design. These systems can be edited on the Materials page. Predefined Ancon Shearfix systems are also available for selection from this drop-down list.
Max Overhang Factor
The maximum distance, as a function of effective depth “d”, to allow the critical sections to extend from the originating shape (column or SSR group). The sections will be generated without limitation, then trimmed to the specified distance.
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Align with Rectangular Columns
Aligns the punch check angle with the rectangular column angle during a “calc all”.
Design SSR if Necessary
Generates an SSR design (if possible) where the unreinforced strength is insufficient.
Align SSR w/ Punch Check Axis
Aligns the SSR with the punch check axis. For example, it is intended to be used when the slab edge is not parallel to the column faces and it would be preferable to have the rails align with the slab geometry instead of the column face. Note: This option is not available for AS3600 as the SSR are always aligned with the punching check axis.
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27.2.2 Ancon Shearfix Parameters Top and Bottom Cover The cover is used in conjunction with the slab depth to determine the physical rail depth. Stud Size The Ancon Shearfix stud size (diameter) to use in the design. If “auto” is selected, RAM Concept will design the smallest stud size possible for the maximum stud spacing and fixed rail layout. Note: These parameters are only used when the “Use Ancon Shearfix SSR System” option is selected. Use ACI 421.1R-99 Increased Max Vn Suggestion Allows the use of a higher maximum ΦVn for SSR design. Use ACI-421.1R-99 Increased Vc Suggestion Allows the use of a higher vc value for use in strength computations for SSR design. Use ACI-421.1R-99 Increased Max Stud Spacing Suggestion Allows higher maximum stud spacings, depending upon the stress levels in the critical sections. Note: Although ACI 421.1R-99 is an ACI publication, it is not officially recognized by the ACI 318 standard. As such, it should only be utilized under the discretion and judgment of an Engineer with a full understanding of the provision and its recommendations.
27.2.3 AS3600 specific options Closed Ties In R/S-Axis Torsion Strip Use these options if you are providing minimum closed ties in the torsion strips in accordance with AS3600. RAM Concept does not actually design this reinforcement, but uses the appropriate code provisions in calculating the punching capacity. You should ensure that this reinforcement is provided if using these options.
27.2.4 BS 8110/EC2 specific options Rail Layout Pattern Controls the layout of the primary rails around a column. The cruciform layout selection will provide parallel rails along each column face and a diagonal rail in each corner. The radial layout selection will provide rails that are radial from the punch check center. Note that for columns with small dimensions it is possible for the layout selection to produce identical layouts. Apply supplemental max stress limit
This option provides a supplemental maximum stress limit on the basic control perimeters as suggested in the paper “Effectiveness of punching shear reinforcement to EN 1992-1-1:2004” in The Structural Engineer 87 (10) May 2009.
Reinforcement Ratio
For specification of ρ1 for equation 6.47. You should calculate the input value using the equation in clause 6.4.4 of the EN 1992-1-1:2004 code. This value is only used if the Auto Calc Reinforcement Ration option is not specified.
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Defining Punching Shear Checks Drawing punching shear checks Auto-Calc Reinforcement Ratio
Automatically calculate the ρ value used in equation 6.47 using the user reinforcement on the specified face. Program reinforcement is not used in this calculation. See the notes on auto calculation of ρ1 (on page 1206).
Bar Location
Specifies the user bar location (top or bottom) to use in the auto calculation of reinforcement ratio.
Beta Factor
This represents a ratio of the maximum stress on a critical section (including shear and moment transfer) over the maximum stress due to shear only. This option allows the user to select Auto Calc, 1.15 (interior), 1.4 (edge), 1.5 (corner), or input any positive value for Beta directly. The factors for each column condition are taken from clause 6.4.3 (6) of the EN 1992-1-1:2004 Code and are meant to be used only when lateral stability does not depend upon frame action and where adjacent spans do not differ in length by more than 25%. Auto Calc uses the model and calculation methods described in Chapter 66, Punching Shear Design Notes (on page 1188).
27.3 Drawing punching shear checks You can draw punching shear checks for all columns simultaneously. 1. Choose Layers > Design Strips > Punching Checks Plan. 2. ). Select the Punching Shear Check tool ( 3. Fence the columns. A circle of the prescribed radius appears at each column within the fence.
27.4 A final word on punching shear checks Punching shear checks are extremely powerful tools, but that is all they are: tools. It is important that you understand the calculations that these tools perform, so you can determine the appropriateness of the calculation for the situation under consideration, and so you can set the tools’ parameters correctly.
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Drawing Reinforcement Bars Note: Drawing your own reinforcement bars is not necessary but an advanced feature you may wish to utilize once you are experienced with the program. The Reinforcement layer allows you to: • supplement the Program reinforcement by drawing actual (User) bars on plans using various tools • change some Program bars to User reinforcement The Reinforcement layer facilitates a production quality reinforcement layout.
28.1 Reinforcement bar definitions 28.1.1 About User and Program Reinforcement There are two types of reinforcement bar: Program and User. All reinforcement is tagged (identified) as one type or the other. When performing design calculations, RAM Concept generates Program reinforcement required in addition to any existing User reinforcement. In subsequent calculations, RAM Concept removes all of the Program reinforcement before starting the calculations. You can change Program Concentrated Reinforcement to User Concentrated Reinforcement merely by changing its tag (in the object properties window). You might do this to modify RAM Concept's design. When performing subsequent calculations, RAM Concept only designs reinforcement needed in addition to the reinforcement tagged as User. You could also change “User” reinforcement to “Program” reinforcement, but this has no value since RAM Concept removes all existing program reinforcement when it generates new “Program” reinforcement.
28.1.2 Reinforcement object types There are seven object types in the Reinforcement layer: • Concentrated Reinforcement - a fixed number of bars over a parallelogram area
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Drawing Reinforcement Bars Reinforcement properties • • • •
Distributed Reinforcement - a bar spacing applied over a polygon area. Individual Bars - single bars that are generated from Concentrated and Distributed Reinforcement. Transverse Reinforcement - a fixed number of transverse bars at a fixed spacing. Transverse Individual Bars - single transverse bars (strirrups/links/ligatures) that are generated from Transverse Reinforcement • Stud Shear Reinforcement (SSR) Callouts - a fixed number of SSR rails with a fixed number of studs. • SSR Rails - individual rails that are generated from SSR Callouts. You can directly create (by drawing) Concentrated Reinforcement, Distributed Reinforcement, and Transverse Reinforcement. You cannot directly create any of the other types of reinforcement.
28.2 Reinforcement properties
Figure 119: Concentrated rebar properties - General
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Drawing Reinforcement Bars Reinforcement properties
Figure 120: Distributed rebar properties - General Span Set Determines the set the reinforcement belongs to: latitude or longitude. Elevation Reference The choices are: • Absolute: the elevation relative to the zero datum. This is not recommended other than for very complicated geometry. • Above Soffit: The elevation is measured from the soffit elevation to the center of the bar. • Above Surface: The elevation is measured from the surface elevation to the center of the bar. The value is almost always negative • Top Cover: The elevation is measured from the surface elevation to the top of the bar. The value is always positive. • Bottom Cover: The elevation is measured from the soffit elevation to the underside of the bar. The value is always positive. Elevation The distance used with the elevation reference. Ending at End 1 The choices are: • • • •
Straight: 90 Hook: 180 Hook: Anchored:
Ending at End 2 Similar to End 1 Slab Face This is used for (1) graphic display purposes (2) design rules. The choices are:
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Drawing Reinforcement Bars Transverse Reinforcement properties • • • • •
Per Elev. Reference - the default and typical setting Top Bottom Both Auto
Note: Special Caution - Reinforcement set to “Auto” face will not appear on either the “top” or the “bottom” reinforcement plans. If you use “Auto” face reinforcement, change the default plan settings (or add some plans) to be certain that all of the reinforcement used is visible on the plans in your report. Bar Type The label used to identify the reinforcing bar. The label is not necessarily the bar size. Reinforcement bar labels (and their properties) are specified in the Criteria > Materials. Bar Extent Skew The orientation of the bar’s extent line in degrees (concentrated reinforcement only - see “The Skew Reinforcement Extent tool” for more information). Quantity Type The choices are: • Quantity: number of bars • Spacing: bar spacing Number of bars Only editable if Quantity Type is set to Quantity Spacing Only editable if Quantity Type is set to Spacing. Orientation The plan angle of the reinforcement (distributed reinforcement only - see “The Orient Reinforcement tool” for more information). Zone Width The width of the concentrated reinforcement zone. Designed By The choices are: • User: Bars drawn by the user • Program: Bars calculated and drawn by RAM Concept. Note: See “Concentrated and distributed reinforcement callouts” for discussion on the second (Presentation) tab. Related Links • The Skew Reinforcement Extent tool (on page 294) • The Orient Reinforcement tool (on page 293)
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Drawing Reinforcement Bars Transverse Reinforcement properties
28.3 Transverse Reinforcement properties
Figure 121: Transverse rebar properties - General In addition to properties that are common with longitudinal reinforcement, transverse reinforcement has the following special properties: Shape
The choices are: Open: Capable of resisting shear only Closed: Two legs are capable of resisting torsion in addition to shear
Number of Legs
The number of vertical legs in the transverse reinforcement
Spacing Control
If the length/spacing are not in equal increments, this controls which is the independent property (that remains fixed) and which is the dependant property (that gets adjusted). The choices are: Length Fixed: The length remains fixed, and the input spacing is taken as a maximum spacing and adjusted down to create an equal number of spaces. Spacing Fixed: the spacing remains fixed, and the input length is adjusted up to an equal increment of the input spacing. The length is always adjusted at the end of the transverse rebar object, and the start point remains fixed.
Length
The specified length of the region which contains transverse reinforcement.
Spacing
The specified spacing between the transverse reinforcement along the region.
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Drawing Reinforcement Bars About drawing reinforcement
28.4 About drawing reinforcement You can draw reinforcement in a number of ways: • A group of one or more concentrated reinforcement bars using one of the three Concentrated Reinforcement tools • A group of distributed reinforcement bars using one of the three Distributed Reinforcement tools • A region of transverse reinforcement using the Transverse Reinforcement tool
28.4.1 Expected workflows It is expected that you will typically convert the “Program” reinforcement to “User” reinforcement and modify it. One common exception to this might be that you may want to specify a bottom mat of reinforcement. There is no difficulty if you convert some reinforcement and directly draw other reinforcement.
28.5 Drawing concentrated reinforcement Concentrated reinforcement consists of one or more bars located within a parallelogram. The parallelogram is initially a rectangle with a default width, but you can use the stretch tool to edit the width and the skew tool to change the shape.
28.5.1 Drawing concentrated reinforcement You can draw concentrated rebar by specifying the end points or specifying the midpoint and one endpoint. 1. Select the Concentrated Reinforcement tool ( 2. Click at one endpoint. 3. Click at the other endpoint.
).
Note: See “Drawing concentrated bottom bars” for more information.
To draw concentrated reinforcement #2 1.
Select the Concentrated Reinforcement tool ( 2. Click at the midpoint. 3. Click at one endpoint.
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Drawing Reinforcement Bars Drawing distributed reinforcement Note: See “Drawing concentrated bottom bars by defining the midpoint” for more information.
28.5.2 Drawing concentrated reinforcement in two directions You can draw concentrated rebar in two directions by specifying the midpoint and one endpoint. 1. Select the Concentrated Reinforcement Cross tool ( 2. Click at the midpoint. 3. Click at one endpoint.
).
Note: This creates two reinforcement objects: one that belongs to the latitude reinforcement layer and one that belongs to the longitude reinforcement layer. Note: See “Drawing concentrated bottom bars in two directions” for more information.
28.6 Drawing distributed reinforcement Distributed reinforcement consists of a group of bars located within a polygon.
28.6.1 Drawing distributed reinforcement You draw distributed reinforcement within a polygon. This is done by defining the polygon with mouse clicks or using the slab perimeter. 1. Choose the Distributed Reinf. tool ( ). 2. Click at each polygon vertex consecutively. 3. Snap to the first vertex and click to close the polygon (or type “c” and press ). Note: This creates two objects: a polygon and a reinforcement object that belongs to either the latitude reinforcement layer or longitude reinforcement layer. Note: Once the file is run you can view the individual bars through the Visible Objects dialog box. Note: See “Drawing distributed bottom bars over part of the floor” for more information.
To draw distributed reinforcement #2 1. Choose the Distributed Reinf. in Perimeter tool ( ). 2. Click somewhere on the slab. 3. Click at another point to define the orientation of the reinforcement.
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Drawing Reinforcement Bars Drawing transverse reinforcement Note: This creates two objects: a polygon matching the slab outline and a reinforcement object that belongs to either the latitude reinforcement layer or longitude reinforcement layer. Note: Once the file is run you can view the individual bars. Note: See “Drawing distributed bottom bars over the entire floor” for more information.
To draw distributed reinforcement #3 1. Choose the Distributed Reinf. Cross in Perimeter tool ( ). 2. Click somewhere on the slab. 3. Click at another point to define the orientation of the reinforcement. A polygon appears that is the shape of the slab. Once the file is run you can view the individual bars. Note: This creates three objects: a polygon matching the slab outline, a reinforcement object that belongs to the latitude reinforcement layer and a reinforcement object that belongs to the longitude reinforcement layer. Note: See “Drawing a bottom mat over the entire floor” for more information.
28.7 Drawing transverse reinforcement Transverse reinforcement consists of one or more transverse bars located along a line segment.
28.7.1 Drawing transverse reinforcement You can draw transverse reinforcement by specifying the end points. 1. Select the Transverse Reinforcement tool (
).
You can use the stretch tool to edit the length and location of the region, or change the length and/or spacing properties. The transverse reinforcement line segment must intersect any shear cores in cross sections you want to reinforce. The size, shape, and orientation of the transverse reinforcement take on the size and shape of the containing shear core.
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Drawing Reinforcement Bars Concentrated and distributed reinforcement drawing examples
28.8 Concentrated and distributed reinforcement drawing examples 28.8.1
Drawing concentrated bottom bars
Figure 122: Concentrated bars drawn by clicking at points A and B with the first Concentrated Reinforcement tool.
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Drawing Reinforcement Bars Concentrated and distributed reinforcement drawing examples
28.8.2
Drawing concentrated bottom bars by defining the midpoint
Figure 123: Concentrated bars drawn by clicking at points A and B with the second Concentrated Reinforcement tool.
28.8.3
Drawing concentrated bottom bars in two directions
Figure 124: Concentrated bars in two directions drawn by clicking at points A and B with the Concentrated Reinforcement Cross tool.
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Drawing Reinforcement Bars Concentrated and distributed reinforcement drawing examples
28.8.4
Drawing distributed bottom bars over part of the floor
Figure 125: Distributed bar polygon drawn over part of the slab by clicking at 5 vertices with the Distributed Reinforcement tool. Hatching is turned ON.
Figure 126: Individual distributed bars shown via Visible Objects dialog box. Hatching is turned OFF.
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Drawing Reinforcement Bars Concentrated and distributed reinforcement drawing examples
28.8.5
Drawing distributed bottom bars over the entire floor
Figure 127: Distributed bars polygon drawn over the slab by clicking at points A and B with the Distributed Reinforcement in Perimeter tool. Hatching is turned ON.
Figure 128: Individual distributed bars shown via Visible Objects dialog box. Hatching is turned OFF.
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Drawing Reinforcement Bars Transverse reinforcement drawing examples
28.8.6
Drawing a bottom mat over the entire floor
Figure 129: Distributed bottom mat polygon drawn over the slab by clicking at points A and B with the Distributed Reinforcement Cross in Perimeter tool. Hatching is turned ON.
Figure 130: Individual distributed bars shown via Visible Objects dialog box. Hatching is turned OFF.
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Drawing Reinforcement Bars Transverse reinforcement drawing examples
28.9 Transverse reinforcement drawing examples
Figure 131: Two scenarios of user transverse reinforcement, both resulting in individual bars that are coplanar to the cross sections that the line segment intersects.
Figure 132: Resulting individual transverse bars when with no cross section trimming
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Drawing Reinforcement Bars Other reinforcement plan tools
Figure 133: Resulting individual bars when cross section trimming is set to Slab Rectangle
28.10 Other reinforcement plan tools There are three special tools in the Reinforcement layer that you can use to edit the plan properties of reinforcement.
28.10.1 The Orient Reinforcement tool This tool allows you to draw a line segment that represents the desired orientation of selected reinforcement objects’ individual bars. After you draw this line, RAM Concept rotates any selected concentrated reinforcement objects, and orients any distributed reinforcement parallel to the drawn line. The selected reinforcement creates individual bars of the same orientation after calculation. 1. 2. 3. 4.
Select the reinforcement object. Choose the Orient Reinforcement tool ( ). Click anywhere on the plan. Click at a location on the plan to create a line parallel to the desired direction of the reinforcement.
Note: Use snap orthogonal or snap to perpendicular to help with orientation where appropriate Note: Selecting both reinforcement objects created with the Concentrated Rebar Cross tool or the Distributed Rebar Cross in Perimeter tool orientates both reinforcement objects. Note: See “Orientating concentrated reinforcement” for more information.
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Drawing Reinforcement Bars Other reinforcement plan tools
28.10.2 The Skew Reinforcement Extent tool This tool allows you to draw a line segment that represents the desired orientation of selected Concentrated Reinforcement objects' extent line. This tool allows you to create parallelogram regions of Concentrated Reinforcement. Distributed reinforcement cannot be skewed. 1. 2. 3. 4.
Select the concentrated reinforcement object. Choose the Skew Reinforcement Extent tool ( ). Click anywhere on the plan (but preferably near the reinforcement object) Click at a location on the plan to create a line parallel to the desired extent line.
Note: See “Skewing concentrated reinforcement” for more information.
28.10.3 Auto Hook tool This tool allows you to automatically extend concentrated rebar callouts in close proximity to the slab edge and apply hooks to a selected set of user reinforcement. To apply hooks to reinforcement near the slab edge 1. Select the user concentrated reinforcement that you wish to modify. 2. ). Choose the Auto Hook tool ( 3. Select the hook type from the drop down menu. 4. Set the Edge Detection Tolerance. Only bar ends within this distance of a slab edge will be modified 5. If you want the bar end extended to the slab edge, check the “Perform Bar Extension” box and set the desired edge cover and bar rounding length. 6. Click “OK”. Note: See “Automatically applying hooks to user reinforcement” for more information.
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Drawing Reinforcement Bars Other reinforcement plan tools
Orientating concentrated reinforcement
Figure 134: Using the Orient Reinforcement tool to define the line A B parallel to the desired orientation
Figure 135: The reoriented concentrated reinforcement
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Drawing Reinforcement Bars Other reinforcement plan tools
Skewing concentrated reinforcement
Figure 136: Using the Skew Reinforcement tool to define the line A B parallel to the desired skewed ends
Figure 137: The skewed concentrated reinforcement with the extent line parallel to line AB.
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Drawing Reinforcement Bars Other reinforcement plan tools
Stretching concentrated reinforcement
Figure 138: Using the stretch tool at point A to widen the concentrated reinforcement parallelogram
Figure 139: The stretched concentrated reinforcement
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Drawing Reinforcement Bars Layout and Detailing Parameters
Automatically applying hooks to user reinforcement
Figure 140: Use the auto hook tool to apply hooks to all four concentrated bar callouts
Figure 141: Hooks applied and bars extended to the slab edge
28.11 Layout and Detailing Parameters There are five calculation option parameters that influence how RAM Concept lays out and details reinforcement. Refer to “Reinforcement layout and detailing parameters” in Chapter 28, “Calculating Results”.
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Drawing Reinforcement Bars Reinforcement Text Formatting
28.12 Reinforcement Text Formatting Concentrated Reinforcement, Distributed Reinforcement and SSR Callouts all have format specifiers that you can modify so the reinforcement is described per your office standards.
28.12.1 Concentrated and distributed reinforcement callouts
Figure 142: Concentrated rebar properties - Presentation
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Drawing Reinforcement Bars Reinforcement Text Formatting
Figure 143: Distributed rebar properties - Presentation Callout by The Concentrated and Distributed Reinforcement format specifiers use the following key Quantity/Spacing values: Format • $Q - Bar quantity • $F - Bar face • $B - Bar name • $L - Bar length • $U - Bar length units • $u - Bar spacing units • $S - Bar spacing • \n - Start new line
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Drawing Reinforcement Bars Reinforcement Text Formatting
28.12.2 Transverse reinforcement callouts
Figure 144: Transverse reinforcement properties - Presentation Callout Format
The transverse reinforcement format specifiers use the following key values: • • • • • •
$B - Bar name $S - Spacing $N - Number of spaces $L - Number of legs (and shape) $U - Spacing units \n - Start a new line
28.12.3 SSR Callout The SSR Callout format specifiers use the following key values: • • • • • • • •
$R - Rail quantity $S - Studs per rail $F - First stud spacing $T - Typical stud spacing $N - SSR system name $U - Stud spacing units $S - Stud spacing \n - Start new line
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Drawing Reinforcement Bars About SSR callouts and SSR rails: The SSR Callout format specifier “($R)$S@$T First Spacing = $F $U\n$N” would generate text on the plan view such as: (12)8@3 First Spacing = 2.5 inches 3/8” SSR For the same SSR Callout, the format specifier “$R rails with $S studs” would generate the text: 12 rails with 8 studs
28.12.4 Examples of reinforcement text formatting The following examples show generated text for different codes. ACI 318-05 The Concentrated Reinforcement format specifier “$Q $B x $L $U $F@$S $u” would generate text on the plan view such as: 28 #5 x 15 feet T @ 12.1 inches For the same Concentrated Reinforcement, the format specifier ($Q)$Bx$L$F" would generate the text: (28)#5x15T AS 3600-2001 The Concentrated Reinforcement format specifier $Q $B x $L $U $F@$S $u" would generate text on the plan view such as: 28 N16 x 4.57 m T @ 307 mm For the same Concentrated Reinforcement, the format specifier “($Q)$Bx$L$F” would generate the text: (28)N16x4.57T BS 8110 : 1997, EC2 and IS456-2000 The Concentrated Reinforcement format specifier $Q $B x $L $U $F@$S $u" would generate text on the plan view such as: 28 T16 x 4.57 m T @ 307 mm For the same Concentrated Reinforcement, the format specifier “($Q)$Bx$L$F” would generate the text: (28)T16x4.57T
28.13 About SSR callouts and SSR rails: RAM Concept generates SSR Callouts and SSR Rails from the results of its punching shear calculations. This generated reinforcement is for display purposes only - it is not used in calculations and cannot be changed to “user” reinforcement.
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29
Defining Tendons Note: You could bypass this chapter if you are designing a structure with only bar reinforcement. There is no unique quantity or layout of post-tensioning that provides a satisfactory PT design. This is particularly true with partial prestress design where the emphasis is on strength, deflection and crack control rather than hypothetical service stresses. Historically, many 2D programs have used allowable service stresses to drive their algorithms for providing a PT solution. This is fast losing favor; some codes have all but abandoned using (hypothetical) service stresses as a design criterion, and other codes (such as ACI 318) are moving in that direction. Some computer generated tendon layouts are not practical for real design. Whereas you expect a 2D program to help provide a workable tendon design based upon spans, sections and loads, the possible randomness of supports makes this extremely difficult in 3D. Thus, in RAM Concept, it is necessary for you to define the tendons by generating or drawing them in plan and specifying parameters such as profile and number of strands. For guidance, you should use one of the following for your first estimate: • • • •
your experience a preliminary run with Strip Wizard a logical guess based upon precompression (P/A) considerations a random guess (correctly drawn design strips flag incorrect guesses, and you can use “The Auditor” for help in iterating)
RAM Concept's PT Optimization feature (see Designing and Optimizing Post-tensioning (on page 331)) automates the search for an economical design and eliminates the need for manual iteration.
29.1 Tendon definitions 29.1.1 Post-Tensioning terminology and definitions • Strand - a single wire or group of bundled wires. In post-tensioned construction a strand is a unit of posttensioning reinforcement, similar to a reinforcing bar being the unit of RC reinforcement. • Duct - a tube, conduit, or sheathing containing one or more strands with a single anchorage. The maximum number of strands in a duct is defined in the prestressing material properties. For monostrand tendons (bonded or unbonded), each duct contains a single strand.
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Defining Tendons Tendon Parameters Layer • Tendon - In practice, the PT industry defines a tendon as a group of strands that share a common anchorage. The “group” may be just one strand, as is the case with most unbonded systems, or “monostrand”. It is not always necessary for real tendons to match RAM Concept tendon exactly. For example, it is common practice in monostrand to group tendons together in the field. For this situation, it is usually convenient to specify the total number of strands in the group in a single RAM Concept tendon. In this case the correct number of ducts can still be calculated correctly using the input duct properties.
29.1.2 Using the latitude and longitude prestressing folders RAM Concept has two folders for prestressing called latitude and longitude. By using RAM Concept’s two tendon folders, you can separate tendons and tendon parameters into two groups. Separating orthogonal tendons allows for easier editing and a clearer presentation. Each folder contains three layers: • Tendon Parameters Layer - defines high level objects used for the generation of individual tendons. This layer facilitates a production quality presentation of high level tendon layout information. • Generated Tendon Layer - contains the individual tendons generated from the parameter objects on the Tendon Parameters Layer. The generated individual tendons can not be edited, but can be selected and copied to the Manual Tendon Layer for further manipulation. • Manual Tendon Layer - contains individual tendons drawn or otherwise manipulated manually by the user. During analysis and design, all tendons on the generated tendon layers (latitude and longitude) and the manual tendon layers (latitude and longitude) are included in the calculations. Therefore it is important not to duplicate tendons on the generated and manual layers. Note: Latitude and longitude are just names. You could define all tendons, which might be at various plan angles, on one plan.
29.2 Tendon Parameters Layer 29.2.1 Tendon Parameters object types There are six object types in the Tendon Parameters Layer: • Banded Tendon Polyline - a polyline representing a specification for generation of a group of tendons at a fixed spacing and parallel to the polyline segments. • Distributed Tendon Quadrilateral - a quadrilateral representing a specification for generation of an array of tendons at a specified angle within the shape. • Distributed Tendon Overlap - a graphical only object that displays the cumulative force or number of strands in an area of overlapping distributed tendon quadrilaterals. • Tendon Void - a polygon shape that represents an area where no tendons are to be generated. Typical usage might be stressing blockouts or small slab areas that are too short for tendons to get stressed.
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Defining Tendons Tendon Parameters Layer • Profile Polyline - a polyline that defines a tendon elevation at the location where any banded tendon polyline or distributed tendon quadrilateral intersects it. • Jack Region – a polygon shape with jack properties that applies a jack on the generated tendon layer to all generated tendon ends that are contained within it.
29.2.2 Banded Tendon Polyline and Distributed Tendon Quadrilateral Properties
Figure 145: Distributed tendon quadrilateral properties - General
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Defining Tendons Tendon Parameters Layer
Figure 146: Banded tendon polyline properties - General Group
Allows for selection of a banded tendon or distributed quadrilateral group which will control some of this object’s properties. If a group is selected, the following properties are set by the assigned group: • • • • •
Effective Force/Number of Strands PT System Inflection Point Ratio Tending Spacing (Distributed Tendon Quadrilateral only) Optimization Properties
See Tendon Parameters Group (on page 310) for additional information about groups. Tendon Determines the mode for specifying strand quantities that go into the generated tendons. Specification Type The choices are: • Force • Strands
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Defining Tendons Tendon Parameters Layer Effective Force
Only enabled when “force” is selected for “Tendon Specification Type”. For banded tendon polylines, this value represents the total effective force to be generated in the banded group. For distributed tendon quadrilaterals, this represents the effective force per unit width of slab to generate in the distributed tendon array.
Number of Strands
Only enabled when “strands” is selected for “Tendon Specification Type”. For banded tendon polylines, this value represents the total number of strands to be generated in the banded group. For distributed tendon quadrilaterals, this represents the number of strands per unit width of slab to generate in the distributed tendon array.
Max Strands/ Tendon
For banded tendon polylines, this value defines the maximum number of strands to put into a single generated tendon.
Layout Type
For banded tendon polylines, this value defines the layout type of the generated tendons. The choices are: • Spacing • Width
Tendon Spacing
Defines the lateral spacing between generated tendons.
Layout Width
For banded tendon polylines, defines the total width of the generated tendon layout when “width” is selected for “Layout Type”. The width includes a half space on each side of the outermost generated tendons.
Tendon Type
For banded tendon polylines, defines the behavior of the banded tendon polyline and the properties of the generated tendon. The choices are: • Primary • Added
Added Tendon Generation
For banded tendon polylines, controls the behavior of the automatic generation of added tendons to balance forces at connected banded tendon polyline ends. The choices are: • None • Fixed Length • Span Fraction
Added Tendon Length
For banded tendon polylines when “Fixed Length” is selected for “Added Tendon Generation”, controls the length of the automatically generated banded tendon polyline.
Added Tendon Span Fraction
For banded tendon polylines when “Span Fraction” is selected for “Added Tendon Generation”, controls the length of the automatically generated banded tendon polyline as a function of the span containing the joint that the added tendon is attached.
PT System
The label used to identify the PT system for the generated tendons. The label is not necessarily the size and type of strand. The Materials Specification defines the PT system properties. It is possible to mix systems in a single tendon parameters layer.
Inflection Point Ratio
Determines the distance, x, from end 1 in the span to the point where the tendon curvature changes sign. The inflection point ratio is the ratio of x to the distance from end 1 to end 2. A value of 0.2 places the inflection point 10% of the span distance from end 1 if end 2 is at midspan. This is a commonly used value. Note: An inflection point ratio of zero results in a simple parabola.
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Specifies the tendon segment as having a straight profile (as opposed to a parabolic profile).
29.2.3 Distributed Tendon Overlap and Tendon Void Properties These objects have no user editable properties
29.2.4 Profile Polyline Properties
Group
Allows for selection of a profile polyline group which will control some of this object’s properties. If a group is selected, the following properties are set by the assigned group: • Elevation Reference • Elevation • Optimization Properties See Tendon Parameters Group (on page 310) for additional information about groups.
Elevation
The vertical distance from the elevation reference to the centroid of the tendon’s strands, also referred to as CGS (center of gravity of strand). Note: This version of RAM Concept measures the top and bottom cover to the CGS of the strands. Future versions will allow inputting of duct dimensions and allow a top and bottom cover to the outside of the duct to be input. Note: The CGS is not the same as mid-depth of a bonded tendon’s duct.
Elevation Reference
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The choices are: • Absolute: the elevation relative to the zero datum. This is not recommended other than for very complicated geometry. • Above Soffit: The elevation is measured from the soffit elevation to the CGS of the tendon.
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• Above Surface: The elevation is measured from the surface elevation to the CGS of the tendon. The value is almost always negative. • Top Cover: The elevation is measured from the surface elevation to the CGS of the tendon. The value is always positive. • Bottom Cover: The elevation is measured from the soffit elevation to the CGS of the tendon. The value is always positive. Profile Location
Determines the orientations of the created tendon half-spans (and the corresponding inflection point location). The choices are: • Support • Span The support profile polylines are displayed graphically as solid lines on plan, while the span polylines are displayed as dashed lines.
29.2.5 Jack Region Properties Set the default jack properties in the Default Jack Properties dialog box by double clicking the Jack Region tool ). You can choose to ignore the jack region property values in the Jack Region Properties dialog and instead ( use the PT System values. The following is a list of jack region properties: Jacking Stress
The stress in the strand at the jack at jacking.
Anchor Friction Coefficient
Loss of stress due to friction in the anchorage. It is a fraction with no units. You would enter a 2% loss as 0.02. Most PT suppliers recommend a value of zero for unbonded tendons. You might consult with a local PT supplier regarding bonded tendons.
Wobble Friction Coefficient
Friction calculations use this property (k) to estimate losses due to accidental curvature (in the horizontal and vertical planes). It is the product of the angle friction coefficient and the accidental angular change per unit length. Note: Some engineering communities (Australia in particular) use a definition of wobble coefficient that is the accidental angular change per unit length. These communities can calculate the wobble coefficient that Concept uses, k, with the following relationship: k = AngularWobbleCoefficient * mu.
Angle Friction Coefficient
Loss due to deliberate curvature (in the horizontal and vertical planes). Most designers know it as mu.
Seating Distance The distance that the wedges recede into the anchorage. This occurs when the field operator releases the tension in the jack. Long Term Losses
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The sum of losses such as creep and shrinkage of concrete, and relaxation of strand. It also includes the loss due to elastic shortening of the concrete even though it is a short-term loss.
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29.3 Tendon Parameters Group In some instances, it is beneficial for multiple banded tendon polyline objects, distributed tendon quadrilaterals object, or profile polyline objects to have identical properties. One example is in symmetrical structures, where for practicality the resulting tendon layout and design should also be symmetrical. It might also be desirable for many different profile elevations to be identical for a typical span in a structure. This can be accomplished using Tendon Parameters Groups. Once groups are created, they can be selected and assigned to any number of their respective object types, at which point those objects will belong to that group. The properties of the banded tendon polyline, distributed tendon quadrilateral, or profile polyline that are in the group will then be controlled by the group properties, allowing multiple object properties to be updated by changing the group property value. Groups can also be useful for optimization, especially in cases where it may be practical or desirable to optimize multiple objects in unison or to reduce the number of optimizable objects in the problem. See Designing and Optimizing Post-tensioning (on page 331) for additional information.
29.3.1 Viewing the Tendon Parameters Group The Tendon Parameters Groups window (opens when Criteria > Tendon Parameters Groups is selected) shows the names and properties of the banded tendon polyline groups, the distributed tendon quadrilateral groups, and the profile polyline groups. New groups can be created by selecting Add Banded Tendon Polyline Group, Add Distributed Tendon Quadrilateral Group, or Add Profile Polyline Group.
Selecting the objects in a group The objects belonging to a group or multiple groups can be selected by selecting Select Banded Tendon Polyline Group, Select Distributed Tendon Quadrilateral Group, or Select Profile Polyline Group. Upon selecting the desired group(s) and clicking OK, all objects belonging to the selected groups on any plan that has the Tendon Parameters Layer as the active layer will be selected.
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29.4 Manual Tendon Layer 29.4.1 Tendon properties Before you begin drawing tendons, specify the default properties for the tool(s) you will use. The default values are set in the Default Properties dialog box. Double click one of the tendon drawing tools (Half Span Tendon ( ), Full Span Tendon ( properties.
), Half Span Tendon Panel (
), or Full Span Tendon Panel (
)) to edit its
Note: Setting the default properties for one tendon drawing tool sets properties for all the tendon drawing tools. The following is a list of RAM Concept tendon properties: PT System The label used to identify the PT system for the generated tendons. The label is not necessarily the size and type of strand. The Materials Specification defines the PT system properties. It is possible to mix systems in a single tendon layer. Strands per Tendon Specifies the number of strands in the selected tendon(s). It need not be an integer value. While the total number of strands in RAM Concept and the real structure must match, the grouping of strands into tendons need not be the same in RAM Concept as in the real structure. It is usually not necessary to model each real tendon as a RAM Concept tendon - fewer RAM Concept tendons (with a larger number of strands per tendon) are often used. An exception is for specific code rules that require a deduction in shear area for duct size. In those situations you should specify the correct duct size and number of strands per tendon. For example, if you model six 4-strand ducts containing 2 strands each, as three 4-strand ducts containing 4 strands each, RAM Concept considers the correct number of strands (12), but only three of the six ducts. Elevation (Elevation Value at end 1 and Elevation Value at end 2) The vertical distance from the elevation reference to the centroid of the tendon’s strands, also referred to as CGS (center of gravity of strand). Note: This version of RAM Concept measures the top and bottom cover to the CGS of the strands. Future versions will allow inputting of duct dimensions and allow a top and bottom cover to the outside of the duct to be input. Note: The CGS is not the same as mid-depth of a bonded tendon’s duct. Elevation Reference The choices are: • Absolute: the elevation relative to the zero datum. This is not recommended other than for very complicated geometry. • Above Soffit: The elevation is measured from the soffit elevation to the CGS of the tendon. • Above Surface: The elevation is measured from the surface elevation to the CGS of the tendon. The value is almost always negative. • Top Cover: The elevation is measured from the surface elevation to the CGS of the tendon. The value is always positive. • Bottom Cover: The elevation is measured from the soffit elevation to the CGS of the tendon. The value is always positive.
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Defining Tendons About creating tendons The dimension from the elevation reference (at that exact plan location) to the CGS is the Elevation Value. Thus, if a profile point is located over a slab thickening (drop cap, beam etc.) then the thickening should be taken into account if the elevation reference refers to the changing surface. RAM Concept does not currently use dimensions to underside of duct, or cover, to determine elevation values. Future versions will incorporate this calculation. The path of a tendon along with the number of strands determines the forces the tendon exerts on the concrete. Profile points (that are usually the tendon high and low points) define this path. If necessary, you can introduce intermediate profile points. Tendons are comprised of segments. For elevated floors, each segment has a high point (end 1) and a low point (end 2). For mats, the reverse is generally true. Each segment can represent a half of a span, or a partial half span. Most user defined spans have a tendon with two segments. Cantilevers and some user defined spans have tendons with one segment. Selections for Elevation Value and Elevation Reference should consider cover and load balancing. Profiles typically vary according to span lengths. Note: Profile values displayed in RAM Concept are always from the soffit. When structure and/or tendon changes are made, the profile values can be temporarily out of date and incorrect. In order to update the profile values, use the “Generate Tendons” command or run a “Calc All”. Inflection Point Ratio Determines the distance, x, from end 1 in the span to the point where the tendon curvature changes sign. The inflection point ratio is the ratio of x to the distance from end 1 to end 2. A value of 0.2 places the inflection point 10% of the span distance from end 1 if end 2 is at midspan. This is a commonly used value. Note: An inflection point ratio of zero results in a simple parabola. Harped Specifies the tendon segment as having a straight profile (as opposed to a parabolic profile). Half Span Ratio (Half Span Ratio End 1 and Half Span Ratio End 2) Specifies the portion of the half span that this segment represents. The end 2 half span ratio must always be greater than the end 1 half span ratio. Half span ratios of 0 and 1 represent an entire half span. It is not recommended that these values be changed by the user. Position Profile Point 2 for equal balance loads If two entire half span tendon segments in a single span have different values for end 1 then the Position Profile Point 2 for equal balance loads option moves the low point in plan to equilibrate the uplift during an analysis calculation. Note: Do not select this option if the half span ratios of both tendon segments are not 0 and 1 or if the profile values are at the same elevation. A segment with such profiles would have zero uplift and so the formulation does not work.
29.5 About creating tendons There are two ways to generate tendons: • Specification of objects on the tendon parameters layers, resulting in generated tendons on the generated tendon layers.
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Defining Tendons Drawing banded tendon polylines • Drawing individual tendons directly on the manual tendon layers. These tendon generation schemes support a number of workflows related to tendon generation and design. The most common are outlined here:
29.5.1 All tendon definition done on the tendon parameters layers The Engineer specifies all prestressing on the tendon parameters layers, allowing RAM Concept to automatically generate individual tendons from the tendon parameters objects. When making changes to the tendon layout the Engineer will add, delete, or edit objects on the tendon parameters layer only. The Engineer might use the tendon parameter plans or the generated tendon plans for their tendon design plans.
29.5.2 Most tendon definition done on the tendon parameters layers The Engineer specifies most prestressing on the tendon parameters layers but wants to supplement with isolated individually drawn tendons on the manual tendon layers. This might be faster to make minor adjustments than changing tendon parameter objects. The drawing production workflow might be to export tendon parameter and manual tendon plans on the plan(s), then modify those objects in CAD to product the final drawings.
29.5.3 All work done on manual tendon layers The Engineer prefers working with individual tendons for both design and production of final tendon plans. The Engineer can draw the individual tendons on the manual tendon layers, or define objects on the tendon parameters layers to quickly generate a large number of tendons that can then be manipulated manually. Since the tendon objects on the generated tendon layers can not be edited, they will need to be copied and pasted from the generated tendon layers to the manual tendon layers. The objects on the tendon parameters layers would then be deleted to avoid duplication.
29.6 Drawing banded tendon polylines Banded tendon polylines consist of two or more connected points that define a polyline. Once drawn the stretch tool can be used to modify the location of any of the points. 1. 2. 3. 4. 5.
Choose the Banded Tendon Polyline tool ( ). Click at the tendon polyline start point. Click the next tendon polyline point (can be drawn across multiple spans or partial spans). Continue to click tendon polyline points until all are defined. Right click and select enter to complete the operation.
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Defining Tendons Drawing distributed tendon quadrilaterals Note: Banded tendon polylines can be connected at their end points to single or multiple other banded tendon polylines. However, it is an error to define banded tendon polylines that overlap.
29.7 Drawing distributed tendon quadrilaterals Distributed tendon quadrilaterals define a specification to generate a specific force or number of strands per unit width at a given angle within a defined 4 sided polygon. 1.
Choose the Distributed Tendon Quadrilateral tool ( ). 2. Click each of the four vertices of the quadrilateral vertex sequentially (the quadrilateral can extend across multiple spans or bays).
Since distributed tendon quadrilaterals are meant to represent a “smeared” tendon force, the spacing specified isn’t typically critical. However, due to geometrical irregularities inaccuracies can be introduced near the edges of the shape. RAM Concept automatically attempts to provide a half space at each edge of the tendon layout area to minimize this effect. This effect can also be minimized by specifying a smaller spacing, at the expense of a larger number of generated tendons and increased run time. A spacing of 2 ft (0.75 m) will normally provide a good balance between accuracy and computational expense. Notes: Distributed tendon quadrilaterals with common spacing, PT System, inflection point ratio, and harped property can be drawn overlapping and RAM Concept will consider the cumulative force/strands in overlapping regions.
29.8 Defining profiles for banded tendon polylines and distributed tendon quadrilaterals Profiles are determined for banded tendon polylines and distributed tendon quadrilaterals by creating profile polylines. Tendon half spans are created wherever a generated tendon intersects a profile polyline. The generated half span tendons are oriented in the following direction (which will determine the inflection point location): • support polyline - span polyline • support polyline - slab edge • slab edge - span polyline Where generated tendons intersect identical profile polyline types (i.e, both supports), the tendon is oriented from the location of highest absolute elevation to the location of lowest absolute elevation. If the end elevations are the same then the orientation will be random (and not important). Where banded tendon polylines end away from a profile polyline or intersect a slab edge, the tendon is profiled to the mid-depth of the slab at the end or slab edge intersection location. Where distributed tendon quadrilaterals end between two profile polylines or the slab edge, the tendons are profiled as if they were extended to the next adjacent profile polyline or slab edge (representing a partial half
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Defining Tendons Defining profiles for banded tendon polylines and distributed tendon quadrilaterals span). This allows two distributed tendon quadrilaterals with different angles to be drawn adjacent to each other along a span and represent continuous span tendons. Where distributed tendon quadrilaterals intersect the slab edge and there is no profile polyline near the edge, the tendons are profiled to the mid-depth of the slab. Profile polylines can be created in a number of ways: • Drawing them manually. • Generating them for the entire floor in one span direction using the Generate Profile Polylines tool. • Generate span polylines from already defined support polylines using the Generate Span Polylines tool.
29.8.1 Drawing Profile Polylines 1. 2. 3. 4. 5.
Choose the Banded Tendon Polyline tool ( ). Click at the profile polyline start point. Click the next profile polyline point. Continue to click profile polyline points until all are defined. Right click and select enter to complete the operation.
29.8.2 Defining profile polylines using the Generate Profile Polylines tool This tool allows you to generate profile polylines automatically using span segments that have already been defined on the design strip layer. Support polylines are generated from existing span segments. Latitude tendon support polylines are generated from longitude span segments and vice-versa. Span polylines are created from the support polylines created in the first step of the operation. If no span segments are drawn on the corresponding layer then no profile polylines will be created. To generate profile polylines 1.
Choose the Generate Profile Polylines tool ( ). 2. Select the span set to generate profile polylines for. Generally you will select the layer in the prestressing folder you are currently working in. 3. To generate support polylines from the span segments, check the “generate support polylines” box and set the elevation reference and elevation desired for the generated support polylines. 4. If support polylines are generated, to generate span polylines check the “generate span polylines” box and set the elevation reference and elevation desired for the generated span polylines. If the tendon span angle is consistent throughout the floor then set it in the Span Orientation Angle box. This will generate the span polylines in the specified direction between the generated support polylines. If there is more than one span orientation angle in the floor then “Use Medial Axis” can be selected. The Use Medial Axis option will generate span polylines that are equidistant from the generated support polylines. For a single spanning direction, the best results will normally be achieved by setting this angle.
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Defining Tendons Defining profiles for banded tendon polylines and distributed tendon quadrilaterals
Figure 147: Generate profile polylines tool
29.8.3 Defining span polylines using the Generate Span Polylines tool This tool allows you to generate span polylines automatically using support polylines that have been previously generated. To generate profile polylines 1.
Select the support polylines that you want span polylines generated between (
).
2.
Choose the Generate Profile Polylines tool ( ). 3. Set the elevation reference, elevation, and span orientation angle for the generated span polylines. 4. Set the span ratio for the generated span polylines. This is the desired span control point. For a profile control point at mid-span, set this value to 0.5.
Figure 148: Generate span polylines tool 5. Set the optimization parameters when the tendons will be optimized.
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Defining Tendons Other tendon parameter plan objects and tools See Designing and Optimizing Post-tensioning (on page 331) for further details.
29.9 Other tendon parameter plan objects and tools 29.9.1 Drawing Tendon Voids Tendon void polygons can be defined in areas where generated tendons are not desired. This might be used to create a stressing blockout in a banded tendon polyline or to prevent very short tendons from being created in an area covered by a distributed tendon quadrilateral. Tendon void polygons prevent creation of tendons inside their boundaries and apply only to the layer on which they are drawn. These objects do not affect the manual tendon layers. 1.
Select the Tendon Void tool ( ). 2. Click at each polygon vertex consecutively. 3. Snap to the first vertex and click to close the polygon (or type and press ).
29.9.2 Drawing Jack Regions Jack region polygons can be drawn where jacks are desired to be applied to generated tendons. Any discontinuous generated tendon end that lies within a jack region will have a jack defined with the jack region’s properties. 1. Select the Jack Region tool ( ). 2. Click at each polygon vertex consecutively. 3. Either: Snap to the first vertex and click to close the polygon. or Type and press .
29.9.3 Split banded tendon polyline tool The split banded tendon polyline tool is used to segment previously created banded tendon polylines where they cross the defined splitting line. This can be useful, for example, where tendons need to be added in an end span of a previously defined banded tendon polyline.
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Defining Tendons Tendon parameter drawing examples 1. Select the Split Banded Tendon Polylines tool ( ). 2. Click two points defining a line that will segment all banded tendon polylines that cross it.
29.9.4 Split profile polyline tool The split profile polyline tool is used to split previously created profile polylines where they cross the defined splitting line. This can be useful, for example, where different profiles are desired in different bays and the current profile polyline is defined across the bays. 1. . Select the Split Profile Polylines tool 2. Click two points defining a line that will split all profile polylines that cross it.
29.9.5 Generate program tendons tool The generate program tendons tool is used to create tendons on the generated tendon layers from the objects on the tendon parameters layer. It also updates the graphical representation of the objects on the tendon parameters layer such as the fillet data for the banded tendon polylines. These operations will also be performed during a “calc all”, if they are out of date. 1.
). Click the Generate Program Tendons tool ( A log will be displayed if any warnings or errors occurred during the generation.
29.10 Tendon parameter drawing examples Drawing banded tendon polylines
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Defining Tendons Tendon parameter drawing and text formatting
Figure 149: Banded tendon polylines drawn by clicking on points A,B,C,D,E in sequence with Banded Tendon Polyline tool. Drawing distributed tendon quadrilaterals
Figure 150: Three distributed tendon quadrilaterals drawn by clicking on points A-D with distributed tendon quadrilateral tool.
29.11 Tendon parameter drawing and text formatting Banded tendon polylines, distributed tendon quadrilaterals, and distributed tendon overlap areas have drawing controls and format specifiers intended to aid in the production of design quality drawings.
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Defining Tendons Tendon parameter drawing and text formatting
29.11.1 Banded tendon polyline formatting options • Banded tendon polylines have a number of formatting properties to aid in the production of drawings: • Description - a user formatted string used to describe the banded tendon polyline properties. The formatted description strings for the banded tendon polyline use the following key values: • $F - force • $f - force units • $N - number of strands • $P - PT system name • $I - inflection point ratio • $S - spacing • $s - spacing units • $T - number of tendons • \n - new line • Draw Fillets - displays filleted connections between segments of banded tendon polylines using the Fillet Radius property set. The Fillet Radius property can be set to “Use Maximum” or a value smaller than the maximum can be typed into this box. • Profile Points - displays the profile control point information for the banded tendon polyline. The profile values are always referenced from the slab soffit to the CGS of the strands. • Symbol @ End 1,2 - displays the symbol at the end of the banded tendon polyline. Choices are: • None • Stressing End • Dead End
29.11.2 Distributed tendon quadrilateral formatting options • Distributed tendon quadrilaterals have a number of formatting properties to aid in the production of drawings: • Description - a user formatted string used to describe the distributed tendon quadrilateral properties. The formatted description strings for the banded tendon polyline use the following key values: • • • • • • • • • •
$F - force/width $f - force/width units $N - number of strands $n - number of strands/width units $P - PT system name $I - inflection point ratio $S - spacing $s - spacing units $A - angle and units \n - new line
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Defining Tendons Optimization parameters for tendons • Profile Points - displays the profile control point information for the banded tendon polyline. The profile values are always referenced from the slab soffit to the CGS of the strands. In addition to the profile points where the main tendon intersects profile polylines, the following additional points are provided to describe the distributed tendon profiles: • Edges - profiles at the edge of the distributed tendon quadrilaterals or slab edges. • Span Changes - profiles at drastic changes in span profiles. • Concrete Elevation Changes - profile changes where the concrete reference plane changes such as beams or drop caps. • Profile Polyline Ends - profiles at the ends of profile polylines The intent is that with all these points displayed the profiling of all tendons within the distributed tendon quadrilateral are defined by connecting support and span profile points. Profile points are not displayed at slab edges where no profile polylines are used. • Symbol @ End 1,2 - displays the symbol at the end of the distributed tendon quadrilateral main tendon. Choices are: • None • Stressing End • Dead End • Break • Symbol @ Extent Ends - displays the symbol at the end of the distributed tendon quadrilateral extent line. Choices are: • None • Arrow
29.12 Optimization parameters for tendons Banded tendon polylines, distributed tendon quadrilaterals, and profile polylines have optimization parameters that are used only if the optimization process is launched. See Designing and Optimizing Post-tensioning (on page 331) for additional information.
29.12.1 Profile polylines optimization options Profile polylines have parameters that can be defined for the optimization process: • • • •
Optimize - used to define the profile polyline as part of the optimization. Minimum Elevation - the minimum elevation value (from the specified elevation reference). Maximum Elevation - the maximum elevation value (from the specified elevation reference). Elevation Increment - the increment value to explore in the range between the minimum and maximum values.
29.12.2 Banded tendon polyline optimization options Banded tendon polylines have parameters that can be defined for the optimization process:
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Defining Tendons About drawing individual tendons • Optimize - used to enable the optimization of the effective force or number of strands, depending upon the “Tendon Specification Type” selected on the General tab. The input values need not to be integers. • Minimum Effective Force / Number of Strands - the minimum effective force or number of strands. For performance-based codes with no lower limits, it may be reasonable to set the minimum to zero. Otherwise, consider setting any code prescribed minimum limit (such as minimum precompression) as a minimum value. • Maximum Effective Force / Number of Strands - the maximum effective force or number of strands. This value can normally be set to the maximum value that would be practical for the given code. • Effective Force / Number of Strands Increment - the increment value to explore in the range between the minimum and maximum values.
29.12.3 Distributed tendon quadrilateral optimization options Distributed tendon quadrilaterals have parameters that can be defined for the optimization process: • Optimize - used to enable the optimization of the effective force or number of strands, depending upon the “Tendon Specification Type” selected on the General tab. The input values need not to be integers. • Minimum Effective Force / Number of Strands - the minimum effective force or number of strands per unit width. For performance-based codes with no lower limits, it may be reasonable to set the minimum to zero. Otherwise, consider setting any code prescribed minimum limit (such as minimum precompression) as a minimum value. • Maximum Effective Force / Number of Strands - the maximum effective force or number of strands per unit width. This value can normally be set to the maximum value that would be practical for the given code. • Effective Force / Number of Strands Increment - the increment value to explore in the range between the minimum and maximum values.
29.13 About drawing individual tendons You can draw individual tendons on the manual tendon layers in a number of ways: • • • • •
A single tendon one segment at a time using the Half Span Tendon tool (typically used for cantilevers). A single tendon one span at a time using the Full Span Tendon tool. A single tendon with numerous spans using the Tendon Polyline tool. A number of tendons one segment at a time using the Half Span Tendon Panel tool. A number of tendons one span at a time using the Full Span Tendon Panel tool.
You use these tools in different situations. You might find drawing one tendon and then copying it is quicker than using the polyline and panel tools.
29.14 Drawing single tendons The following instructions are relevant for elevated floors where the tendon has a high point at supports and a low point near midspan. For mats, the reverse is generally true.
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Defining Tendons Drawing multiple tendons
29.14.1 Drawing a half-span tendon You might use the half-span tendon tool for cantilevers and short end spans. For such uses, the Profile at End 2 value would commonly be half the slab thickness or the beam centroid dimension. 1.
Select the Half Span Tendon tool ( 2. Click at the tendon high point. 3. Click at the tendon low point.
).
Note: The order of mouse clicks is very important when drawing half-span tendons because the tool measures the inflection point from the high point (end 1).
29.14.2 Drawing a full-span tendon You typically use the full-span tendon tool for conventional spans. 1.
Select the Full Span Tendon tool ( ). 2. Click at the two tendon high points. The low point (End 2) automatically locates at the midpoint of the tendon. The low point can be adjusted with the Stretch tool ( option in the Tendon Properties dialog box.
) or the “Position Profile Point 2 for equal balance loads”
29.14.3 Drawing a multi-span tendon with the tendon polyline The Tendon Polyline tool (
) allows you to draw a series of full span tendons with fewer mouse clicks.
1.
Select the Tendon Polyline tool ( ). 2. Click a series of tendon high points. The low points (End 2) automatically locate at the midpoint of high points. 3. Right-click after clicking the last high point. 4. Click Enter
29.15 Drawing multiple tendons You can draw a group of tendons in one operation with the tendon panel tools. You designate the panel to lay out the tendons, along with the desired tendon spacing, and RAM Concept draws the tendons.
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Defining Tendons Drawing multiple tendons The drawing process requires you to draw the panel points sequentially in a clockwise or counter-clockwise manner to form a quadrilateral.
29.15.1 Tendon panel layout options Layout The choices are Parallel and Splayed.
Figure 151: Tendons with parallel layout and spacing not to exceed five feet. Tendons with splayed layout and spacing not to exceed five feet.
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Defining Tendons Drawing multiple tendons
Figure 152: Tendon Spacing The choices are Fixed, Equal and Auto Connect. “Fixed” draws tendons at exactly the specified spacing distance apart. It is not available with splayed tendons. “Equal (not to exceed maximum)” draws tendons an equal distance apart that is at most the spacing value. “Auto connect (based on last edge)” draws tendons connected to the profile points on the last edge of the tendon panel area. Skip Start Tendon / Skip End Tendon Omits edge tendons.
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Defining Tendons Drawing multiple tendons
Figure 153: Tendons after Auto Connect.
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Defining Tendons Drawing multiple tendons
Figure 154: Tendons after Auto Connect.
To draw a Half-Span Tendon Panel 1.
Select the Half Span Tendon Panel tool ( ). 2. Click at the tendon high and low points of the first tendon in the tendon panel area. 3. Click at the tendon low and high points of the opposite edge of the tendon panel area. The Tendon Panel dialog box appears after the fourth click. 4. Select options (see discussion above).
To draw a Full-Span Tendon Panel 1.
Select the Full Span Tendon Panel tool ( ). 2. Click at the tendon high points of the first tendon in the tendon panel area.
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Defining Tendons Editing tendons 3. Click at the tendon high points of the opposite edge of the tendon panel area (following a clockwise or counterclockwise direction). The Tendon Panel dialog box appears after the fourth click. 4. Select options (see discussion above). Note: A low point (End 2) automatically locates at the midpoint of each tendon.
29.16 Editing tendons As with any object, you can edit tendons on the manual tendon layers after they are drawn.
29.16.1 Calc profile tool You can adjust profiles manually or use the Calc Profile tool (
) for automatic adjustment.
Too much uplift in a tendon can cause deflection reversals that may crack the slab. For this and other reasons, it is a good idea to have the amount of uplift or load balance somewhat consistent from span to span. To edit a tendon based on uplift 1. Select a tendon segment. 2. Click the Calc Profile tool ( ).The Calc Tendon Profile dialog box appears and reports the current balance load. 3. Input the desired balance load (values are typically negative) in the Calc Tendon Profile dialog box and click Calc. The low point (end 2) adjusts to provide the desired uplift. You can select two segments in the same span and RAM Concept calculates the low point based on average uplift. It is generally not necessary to balance exactly the same amount of load in each span. It is not advisable to have an excessive number of different low points. Manually rounding the profile values can produce a more practical design. If the desired balance load is too high then RAM Concept could calculate a negative profile that causes an error when calculating the results. Note: RAM Concept does not check cover violations
29.16.2 Change profiles tool When a plan viewing one of the tendon layers is active, RAM Concept adds a Change Profiles items to the Tools menu. This menu item allows you to change all tendon profiles with a given value to a new value. This can be very useful in circumstances such as change slab or beam depths.
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Defining Tendons About jacks 1. Open a plan from the Latitude Tendon or Longitude Tendon layer. 2. Choose Tools > Change Profiles. The Change Tendon Profiles dialog box appears. 3. Enter the profile value that you wish to change. 4. Enter the new profile value. 5. Uncheck either tendon layer that you do not want edited. 6. Uncheck either end number that you do not want edited, and click OK.
Figure 155: Change tendon profiles tool
29.17 About jacks Jacks can be specified for tendons on manual tendon layers. RAM Concept calculates the force losses in a tendon if you draw jacks at live (stressing) ends. If you draw a jack at each end of a tendon then it is double end stressed. If only one jack is drawn then the other end of the tendon is a dead end. If you draw a single jack on a tendon layer then every tendon on that layer must have at least one jack attached. RAM Concept uses the relevant value of fse (specified in the Materials criteria page) as the effective stress for any tendon without a jack.
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Defining Tendons Drawing the jacks
29.18 Jack properties Set the default jack properties in the Default Jack Properties dialog box by double clicking the Jack tool ( ). You can choose to ignore the jack property values in the Jack Properties dialog and instead use the PT System values. The following is a list of jack properties: Jacking Stress The stress in the strand at the jack at jacking. Anchor Friction Coefficient Loss of stress due to friction in the anchorage. It is a fraction with no units. You would enter a 2% loss as 0.02. Most PT suppliers recommend a value of zero for unbonded tendons. You might consult with a local PT supplier regarding bonded tendons. Wobble Friction Coefficient Friction calculations use this property (k) to estimate losses due to accidental curvature (in the horizontal and vertical planes). It is the product of the angle friction coefficient and the accidental angular change per unit length. Note: Some engineering communities (Australia in particular) use a definition of wobble coefficient that is the accidental angular change per unit length. These communities can calculate the wobble coefficient that Concept uses, k, with the following relationship: k = AngularWobbleCoefficient * mu. Angle Friction Coefficient Loss due to deliberate curvature (in the horizontal and vertical planes). Most designers know it as mu. Seating Distance The distance that the wedges recede into the anchorage. This occurs when the field operator releases the tension in the jack. Long Term Losses The sum of losses such as creep and shrinkage of concrete, and relaxation of strand. It also includes the loss due to elastic shortening of the concrete even though it is a short-term loss.
29.19 Drawing the jacks You draw jacks with the Jack tool (
) by clicking a rectangle around the stressed ends of the tendons.
1. Select the Jack tool ( ). 2. Click at opposite corners of a rectangle encompassing the tendon live ends. Note: You can delete a single jack by double clicking it. To delete multiple jacks, consider making all objects except the jacks invisible, then select and delete the jacks.
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30
Designing and Optimizing Post-tensioning Designing post-tensioning traditionally has been a highly iterative and time-consuming process. There are virtually an infinite number of valid post-tensioning designs for a given concrete floor system. Variations can consist of different numbers of strands, in potentially different locations (layouts), and with different amounts of drape. Each solution requires a different amount of rebar and punching shear reinforcement. The traditional design approach for engineers has been to define a post-tensioning solution that satisfies the minimum precompression and maximum spacing requirements in the system and then add strands until the flexural tension stress limits are satisfied. For codes that do not use flexural tensile stress limits the number of potential solutions is even larger as a wide array of post-tensioning, rebar, and punching shear combinations could be employed. Drapes are often determined using a load balancing approach, where the drapes are set to “balance” a predetermined fraction of the gravity loads. After the strand quantity and drapes have been determined, the corresponding supplemental rebar and punching shear reinforcement are calculated. Because the traditional process can be tedious and time consuming, engineers typically do not investigate many design alternatives (normally only 1 or 2). As such, it is difficult to know how economical the final design is (total cost of materials and labor for concrete, post-tensioning, rebar, and punching shear reinforcement). The post-tensioning optimization feature in RAM Concept uses intelligent search algorithms to compare thousands of design alternatives. This allows engineers to easily review and compare many different solutions side by side and select the best design for the situation. For a given strand layout, the post-tensioning optimization feature automatically weeds out invalid trials that do not satisfy required code criteria, which eliminates the need for manual iteration and saves hours of engineering time.
30.1 What does RAM Concept’s optimization achieve? Once you have set the initial post-tensioning layout and defined a reasonable range for tendons and profiles, RAM Concept’s optimization process automatically searches for the most economical solution. Economical solutions are defined as ones with lower total material and labor costs, and no failing design criteria. To calculate the material and labor costs, RAM Concept uses the post-tensioning, rebar, and SSR quantities in the resulting design multiplied by their respective cost factors, which are set by the user in the Estimate window (Report > Estimate). Because changing the cost of a single material (due to availability, labor issues, etc.) may result in a different most economical solution, it is important to set the costs in the estimate as accurately as possible for the job and location being designed.
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Designing and Optimizing Post-tensioning How does the optimization work?
30.2 What doesn’t RAM Concept’s optimization achieve? RAM Concept’s optimizer cannot generate a good design from a bad tendon layout. Also, RAM Concept may not find the best solution if the range of tendon quantities or profile elevations is set too narrow such that the best solution lies outside this range.
30.3 How does the optimization work? The optimization calculations are based in genetic algorithms, which takes a pool of the best trials found thus far, mutates (modifies) them, and then crosses them with each other to create a new generation of trials. The best trials from this generation are identified, and this new “elite” group is used to calculate the next generation by mutating them and crossing them with each other. This process is repeated until the improvements over a number of these cycles becomes smaller than a specified convergence tolerance. Since this process requires many trials to be evaluated, cloud computing is employed to calculate many of these trials in parallel. This decreases the optimization computation time and frees the user's desktop for other processes.
30.4 Optimizable Objects Banded tendon polylines, distributed tendon quadrilaterals, and profile polylines are currently optimizable in RAM Concept. This means that the program can automatically adjust the property values defined for these objects to solve for a valid design and find the most economical solution. Manual tendons can be drawn and will be considered in the calculations, but cannot be optimized. Therefore, while optimizing you will normally only work with objects on the tendon parameters layer and not the manual tendon layer.
30.4.1 Banded Tendon Polyline Banded tendon polylines can be optimized by selecting an existing polyline (or the default banded tendon polyline), clicking Edit > Section Properties (or right-click and choose Selection Properties), and then clicking on the Optimization tab.
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Designing and Optimizing Post-tensioning Optimizable Objects
To optimize the banded tendon polyline, check the Optimize option, set the minimum and maximum values in the range, and then the increment values to explore between the range. The values need not be integers. If there are code limits that impose lower and upper values on this range, it is appropriate to set them here (for example, precompression limits). For performance based codes with no lower or upper limits, it may be beneficial to set the lower limit to 0 to explore the entire range of potential solutions.
30.4.2 Distributed Tendon Quadrilateral Like the banded tendon polylines, distributed tendon quadrilaterals can also be optimized by selecting a distributed tendon quadrilateral (or the default distributed tendon quadrilateral) clicking Edit > Section Properties (or right-click and choose Selection Properties), and then clicking on the Optimization tab.
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Designing and Optimizing Post-tensioning Optimizable Objects
To optimize the distributed tendon quadrilateral, check the Optimize option, set the minimum and maximum values in the range, and then the increment values to explore between the range. If there are code limits that impose lower and upper values on this range, it is appropriate to set them here (for example, precompression limits). For performance based codes (with no lower or upper limits, it may be beneficial to set the lower limit to 0 to explore the entire range of potential solutions.
30.4.3 Profile Polylines In RAM Concept, profile polylines control the elevation and control points of the tendon parameter objects that cross them. Normally, these profile elevations are configured to “balance” a certain fraction of the gravity load which often achieves the design objectives. RAM Concept can also optimize these profile elevations by selecting a profile polyline (or the default profile polyline), clicking Edit > Section Properties (or right-click and choose Selection Properties), and then clicking on the Optimization tab.
To optimize the profile polyline, check the Optimize option, set the minimum and maximum values in the range, and then the increment values to explore between the range. Note that the elevation values set in the optimization tab refer to the Elevation Reference set in the general tab. Usually, it is valuable to explore the entire range of physical elevations within a member, as sometimes counterintuitive values work best.
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30.4.4 Optimization Regions RAM Concept has an optimization layer on which optimization regions can be drawn. Optimization regions serve the following purposes: 1. Break up a large optimization problem into smaller parts to keep total solution time in a reasonable range. 2. Identify a specific part of the floor to be optimized. If any optimization regions are drawn, only the objects within the optimization region will be optimized. Optimizable objects outside the optimization region will be considered in the calculations but will not be optimized. If no optimization regions are drawn, the optimizable objects in the whole slab will be optimized. The number of optimizable objects can be displayed on this layer by selecting visible objects and on the Optimization tab check the Number of optimizable objects option. The optimization regions can also be given user defined names by selecting a region and choosing selection properties.
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The number of objects in a single region (or whole model) is limited to 75, with a recommended maximum of 50. This can normally be achieved by drawing optimization regions of a size that might resemble a typical pour in the structure. Note that optimizable objects are not permitted to cross optimization region boundaries. During optimization preprocessing, banded tendon polylines and profile polylines will automatically be split at optimization region boundaries. Distributed tendon quadrilaterals will also automatically be split, provided that the post-split geometry results in quadrilateral shapes. If it does not, RAM Concept will provide an error message that the geometry was too complicated for automatic splitting. Grouped tendon objects that cross optimization region boundaries will also be automatically split and regrouped according to the region in which they occur.
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This can be resolved by manually manipulating the distributed tendon quadrilaterals such that they do not cross optimization boundaries, or modifying the geometry of the distributed tendon quadrilaterals and optimization regions such that splitting at the boundaries will result in quadrilateral shapes.
30.5 The Optimization Process With the optimization objects defined, this section will focus on the process of carrying out an optimization on a floor.
30.5.1 Defining Tendons and Profile Polylines Before an optimization can begin, the tendon parameter objects (banded tendon polylines and distributed tendon quadrilaterals) must be arranged in a logical fashion. This step essentially is no different than if the model was going to be designed by hand. Banded tendons are normally aligned with the long axis of the building, unless the columns align better in the orthogonal direction. A couple of helpful strategies can be employed during this stage: • Single tendon objects can be defined over large slabs, with the idea that the preprocessing will later automatically split them at the optimization region boundaries. • For end spans that are approximately the same length or larger than interior spans, added tendons will often be necessary in these bays. The optimizer can calculate the quantity automatically, but the banded tendon polylines need to be split at the end span and additional overlapping distributed tendon quadrilaterals drawn in the end spans. • Eliminating profile polylines that you do not need is a good idea as it can reduce the number of optimizable objects. • It is also possible to group profile polylines such that adjacent bays with identical spans get the same profile. This may be desirable from the standpoint of the final design; however, caution should be exercised when doing this as sometimes this can prevent the optimizer from arriving at the best solution.
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Designing and Optimizing Post-tensioning The Optimization Process •
You can use the Adjust Profile Polylines tool ( also found at Tools > Profile Polyline Tool) on the Tendon Parameters Layer to help manipulate automatically generated tendons to prepare them for optimization. This tool can automatically extend profile polylines to the slab edge, trim profile polylines to the slab edge, delete short polylines, and connect nearby endpoints for polylines with like properties (which merges them into a single polyline). • In general, draw the distributed tendon quadrilaterals to be smaller than the optimization regions. This helps ensure that the splitting results in quadrilateral objects. One way to achieve this is to draw them just large enough to cover the slab, and later draw the optimization regions to extend outside the slab. This helps ensure that the splitting results in quadrilateral objects. • The high point (support polyline) elevations should normally be set to the highest possible elevation while respecting the required concrete top cover. The low point (span polyline) elevations can be adjusted to achieve the desired balanced load.
30.5.2 Setting Optimizable Properties Once the tendons and profile polylines are defined, the optimizable properties can be selected and ranges and increments set. Generally, all tendon objects (banded tendon polyline and distributed tendon quadrilateral) should be set as optimizable. The ranges should be set broad, even if they are slightly outside values that might be intuitively expected. For supplemental distributed tendon quadrilaterals that are drawn over the primary quadrilaterals, the minimum range can be set to zero in case they are not necessary. For the profile polylines, normally only the low point (span polyline) elevations are adjusted, leaving the high point (support polyline) elevations at the highest possible elevation. These high point elevations should then be set with their Optimize check box left unchecked. The only exception is the high point at a cantilever support, which may sometime need to be reduced from the maximum value so the cantilever is not overbalanced. This, and any other support profile polyline that is appropriate, can be set to be optimized with a reasonable range. Normally, all span profile polylines will all be set to be optimizable, with a range set to the entire physical range of valid profiles that fit within the concrete while respecting covers. The increments for profile polylines can be set to standard support chair increments, or something large, if desired.
30.5.3 Defining Optimization Regions Once the tendons and profile polylines are defined and optimizable properties are set, you can define optimization regions by using the Optimization Layer using the Optimization Region tool ( Tools > Optimization Region).
also found at
The maximum recommended number of optimizable properties in a single region is 50, with a hard limit set at 75. There are two ways to see how many optimizable properties are currently defined: 1. Clicking the optimize tendons tool will bring up a dialog that displays the number of optimizable properties in each region (see next section for more details). 2. Alternatively, if optimization regions are defined the number of optimizable properties can be displayed as a property of that region using visible objects. A good rule of thumb that will normally result in an acceptable number of optimizable objects in each region is to define the optimization regions in a similar way to how the floor is expected to be broken into pours. This has
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Designing and Optimizing Post-tensioning The Optimization Process the added benefit that tendon quantities can change at region boundaries (due to object splitting), which is also normally possible at pour breaks. It is good practice to draw optimization regions using snaps in such a way that their corners along a common edge are connected to prevent small gaps or overlaps causing problems with the optimization.
30.5.4 Starting an Optimization Before optimizations can be run in RAM Concept, the user must be signed into the CONNECTION client and a project must be associated with the model. A new optimization can be started by selecting the Optimize Tendons tool ( also found at Optimize > Optimize Tendons). This will start a preprocess that performs a series of checks, and splits the tendon and profile polyline objects (if necessary). If this preprocess changes the file, you will be prompted with a Save As dialog to have the opportunity to keep the original version as well as the modified version. Then the Start Optimization dialog will open.
It is possible to start a series of parallel optimizations on the same file, with each of these optimizations called a scenario.
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This box identifies each optimization region (by name, if any) and the number of optimization properties associated with it. If no optimization regions are defined, “whole slab” will appear of the region name.
Number of Trials
This slider tells the optimizer how hard to look for the best solution, with the left end representing a less intensive search with the lowest usage cost, and the right end representing the most intensive search with the highest usage cost. For most situations, the slider can be placed at the default location in the center with a good chance of finding the optimal solution at a low cost.
Seed with model’s current parameters
This option tells the optimizer to use the current tendon and profile parameters as a starting point in the optimization. This may reduce the total number of iterations needed to complete the optimization. You could check this if you have manually iterated to what you think is a good design and you want the optimizer to see if it can improve it.
Maximum Number This value tells RAM Concept to stop the optimization after the specified number of of Iterations search iterations, even if the given convergence criteria has not been met. This parameter could be used to stop a model that is struggling to converge and running indefinitely. Most models will converge in less than about 100 iterations, so this should not normally be a factor. Number of NonImprovement Iterations
This value tells the optimizer the range over which to measure the % change for convergence purposes. For example, a value of 20 tells the optimizer to take the percentage change between the best solution found through this iteration and the best solution found 20 iterations ago when testing against the Improvement Tolerance.
Improvement Tolerance (%)
This value tells the optimizer when to stop because it thinks it has converged upon an optimum solution. The percent change is measured over the number of nonimprovement iterations value. Setting this number very small could cause the optimizer to calculate a large number of iterations with little improvement, driving up the cost of the optimization.
Maximum ACU Consumption
This value tells the optimizer to stop when a specified number of ACUs are consumed. When the threshold is reached and the optimization is stopped, the Edit button can be used to increase the specified maximum value. The optimization can then be continued by clicking Resume.
Clicking OK on this dialog will start the optimization. Related Links • To Associate a CONNECTED Project with Your File (on page 154) • To Register a CONNECTED Project (on page 157)
30.5.5 Saving Optimization Data When an optimization is started, RAM Concept automatically creates a local scenario folder to store the results of the optimization. RAM Concept also saves a copy of the Concept (.cpt) file in the scenario folder along with the scenario data. This model is referred to as the “scenario model.” This behavior is to ensure consistency between the Concept file and any optimization data stored with it. The scenario model represents a snapshot of the model at the point in time that the optimization was run. The original model, referred to as the “base model,” is not affected by this behavior and can be modified after an optimization is run. Any number of optimizations (which create associated scenario models) can be generated from a single base model. When viewing the optimization
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Designing and Optimizing Post-tensioning The Optimization Process manager with a base model open, the scenario table will show all optimizations that were started with that base model. If you select any scenario and choose “load scenario model,” it will open the scenario model associated with that scenario. The scenario model will also be automatically loaded when loading any trial from the Trials table. This will close the base model (after prompting to save any unsaved changes that have been made). You can make changes to a scenario model, but the changes cannot be saved as that would corrupt the scenario model. Any changes made to a scenario model will be discarded without warning when loading any other trial or loading the base model. It is possible to “save as” any changes to a scenario model and choose a different file name. Once a scenario model is loaded, it is possible to navigate back to the base model it was created from by choosing “Load Base Model.” This will close the scenario model (after prompting to save any unsaved changes that have been made). The scenario model and base model can get out of sync if any changes are made to the base model after the optimization is run, but this makes it possible to load and examine the state of any model at the time any previous optimization was run.
30.5.6 Monitoring a Running Optimization At any time, the status of a running optimization can be monitored by selecting the Optimization Manager tool ( also found at Optimize > Optimization Manager) which launches the Optimization Manager dialog.
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Scenarios Table The top table shows information for scenarios that are running, completed, or stopped running during the optimization.
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Column
Description
Name
The unique name that given to the scenario when it was started
Status
The state of the optimization (whether it is running, finished, stopped, or failed due to a runtime error
Iterations Completed
Indicates how many iterations the optimization has completed
% Improvement
The percentage improvement of the best trial in the last iteration, measured against the best trial in the specified Number of NonImprovement Iterations. Until the number of Non-Improvement iterations is reached, it will display N/A.
ACU (Analytical Compute Unit)
The standard unit of consumption for Bentley analytical cloud compute resources. The total number of ACU's consumed for a
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Column
Description single optimization is calculated based on the total optimization time and the Resource Consumption Rate noted in the Number of Trials box.
Stop
Suspends an optimization (it can be subsequently resumed).
Resume
Restarts an optimization that is not running, either because it was stopped, experienced an error, power outage, etc.
Edit
Edit the properties, such as stopping criteria, of a stopped optimization.
Delete
Deletes the scenario, including any local files and folders as well as any cloud storage. Note: This cannot be undone.
Load Scenario Model
Load the scenario model associated with the selected scenario (this action will close the currently open model)
Export Scenario Exports the cost information for each trial of the scenario selected in the Scenarios Table to Data a CSV file. Load Base Model
Load the base model associated with the currently loaded scenario model (only available when a scenario model is open - this action will close the currently open model)
New Scenario
Launches the Start Optimization dialog to start a new optimization/scenario.
Convergence Chart
Tabulates the Total Cost (y-axis) versus Total ACU's consumed (x-axis) for the selected scenario. Three lines are plotted: Best Overall Design (w/ penalty for failures), Best Overall Design (w/o failure penalty), Best Valid Design (no failure).
Trials Table
The bottom table displays the cost information and failures for each trial that is calculated. The tables can be sorted by clicking on the column headers. Column
Description
Optimized Cost Sum of the material and labor costs for all the PT, rebar, and SSR in the trial. The lowest value here is generally the most economical solution.
Load Best
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PT Cost
Cost of material and labor for the PT in the trial.
Rebar Cost
Cost of material and labor for the rebar in the trial.
SSR Cost
Cost of the material and labor for the SSR in the trial.
Failures
The number of design code criteria failures in the trial. The optimizer should eliminate these, if possible, as the solution progresses. Any trial with a failure is not considered a valid solution.
Model Cost
Sum of the material and labor costs for PT, rebar, and SSR (Optimized Cost) and the material and labor costs for concrete and formwork
Allows you to load the best trial that has been found to date in the model. The model can then subsequently be run so that the details of the trial and its associated results can be viewed and investigated. (this action will load the scenario model associated with the current loaded scenario)
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Allows you to load the trial selected in the Trials Table. The model can then subsequently be run so that the details of the trial and its associated results can be viewed and investigated. (this action will load the scenario model associated with the selected trial)
30.6 How Optimization Achieves Better Designs With a good tendon layout provided, the optimization process in RAM Concept generally results in more economical designs than an engineer would arrive at if designing manually in only a small fraction of the engineering time. It does so by exploring a much wider array of alternatives and comparing them side by side, where the manual design process is limited to only comparing a handful of alternatives due to the time it takes to investigate each one. For example, the optimizer does a good job of adjusting profile elevations to balance the moments at each of the column joints, thereby limiting or eliminating punching shear reinforcement as well as the demand on the columns. It is impractical for an engineer to do this manually due to the time it would take. The optimizer produces best results that are not always intuitive, which is why it is difficult for engineers to arrive at these solutions manually by looking at only a few alternatives.
30.6.1 Slab Thickness Comparison Analysis Because the optimizer can solve for the design, it makes it quick and easy to compare solutions with different slab thicknesses. This is prohibitive to do manually due to the time it takes to solve for the design for each slab thickness. By referencing the span elevations from the soffit and the support elevations from the surface, virtually no changes are required to set up an optimization model for a different slab thickness. These different thickness runs can also be performed in parallel, using separate scenarios models created from the same base model. To accomplish this: 1. Start an optimization scenario from the model with a given slab thickness. 2. On the mesh input layer, change the slab thickness and re-mesh. Regenerating the mesh is important because the model is not re-meshed when it is passed into the optimizer. 3. Make any adjustments necessary to the properties in the model. Normally this will be minimal, the most common being adjustments to the tendon optimization ranges to enforce proper precompression limits. 4. Start a new optimization scenario. If you want to explore multiple different slab thicknesses simultaneously, you can repeat this process for each different slab thickness. Generally setting up each different thickness model only takes a few minutes. After the optimizations are finished, you can load the scenario models, load the best trials, and compile the best design data into a chart to allow side by side comparison.
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From a chart like this, it is easy to see that the most economical slab depth is 10". There may be other performance/serviceability considerations, but these can be easily explored by loading the best model from each thickness optimization and comparing them side by side.
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Using Live Load Reduction RAM Concept can automatically perform live load reduction calculations on columns, punching checks, design strip segments and design sections per the requirements of the selected live load reduction code.
31.1 About Live Load Reduction Most design codes allow the design of members supporting large areas to ignore a fraction of the live load effects on the member. This “live load reduction” is allowed because the probability of all of a large supported area being simultaneously fully loaded is small. While each code has its own rules, the common approach is that the larger the supported area, the larger the allowed reduction, up to a limit.
31.2 Live Load Reduction Options RAM Concept currently allows several different live load reduction calculation options: ASCE 7-02 – Reduction using ASCE 7-02, section 4.8. ASCE 7-10 – Reduction using ASCE 7-10, section 4.7. ASCE 7-16 – Reduction using ASCE 7-16, section 4.7. IBC 2003 – Reduction using IBC 2003, section 1607.9. IBC 2006 – Reduction using IBC 2006, section 1607.9. IBC 2009 – Reduction using IBC 2009, section 1607.9. IBC 2012 – Reduction using IBC 2012, section 1607.10. IBC 2015 – Reduction using IBC 2015, section 1607.10. UBC 1997 – Reduction per UBC 1997, section 1607.5. AS/NZS 1170.1-2002 – Reduction per AS/NZS 1170.1, section 3.4.2. BS 6399-1:1996 – Reduction per BS 6399, sections 6.1 through 6.3. IS 875 (Part 2) - 1987 Live Load Reduction – Reduction per IS 875 (Part 2) section 3.2 Eurocode 1-2002 (UK Annex) Reduction per clause 6.3.1.2 and UK Annex 2.5-2.6 National Building Code of Canada 2005 – Reduction per clause 4.1.5.9 None – No live load reduction is performed.
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Using Live Load Reduction Live Loading Types
31.3 Setting the Live Load Reduction Code You choose the live load reduction code in the Calc Options. The default live load reduction code is “None”, causing no reductions to be used. 1. Choose Criteria > Calc Options 2. Choose the General tab 3. Choose the live load reduction code, as shown in the following figure.
Figure 156: Calc Options Dialog
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Using Live Load Reduction Live Load Reduction Parameters
31.4 Live Loading Types RAM Concept allows several different live loading types. These types are affected by live load reduction in different ways, depending upon the design code. The types are: Live (Reducible) Loading Standard live load reduction is performed Live (Unreducible) Loading No live load reduction is performed Live (Storage) Loading Special “storage” live load reduction is performed if allowed in the specified code. Live (Parking) Loading Special “parking” live load reduction is performed if allowed in the specified code. Live (Roof) Loading No live load reduction is performed. These loading types are specified in the Loadings window. See section 10.2 though section 10.6 of Chapter 10, “Specifying Loadings” for more information. Note: Live (Roof) Loading is reducible in the RAM Structural System, but not in RAM Concept.
31.5 Live Load Reduction Parameters RAM Concept uses up to six parameters to determine the allowed reduction factors: Loading type - Only certain loading types may be reduced (as is discussed above) Member type - Most codes have special reduction rules for certain member types (such as columns) Maximum allowed reduction - The user may specify a maximum reduction value for each member. Number of levels supported - Most codes consider the number of levels supported when calculating the allowed reductions. If RAM Concept's automatic calculation of areas is used, then the number of levels supported is assumed to be one. Tributary area - Most codes use the tributary area of the member as the primary live load reduction parameter. Influence area - RAM Concept has options for two codes that use the influence area of the member as the primary live load reduction parameter. RAM Concept calculates the last three parametric values. You can view the values on plan as described in “To view the column element LLR results” and “To view the latitude design strip LLR results”. You can override the calculation by specifying the parameters’ values. The next section describes how to edit these values.
31.6 Specifying Live Load Reduction Parameters You can specify live load reduction values for columns, punching checks, design strip segments and design sections. To specify overriding values for number of levels supported, tributary area, and influence area
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Using Live Load Reduction Implementation of Live Load Reduction 1. 2. 3. 4.
Open the appropriate plan Select the object(s) Choose Edit > Selection properties In the Default Properties dialog box (see the following figure): a. Click the Live Load Reduction tab b. Check the Use Specified LLR Parameters box c. Set the values for LLR Levels, Trib Area, and Influence Area. 5. Click OK.
Figure 157: Live Load Reduction Properties
31.7 Implementation of Live Load Reduction See Live Load Reduction Notes (on page 818) for information on RAM Concept’s implementation of live load reduction.
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Calculating Results You generally calculate results many times during the modeling and design process. You can calculate as soon as elements have been generated (e.g. self-weight deflection) or wait until modeling is close to finished. It is conceivable that you would not calculate results until all tendons, loads and design strips are drawn. It makes sense, however, to “run” the file during modeling to check for errors. That way you could avoid repeating the same modeling error.
32.1 Calculating the results You can calculate all or some of the results with or without a review of the calculation options.
32.1.1 Calculating all of the results 1. Click Calc All (
), or choose Process > Calc All.
Modeling errors are common and you may encounter error messages when calculating results. If the file runs successfully without errors, the Calc All icon becomes grayed-out. If errors occur then the calculator does not become grayed-out. See “About analysis errors” for more information. Related Links • About analysis errors (on page 360)
32.1.2 Partially calculating the results 1. Do either of the following: Click Calc Partial (
)
or Select Process > Calc Partial
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Calculating Results Calculating the results
Figure 158: Calc dialog box The slider on the left side of the Calc dialog box determines the level to which RAM Concept performs the calculations. The options are: Through analysis
Calculations are performed up to and including the global slab analysis (slab moments deflections, etc.) and the strip and section forces.
Through design RAM Concept performs the design of strips, sections and punching shear checks, in addition to all the Through analysis calculations. Through layout RAM Concept performs the layout of program reinforcement on the Reinforcement layer, in addition to all the Through design calculations. All
RAM Concept performs the detailing of program reinforcement into individual bars (viewable in perspectives), in addition to all the Through layout calculations.
The checkboxes on the right side of the Calc dialog window provide options on how RAM Concept performs the calculations. The options are: Skip warnings
Optional warnings do not stop the calculations, but are added as notes to the Calc Log. This setting is off by default.
Calculate only out-ofdate items
Existing calculation results are not replaced by new calculations unless RAM Concept detects that the existing calculations are out-of-date. This setting is on by default.
Warnings invalidate calculations
Previous calculation warnings are considered to invalidate their associated results, causing the re-calculation of the item that caused the warning. This setting is on by default.
32.1.3 Calculation options You can review and change the calculation options. To access the Calc Options 1. Choose Criteria > Calc Options.
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Calculating Results Calculating the results 2. Choose the General tab.
Figure 159: Calc options dialog, General tab The following describes the calculation options:
32.1.4 General options Auto-stabilize structure in X- and Y-directions Auto-stabilization introduces a small horizontal brace for structures that have no horizontal restraint. This is only suitable for structures with no external horizontal loads. Create viewable self-dead loading This setting controls whether RAM Concept creates loads that are viewable in plans and perspectives for the self-dead loading. This setting has no effect on the actual loading calculations. You would normally leave this unchecked. Include supports above slab in self-dead loading This includes the weight of supports (columns and walls) as loads. You should consider that RAM Concept bases punching shear calculations at columns below on the total column reaction that includes any loads applied directly above.
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Calculating Results Calculating the results Include tendon component in punch check reaction This includes the vertical component of the tendon force within the punch zone (which often reduces the punch check reaction). See “Contribution from the Vertical Component of Prestress” in Step 1: Determine the force envelopes to be checked (on page 1189) for more information. Check capacity of long. user reinf. without designing additional program reinf. This option instructs RAM Concept to perform a check of the existing defined longitudinal user reinforcement and post-tensioning and report any failed locations. Since RAM Concept does not currently have user defined transverse (shear) reinforcement, RAM Concept always performs a transverse shear (and SSR design for punching shear) design for the given longitudinal reinforcement. When a “calc all” is run using this option, any program reinforcement will be deleted before the start of the analysis and no additional program reinforcement will be designed. Related Links • Rebuilding load combinations (on page 105)
32.1.5 Code options Design The applicable design code. You can switch design codes during the design process. Note that switching codes does not automatically change the load factors. See “Rebuilding load combinations” for information on changing code specific load factors. Live load reduction The applicable loading code. See Chapter 27, “Using Live Load Reduction”, for information on the loading code.
32.1.6 Zero tension iteration options If a mat is flexible or there are large overturning loads then the springs may initially be resisting tension. You can reduce this tension by iteration. Zero tension iterations use an “accelerator” factor to make convergence faster. An accelerator value of 1 results in no acceleration, while a value that is too large may result in wild oscillations instead of convergence. RAM Concept calculates the accelerator value as follows: accelerator = (T j / T i )power ≤ maxAccelerator where = Tj = Ti power = maxAccelerator =
the tension force offset in iteration j (j = i+1) the tension force offset in iteration i the user-controlled “Accelerator Power” (typically 1.0) the user-controlled maximum allowed acceleration (typically 1.5)
Iterations to use The number of iterations used in calculations. The higher the number of iterations, the closer the tension is to zero. Accelerator Power The power in the above formula; typically this is 1. Max. Acceleration The maximum allowed acceleration.
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Calculating Results Calculating the results
32.1.7 Reinforcement layout and detailing parameters There are five parameters that influence how Concept lays out and details reinforcement. Three of the parameters are layout “cost” values that affect RAM Concept's priorities when laying out program reinforcement. They have no effect on user reinforcement. The cost parameters are: Bar Length Cost When this value is increased RAM Concept gives a higher priority to minimizing the weight of the reinforcement. This also causes RAM Concept to create a larger number of callouts. Bar Group Length Cost When this value is increased RAM Concept gives a higher priority to minimizing the total length of all of the callouts summed together. This also causes RAM Concept to use more reinforcement than necessary in some areas. Bar Callout Cost When this value is increased RAM Concept gives a higher priority to minimizing the total number of callouts. This also causes RAM Concept to use more reinforcement than necessary in some areas, and may cause RAM Concept to provide reinforcement where none is required. Using the default values for these three cost parameters usually results in acceptable program reinforcement layouts. However, you may want to try adjusting these parameters if you want RAM Concept to arrive at different layouts. The other two parameters are as follows: Bar Rounding Length RAM Concept lays out the program reinforcement with lengths that are a multiple of this value. The only instance where the program reinforcement does not use this rounding length is where both ends of a reinforcement callout are not straight (they are hooked or anchored). Bar End Cover RAM Concept uses this value when detailing both user and program reinforcement. Bar ends except for bar ends with anchors - are always pulled back from slab edges by this amount.
32.1.8 Load History / ECR tab These are parameters that apply to RAM Concept's load history calculations.
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Calculating Results Calculating the results
Figure 160: Calc options dialog, Load History / ECR tab
Load History Options Creep/Shrinkage The design code model used to determine creep and shrinkage strains over time. Available Model selections include ACI 209R-92 (ECR Values), ACI 209.2R-08/GL 200, AS 3600-2018, and Eurocode 2-2004. See Creep and Shrinkage Models (on page 1180) for additional information. Initial Load Application
The time of application of the initial loads. This becomes the start time of the first load history step specified in the Load History Criteria page.
Cure Duration
The duration of the moist cure period. This is used in the calculation of shrinkage strains.
Ageing Coefficient
The coefficient that accounts for various behaviors in the calculation of sustained loads. See Load History Deflections (on page 1176) for additional information.
External Shrinkage Restraint
A percentage of the free shrinkage strain to consider as externally restrained. The shrinkage restraint is used to calculate a hypothetical tension strain which is included in the tension stiffening calculations. The user may select one of the pre-set options mapped below or enter a specific value in the field box. See Load History Deflections (on page 1176) for additional information.
Basic Creep Coefficient
(ACI 209.2-08/GL2000, AS 3600-2018, and Eurocode 2-2004 only). The unadjusted creep factor or coefficient as defined by the selected code model. When “code” is selected the coefficient is determined as outlined in Creep and Shrinkage Models (on page 1180). You may also enter a specific value in the field box.
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Calculating Results Calculating the results Basic Shrinkage Strain
(ACI 209.2-08/GL2000 only). The unadjusted shrinkage strain as defined by the selected code model. When code is selected the coefficient is determined as outlined in Creep and Shrinkage Models (on page 1180). You may also enter a specific value in the field box.
Basic (AS 3600-2018 and Eurocode 2-2004 only). The unadjusted autogenous shrinkage strain Autogenous as defined by the selected code model.. When code is selected the coefficient is determined Shrinkage Strain as outlined in Load History Deflections (on page 1176). You may also enter a specific value in the field box. Basic Drying (AS 3600-2018 and Eurocode 2-2004 only). The unadjusted drying shrinkage strain as Shrinkage Strain defined by the selected code model. When “code” is selected the coefficient is determined as outlined in Load History Deflections (on page 1176). The user may also enter a specific value in the field box. Relative Humidity
(ACI 209.2-08/GL2000 and Eurocode 2-2004 only). The relative humidity as a percentage used to determine adjustment factors for the basic creep coefficient and/or basic shrinkage strain.
Environment
(AS 3600-2018 only). The environment classification used to determine adjustment factor k4 for the basic drying shrinkage strain that is defined in AS 3600-2018 3.1.7.2
Exposure
Option
Description
Arid
k4 = 0.7
Interior
k4 = 0.65
Temperate Inland
k4 = 0.60
Tropical/Coastal
k4 = 0.50
(ACI 209.2-08/GL2000, AS 3600-2018, and Eurocode 2-2004 only).Option to define the concrete surfaces subject to shrinkage, which is used as an adjustment factor for creep and shrinkage strain in some code models. Options
Description
Top and Bottom Both top and bottom of the cross section used to calculate surface area subject to shrinkage.
Cement Class
Top Only
Only the top of the cross section used to calculate surface area subject to shrinkage.
Bottom Only
Only the bottom of the cross section used to calculate surface area subject to shrinkage.
(ACI 209R-92 (ECR Values), ACI 209.2-08/GL2000, and Eurocode 2-2004 only). The cement type used to determine adjustment factors for various parameters in the creep and shrinkage models. Options for ACI 209R-92 (ECR Values) and ACI 209.2-08/GL2000 are Type I, Type II, and Type III. For ACI 209R-92 (ECR Values) Type II results is assumed equivalent to Type I. Options for Eurocode 2-2004 are Class S, Class N, and Class R.
ECR Options RAM Concept calculates an effective curvature ratio (ECR) at every cross section: ECR = Ce/Cg where
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Calculating Results Calculating the results Ce Cg
= =
the effective cross section curvature the gross section curvature
RAM Concept calculates Ce by the approximate formula: Ce = (kc BSR Cg) + ((1 – BSR)Cccs) where kc
=
the concrete design creep factor (often 3.35) = total strain / elastic strain Note: Most standards utilize a creep coefficient which is the ratio of creep strain to initial strain. The creep factor in RAM Concept represents the ratio of total strain (initial strain plus creep strain) to initial strain. Before inputting into RAM Concept, a creep coefficient representing only the creep strain would need to be increased by 1.0 to transform to a creep factor representing the total strain. ACI 209 reports the value of 2.35 as an average creep coefficient, so the corresponding creep factor would be 3.35. RAM Concept files adopt this value as a default.
BSR Cccs
= =
Branson's Stress Ratio the cross section curvature considering cracking, creep and shrinkage
See Section Design Notes (on page 806) for further explanation. Creep factor, kc As defined above. The input value should represent the final ultimate creep value and should take into account concrete mix, environmental considerations, etc. and can reflect any considerations required by regional building codes. Shrinkage strain
The design shrinkage value used to determine long-term curvature in cross sections. The input value should represent the final ultimate shrinkage and should take into account concrete mix, environmental considerations, etc. and can reflect any considerations required by regional building codes.
Load History Convergence Options These parameters apply to RAM Concept's load history calculations. Convergence Tolerance
The maximum specified difference in calculated deflection between iterations in order to consider RAM Concept to have converged upon the solution.
32.1.9 Vibration options Vibration and footfall analysis options are accessible on the vibrations tab. These are parameters that apply to RAM Concept's vibration calculations.
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Figure 161: Calc options dialog, Vibrations tab Number of modes
The number of modes for RAM Concept to calculate in the Eigenvalue analysis.
Dynamic The ratio of concrete modulus of elasticity to use in the dynamic analysis over the concrete concrete modulus of elasticity defined for the static analysis. modulus factor Stiffness matrix Controls the stiffness matrix that is used to solve the Eigenvalue analysis. The global linear elastic analysis model can be used, or any load history step can be selected. Minimum footstep frequency
The minimum footstep frequency to consider in the footfall analysis. Normal footstep rates range from 1.5 to 2.5 Hz.
Maximum footstep frequency
The maximum footstep frequency to consider in the footfall analysis. Normal footstep rates range from 1.5 to 2.5 Hz.
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Calculating Results Calculating the results Damping Ratio The damping ratio to use in the vibration analysis, as a fraction of critical damping (damping ratio = 1). Normal range for concrete buildings is 0.01 to 0.04. Response Type Select one or both of the types:
Resonant Response Options
Excitation Nodes
Type
Description
Resonant response
Check this option to perform a resonant response calculation. A resonant response tends to build up over time, and is generally most critical for lower frequency modes less than about 4 times the footstep frequency.
Impulsive response
Check this option to perform an impulsive response calculation. An impulsive response tends to dissipate before the next footstep, and is generally most critical for higher frequency modes.
Option
Description
Simplifed (fast) calculation
This analysis uses a fast calculation technique that is generally suitable for day to day design where RMS velocity values are not required.
Modal Analysis
This analysis uses a comprehensive dynamic modal superposition analysis which is suitable for structures that are vibrationally sensitive or if RMS velocity values are required.
Parameter
Description
Duration, Time Increment
Defines the number of time points that are used to calculate the modal analysis. The duration should generally be set to capture at least 30 cycles of forcing and the time increment should be set to at least 10 times shorter than the 4th harmonic of the fastest walking frequency.
Weight of Person
The static weight of the person walking.
Max natural frequency
Defines the maximum natural frequency that is used in the dynamic analysis for the resonant response.
Option
Description
All nodes
Will consider excitation at every node.
Critical Nodes Will consider excitation only at nodes where the expected response factor is greater than or equal to the Excitation Response Factor Threshold.
Response Nodes
RAM Concept
Parameter
Description
Excitation Response Factor Threshold
When considering Critical Nodes, the threshold value of interest.
Option
Description
All DOF at all nodes
Will calculate a response at every DOF at every node for the Modal Analysis (not recommended).
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Option
Description
Vertical DOF at all nodes
Will calculate a response at every node, but only for vertical DOF.
Vertical DOF at only excited node
Will calculate a response only at the excited nodes.
32.2 About analysis errors Two types of errors can occur during calculation: fatal and non-fatal. RAM Concept generates an Analysis Error message if an error occurs. If a fatal error occurs, analysis cannot continue. You must correct the problem, then recalculate. For example, if the structure is unstable then RAM Concept cannot triangularize the stiffness matrix. After non-fatal error occurs, you can choose whether to continue the analysis calculation or not. For example, if a point load is not located on the structure, you can do one of the following: • continue the analysis and ignore the point load • fix the problem and continue calculation • stop the analysis
32.3 Recalculating Some or all of the calculation analysis information becomes out-dated when you edit the model. Click Calc All (
) to run a new analysis calculation. If the Calc All option is grayed-out (
), the analysis results are current.
When you recalculate, the analysis starts from the point where the information is no longer valid. For example, if you were to add a load, it would not affect the stiffness matrix. The recalculation would start with the analysis of loads and then move on to design. If you were to edit the concrete elements however, the calculation would start from the beginning.
32.4 Calculating load history deflections To calculate results 1. Click Calc Load History Deflections(
), or choose Process > Calc Load History Deflections.
If any calculations are out of date at the time, a “Calc All” will effectively be performed prior to calculating the Load History Deflections.
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Calculating Results Calculating vibration analysis
32.5 Calculating vibration analysis To calculate results 1. Click Calc Vibration Analysis(), or choose Process > Calc Vibration Analysis. Note: If a load history stiffness matrix is selected, the load history analysis must be run after specifying the load history step to use and prior to running the vibration analysis.
32.6 Reviewing the calc log After RAM Concept calculates results, you can review the calc log to check for detected errors.
32.6.1 To open the Calc Log 1. Choose Report > Calc Log.
32.6.2 To open the Load History Calc Log 1. Choose Report > Load History Calc Log.
32.6.3 To open the Vibration Calc Log 1. Choose Report > Vibration Calc Log.
32.7 Decreasing calculation time The time it takes RAM Concept to calculate results is dependent upon a number of parameters. You have control over some of these parameters. Desired Element The time to analyze the stiffness matrix is a function of the number of finite element nodes. Size You can speed up the analysis time by using larger finite elements for preliminary work. This means specifying a large Desired Element Size when generating the mesh.
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Calculating Results Decreasing calculation time Design Strip “Min Number of Divisions” and “Max Division Spacing”
The calculation time is a function of the number of span segment strip cross sections and design sections on the slab. Each span segment strip with “n” internal divisions produces at least “n+1” design cross sections; more if the maximum spacing governs. You can speed up the analysis time by using a small number of divisions and large maximum spacing for preliminary design.
Enveloping
Load patterns and alternate envelope factors produce additional calculations. The RAM Concept algorithms for enveloping are quite efficient and so do not slow down the calculations very much. You could, however, speed up the calculation time by eliminating load patterns and setting alternate envelope factors to the same as load factors in the Load Combinations window (Choose Criteria > Load Combo to open the Load Combinations window).
SSR Design
Stud shear reinforcement design adds significantly to the calculation time. You might consider delaying the drawing of punching checks until most of the design is close to finish.
Detailed Section A cracked section analysis takes significant time. If you are not interested in these results Analysis or they are not appropriate then you can turn the detailed section analysis off. In order to turn off a detailed section analysis, select Criteria > Design Rules and then clear the Include detail section analysis check box in each design rule. Load History Deflections
RAM Concept
Load history deflection calculation time is affected significantly by the number of cross sections and the convergence tolerance/iterations to use. Calculation time can be reduced by reducing the number of cross sections or increasing the convergence tolerance and/or reducing the iterations to use.
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Viewing the Results RAM Concept produces a large volume of results from the model analysis. If you take the time to understand how RAM Concept calculates results (and their accessibility), RAM Concept can be a much more powerful tool in your workplace.
33.1 Type of results You can view the results generated via text tables, plans, and perspectives on layers of the following types: • • • • • •
Loading Load Combination Rule Set Design Vibrations Design Status Load History Deflections
To locate a particular result, you need to know on which layer it belongs. Only that layer contains the plans, perspectives and text tables that show those results. For example, you find the Live Loading: Deflection Plan on the Live Loading layer, but the service deflection is in the Service LC layer.
33.2 Viewing frequently used results In general, using plans is the most useful way to view results. Most results of interest relate to the following: • • • • • • • • • •
reinforcement quantities status deflections support reactions precompression load balance bending moment contours section stresses (for some codes) punching shear bearing pressures
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Viewing the Results Viewing frequently used results This section explains how to find such results. Note: When you create a new file without using a template, the file hasRAM Concept's default new file setup. The default new file setup provides preconfigured plans to show some of the results in an organized way. You can change these plans by editing the visible objects and plots. Keep in mind that this may void or make irrelevant some of the instructions below.
33.2.1 Viewing reinforcement results RAM Concept stores the envelope of all required reinforcement for all rule set designs in the Design Status folder. There are a number of plans available to show different reinforcement. The names of reinforcement plans in the default new file setup match the visible reinforcement.
To view reinforcement 1. Choose Layers > Design Status > Reinforcement Plan. If this plan shows more information than you require, consider using an alternate plan such as the Longitude Bottom Reinforcement Plan.
To view longitudinal direction bottom reinforcement 1. Choose Layers > Design Status > Longitude Bottom Reinforcement Plan.
To view a reinforcement plot 1. Choose a reinforcement plan. 2. Choose View > Plot ( ). The Plot dialog box appears with the Section Design dialog. 3. Check the Active box. 4. Select a reinforcement radio button. 5. Enter the Min Frame # and Max Frame #, and click OK.
33.2.2 Viewing status It is possible for a concrete member not to comply with code irrespective of the reinforcement provided. For example, there is a limit on how much shear a member can resist. RAM Concept reports a violation when the shear exceeds the limit. Status refers to code violations. When a design strip complies with all code rules in a rule set design then its status is “OK”. If there are violations then the status is “Failed” or “Exceeded” (depending on the rule) and RAM Concept identifies the code rule. RAM Concept stores the envelope of status for all rule set designs in the design status layer folder. 1. Choose Layers > Design Status > Status Plan.
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Viewing the Results Viewing frequently used results Note: There is no consideration of deflection limits in the status report.
33.2.3 Viewing deflections You may be interested in a number of different deflection plans. Usually these are for vertical deflection but RAM Concept does calculate lateral deflections and hence these are viewable. All deflection intensity and contour plots use uncracked section (Igross) results and do not consider cracking (unless the load factors have been increased for this purpose). Note: Intensity and contour plots are accessed via the plot “Slab” tab. Deflection results that do consider cracking are available via plots that use the Section Analysis tab and L.T. Deflection plot. Note: You could change these plans with the plot setting such that the plot is no longer consistent with the plan name. As such, changing the plot is discouraged. See Chapter 65, “Load History Deflections” for more information. Note: “Slab” (identified by the plot tab) deflection plots are available for loadings and load combinations. “Section Analysis” (identified by the plot tab) deflection plots are available for rule sets.
To view service deflection 1. Choose Layers > Load Combinations > Service LC > Max Deflection Plan.
To view the strip-based long term deflection for ACI318 or BS8110 1. Choose Layers > Rule Set Designs > Service Design > L.T. Deflection Plan.
To view the strip-based long term deflection for AS3600 1. Choose Layers > Rule Set Designs > Max Service Design > L.T. Deflection Plan.
To view the strip-based long term deflection for EC2 1. Choose Layers > Rule Set Designs > Quasi-Permanent Service Design > L.T. Deflection Plan.
33.2.4 Viewing support reactions Support reaction plans are available by default for most loadings and some load combinations. Filtering can make trivial reactions invisible.
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To view self-weight reactions 1. Choose Layers > Loadings > Self-Dead Loading > Reactions Plan.
To view live load reactions 1. Choose Layers > Loadings > Live Loading > Std Reactions Plan.
To view dead load reactions 1. Choose Layers > Load Combinations > All Dead LC > Std Reactions Plan.
To view factored load reactions 1. Choose Layers > Load Combinations > Factored LC > Std Reactions Plan.
33.2.5 Viewing post-tensioning precompression (P/A) Precompression plans can be useful for viewing the level of tendon prestress and the effect of restraining supports. The default plans plot axial stress at mid-depth at each finite element node. These values include the effects of the post-tensioning and the restraining effects of walls and columns in the specified direction. To view the precompression in the x-direction 1. Choose Layers > Loadings > Balance Loading > Fx Precompression Plan. Strip-based precompression plots with options to include or exclude the restraining effects can also be plotted. Related Links • Creating new result plans (on page 370)
33.2.6 Viewing balanced load percentages You can view the percentage of load that is balanced by the post-tensioning within design strips. To view the balanced load percentages on the latitude design strips plan 1. Choose Layers > Design Strips > Latitude Design Strips Plan 2. Choose View > Visible Objects ( ). 3. Check the Balanced Load Percentages box, and click OK. Note: See “Calculating the balanced load percentages” for more information. Related Links • Calculating the balanced load percentages (on page 801)
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Viewing the Results Viewing frequently used results
33.2.7 Viewing bending moment contours Bending moment contour plans can be useful for understanding the flexural behavior of complicated floors. The Bending Moment Distribution tool (
) increases the usefulness of the plan.
To view the factored moments about the x-axis 1. Choose Layers > Load Combinations > Factored LC > Mx Plan.
33.2.8 Viewing section stresses Some codes have concrete stress limits for post-tensioned floors. You may want to know these stresses for the Initial Service Design and Service Design. Usually you want to view stresses based upon the design strips rather than contours, as the design process rarely uses peak stresses derived from contours.
To view the strip-based initial top stresses 1. Choose Layers > Rule Set Designs > Initial Service Design > Top Stress Plan.
To view the strip-based initial bottom stresses 1. Choose Layers > Rule Set Designs > Initial Service Design > Bottom Stress Plan.
To view the strip-based service top stresses 1. Choose Layers > Rule Set Designs > Service Design > Top Stress Plan.
To view the strip-based service bottom stresses 1. Choose Layers > Rule Set Designs > Service Design > Bottom Stress Plan. Note: If too much information is visible then edit the plot. You could make the capacities invisible, or limit the range of strip numbers
33.2.9 Viewing punching shear results RAM Concept checks punching (or two-way) shear for the appropriate code. It calculates the stresses at each vertex of a potential failure plane and compares the calculated stresses to allowable values. To view the punching shear status 1. Select Layers > Design Status > Punching Shear Status Plan.
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Viewing the Results Viewing frequently used results Note: “USR” is unreinforced stress ratio Note: “RSR” is reinforced stress ratio Note: “CTSR” is closed ties stress ratio. This is only available for AS3600. See The “AS 3600 Punching Shear Model” of Chapter 66, “Punching Shear Design Notes”. Related Links • AS 3600 Punching Shear Design (on page 1200)
To view the punching shear SSR 1. Choose Layers > Design Status > SSR Plan.
33.2.10 Viewing live load reduction results You can view live load reduction results for each “member” (columns, punching checks, design strip segments and design sections) and some loadings. To view the column element LLR results 1. Choose Layers > Element > Slab Summary Plan. 2. ). Choose View > Visible Objects ( 3. Check the LLR Parameters box, and click OK.
To view the latitude design strip LLR results 1. Choose Layers > Design Strip > Latitude Design Strip Plan. 2. Choose View > Visible Objects ( ). 3. Check the LLR Parameters box, and click OK.
33.2.11 Viewing soil bearing pressures Files created with “Mat foundation” checked in the New File dialog box have bearing pressure plans provided. To view live loading soil bearing pressure 1. Choose Layers > Loadings > Live Loading > Max Soil Bearing Pressure Plan.
To view service soil bearing pressure 1. Choose Layers > Load Combinations > Service LC > Max Soil Bearing Pressure Plan. Note: You can add soil bearing pressure plans to files. See “Creating new result plans”.
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Viewing the Results Viewing other results Related Links • Creating new result plans (on page 370)
33.3 Viewing other results There are times when the result you seek is not visible on the default plans. The following describes how to show such results.
33.3.1 Changing which result objects are visible In the default new file setup, specific objects are visible by default. You can modify the visible objects to show less or more results. 1.
Choose View > Visible Objects ( ). 2. Choose options in the Visible Objects dialog box and click OK Note: See “Controlling views” for more information. Related Links • Controlling views (on page 60)
33.3.2 Changing which results plot The plot settings control which results plot on a plan or a perspective. The default file setup has specific plot settings for particular plans or perspectives. You may decide to change the settings to suit your requirements, or to make the plan easier to read. 1.
Choose View > Plot ( ). The Plot dialog box appears. 2. Make changes and click OK. Note: The way plans and perspectives are named is often a reflection of the plot settings used. If you change the plot settings, you might make the names inaccurate. Note: You must first open the plan or perspective before you can use the plot command.
Plotting the strip bending moment on an existing plan The following example demonstrates plotting the bending moment envelope on the Strength Design: Reinforcement Plan:
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Viewing the Results Viewing other results • Choose Layers > Rule Set Designs > Strength Design > Reinforcement Plan. • Choose View > Plot ( ). • On the Strip tab, check “Active”. • Select “Bending” • Check “Maximum Moment”, and “Minimum Moment”. • Click OK.
33.3.3 Creating new result plans You can create new plans for results that are not available in the plans in the default new file setup. See Creating new plans (on page 59) and Creating new perspectives (on page 60) for more information on how to create new plans and perspectives. Related Links • Creating new plans (on page 59) • Creating new perspectives (on page 60) • Viewing post-tensioning precompression (P/A) (on page 366)
Creating a new bending moment plan The following example demonstrates creating a bending moment plot plan for the Strength Rule Set. 1. Choose Layers > New Plan. 2. Type a name. For example, Strength BMD. RAM Concept automatically appends the word “plan” to the name and prepends the layer name. 3. Select the Strength Design layer and then click OK. The Visible Objects dialog box appears. 4. Click Show Nothing and then and click OK. 5. Choose View > Plot ( ). The Plot dialog box appears. 6. Select the Section Analysis tab. 7. Check Active. Keep the Value as Bending Moment 8. Uncheck Maximum Capacity and Minimum Capacity. 9. Click OK. Note: You can select specific frame numbers in the dialog box. This could be used to show a plot for, say, a single beam. Note: You can selectively turn off left, middle and right strips. Left and right are the “half” middle strips. Center is the column strip.
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Viewing the Results Viewing other results
Creating a new reactions plan The following example demonstrates creating a Service LC reactions plan: 1. Choose Layers > New Plan. 2. Type a name. For example, Reactions. RAM Concept automatically appends the word “plan” to the name and prepends the layer name. 3. Select the Service LC layer and then click OK. The Visible Objects dialog box appears. 4. Click OK. 5. Choose View > Plot ( ). The Plot dialog box appears. 6. Select the Reaction tab. 7. Check Active. 8. Select Standard. 9. Check the supports (under Value) for which you want to view reactions.
Creating a new precompression plan The following example demonstrates configuring span segments to calculate precompression and then creating a precompression plan for the User Minimum Rule Set. To create the precompression plan: 1. Choose Layers > New Plan. 2. Type a name. For example, Precompression. RAM Concept automatically appends the word “plan” to the name and prepends the layer name. 3. Select the User Minimum layer and then click OK. The Visible Objects dialog box appears. 4. Click Show Nothing and then click OK. 5. Choose View > Plot ( ). The Plot dialog box appears. 6. Select the Section Analysis tab. 7. Check Active. 8. Toggle Precompression under Value. 9. Click OK. The span segments must be configured to calculate precompression prior to viewing precompression stresses. To configure existing span segments: 1. Select one or more existing span segments modeled on Layers > Design Strip > Latitude Design Spans Plans. 2. Choose Edit > Selection Properties. The Edit Selected Items dialog box appears. 3. Select the General tab. 4. Check Consider as Post-Tensioned.
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Viewing the Results Section distribution plots 5. Select FseAps/Ac for Precompression Calc. This will plot the effective tendon force multiplied by the perpendicular vector component of the tendon area intersecting the section divided by the cross section area and will not include restraining effects of walls and columns. 6. Click OK.
33.4 Section distribution plots RAM Concept’s section distribution plots allow you to see the variation of analysis values across any line drawn on the structure. These distribution plots can be very helpful in understanding the behavior of the structure (especially for moments and deflections), but they are not intended to be used for quantitative design purposes.
33.4.1 Distribution plot values Distribution plots are created using the Bending Moment Distribution tool (
), Vertical Shear Distribution tool
( ), Axial Force Distribution tool ( ) and Selected Plot Distribution tool ( ). These plots display predictions of values along the lines drawn across the slab. RAM Concept bases these predictions on the calculated results of the individual elements. RAM Concept’s calculation method guarantees that the results for design strip segments and design sections are in equilibrium with the nodal loads. The results for plots across elements are not necessarily exact, however, and can be much less accurate for coarse meshes or elements with high aspect ratios. Even though RAM Concept's calculation method guarantees stored elastic energy of the stresses in each element is equal to the energy of the loads applied to the element, for some oddly shaped elements (such as pointy triangles), the energy formulation can result in local fictitious stress spikes. Note that this limitation does not affect design strip segments or design sections and does not affect RAM Concept’s reinforcement calculations.
33.4.2 Moment distribution plots You can create moment distribution plots using the Bending Moment Distribution tool ( ). The plot displayed along the drawn line shows the distribution of bending moment about the axis of the line. The values in the main 2D plot (if any) controlled by the Plot ( ) dialog box have no effect on the moment distribution plot. The integrated moment value shown below the moment distribution plot is the sum of the area of the plot, but does not include the bending moment that is due to axial forces and variations in the centroid elevation of the slab (such as the bending moment caused by axial forces in the web and flanges of a T-beam). You should use design strips and design sections to determine design quantities as they capture both components of the bending moment. The following figure shows a moment distribution plot for My moments drawn on a contour plot for Mx moments. The distribution plot shows My moments because the line drawn on the plan is parallel to the y-axis. The distribution plot has an integrated value of –657 kip-ft and a peak value of –73.9 kips (or –-73.9 kip-ft/foot). The contour plot values have no effect on the distribution plot values. If you used the Selected Plot Distribution
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Viewing the Results Section distribution plots
tool ( ) instead of the Bending Moment Distribution tool ( would display the same values.
), the contour plot and the distribution plot
Figure 162: Moment distribution plot showing My moments on an Mx contour plot.
33.4.3 Shear distribution plots You can create shear distribution plots using the Vertical Shear Distribution tool ( ). The plot displayed along the drawn line shows the distribution of vertical shear force across the line. The values in the main 2D plot (if
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any) controlled by the Plot ( ) dialog box have no effect on the shear distribution plot. The integrated shear value shown below the shear distribution plot is the sum of the area of the plot. Design strips and design sections provide a more accurate calculation of this integrated value.
33.4.4 Axial force distribution plots You can create axial force distribution plots using the Axial Force Distribution tool ( ). The plot displayed along the drawn line shows the distribution of axial (horizontal) force across the line. The values in the main 2D plot (if any) controlled by the Plot ( ) dialog box have no effect on the axial force distribution plot. The integrated axial force value shown below the axial force distribution plot is the sum of the area of the plot. Design strips and design sections provide a more accurate calculation of this integrated value.
33.4.5 Selected distribution plots You can create selected distribution plots using the Selected Plot Distribution tool (
). The plot displayed along
the drawn line shows the distribution of the values shown in the main 2D plot (controlled in the Plot ( ) dialog box). The integrated value shown below the distribution plot is the sum of the area of the plot. This integrated value may or may not be useful depending upon the plotted quantity (for example, the integration of a top-stress plot is a force/length value, which is largely useless). You need to take special care when using the Selected Plot Distribution tool ( ) with the “max” and “min” axis contour plots (such as a Service LC Max Bottom Stress Plan). The “max” and “min” stress plots show the maximum or minimum principal value at every point in the slab. At each point along a selected plot distribution of the principal values, the principal axes may be different. The integrated value for the distribution plot has mathematical meaning, but does not have any structural meaning. If you want to see the distribution of stresses (or moments, etc.) about a particular axis, you can use the Plot ( ) dialog box to set the contour plot axis (using the Value Plotted Axis) to be the axis of the results you want to view. The Selected Plot Distribution tool ( ) then shows the values for that axis.
33.4.6 Effects of averaging Distribution plots display the calculated results of the individual elements. At the shared edge of two elements, RAM Concept uses simple averaging. This produces reasonable results in most cases, but can cause distortions of the integrated result when RAM Concept averages a small element’s result with a large element’s result. The selected distribution plots are additionally affected by the plan averaging that occurs in the 2D plot controlled by the Plot (
) dialog box.
This distortion caused by averaging is another reason why you should always use design strips and design sections to determine design quantities.
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Viewing the Results Miscellaneous results information
33.4.7 Summary Section distribution plots allow you to see the variation of analysis values across any line draw on the structure. These distribution plots are very helpful in understanding the behavior of the structure, but you should not use them for quantitative design purposes. You should always use design strips and design sections to determine design quantities.
33.5 Miscellaneous results information The following sections are for clarification of some results.
33.5.1 Top and bottom longitudinal reinforcement RAM Concept shows longitudinal reinforcement on plan with the following parameters: • • • •
number of bars bar type (as defined as a design strip property) length of the bars bar spacing
The reinforcement shown on the Rule Set Designs and Design Status layers represents what is required in addition to any specified user reinforcement and does not include development length considerations. For a complete consideration of all parameters including development length refer to the Reinforcement Layer. The following two figures show top reinforcement at a column. There are two callouts because the design strips terminate at the column. The required reinforcement is different on each side, as often happens. You need to rationalize this information and detail the bars in a logical manner. The left hand reinforcement is nine #5 bars, each 6.5 ft. long [nine 16 mm bars, each 1.8 m long].
Figure 163: Design Status: Latitude Top Reinforcement Plan (US units)
Figure 164: Design Status: Latitude Top Reinforcement Plan (metric)
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Viewing the Results Miscellaneous results information The following two figures show bottom reinforcement. The reinforcement is thirteen #4 bars, each 9.5 ft. long [fifteen 12 mm bars, each 2.9 m long].
Figure 165: Design Status: Bottom Reinforcement Plan (US units)
Figure 166: Design Status: Bottom Reinforcement Plan (metric)
33.5.2 Reinforcement bar lengths RAM Concept calculates the reinforcement bar lengths by determining termination points. The termination points are located at design strip segment cross sections where the bars are no longer required for any rule set design. The bar lengths shown on plan do not include development or embedment lengths.
33.5.3 Orientation of reinforcement RAM Concept draws and plots reinforcement along an axis determined by the first and last cross section of the design strip. Top bars appear “over” the axis and parallel to it. Bottom bars appear “under” this axis and parallel to it. Reinforcement plots are perpendicular to the axis. The following figure shows the axis, line A-B, for a middle strip. Point A is at the midpoint of the first middle strip cross section, and point B is the midpoint of the last middle strip cross section. Design and capacity calculations always assume that the reinforcement (other than tendons) is perpendicular to the cross sections. If the reinforcement is placed away from the perpendicular orientation (such as that shown in the following figure), the reinforcement quantity may need to be increased.
Figure 167: Reinforcement drawing and plotting relative to local axis
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33.5.4 Shear reinforcement RAM Concept shows shear reinforcement zones on plan with the following parameters: • • • •
number of spaces in the zone number of legs per shear reinforcement set spacing of the sets length of the zone
The following figure shows shear reinforcement. For US units and bar size, the zone is 2.78 ft. long and has 4 spaces with two #4 legs @ 8.34” centers. For metric units and bar size, the zone is 0.772 m long and has 4 spaces with two 12 mm legs @ 193” centers. For both unit systems, there are five shear reinforcement sets (spaces + 1).
Figure 168: Design Status: Shear Reinforcement Plan (US and metric units).
33.5.5 Punching Shear Results Punching shear design notes appear in Chapter 66, “Punching Shear Design Notes”. Non-Standard Sections: ACI 318 and CSA A23.3 Some times the punching shear status is “Non-Standard Section”. This is a warning, not an error. “Non-Standard Section” means that at least one of the critical sections that RAM Concept is investigating for that column does not perfectly fit one of the three cases: interior, edge and corner. When you get a “Non-Standard Section”, you need to inspect the critical sections that RAM Concept has defined, and use your engineering judgment to determine if you feel they fit the ACI/CSA punching model (you should always visually inspect the critical sections, even if RAM Concept does not flag them as non-standard). RAM Concept still calculates a stress ratio for non-standard sections. Non-Standard Sections: AS3600, BS8110, EC2 and IS 456
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Viewing the Results Miscellaneous results information Some times the punching shear status is “Non-Standard Section”. This is a warning, not an error. “Non-Standard Section” means that at least one of the critical sections that RAM Concept is investigating for that column does not perfectly fit one of the three cases: interior, edge and corner. When you get a “Non-Standard Section”, you need to inspect the critical sections that RAM Concept has defined, and use your engineering judgment to determine if you feel they fit the code punching model (you should always visually inspect the critical sections, even if RAM Concept does not flag them as non-standard). RAM Concept still calculates a stress ratio for non-standard sections. If a punching section can be classified by any of the “standard” rules, it is considered to be a “standard” section. The rules for “standard” sections are: 1. Interior Rectangular: • must be uniform thickness • must have 4 sides • section centroid must coincide with column centroid • opposite sides must be parallel and have same length • adjacent sides must be perpendicular • must be continuous (no gaps) 2. Edge Rectangular: • must be uniform thickness • must have 3 sides • opposite sides must be parallel and have same length • adjacent sides must be perpendicular • can only have two discontinuous ends (assumed at slab edge) 3. Corner Rectangular: • must be uniform thickness • must have 2 sides • sides must be perpendicular • can only have two discontinuous ends (assumed at slab edge) 4. Interior Round (circular shape idealized into straight line segments): • must be uniform thickness • section centroid must coincide with column centroid • all segment ends must be on same radius from the center of the column • must be continuous (no gaps) 5. Corner or Edge Round (circular shape idealized into straight line segments): • • • •
must be uniform thickness column must be round can only have two discontinuous ends (assumed at slab edge) can only have two segment end points that are a different radius from the center of the column than all other segment end points (assumed at slab edge) • discontinuous segment end points must be the “off radius” points (at slab edge)
Note: The rules are applied to EC2 sections before the corners are filleted.
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Plotting Results The plot settings control which results plot on a plan or a perspective. The default file setup has specific plot settings for particular plans and perspectives. You can customize these settings or create new plans and perspectives that show your desired plots. Plot settings are controlled via the Plot dialog which is accessed through the Plot command (
).
34.1 Setting the plotted results You may decide to change the settings to suit your requirements. To change a plot setting 1. Open the plan or perspective you want to change. 2. ). ChooseView > Plot ( The Plot dialog box appears. 3. Select a tab and check Active to make that plot active. 4. Make changes and click OK. Note: The name of a plan or perspective is often indicative of its plot settings. If you change the plot settings, you may want to rename the plan or perspective.
34.2 Slab Checking the Active box in the Slab tab allows you to display and control various slab analysis plot quantities such as moment, shear, axial, torsion, deflections, and area spring reactions. For plotting axial stresses or inplane shear stresses, select the depth at which to plot the value. Other plot values are not dependent upon depth. For load history layer plots only, some additional plot quantities are available - see Load History Deflections (on page 1176) for more information. We recommend curve smoothing for contour plots. Without curve smoothing, contours will be plotted element by element, which can make it difficult to observe the results of a larger region (also, for some plotted quantities, nothing will be shown unless curve smoothing is on). RAM Concept allows you to define a resolution for the selected plot value. Finer plot resolutions require longer screen regeneration times.
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Plotting Results Slab For contour plots, you can control the frequency of the contour lines by unchecking “Use default magnitudes” and entering the desired contour value. For color contour plots, you can set the upper and lower limits of the contour values by entering the minimum and maximum values. Slab plots are available for loading, load combination, rule set, and load history layers.
Figure 169: The plot dialog with slab result plotting active. The “Animation Control” is described in more detail in the section, “Plotting Results.”
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Plotting Results Slab
34.2.1 About slab plotting contexts There are three possible contexts: “Standard”, “Max” and “Min”. The Max and Min context are used to envelope the maximum and minimum values for each point in the slab. While the meaning of the Standard, Max and Min contexts is somewhat self-evident, the following table lists how RAM Concept calculates these values considering load patterns and standard and alternate load factors.
34.2.2 Max and Min context slab plot limitations RAM Concept stores only a limited number of slab analysis values. For example, standard, maximum and minimum Mx, My and Mxy values are stored, while moment values about other axes (not x- or y- axis) are calculated via Mohr’s Circle calculations. Similarly, standard, maximum and minimum Px, Py, Vxy, Mx, My and Mxy values are used to calculate stress values at the top, center and bottom of the slab. Because minimum and maximum values are not stored for these derived values, the calculation of the minimum and maximum values is approximate. Example: if one loading pattern gives an x-deflection of 10 and a y-deflection of 0, while another pattern gives a x-deflection of 0 and a y-deflection of 10, the Max context deflection will be reported as 14.4, even though the true maximum deflections never exceeded 10. The following slab maximum and minimum context plot values should always be considered approximate: • • • •
Values for any axis that is not the x- or y- axis. Stress values for any depth that is not mid-depth. Lateral deflection values for any depth that is not mid-depth. Lateral deflection values where the center of the slab is not at elevation zero.
Table 15: Calculation of Standard, Max and Min values Layer Type
Standard
Loading
Values with full applied Maximum values that loads (no pattern loading) occur considering each pattern loading (complete with pattern factors) and the full loading.
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Min Minimum values that occur considering each pattern loading (complete with pattern factors) and the full loading.
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Layer Type
Standard
Max
Min
Single
Linear combination of Loading Standard values using the Standard load factors
Values that occur when combining all loadings, taking the maximum value of the following four values for each loading:
Values that occur when combining all loadings, taking the minimum value of the following four values for each loading:
• Standard Load Factor * Max • Alt Load Factor * Max • Standard Load Factor * Min • Alt Load Factor * Min
• Standard Load Factor * Max • Alt Load Factor * Max • Standard Load Factor * Min • Alt Load Factor * Min
Values that occur when combining all gravity loadings, taking the maximum value of the following four values for each loading:
Values that occur when combining all gravity loadings, taking the minimum value of the following four values for each loading:
• • • •
• • • •
Load Combination
Lateral Group
(not available)
Load Combination
Rule Set
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Std Load Factor * Max Alt Load Factor * Max Std Load Factor * Min Alt Load Factor * Min
Std Load Factor * Max Alt Load Factor * Max Std Load Factor * Min Alt Load Factor * Min
Plus the maximum single value of all of the lateral loadings' (of the correct type) values:
Plus the minimum single value of all of the lateral loadings' (of the correct type) values:
• Std Lateral Load Factor * Max • Alt Lateral Load Factor * Max • Std Lateral Load Factor * Min • Alt Lateral Load Factor * Min
• Std Lateral Load Factor * Max • Alt Lateral Load Factor * Max • Std Lateral Load Factor * Min • Alt Lateral Load Factor * Min
Maximum of all of the related load combination values
Minimum of all of the related load combination values
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34.3 Reaction Checking the Active box in the Reaction tab allows you to display and control analysis reaction quantities. Selecting the Standard context button displays reactions corresponding to the standard results (more information about standard and enveloping results is available in Chapter 50, “Analysis Notes”). For the standard results, you can display any number of reactions for column above/below, wall above/below, point spring/support, line spring/support, and the standard reactions used for the punching checks. If a column above and below occur at the same location in plan, and both Column Above and Column Below boxes are checked, the sum of the reactions is shown at that location. The same holds true for walls above and below. The other buttons in the Context group are for the enveloped results. RAM Concept displays reactions for columns (above/below) and punching checks for the envelope result of the selected context. Wall reactions will be enveloped and available for plotting in future versions. The “standard” reaction context values are only available for loading and load combination layers, while the six enveloped contexts are available for loading, load combination and rule set design layers.
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Plotting Results Reaction
Figure 170: Plot dialog reaction tab
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Plotting Results Reaction
Figure 171: Plot dialog reaction tab
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Plotting Results Strip
Figure 172: Plot dialog reaction tab
34.4 Strip Checking the Active box in the Strip tab allows you to display analysis results for the design strips. Each plot value represents the variation of the selected value at each design strip segment cross section (along the axis of each strip selected). Plots related to the maximum and minimum moments and shears can be displayed, enabling the envelope for a particular plot value to be displayed.
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Plotting Results Strip The Torsion value is the torsion about the centroid of the design strip segment, in equilibrium with the element nodal forces. The Twist value is the component of the torsion due to the slab twisting moment (Mxy for design strips parallel to the x- or y- axes) calculated from the element stress predictions (and is not necessarily in equilibrium with the element nodal forces). The Twist value is not recommended for use in torsion design. Absolute Twist is the sum of the absolute value of the twist along the cross section. This value differs from the “Twist” value in that it is always positive, and that in its calculation, twist values of different signs do not cancel out. The Absolute Twist value is not used in design unless Wood-Armer torsion design is selected. Note: The accuracy of the Twist and Absolute Twist values are determined from element stress predictions and are dependent upon the quality and the refinement of the mesh. Unlike the Torsion value, there is no guarantee that these values will be in equilibrium with the applied nodal loads. Definitions of other values can be found in Chapter 50, “Analysis Notes”. The “standard” strip context values are only available for loading and load combination layers, while the four enveloped contexts are available for loading, load combination and rule set design layers.
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Plotting Results Section Analysis
Figure 173: Plot dialog strip tab.
34.5 Section Analysis Checking the Active box in the Section Analysis tab allows you to display analysis and design results for the design strips including moments, shears, stresses, crack width, and effective curvature ratio. The plotted analysis results are for the envelope results. They can be plotted against the design capacity resulting from RAM Concept’s final design. Note that some quantities may not have capacity values defined.
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Plotting Results Section Design Section analysis plots are only available for rule set design layers.
Figure 174: Plot dialog section analysis tab.
34.6 Section Design Checking the Active box in the Section Design tab allows you to plot top, bottom and shear reinforcement quantities corresponding to RAM Concept’s final design or a design for a particular rule set.
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Plotting Results Section Design The “Top Developed” and “Bottom Developed” values represent the amount of fully developed top and bottom reinforcement that is required at each location. Section design plots are only available for rule set designs and the design status layers.
Figure 175: Plot dialog section design tab
34.6.1 About section design “context” plots The Section Design plot group box, “Context” allows for three possible contexts:
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Plotting Results Section Design • With Span Detailing • Without Span Detailing, and • User Provided Reinf. Span detailing is explained in Section 53.1 in Chapter 53, “Reinforcement Notes”. The effects of the Span Detailing Contexts on plots are explained in the following two tables. For the Design Status layer, the context of “With Span Detailing” includes the effects of the assumed reinforcement development calculations in the plots of developed reinforcement.
34.6.2 About skyline plots When you select the “With Span Detailing” or “User Provided Reinf” contexts, RAM Concept plots the reinforcement with a “skyline” plot. In a skyline plot, each calculated value is valid for a portion of the span (as shown by a horizontal line) instead of the values being interpolated between cross sections. While this is primarily just a graphical difference, the actual detailing of the reinforcement into bar callouts is performed using the skyline plot values. For rule set designs, the effects of the Span Detailing Context (other than the skyline plotting) are as shown in the following table. For the Design Status layer, the effects of the Span Detailing Context (other than the skyline plotting) are as shown in the second table below. Table 16: Effects of span detailing context on rule set plots Value
Without span detailing
With span detailing
User provided reinforcement
Top
As calculated per section
Values calculated per section are lengthened according to the span detailer rules (see Section 53.1 “Span detailing” of Chapter 53, “Reinforcement Notes”) .
Vector component of area of user individual bars intersected by the cross sections
As calculated per section
As calculated per section
Vector component of developed area of user individual bars intersected by the cross sections
As calculated per section
As calculated per section
(none)
Bottom Top and Bottom
Top Dev Bottom Dev
Shear Shear Density Shear Spacing
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Plotting Results Punching Analysis Table 17: Effects of Span Detailing Context on Design Status Plots Value
Without span detailing
With span detailing
User provided reinforcement
Top
As calculated per section
Values calculated per section are lengthened according to the span detailer rules (see Section 53.1 “Span detailing” of Chapter 53, “Reinforcement Notes”) .
Vector component of area of user individual bars intersected by the cross sections
As calculated per section
Plotted values are the maximum of the reinforcement calculated per section and the amount of developed reinforcement calculated from the span-detailed amounts of nondeveloped reinforcement (see Section 53.1 “Span detailing” of Chapter 53, “Reinforcement Notes”) .
Vector component of developed area of user individual bars intersected by the cross sections
Bottom Top and Bottom
Top Dev Bottom Dev
These values are used in the final capacity check calculations. Shear
As calculated per section
As calculated per section
(none)
Shear Density Shear Spacing
34.7 Punching Analysis Checking the Active box in the Punching Analysis tab allows you to display information about the punching analysis including stresses for each critical section for any of the enveloped force sets. The values displayed are for the selected critical section(s) with the selected force set, and are not necessarily the worst case for the column. The most critical punching case can always be displayed by selecting the Max Stress Ratio button and checking Section 1. Punching analysis plots are only available for rule set design and the design status layers.
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Plotting Results Punching Analysis
Figure 176: Plot dialog punching analysis tab
34.7.1 Punching Shear Results Punching shear design notes appear in Chapter 66, “Punching Shear Design Notes”. There is discussion of “Non-Standard Section” in “Punching Shear sesults”.
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Plotting Results Vibration Analysis
34.8 Vibration Analysis 34.8.1 Vibration Results Vibration analysis notes can be found in Vibration Analysis Notes (on page 1211).
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Plotting Results Plot Animation Controls
Figure 177: Plot dialog vibration analysis tab
34.9 Plot Animation Controls Slab and Vibration plot data can be animated in an endless loop. The animation scales most plot values from their normal values to zero and back. Vibration mode plot values are scaled from +1 to -1 to simulate oscillating values. You have control over playing the animation, the number of animation frames, and the animation speed.
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Plotting Results Difference Plot Controls
Figure 178: Plot animation setup To enable animation 1. Check the Enable Animation box. 2. Enter a positive number in # Frames.
34.9.1 Playing the Animation When the Plot Settings dialog is confirmed, the first frame of the animation is displayed with the maximum plot values. When the animation is played, the data will shrink to the minimum values, then grow to the maximum and repeat.
Figure 179: Plot animation controller Playing the animation is controlled by buttons in the main tool bar. Press the play/pause button to play or pause the animation. The slider controls the duration of the animation. When set at the leftmost value (-), the duration of the animation (from minimum to maximum values) will be approximately 10 seconds. The next slider positions set the duration to 5 seconds, 2 seconds and 1 second. The rightmost value (+) plays the animation as fast as possible. Many Concept functions, such as zooming and panning, will function while the animation is playing, although some mouse motions will freeze the animation temporarily. The animation speed slider can be changed at any time. The geometry for each animation frame is cached the first time the frame is displayed. A small status box is displayed when the frame is being computed. Each subsequent display of a frame uses the cached geometry for fast display. Pausing or resuming the animation while the animation frames are being computed does not affect the cached data. However, the animation geometry cache is discarded when switching to another plan or perspective view, and must be recomputed when switching back. Any change to the plot settings also invalidates the cached geometry. The cached geometry can consume a significant amount of process memory. Memory consumption grows linearly with the number of frames. Intensity plots generally consume more memory than Color Contour plots, and Color Contour plots consume much more memory than Contour line plots. The static portions of the scene, e.g. slabs, walls and columns, do not contribute to the memory consumption.
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Plotting Results Difference Plot Controls
34.10 Difference Plot Controls The difference between two plot layers can be plotted if the results of the two layers are compatible. Select the layer to be subtracted from the Diff Layer choice box, or None if no difference is desired.
Figure 180: Plot difference control Section Analysis, Section Design, Punching Analysis and Vibration results cannot be differenced. Otherwise, a difference layer is compatible with the plot layer if the difference layer has results available for the data selected in the plot layer. The dialog cannot be be confirmed if there is a difference incompatibility. For example, consider Plot Layer set to Self-Dead Loading and Diff Layer set to Code Minimum Design. The Code Minimum Design layer has results for Slab, Reaction and Strip, therefore any (or all) of these layers can be active. The Code Minimum Design layer does not have standard context results; selecting the standard context on any of the tabs will be incompatible. The text next to the Diff Layer choice box will describe the first incompatibility detected. Now consider the layers reversed, Plot Layer set to Code Minimum Design and Diff Layer set to Self-Dead Loading. Any settings can be differenced on the Slab, Reaction and Strip tabs, because the Code Minimum Design layer contains a subset of the results available in the Self-Dead Loading layer. However, activating any one of the Section Analysis, Section Design or Punching Analysis tabs will be incompatible.
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Using the Auditor There will be times when a design result calculated by RAM Concept may be confusing or unexpected. This could be due to incorrect input, an unusual set of resultants (for example: a negative moment at mid-span), or a code rule interpretation. The Auditor assists in displaying design information for you to review.
35.1 How the Auditor can assist the design process The Auditor is a tool that displays input data, parameters, resultants and code specific results for design strip cross sections, design sections and punching checks. The Auditor displays information that could be useful for: 1. 2. 3. 4. 5.
Checking input data such as reinforcement bar cover. Checking calculated data such as the elevation of the center of a reinforcement bar. Reviewing the rule set designs (service, strength etc.) Checking the envelope of resultants (moment, shear force, axial force etc.). Revising the number of strands in a tendon to satisfy code stress limits.
35.2 About the three design steps RAM Concept performs its design in 3 steps: Step 1: Each Rule set performs its “Pass 1” selection of reinforcement. For most rule sets this is the entire design. Step 1b: The selected reinforcement of all the rule sets is summarized. Step 2: Each Rule set performs its “Pass 2” selection of reinforcement needed in addition to that summarized in step 1b. For most rule sets nothing happens in this step, but for some rule sets –such as shear design and ductility design the summarized step 1 reinforcement needs to be known before the design can be performed. Step 2b: The selected reinforcement of all the rule sets is summarized. Step 3: Each Rule set performs a final check (no reinforcement is added in this step) and final analysis. The Auditor reports the three steps as the following: • Pass 1 • Pass 2 • Final check
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Using the Auditor About the information displayed by the Auditor
35.3 About the information displayed by the Auditor The Auditor display information for a single cross section of one span segment strip, or a design section. The Auditor displays the following: 1. Design strip and cross-section number, or design section number 2. Concrete components for a cross section • • • • • • •
number of concrete blocks top and bottom elevation of each block depth and width of each block initial and final strengths (cylinder and cube) initial and final Ec (modulus of elasticity) values density inclusion or exclusion of block from shear core
See “Concrete “Core” Determination” for discussion of shear core. 3. Reinforcement properties for each bar type • elevation • yield stress • Ec (modulus of elasticity) value • bar area • bar diameter 4. Tendon properties for each tendon type • • • • • • • • • • • • • • • •
elevation of cgs (center of gravity of strand) above datum ultimate strength (stress) yield stress effective stress Ec (modulus of elasticity) value area of strand bonding R-component [the component of the tendon parallel to the design strip cross section (perpendicular to the design strip spine)] S-component [the component of the tendon perpendicular to the design strip cross-section (parallel to the design strip spine)] Z-component [the vertical component of the tendon across the cross-section (only used for hyperstatic calculations)] length initial concrete strain duct width number of strands per duct cross sectional area per strand number of ducts
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Using the Auditor About the information displayed by the Auditor 5. Base design envelopes (for each Rule Set Design): The envelopes for maxima and minima of moment and shear force are displayed. These are modified, as appropriate, for torsion and axial force design. The envelopes list the following resultants: • Vr (horizontal shear) • Ps (axial tension) • Vz (vertical shear) • Mr (bending) • Ts (torsion) • Mz (diaphragm bending) 6. Reinforcement (for each Rule Set Design): Depending upon the rule set, RAM Concept adds reinforcement to the cross section. • • • • •
As Top As Bot. As Shear Density As Shear Spacing As Shear (density multiplied by spacing)
Brackets appear after each result showing which code rule governed. 7. Cross Section Forces (Analysis) Depending upon the rule set, the Auditor displays cross section forces and other information. • Cross Section Strains • curvature • top, centroid and bottom strains • Concrete Forces for each block • top and bottom stress • force • force elevation • Untensioned reinforcement forces for each bar • elevation • strain • stress • bar area • force • Post-tensioning forces for each tendon • • • •
elevation cross-section strain component cross-section strain (considers tendon angle) Tendon Force (effective force in cross section plane)
Related Links • Concrete “Core” Determination (on page 816)
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Using the Auditor Using the Auditor
35.4 Using the Auditor The Auditor can be used for specific rule set designs, or for the design summary. Note: A rule set audit has significantly less data than a design summary audit. As such, a rule set audit may be more useful. 1. 2. 3. 4.
Choose Layers > Rule Set Designs > Selected Design > Selected Plan Select the Auditor tool ( ). Click on the plan at the design strip cross-section, or design section, you wish to audit. Scroll to find the information you require.
Note: You may find it convenient to make the design cross sections visible for the purpose of selecting the correct one. Note: The Auditor selects either (i) the nearest cross-section (of a visible span segment strip) to the point you click, or (ii) nothing, if there is no cross section within 3 feet [1m] of the point you click. The cross-sections themselves do not need to be visible. Note: The Auditor will not display results if a Calc All has not been performed. The Auditor’s results may not be current if the analysis is not current. (If the Calc All option is grayed-out ( the analysis results are current).
),
35.4.1 To use the Auditor for the design summary 1. Choose Layers > Design Status > Selected Plan. 2. Follow instructions for “strength rule set design” above.
35.5 Using the Auditor for guidance on post-tensioning Certain codes limit the service stresses and designers are required to comply with the limits. The Auditor displays advice on how much additional post-tensioning strand is required in a design strip to satisfy certain code clauses. This information is accessible from many plans, but the instructions below are for using the Service Rule Set Design. 1. Choose Layers > Rule Set Designs > Service Design > Status Plan 2. Select the Auditor tool ( ).
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Using the Auditor About the information displayed by the Punching Check Auditor 3. Click on the plan at the design strip cross-section which has failed a stress criterion and for which you require guidance. 4. Scroll to the text bordered by two lines of asterisks (top and bottom) near the bottom of the audit. 5. Open all items 6. Search for the string "SUGGESTIONS" using the Report Viewer Find tool If the maximum tensile stress is within code then the search string will not be found. If the calculated concrete tensile stresses exceed the allowable limit then the Auditor suggests the percentage increase in strand required to satisfy the stress limit. SUGGESTIONS: Top Stress Exceeds Tensile Limits: Suggest increasing number of tendons by 8.4% or more. (Due to diversion of prestress into other areas, above percentage may not be exact) Figure 181: Auditor text indicating percentage increase required to comply with code. Note: The precompression and balance effects of a tendon are not necessarily limited to the area (and design strip) where the tendon is located. Due to the diversion of prestress (bleed of P/A) beyond the design strip the suggested percentage increase may not be exact. Note: If there are tendons intersecting the cross-section at an angle other than ninety degrees then the suggested percentage increase may be inaccurate.
35.6 About the information displayed by the Punching Check Auditor The information displayed by the Punching Check Auditor is for a punching check at a single column. The Auditor displays the following: 1. Punching check number 2. Location (coordinates) 3. Geometry
4. 5. 6. 7. 8.
• axis angle • radius Cover to CGS Concrete Strength Precompression Resultant envelopes Critical section perimeter properties
• number of critical sections • perimeter length • perimeter depth • torsion strip properties (for AS3600) 9. Unreinforced stress ratio 10. Stud shear reinforcement rail properties (if required for design). 11. Summary
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Using the Auditor Using the Punching Check Auditor
35.7 Using the Punching Check Auditor The Auditor can be used for the strength rule set design, or for the design summary. 1. Choose Layers > Rule Set Designs > Strength Design > Selected Plan 2. Select the Punching Check Auditor tool ( ). 3. Click on the plan at the punching check location you wish to audit. Note: The Auditor will not display results if a Calc All has not been performed. Note: The Auditor’s results may not be current if the analysis is not current. (If the Calc All option is grayed-out (
), the analysis results are current).
35.7.1 To use the Auditor for the design summary 1. Choose Layers > Design Status > Selected Plan. 2. Follow instructions for the “strength rule set design” above.
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Using the Report Viewer It is sometimes desirable to search, save or print a report for a particular aspect of the design. The report viewer provides this functionality for auditor or punch check results.
36.1 Using the Report Viewer The Report Viewer can be invoked for punch checks from the design strip layer, the design summary layer, or for an individual rule set design layer. The information the report contains will always be the entire design summary. 1.
Select the Report Viewer tool ( ). 2. Draw a rectangle around all the punch checks you wish to generate a report for. The Report viewer window opens. 3. A report for each punch check will be contained on an individual tab. Select the tab for the desired punch check. Note: No report will be displayed if a Calc All has not been performed. Note: The generated report’s results may not be current if the analysis is not current. (If the Calc All option is grayed-out (
), the analysis results are current).
36.2 Collapsing Sections Cross Section Audit reports are displayed with collapsible sections to assist in managing the lengthy reports. Clicking on the triangle next to a section heading opens or closes that section. All sections in the report can be opened (or closed) by clicking on the Open/Close All Items button at the bottom of the window.
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Using the Report Viewer Saving Reports
36.3 Searching for Text The report viewer has a Find Text feature to assist in locating the desired information. The search text entry area is located at the bottom of the screen, next to the word “Find”. The page is repositioned at the next occurrence of the text entered. The Next/Prev buttons position the page down/up to the next/previous occurrence of the search string. The Match Case button controls whether the upper or lower case of the text is considered. The Highlight All button causes all matching text to be highlighted. Note: Only displayed text is searched. You may want to open all items before searching.
36.4 Saving Reports It will sometimes be desirable to save generated reports. Reports can be saved individually as an HTML5 file or as a zipped bundle of HTML5 files.
36.4.1 Saving One Report To save the report displayed in the current tab of the Report Viewer 1. Select File > Save Tab from the Report Viewer menu. 2. Enter a filename and save the file. The file will be saved as an HTML5 file, which may be opened by any web browser. Note: As of this writing, not all web browsers available are capable of displaying the collapsible sections.
36.4.2 Saving All Reports To save all reports in a zipped bundle of files 1. Select File > Save All from the Report Viewer menu. 2. Enter a filename and save the file. The file created is a zip file of each tab's HTML5 output. The default file extension is .crvz.
36.5 Opening Previously Saved Reports 1. Select File > Open from the Report Viewer menu or the RAM Concept menu. Select “HTML” under “Files of type:” to open a single report file or “RAM Concept Reports” to select a zipped bundle of reports. 2. Type or select the name of the file to be opened.
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Using the Report Viewer Printing Reports The file will be opened in a new tab. If a bundle is selected, each file in the bundle will be opened in a new tab.
36.6 Printing Reports 1. Select File > Print from the Report Viewer menu. The current tab will be opened in the print preview window. 2. Configure the desired print settings and select the print icon from the toolbar. Note: The resolution of the printed report can be controlled by using the zoom controls on the View menu of the Report Viewer.
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Using the estimate When preparing a design, it can be useful to know the amount and cost of the materials used in the model. The estimate window serves this purpose. The estimate is particularly useful for comparing preliminary schemes. You can also use it to compare changes made to a design and in the optimization process. RAM Concept automatically calculates material quantities. Specified unit costs allow supply and installation costs to be calculated.
37.1 Viewing the estimate The Estimate window lists the different material quantities and their unit costs for supply and installation (labor). 1. Choose Report > Estimate.
37.2 What the estimate calculates The material quantities calculated are: Concrete
The volume of the concrete floor excluding supports.
Formwork
The area of horizontal soffit formwork.
Post-Tensioning
The weight of strand based upon tendon plan length. This does not include stressing tails or allowance for drape.
Mild Steel Reinforcing
The weight of reinforcement based upon the detailed reinforcement in the Reinforcement layer. This does include bar hooks, but does not include laps. The quantities do not include bars not shown in the Reinforcement layer such as “detailing” or tendon support bars.
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Using the estimate About unit costs
37.3 Editing the unit costs You can only edit unit costs. The estimate separates unit costs into materials and installation (labor). 1. Choose Report > Estimate. 2. Enter the costs for each material. Note: The costs update when you press or .
37.4 About unit costs Unit costs can vary for many reasons, including the following: • • • •
Region (labor availability and skill). Size of the floor and the project. Formwork system (usually flat slabs are more economical to form than beams). Post-tensioning costs are not the same for different systems. Unbonded systems are often less expensive in some countries, but this may not be true if large bonded tendons are used in beams. • Large diameter reinforcing bar is generally less expensive than small diameter bar for materials and labor.
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38 Printing
RAM Concept provides a range of printing customization options to help you create professional printouts and reports. You control the information included on a page and in a report. Every window in RAM Concept can be printed individually or as part of a report. This chapter describes the printing features you can use to achieve the result you want and offers techniques for printing efficiently. Note: See “Determining the fit of plans” for more information on setting the print scale of plan windows.
38.1 Basic printing instructions You can selectively print windows, or the entire report. To print a window 1. 2. 3. 4.
Make the window you want to print the active window. Choose Report > Print Window. Select the printing options you want. See “General printing options” for more information. Click Print.
Related Links • General printing options (on page 410)
38.1.1 To print the report 1. Choose Report > Print Report 2. Select the printing options you want. See “General printing options” for more information. 3. Click Print. Note: To make sure you get the desired printing results, preview the print job before you print. See “Previewing the print job” for more information. Related Links • General printing options (on page 410)
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Printing General printing options
38.2 General printing options The Print dialog tells RAM Concept what printer to use, which pages to print, and how many copies you need. Review these settings every time you print a window or report.
38.2.1 Printer selection Specify the printer you want RAM Concept to print via the Select and Configure Printers menu item. The printer can also be selected in the Select Printer section of the Print dialog, but the per printer stored settings will not be used. With the latest compatible drivers installed, RAM Concept can print on any Windows printer or plotter connected directly to your computer or connected via a network. Consult your printer documentation for information on setting up your printer and selecting the appropriate printer driver.
38.2.2 Page range In the Page Range section of the Print dialog box, select which pages to print: • Use the All option to print all the pages in the report, or all the pages that are required to print the active window. • Specify the range of pages you want to print. Type a hyphen between two numbers to print the pages in that range (inclusive). You must type the numbers separated by hyphens in ascending order (4-7, not 7-4).
38.2.3 Number of copies In the Print dialog box, the Number of copies option indicates the number of printed copies of the print job you want. Enter a value from 1 to 9999.
38.2.4 Printing to PDF RAM Concept has the ability to print directly to the .pdf file format. Desired paper size, orientation, and margins can be set up by choosing the Report > Setup PDF Export dialog.
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Printing Select and Configure Printer options
38.3 Select and Configure Printer options In the Select and Configure Printer dialog box, you can set the printer, page size and source, default orientation, and margin size for your printed pages. These per-printer settings are stored on your system and are used as the default settings every time you print.
38.3.1 To change the print setup options 1. 2. 3. 4.
Choose Report > Select and Configure Printers. Select the printer that is of interest. Click on the Page Setup button and select the options that you want in the dialog that opens. Click OK.
38.3.2 Printer selection The last printer selected in the Select and Configure Printers dialog is the default printer for RAM Concept. RAM Concept can print on any printer with the appropriate printer drivers installed.
38.3.3 Paper size and source Select the paper size and paper source the printer uses from the Paper section of the Page Setup portion of the Select and Configure Printer dialog. The printer selection dictates the options for the size and source.
38.3.4 Default orientation In the Orientation section of the Page Setup portion of the Select and Configure Printers dialog, select the default page orientation: • Use Portrait for a vertical page orientation. • Specify Landscape for a horizontal page orientation. Page orientation is also customizable for each individual printed window in the Report Contents window. See “Printing optimizations” for more information.
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Printing Determining the fit of plans
38.3.5 Margin size Set the page margins in the Margins section of the Page Setup portion of the Select and Configure Printers dialog. If the left, right, top, or bottom margin sizes you select overlap, or they are off the paper, an alert message appears.
38.4 Determining the fit of plans Plans print according to their Print Area and Print Scale settings. Everything within the printing area boundary prints using as many pages as necessary to print at the desired scale.
38.4.1 To specify the print scale 1. Select the Print Scale tool ( ). 2. Enter the scale in the Print Scale dialog and click OK. Note: Typically, you want to check “Set for all plans” in the Print Scale dialog if you are printing a report.
38.4.2 To specify the printed area on the plan 1. Select the Print Area tool ( ). 2. Click at two opposite corners to identify the rectangular boundary.
38.4.3 To specify the printed area with coordinates 1. Choose View > Print Area or double click on the Print Area tool ( ). 2. Uncheck the option to “Automatically calculate printing area” and enter the left, right, top, and bottom coordinates in the Printing Area Setup dialog. Check “Set for all plans” if you want this printing area to be used by all plans. 3. Click OK.
38.5 Printing the desired perspective viewpoint The saved print viewpoint determines how a perspective window prints. Sometimes a viewpoint that looks good on screen may not appear as desired in print due to the dimensions of the page. Remember to examine the print
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Printing Previewing the print job preview carefully after setting the print viewpoint to verify that the scale and orientation of the model fit on the page as intended. Use the Set Print Viewpoint tool ( ) to save the print viewpoint to what is visible on screen. This viewpoint does not change unless you reset it. You can manipulate the model on screen without affecting the saved print viewpoint. To display the saved print viewpoint, use the Show Print Viewpoint tool ( ). To set the print viewpoint 1. Adjust the on screen viewpoint by: a. ). Setting the relative scales of the coordinate axes using the Scale tool ( b. ) and the Rotate about z-axis tool ( ). Rotating the model with the Rotate about x- and y-axes tool ( c. Zooming to show the desired portion of the model. d. Setting the projection to Parallel Projection ( ) or Perspective Projection ( ) and the modeling to Solid Modeling ( ) or Wire Modeling ( 2. Click Set Print Viewpoint ( ).
).
38.5.1 To show the set print viewpoint on screen 1. Click Show Print Viewpoint (
).
38.6 Previewing the print job Preview the print job before you send it to the printer to ensure the images and text fit as desired on the chosen paper with the specified margin, and orientation settings. See “Select and Configure Printer options” for more information on how to change the page setup.
38.6.1 To preview the active window print job 1. Choose Report > Window Preview. 2. Examine the preview as described in the following sections and click Close.
38.6.2 To preview the report print job 1. Choose Report > Report Preview. 2. Examine the preview as described in the following sections and click Close.
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Printing Printing optimizations
38.6.3 Zooming Scale the print preview by setting the zoom percentage in the print preview window. You can choose a zoom factor of 500%, 200%, 150%, 100%, 75%, 50%, 25%, 10%, Fit Page or Fit Width, or you can type a numeric percentage of your choice (between 5% and 500%).
38.6.4 Viewing multiple pages at once You can view the print preview one, two, or four pages at a time. Use One Page ( job at a time. Click Multi Page ( once.
) to view one page of the print
) and select 2-up to view two pages at a time or 4-up to view four pages at
38.6.5 Paging through the print job The print preview automatically opens to the first page in the print job. Use Next ( the print job and Previous (
) to page forward through
) to page back.
38.7 Printing optimizations To achieve the best possible results when printing, you may need to customize the page orientation and appearance settings for the individual report items (or windows).
38.7.1 Customizing page orientation You can print each window or report item in RAM Concept in Portrait or Landscape orientation. The default page orientation is set in the Select and Configure Printer dialog box. See “Select and Configure Printer options” for more information on setting the default orientation. You may want some items in a report or a specific window to print in a different orientation than the rest. Use the Orientation column of the Report Contents window to specify the orientation of an item. Choose Default to use the Page Setup settings, or Portrait or Landscape to override the Page Setup orientation. To set the orientation of a particular window or item 1. Make sure the Orientation column is visible in the Report Contents window. You may need to widen the window or scroll horizontally.
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Printing Changing the report contents 2. Click on the Orientation column value for the item to toggle between Default, Portrait and Landscape. A value of Default in the Orientation column sets the orientation to the default orientation set in the Page Setup dialog box.
38.7.2 Customizing the printed appearance of plans and perspectives In the same way that you change the colors, font, and line type of plan and perspective windows on the screen, you can customize their appearance in print. Use the Print tab for schemes in the Appearance dialog to set the appearance settings for a plan or perspective you wish to print. See “Changing colors, font, and line type” for more information about appearance schemes and changing appearance settings. If you want the printed plan or perspective to have the same appearance settings as what you see in the respective window, click Set Same As Screen on the Print tab. In most cases, you want: • background color in printing to be white (no printed background) • print font size to be smaller then the screen font • print line scale to be larger then on screen To change the printed appearance of a plan or perspective 1. Make the Plan or Perspective the active window. 2. Choose View > Appearance. 3. Specify options on the Print tab of the Appearance Settings dialog box and click OK. Related Links • Changing colors, font, and line type (on page 64)
38.8 Changing the report contents The contents of the report are customizable to suit your specific needs. You have control over what plans, perspectives and text items are included in a report and their order and orientation. You change the report contents through the Report Contents window.
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Printing Changing the report contents
Figure 182: In the Report Contents Window, you can change the order of report items, set whether an item is included in the report, and change the printed orientation or an item.
38.8.1 Including items in the report Any window can be included as an item in the report. Modify the selection of plans, perspectives and tables to be included in the report via the Report Contents window. Toggle the Include column value to specify whether an item is included in the report or not. For something to print in the report, it requires that its Include value is “Yes” and every item above it in the report hierarchy is also “Yes”. For example, if you want the Standard Plan on the Latitude Tendon Layer to be included in the report, the plan itself should have an Include value of “Yes”, the Latitude Tendon layer should be “Yes” and the Layers folder should be “Yes”. Likewise, with an Include value of “No” for the Criteria folder, RAM Concept does not include anything in that folder in the report.
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Printing Changing the report contents This functionality is especially useful if you want to omit everything on a particular layer from the report. You can do so with one click, rather then changing the Include value of every plan, perspective, and text table on that layer to “No”. 1. Make sure the Include column is visible in the Report Contents window. You may need to widen the window or scroll horizontally. 2. Click on the Include column value for the item you wish to include or exclude to toggle between Yes and No. A value of Yes in the Include column includes the item in the report printout while a value of No excludes the item. Note: If you want to include an item in the report, make sure every item in the hierarchy above it is also included.
Example The following is an example list of windows you might include in a report for an elevated PT slab using the ACI 318 design approach: • • • • • • • • • • • • • • • • • • • • • • • • • • • •
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Report Cover Units Signs Materials Loadings Load Combinations Design Rules Estimate Element: Standard Plan Element: Slab Summary Plan Element: Structure Summary Perspective Latitude Tendon: Standard Plan Longitude Tendon: Standard Plan Temporary Construction (at Stressing) Loading: All Loads Plan (if used) Other Dead Loading: All Loads Plan Live (Reducible) Loading: All Loads Plan Live (Unreducible) Loading: All Loads Plan [other live loadings (Storage, Roof) if used] Service LC: Deflection Plan Factored LC: Mx Plan Factored LC: My Plan Factored LC: Reactions Plan Reinforcement: Latitude Bars Plan Reinforcement: Longitude Bars Plan Reinforcement: SSR Plan Design Status: Status Plan Design Status: Punching Shear Status Plan Load History Deflection Plans
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Printing Changing the report contents
38.8.2 Reordering report items The order of report items in the Report Contents window is the order they print in the report. You can reorder items that are within the same folder or layer by dragging them to a new position. You cannot move items outside their folder or layer. For example, you can move the Units item to a new location inside the Criteria folder but you cannot move it into the Layers folder. To change the location of a report item 1. In the Report Contents Window, press down on the left mouse button over the report item you want to move. 2. Drag the report item to its new location and release the left mouse button. (RAM Concept does not allow you to move a report item outside of it’s folder or layer)
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Exporting Plans and Tables You can export any plan or text table in RAM Concept. RAM Concept supports export of plans as .dwg or .dxf files in AutoCAD® R12 through AutoCAD® 2004 format. Tables export as text files, which you can open with most spreadsheet software.
39.1 Exporting a plan RAM Concept exports a plan with whatever information is visible at the time. You need to open a plan and make it the active window before exporting. You make a plan the active window by clicking on it. To export the active plan 1. Choose File > Export Drawing. The Export Drawing dialog box appears. 2. Choose a name and type for the AutoCAD file and click Save. The File Units dialog box appears. 3. Select the units for the AutoCAD file and click OK.
39.1.1 Selecting the text size The exported text size depends on the visible text size on the screen. You can change the text size to suit the export. 1. Choose View > Appearance. 2. In the Font section of the Appearance dialog box, click AaBbZz to select a font. The point size of text is 72 times the actual size. Thus, 9 points is one-eighth of an inch. 3. In the Select Font dialog box, choose the font size and click OK. 4. Set the font scale to zero and click OK. Note: Do not use Enlarge Fonts (
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Exporting Plans and Tables Exporting a table
39.2 Exporting a table Text tables export to tab-delimited text files that you can open with most spreadsheet software. 1. Open the text table you wish to export. 2. Click Export (at the top of the window). 3. Enter a name for the text file and click Save.
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40
Exporting a Database to the RAM Structural System Note: In many places in this chapter the RAM Structural System is referred to as “RSS”. RAM Concept has functions that can export reactions and geometry to the RAM Structural System.
40.1 About the export of reactions RAM Concept has a function that exports wall and column reactions to the RAM Structural System.This export capability allows RSS to use RAM Concept's accurate load distribution to calculate wall, column and foundation gravity forces. The export capability also allows RSS to consider the effects of floor tendons on columns and walls for post-tensioned structures. This export capability only applies to elevated slab models created in RAM Concept by importing from the RAM Structural System. Note: The RAM Structural System requires RAM Concrete to consider the exported Concept reactions. The RAM Concept force export function transfers column and wall reactions to the RAM Structural System database. The export only sets the wall and column reactions for the end of the columns and/or walls that are touching the elevated slab. Exporting of reactions does not affect the support axial force of walls and columns above the slab. The structure above the column or wall determines the axial force. RAM Concept only exports reactions from gravity loadings imported from RSS back to RSS. For example, if you add “Swimming Pool Loading” to a RAM Concept file, the export function will not transfer reactions from that loading to RSS. Note: RAM Concept does not export Construction Dead Loading reactions, as they would have no further use in RSS. Note: RAM Concept never exports lateral loadings (imported from RSS or otherwise) to RSS. Note: “Loadings” in RAM Concept are analogous to “load cases” in RSS.
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Exporting a Database to the RAM Structural System About the export of reactions
40.1.1 Special handling of the Self-Dead Loading and the Balance Loading during export RAM Concept adds the “Self-Dead Loading” reactions to the “Dead Load” reactions during export. This ensures that the RAM Concrete Analysis of the structure considers the self-weight of the slab. Note: The RAM Structural System provides the option to have beam and slab self-weights calculated automatically, or input manually as part of the dead load case. Conversely, RAM Concept always automatically includes beam and slab self-weights in its analysis. We recommend that, when using RSS in combination with Concept, you have RSS automatically calculate the beam and slab self-weight loads. That will eliminate any confusion regarding whether self-weight loads are included in the analysis or need to be manually specified as part of the dead load case, even when some levels are designed with RSS and some levels are designed with Concept. RAM Concept does not currently export “Transfer” loading reactions to RSS. When analyzing a building with a transfer slab, RSS uses its own internal distribution of the transfer forces in the slab rather than forces from RAM Concept's floor analysis. RAM Concept’s exported “Direct” loading reactions will be used by RSS, if you so direct. See “Using RAM Concept reactions in RAM Concrete” for further information. RAM Concept exports the balance loading reactions to a “hyperstatic” load case that is only visible in RAM Concrete. Generally, balance forces and hyperstatic forces are not the same, but for a support that contains no tendons, however, the balance forces are equal to the hyperstatic forces. Note: See “Post-tensioning loadings” for a discussion of balance and hyperstatic loadings. Related Links • Using RAM Concept reactions in RAM Concrete (on page 424)
40.1.2 Special handling of the Partition Loading during export RAM Concept adds the “Partition Load” reactions to the “Live Load Unreducible” reactions during export.
40.1.3 The export of reactions process You can export reactions to RSS at any time after you perform a “Calc All” operation and you save the file. To export to the RAM Structural System Choose File > Export Reactions to RAM Structural System. A dialog box, as shown in the following figure, opens with a list of RSS story names to which you can export reactions. RAM Concept labels one story name as “Source Story”. This is the RSS story previously imported to create this RAM Concept file. RAM Concept lists other stories in the RSS file with the same floor type, and labels them “Identical Story” or “Compatible Story”. A story is compatible with, but not identical to, the source story if it has a different story height, member sizes, or (for the top story of the type) any columns above it have different orientations.
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Exporting a Database to the RAM Structural System About the export of reactions Select any combination of stories, and click “OK”. RAM Concept displays a log detailing the results of the export operation when the export is completed.
Figure 183: Export Reactions to RAM Structural System dialog box
40.1.4 About export reactions access and consistency checking RAM Concept performs consistency checking before the actual export operation to ensure that it can export reactions correctly. RAM Concept performs the checks before and after choosing the export stories.
40.1.5 Checks performed before choosing export stories The first check performed is your access to the RSS file from which the RAM Concept floor was imported. The export operation can proceed only if the RSS file exists, it is not currently open in RSS and you are able to access and modify it. RAM Concept also checks the RSS file for changes made to the source story since importation into the RAM Concept file. If someone has made a “major” change to the source story, you must reimport from RSS and recalculate results before exporting. If someone has made a “minor” change to the source story, RAM Concept gives you the option of reimporting. Major changes include adding or deleting columns or walls. Changing a column size is a minor change.
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Exporting a Database to the RAM Structural System About the export of reactions RAM Concept cannot export the file if someone has added columns or walls after importing from RSS, or if any springs or rigid supports are present in the RAM Concept model.
40.1.6 Checks performed after choosing export stories RAM Concept checks each story you choose to export against the RSS file in detail. If RAM Concept detects any errors, you may cancel the export operation or return to the story selection window to deselect the stories with errors. If RAM Concept issues only warnings, you may continue with the export or return to the story selection window. RAM Concept generates warnings for any columns or walls above the RAM Concept slab that do not have matching columns or walls above the export story selected. This typically only happens at the highest story of the floor type, where it transitions to a different floor type or the roof. RAM Concept also generates warnings if a selected story's height is different from the source story height.
40.1.7 Using RAM Concept reactions in RAM Concrete Once you export the column and wall reactions to RSS, they become available to RAM Concrete for analysis and design purposes, but only if you inform RSS that you want to use them. To set RAM Concrete to use RAM Concept’s reactions 1. Start RAM Concrete 2. Choose Criteria > Column Forces Select the button at the top to “Use RAM Concept Analysis Forces at selected levels”. Select the levels by checking the box in the “Use” column. You can use this dialog to review the RSS levels that have RAM Concept forces and the RAM Concept file name from which you exported the forces. The “Read” column displays the date you imported each level from RSS into RAM Concept. The “Saved” column displays the date you exported member reactions from RAM Concept to that level. The “Source Story” column indicates the source story of the RSS file used to import data into the RAM Concept file. If the “Source Story”, “Saved” and “RAM Concept File” entries are empty, then you have not exported member forces to that level. If the “Read” entry is empty, then you have never imported that level to RAM Concept. Note: RSS uses Concept wall reactions on all levels where Concept column reactions are used. Note: After exporting Concept reactions to RSS, you will need to perform a RAM Concrete reanalysis of the structure before designing any members or importing any member forces from RSS to Concept (such as for a mat foundation).
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Exporting a Database to the RAM Structural System About the export of geometry
40.1.8 How the RAM Structural System - RAM Concept link works The key to the export of RAM Concept's reactions to RSS are the imported walls and columns and the imported direct gravity loadings. Walls and columns that you import from RSS have special RSS identifiers “tagged” to them. These identifiers allow RAM Concept to match its column and wall elements to the corresponding members in RSS. RAM Concept will even allow you to move the walls and columns slightly (up to 50mm or 2"). RAM Concept will not allow you to export if you add, delete, or significantly move imported columns or walls (or do not import walls and columns). RAM Concept does this to ensure transfer of the full equilibrium gravity load between RAM Concept and RSS. Note: If you accidentally delete an imported support, or the supports change in RSS, you can always reimport the walls and columns. RSS tracks a fixed set of gravity loadings through the structures. These loadings are Dead Load, Live Load Reducible, Live Load Unreducible, Live Load Storage and Live Load Roof (when RAM Concept and RAM Concrete are used the Hyperstatic loading is tracked as well). To ensure compatibility with RSS, RAM Concept will not allow you to delete these imported gravity loadings. RAM Concept does allow you to modify the imported RSS gravity loading and to add more gravity loadings. RAM Concept assumes that you are fully aware that it considers only the loads that appear in the imported RSS loadings in the reactions it exports back to RSS.
40.2 About the export of geometry Column and wall geometry can be exported to a new or existing RAM Structural System database file. This geometry can only be exported to a new RSS floor type. To export geometry to the RAM Structural System 1. Choose File > Export Geometry to RAM Structural System. Note: The menu item is disabled if there is no model currently open. A file browser appears which allows the selection of an RSS file. 2. Select a RSS file or enter a new filename. If a new RSS filename is entered, a new RSS database is created with the current RAM Concept model’s units. If the RAM Concept model design code is ACI 318-99, ACI 318-02, ACI 318-05 or BS8110, the design code of the RSS database is set accordingly. Otherwise the database design code of the new RSS database will be the user's default design code. After a file is selected, the “Export Geometry to RAM Structural System” dialog appears, as shown in the following figure.
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Exporting a Database to the RAM Structural System About the export of geometry
Figure 184: Export Geometry to RAM Structural System dialog box The dialog lists the floor types present in the RSS file. 3. Enter the new floor type name in the “New Floor Type Name” text field. A popup notifies you if the floor type name entered is already defined. The “General snapping distance” is the maximum distance structural features could be moved in order to merge closely spaced objects together. If the “Snap slab/deck edges to wall centerlines” box is checked, RAM Concept will attempt to move slab and deck edges that are close to wall centerlines to be coincident in the exported data. The originating RAM Concept data will not be modified. This will potentially eliminate small elements in the RSS mesh and thus improve run times. If the “Export uniform thickness deck” box is checked, RAM Concept will export a single deck to RSS of a uniform thickness designated. The concrete properties from the largest slab area in Concept are used if this option is selected. The “Columns (below)”, “Walls (below)”, “Beams”, and “Slabs” check boxes select whether columns, walls, beams, and slabs are exported. RAM Concept exports only the columns and walls below the floor, because it is those elements that are associated with a floor type in RSS. If you check “Start RSS after Export”, then RSS starts on the file after the geometry is exported. This has no effect if RSS is already running. 4. Click “Create New Floor Type” to export the selected members to the new floor type. Note: Column, wall, beam, and slab geometry can only be exported to a new RSS floor type.
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Exporting a Database to the RAM Structural System About the export of geometry
40.2.1 About errors and ambiguities Errors and ambiguities in a RAM Concept model are normally detected and corrected when the model is meshed. RAM Concept allows models to be exported before they are meshed, so some errors are detected and arbitrarily corrected when the geometry is exported. If two or more walls overlap, completely or partially, only one of the overlapping segments will be exported. If two or more columns have the same location, only one column at that location will be exported. In either case, a pop-up dialog describes the columns and wall segments that were not exported. If any columns or wall segments are not exported, the user should check the material properties of the elements that were exported to RSS. If the overlapping columns or walls had different properties, the user may have to reassign the desired values in RSS. The user can also mesh the model and resolve such errors within RAM Concept before exporting. Walls defined in RSS may not intersect other walls or span columns or the ends of other walls. Each RAM Concept wall is split into segments at each of these locations before being exported. The splitting of walls is not reported, but the effect will be seen as individual walls in RSS.
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Using Strip Wizard Strip Wizard is a dialog that automates the initial steps in the process of creating a model in RAM Concept. When modeling a straightforward slab or beam, you can efficiently use Strip Wizard to enter the structural data without having to draw in a plan window. With the wizard, you can enter the spans, tributaries, loads and posttensioning in the same way you would with a conventional two-dimensional program. Since entering the structural data in Strip Wizard is so quick and easy, it is particularly useful for preliminary design of slabs, beams, and joists. Strip Wizard uses the structural information you provide to build a model in a new RAM Concept file. You can then modify the file by drawing openings, surface steps, point loads, and such using plan windows. Strip Wizard is deliberately simple, so use it to create the basic structure, and then modify the structure in plans if necessary. The authors intend that Strip Wizard be largely for assessment of two-dimensional behavior. The (automatic) design results are only for one direction (the x-axis). Since RAM Concept is a three-dimensional program, line supports are automatically included along the edges of the model that allow deflection but no rotation. This closely simulates two-dimensional behavior.
41.1 Starting Strip Wizard When you start Strip Wizard, it prompts you to create a new RAM Concept file. This file is where the wizard generates your model once you enter all the structural data. Strip Wizard uses all the generic settings defined in the new file (such as units, materials, loadings, etc). If you want Strip Wizard to use your custom settings, create the new file from a template. For example, if you want certain concrete mixes to be available when specifying general design parameters, you should create the new file from a RAM Concept template with these concrete mixes. After you have chosen options in the New File dialog, the Strip Wizard dialog appears. At this point, you can load previously saved Strip Wizard settings if you want (see “Loading and saving Strip Wizard settings” for more information). To start defining your strip, proceed to the next page in the wizard by clicking Next. 1. Choose File > Strip Wizard. 2. Specify options in the New File dialog box and then click OK. The Strip Wizard dialog appears. 3. Click Next to proceed or you can load Strip Wizard Settings (see “Loading and saving Strip Wizard settings” for more information).
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Using Strip Wizard Entering span data
41.2 Specifying general parameters Specify the structure type, spans and concrete mixes on the General Parameters page of the Wizard. Structure Type
Decide what type of structure you want Strip Wizard to create and whether to use posttensioning. The floor can be set up as post-tensioned or reinforced and can be one of the following systems: • • • •
Two-way slab One-way slab Beam Joist
Spans
Enter the number of spans for the strip (not including cantilevers). Decide if you are using start or end cantilevers. Check “Asymmetric” to allow the model to have different tributaries on either side of the columns.
Concrete Mixes
Choose a concrete mix for the slabs and beams and one for the supports.
Note: The concrete mixes available are the mixes in the new file created when you started Strip Wizard. If you want to use specific mixes, use a template when creating the new file.
41.3 Entering span data The table you see on the Span Data page depends on the information you entered on the General Parameters page. The cantilevers and spans appear as rows in the table. The table columns depend on whether you are modeling a one-way or two-way system, beam system, or joist system. For this table and subsequent pages, the top data row’s name is “Typical”. Data entered here automatically copies to the rows below. You can overwrite the copied data.
41.3.1 One-way and two-way systems Span length, slab thickness and tributary width define these systems. They can vary span by span. Length
The span length from center to center of supports.
Thickness
The span length from center to center of supports.
Start Width The slab width at the beginning (or left hand end) of the span. For asymmetric strips, L Start Width is the left start width, and R Start Width is the right start width. End Width
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Using Strip Wizard Entering support data
41.3.2 Beam systems Span length, beam depth, beam width, slab thickness and tributary width define these systems. They can vary span by span. Length
The span length from center to center of supports.
W Depth
The beam web structural depth (including the flange depth).
W Width
The beam web width.
F Depth
The flange (slab) depth (thickness).
Start Trib Width The tributary (and hence slab) width at the beginning (or left hand end) of the span. For asymmetric strips, L Trib Start Width is the left tributary start width, and R Trib Start Width is the right tributary start width. End Trib Width
The tributary (and hence slab) width at the end of the span. For asymmetric strips, L Trib End Width is the left tributary end width, and R End Width is the right tributary end width.
41.3.3 Joist systems Span length, web properties (depth, width, spacing and number), slab thickness and tributary width define these systems. They can vary span by span. This system does not allow asymmetry. Length
The span length from center to center of supports.
W Depth
The joist web structural depth (including the flange depth).
W Width
The joist web width.
F Depth
The flange (slab) depth (thickness).
Pan Start Offset
The distance from the beginning (or left hand end) of the span to the pan (or void former).
Pan End Offset
The distance from the end of the pan (or void former) to the end of the span.
Additional Web Properties
The following properties determine the tributary width for the whole model. The width cannot vary span by span.
Spacing
The center-to-center spacing of the webs.
Number
The total number of webs
41.4 Entering support data The Support Data page is for entering supports above and below. You must specify supports below but they are optional above.
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41.4.1 Support (above and below) properties Depth, width, height, bottom fixity and top fixity define the supports. They can vary span by span. Strip Wizard interprets a support with a width four or more times the depth as a wall. Otherwise, it is a column. Depth
The support dimension parallel to the span.
Width
The support dimension perpendicular to the span (enter zero for round columns).
Height
The support’s height from its base to mid-depth of the floor.
Bottom Fixity
The moment connection at the base of the support.
Top Fixity
The moment connection between the support and the floor.
41.5 Adding drop caps and drop panels The Drop Caps and Drop Panels page is for entering drop caps and drop panels for two-way slabs. The page is not available for one-way slabs, beams or joists. Strip Wizard uses drop caps for punching shear only; it ignores them for flexural design. Some codes provide guidance on what dimensions are required to consider a thickening as a drop panel. Strip Wizard does not check such rules.
41.5.1 Drop cap and drop panel properties Thickness, width, before length and after length define the drops. They can vary span by span. It is possible to have drop caps and drop panels at the same support. The drop cap should be the thicker of the two. Thickness
The total thickness (structural depth) of the drop. This is not the incremental increase in thickness.
Width
The drop dimension perpendicular to the span.
Before Length The dimension parallel to the span from the beginning of the drop to the support center. After Length
The dimension parallel to the span from the support center to the end of the drop.
41.6 Entering the loads The Loads page is for entering area and line loads in the z-direction for two standard loadings.
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41.6.1 Load properties Area and line loads can be input for two different loadings on each span. Dead Area Load The area load over the entire span. Dead Line Load The line load from the first support center to the second support center for each span. Live Area Load
The live load over the entire span.
Live Line Load
The live load from the first support center to the second support center for each span.
Loadings to use The Dead and Live are just names. You can specify the loads as belonging to any of the Standard loadings in the RAM Concept file. “Dead”
This can be any one of the standard loadings in the RAM Concept file.
“Live”
This can be any one of the standard loadings in the RAM Concept file (except for that used for “Dead”).
41.7 Specifying the post-tensioning The Post-Tensioning page is only available if you checked “Post-Tensioned” in the Structure Type section of the General Parameters page. Most of the data entered on this page relates to minimum precompression, load balancing and tendon cover. Strip Wizard uses this data in conjunction with data for spans, depths and loads to generate a single profiled tendon.
41.7.1 General PT information You specify the type of tendon and information that helps to determine the number of strands. PT System Specifies the size and type of strands for the tendon (as defined in the Materials Specification of the RAM Concept file). Stressing
Specifies the stressing (jack) locations. RAM Concept calculates tendon friction and other losses if jacks are located at one or both ends.
Min P/A
The minimum average precompression required for the concrete. Following the code minimum does not usually result in the most economical design.
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41.7.2 Balance load Balance load refers to the amount of uplift provided by the tendons. The industry has traditionally expressed this as a percentage of gravity loads. Min Balance Load Percentage:
The percentage of the specified load balanced by tendons.
Balance Load Considers:
Specifies the loadings that the balance loading is based upon. The choices are self-weight of concrete, self-weight plus “dead”, or total load.
41.7.3 Profiling These selections vary the tendon profile shape. Straight Profile Distance at Supports
The length of tendon that is horizontal at a support. The dimension is the total flat distance, not the distance each side of the support.
Round Profiles to Nearest
The profile distance increment. This allows rounding of tendon high and low points to convenient values. If this value is too large it may cause cover violations.
41.8 Specifying reinforcement The Reinforcement page is for specifying reinforcement bars and general covers.
41.8.1 Reinforcing bar You specify the bars from those available in the RAM Concept file. Top
Name of reinforcement bar used in the top face for flexural design.
Bottom
Name of reinforcement bar used in the bottom face for flexural design.
Shear
Name of reinforcement bar used for one-way shear design.
41.8.2 Reinforcement clear cover The covers are for bars and tendons. Rounding of tendon profiles could override the tendon covers. Top
Clear cover to the top longitudinal bars and tendons.
Bottom
Clear cover to the bottom longitudinal bars and tendons.
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Using Strip Wizard Completing Strip Wizard
41.8.3 Punching shear checks You decide if RAM Concept performs punching shear calculations. Perform punching Checking this box instructs RAM Concept to draw punching shear checks at each column. shear checks Cover to CGS
The distance from the top of the slab to the centroid of the top reinforcement. Usually this is the distance from the top of the slab to the bottom of the top bar. RAM Concept subtracts this distance from the slab thickness to determine the “d” distance.
41.9 Completing Strip Wizard The Completing Strip Wizard page is the final page in the wizard dialog. At this point, you can choose to save the information you have just entered so that you may load it into the wizard later. See “Loading and saving Strip Wizard settings” for more information. When you click Finish on the Completing Strip Wizard page, Strip Wizard draws your model in the RAM Concept file based on the data you have provided. The leftmost support of your model is located at the origin (0,0). Open plans on the Mesh Input, Latitude Tendon, and Design Strip layers to view your model. You cannot view the finite element mesh, however, until you generate the mesh. 1. Click Finish on the Completing Strip Wizard page.
41.10 Generating the mesh and calculating results After completing Strip Wizard, you are ready to generate the mesh and run an analysis calculation on your model. To get the best finite element mesh you need to regenerate twice: once before, and once after, calculating.This is because calculating generates the design strips, which in turn can be used to improve the mesh the second time you generate. See Chapter 18, “Generating the Mesh” and Chapter 28, “Calculating Results” for further information.
41.11 Loading and saving Strip Wizard settings The data you entered into the Strip Wizard can be saved as a Strip Wizard Settings file (with a filename extension of .cptstrip) and reloaded into the wizard later. The Strip Wizard Settings file contains only the
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Using Strip Wizard Loading and saving Strip Wizard settings information you entered into the wizard pages. Save your Strip Wizard Settings before you click Finish on the final page of the dialog. Loading Strip Wizard Settings just sets the values in the Strip Wizard dialog to the values stored in the Settings file. After you load your Strip Wizard Settings, you then page through the dialog as usual by clicking Next. You can change the data in the wizard to create a different strip. This does not affect the Settings file you loaded. You must save a new Strip Wizard Settings file if you want your changes to be stored for later use.
41.11.1 To load strip wizard settings 1. Click Load on the Welcome to Strip Wizard page. 2. Select the Strip Wizard Settings file (with a filename extension of .cptstrip) and click Open.
41.11.2 To save Strip Wizard settings 1. Click Save on the Completing the Strip Wizard page (before you click Finish). 2. Enter the name of your Strip Wizard Settings file and click Save.
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General Tips This chapter provides advice on learning RAM Concept and tips that are not explained elsewhere. Note: It is strongly suggested that you refer to Learning RAM Concept (on page 47) before reading this chapter.
42.1 Beams You should be careful when modeling beams. If you use standard finite elements then the beam’s torsional stiffness could be overestimated, which could erroneously reduce the deflection in the adjacent slabs. In RAM Concept, there is no difference between standard slab and beam elements, and standard elements have a torsional stiffness that is proportional to their depth cubed. The actual torsional stiffness of a beam is proportional to the cube of the lesser value of depth and width. Standard elements thus overestimate the torsional stiffness of beams that are deeper than they are wide. For this reason, you should consider using the “No-torsion” behavior for beams, especially deep edge beams. See “Beam properties” for more information.
Figure 185: No-torsion beam setting
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42.2 Walls 42.2.1 Drawing connecting walls It is recommended that intersecting walls are drawn such that one wall terminates at the centerline of the other, as shown in the following figure.
Figure 186: Connecting walls
42.2.2 Walls above Walls above behave similarly to beams: they stiffen the floor. This is especially relevant in transfer floors. The floor moments DO NOT include the bending moments in the actual walls. We recommend that if you are in doubt as to the effect of walls above, do not model them.
Figure 187: Comparison of two floors identical in all respects except that one has a wall above (Two images with slab shown, two with no slab shown).
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Figure 188: Effect of wall modeled above: no wall (left) vs. wall above (right) - plot of slab moment about x-axis.
42.2.3 The difference between walls above and upstand beams of similar proportions RAM Concept treats walls above the slab similarly to beams. Using “wall-beams” instead of just thickened slab elements has both advantages and disadvantages; overall it is not recommended to model walls above the slab as beams. Slab elements have two major advantages over wall elements (“wall-beams”): RAM Concept design strip cross sections automatically integrate the forces across slab elements. Wall-beam elements are ignored in these integrations. Also, RAM Concept provides you many controls over how slab element results can be displayed; wall-beam elements (like wall elements) can only plot their reactions to the slab. However, as discussed in “Beams,” RAM Concept’s standard slab elements have a torsional stiffness that is proportional to their depth cubed. This can cause a large over-estimation of the torsional stiffness for a very thick slab element if it is adjacent to relatively thin elements. “Wall-beam” elements do not have this problem. As such, walls above that are modeled as upstand beams should use the “No-torsion” beam setting discussed in “Beams”. When modeling wall-beams, RAM Concept interprets some of the wall element parameters differently. If the wall-beam is not rotationally fixed to the slab then the wall-beam will have zero torsional stiffness. If the wallbeam is not a shear wall then it will have zero axial stiffness. The vertically compressible and rotationally fixed at far end parameters are ignored. Wall-beam elements have one advantage over slab elements. Slab elements of drastically differing thicknesses in the same structure can cause the automatic plotting controls to show (correctly) huge force variations in and adjacent to thick slab elements and almost no variation within the thin slab element areas. This does not generally happen if walls above are modeled as wall-beams.
42.3 Restraint Columns and walls restrain the floor against (post-tensioning induced) axial deformations unless you model columns with rollers and walls as “slip” walls (shear wall property unchecked). It is unlikely that columns above restrain the floor so a roller above will generally be appropriate Restraint generally reduces the precompression and hence increases the service reinforcement. It usually increases strength reinforcement too.
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42.4 Miscellaneous There are many tools and capabilities described in the preceding chapters that are useful but often overlooked.
42.4.1 Templates We have created a template (for the purpose of starting a file) that may or may not suit your needs. You can create your own template with additional plans, materials and settings that you can use when you start a new file. See “About templates”.
42.4.2 Adding plans You can add plans. See “Creating new plans” and “Creating new result plans”.
42.4.3 Copying and moving objects Many users do not appreciate that selected objects can be copied and moved through a combination of holding down the shift key and using the move command (or similar). See “Moving, rotating, stretching, and mirroring objects”. You should also familiarize yourself with using the relative coordinates command. See “Using relative coordinates”. To copy and move an object using relative coordinates 1.
With the Selection tool ( ), select the object. 2. Choose the Move tool ( ). 3. Hold down the key and click anywhere on the workspace. 4. Type the letter “r” followed by the x- and y-coordinates separated by a comma (e.g. r10, 5), and press . This moves a copy of the selection x units to the right and y units upward.
Related Links • Moving, rotating, stretching, and mirroring objects (on page 73)
42.4.4 Expanding tool buttons You can expand many tools to reveal additional capabilities. See “Expanding tool buttons”.
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42.4.5 The Utility tool The Utility tool can save you a lot of time when you need to move and stretch many objects or control points. See “Using the Utility tool to move and stretch”. Related Links • Using the Utility tool to move and stretch (on page 74)
42.4.6 Left Wall and Right Wall tools The Left Wall and Right Wall tools can be very useful. See “Drawing walls”.
42.4.7 Changing multiple tendon profile points You can seek and change profile points that have the same value in one operation. See “Change profiles tool”. Related Links • Change profiles tool (on page 328)
42.4.8 Plotting Results Many users are unaware of the power of the plot capabilities. You can plot many results including (strip based) moments (actual and demand), crack widths and reinforcement, to name just a few. Some clients prefer to plot the reinforcement on new plans rather than use the template plans that show bar call-outs.
42.4.9 Reducing the information shown on plans You can remove trivial results such as small reactions in two different ways. See “Specifying report as zero,” “Reaction,” and “Figure”. Related Links • Specifying report as zero (on page 82)
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42.4.10 Load balancing You can view the percentage of load that is balanced by the post-tensioning within design strips. See “Viewing balanced load percentages”. Related Links • Viewing balanced load percentages (on page 366)
42.4.11 The Auditor This can be invaluable in unlocking the “black-box” of calculations. See Chapter 31, “Using the Auditor”. Note: Many users complain that there is too much information revealed by the auditor. You can reduce the information by auditing a rule set rather than the design summary.
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Frequently Asked Questions This chapter addresses many of the questions that we are frequently asked. It should be read in conjunction with: • Learning RAM Concept (on page 47) • General Tips (on page 436) and • Warnings and Errors (on page 465)
43.1 Capabilities and Modeling Question: What can Concept design? Answer: Elevated (suspended) concrete floors and mat foundations (rafts). They can be reinforced concrete, post-tensioned concrete or hybrid. See “Structural systems” for more information. Question: Is there a limit on the size of structure modeled? Answer: The only limit is the performance of the computer hardware. The analysis run time is approximately proportional to the square of the number of nodes in the model, so large structures may take a significant amount of time to analyze. Design time is approximately proportional to the number of span segment strip cross sections. See Decreasing calculation time (on page 361) for more information. The file size can also be limited by the amount of RAM the computer has available. Question: Is there any restriction to the maximum thickness of slab that can be modeled? Answer: RAM Concept's analysis of slab elements considers shear deformation as well as bending deformation. This ensures that RAM Concept gives reasonable results for both thin slabs and thick slabs. In general, RAM Concept's design provisions apply the code requirements that are appropriate for slabs with typical span-to-depth ratios. If the geometry of your slab is outside the usual ranges, you may need to consider if any special design considerations are necessary. Question: Can Concept design more than one story at a time? Answer: Not by itself. You can use the RAM Structural System to integrate numerous floors into one large model. Question: Can I use Concept to design slab-on-ground? Answer: The expression “slab-on-ground” is often used to described residential house slabs. The designer has to use engineering judgment to determine if mat analysis and design techniques are suitable for such structures. See the FAQ for “Mats (rafts)”. Question: Is Concept capable of running a single design strip for quick preliminary runs without modeling the whole building?
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Answer: Yes. See Using Strip Wizard (on page 428) and Strip Wizard Tutorial (on page 773). Question: Can I model a pour strip? Answer: Yes, although there are limitations. 1. Use the orthotropic properties for the pour strip area such that the axial stiffness perpendicular to the strip is significantly reduced. 2. Terminate tendons either side of the pour strip. Note: Modeling a pour strip in this manner does not consider the temporary situation before the strip is poured back. This could affect deflections and resultants. Question: How can I model curved edges or walls? Answer: Use a series of straight lines. The approximation should have negligible effect. Question: Can Concept be used to design retaining walls by drawing the wall as a slab? Answer: While RAM Concept is not optimized for this use, it can perform most of the analysis and design tasks if you are very careful. Care must be used as RAM Concept assumes that gravity loads are in the downward Z direction. You need to set all of the self-dead loading load factors to zero and create your own self-weight loadings. You probably want to apply these loads at the mid-slab depth; otherwise the eccentricity will add a self-weight moment to the slab. While RAM Concept's design cross sections reports all of the moments and forces on the design cross section, RAM Concept does not perform design considering all of the forces and moments. Specifically, RAM Concept does not consider the Mz value in design, because RAM Concept does not specify the positioning of reinforcement that is important for Mz design. RAM Concept does not consider “P-delta” effects. Question: What does hybrid mean? Answer: A hybrid floor is one that contains both PT and RC areas. Most post-tensioned floors have some RC elements such as pour strips and elevator core slabs. By selecting the appropriate design rules these regions can be designed at the same time as the PT elements.
43.2 Files Question: What is the difference between creating a mat (raft) file and an elevated slab file? Answer: There is really no difference; all files give you the same capabilities. The default files are setup differently because there are usually additional load cases and plans for a mat (lateral load cases, soil bearing plans, etc.). With some work, you could turn any elevated slab file into a mat file and vice versa. Question: Can I save the data file with results? Answer: This cannot be done with the current version - you need to open the file and recalculate. We expect to add this feature in a future version (but the “save with results” files will be huge). Question: Can I work from CAD drawings? Answer: Yes. See Using a CAD Drawing (on page 116). Question: Is it necessary to start a model with a DWG or DXF file?
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Answer: No. For straightforward geometry it may be quicker to draw “from scratch”. It can be useful to specify a grid and then use snap to grid to locate columns and walls. Question: I deleted the imported drawing – can it be brought back? Answer: Yes. It is sometimes a good idea to delete the imported drawing as it affects the extent that RAM Concept displays and prints. Any DWG or DXF file can be re-imported if necessary. If you moved the imported drawing or structure after the first import then the new import will not match. You can move the new drawing if necessary. Question: Can Concept export to a drawing file to aid in drafting? Answer: Yes. See Exporting a plan (on page 419). Question: Can I export results? Answer: Yes. See Exporting a table (on page 419). Question: Can I change the default new file settings? Answer: Yes. See About templates (on page 53). Question: Can I set the default file for an RC design? Answer: Yes. You could create a template that is suited to RC design, such as eliminating the Initial Service Load Combination and Initial Service Rule Set, and unchecking the Consider as Post-Tensioned option in the span segment properties. See About templates (on page 53).
43.3 Plans and perspectives Question: What's the difference between a plan and a layer? Answer: A layer is an organizational concept. A layer is a collection of related objects and results and each object and result resides on one and only one layer. For example, all slab elements are on the Element layer. Plans, on the other hand, are a display and editing concept. Each plan is a filtered view of all of RAM Concept’s layers. A plan can be set up to edit a particular layer, but the plan does not “own” the layer. All changes that are made to the layer using the plan will be visible in all other plans, because all plans are viewing the same set of layers. See Understanding Layers (on page 55) and Using Plans and Perspectives (on page 59) for more information. Question: How do I delete unwanted plans? Answer: 1. Choose Layers > Delete. A dialog box appears. 2. Click OK to confirm the deletion. Question: Can I view all information on one plan? Answer: Yes, but it is generally not advised. You can turn on all objects from one layer in one operation, and then repeat for the next layer. 1. Make the plan or perspective the active window.
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2.
Choose View > Visible Objects ( ). 3. Click on the tab for the object’s layer. The plan or perspective’s layer is the one initially selected. 4. Check the Show All box, and click OK. Note: You can also right click to see a popup menu that includes the Visible Objects command. Question: How can I tell if there is an object on a layer? Answer: See Determining which plans contain objects (on page 57). Question: I have two items at the same location, how do I select just one of them? Answer: Double click at the location and you should select just one object. Hold down and double click again and you select the other object. Question: Why do I see nothing in a perspective display? Answer: The perspective “camera” may be looking in the wrong direction. Click Zoom Extent ( Print Viewpoint ( ). Question: Why can I not see the area springs in a perspective?
) or Show
Answer: Area springs can take a long time to generate in a perspective and so are not turned on in the default files. You need to turn them on with the Visible Objects dialog. Question: What does conflicting mean in a Selected Items field? Answer: This means that more than one object has been selected and they have different values for that property. For example, if you select two slab objects that have different thicknesses then the thickness field displays “conflicting”. Note: In versions prior to 3.0 the field would be blank in such instances.
43.4 Units Question: What units can I use Answer: See Choosing Units (on page 81) Question: Can I switch units after creating a file? Answer: Yes. See Changing the units (on page 81).
43.5 Codes Question: Can I change codes after creating a file?
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Answer: Yes. See Code options (on page 353).
43.6 Sign Conventions Question: What is the sign convention for moments shears and reactions? Answer: See Selecting sign convention (on page 84) and About plot sign convention (on page 86). Question: Can I change the sign convention? Answer: Yes. See Changing the sign convention (on page 86).
43.7 Structure 43.7.1 Mesh Input layer Question: Why is it necessary to have priorities? Answer: Without the priority system the modeling of floors would require one of two methods: • Objects for slabs of different thicknesses, beams, openings etc. could not overlap - this would be very tiresome for all but very simple floors, or • Depths would have to additive. For example, you would have to deduct slab depth from beam depth. If you had to change the slab depth then a change would be required for the beam, unless its depth changed by the same amount. Question: Can I copy columns or walls below to the same above? Answer: Yes. 1. Select all of the columns or walls you wish to copy. 2. Choose Edit > Copy (or right-click and choose Copy from the pop-up menu that appears). 3. Choose Edit > Paste (or right-click and choose Paste from the pop-up menu that appears). The pasted objects are the current selection. 4. Choose Edit > Selection Properties, or right-click and choose Selection Properties. 5. Change Support Set from Below to Above, and click OK. Note: It is important that you do not abandon the process after pasting. Otherwise, you will have two supports below at various locations, which causes calculation errors. Question: The meshing operation produces a very irregular mesh. Is this satisfactory?
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Answer: This depends upon a number of factors. See Deciding what mesh element size to use (on page 178) and Improving the mesh (on page 180). Question: Can I vary the mesh intensity at different locations? Answer: Indirectly. See Selectively refining the mesh (on page 182). Question: What value should I use for the area springs Z force constant? Answer: The geotechnical engineer commonly provides a value called the “subgrade modulus” or “modulus of subgrade reaction”. As a guide only: realistic values vary from 100 pci (approx. 25 MN/m3) for soft clay to 750 pci (approx. 200 MN/m3) for very dense gravel.
43.7.2 Element layer Question: How can I view the slab without the mesh? Answer: Choose Layers > Element > Slab Summary Plan. Question: What is the difference between beam and slab elements? Answer: There is no difference unless you modify their behavior. See discussion of behavior in Slab area properties (on page 172) and Beam properties (on page 175). Question: How many nodes or elements are allowed? Answer: There is no limit, other than the limitations of your computer. Question: How many elements should I use per span or panel? Answer: This cannot be answered directly as it depends upon the structure and loads. See Deciding what mesh element size to use (on page 178).
43.7.3 Columns Question: Do columns restrain the slab? Answer: Depending upon the defined fixity, columns can provide rotational and lateral restraint. If the far end of a column is defined as a “roller” support (or both ends of the column are pinned) then the column does not provide any lateral restraint to the slab. Question: Do columns above the slab support the slab vertically? Answer: No. Columns only restrain the slab rotationally and laterally.
43.7.4 Walls Question: Do walls restrain the slab laterally?
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Answer: Yes, if you select Shear Wall as a property. If the Shear Wall is unchecked then the slab is allowed to slip freely over the top of the wall. The walls rotational stiffness is independent of the Shear Wall setting; use the fixity settings to control the walls rotational stiffness about its longitudinal axis. Question: What is the effect of specifying walls above? Answer: Wall elements can be used to model the stiffness and spanning ability of walls connected to the slab. You should exercise caution when using them. See Walls above (on page 437). Question: Do walls above the slab support the slab vertically? Answer: No, they act like beams. See Walls above (on page 437). Question: Do walls above the slab provide rotational restraint? Answer: There is no restraint at the far end of a wall above. (Even if Rotationally Fixed at Far End is checked, it is ignored).
43.7.5 Mats (rafts) Question: How do I design a mat foundation? Answer: The Mat Foundation Tutorial (on page 751) introduces the concepts for mat design. Question: Does Concept ignore soil tension? Answer: You can reduce the tension by iteration. The tension gets closer to zero with an increase in the number of iterations. See Zero tension iteration options (on page 353) for more information. Question: Does Concept design for soil heave? Answer: Not directly. You could draw spring supports that approximate varying soil support. Question: Do I need to draw the columns above in a mat foundation model? Answer: No, but it is a good idea. It ensures a node is placed at that location where there is likely to be a heavy point load. Question: Can Concept design for pile supports? Answer: Yes. Use either (flexible) columns under, or point springs. Skin friction is not considered. Question: Can Concept design for pile and mat (raft) action together? Answer: Yes, but the results could be very susceptible to variations in geotechnical parameters. For example, if the soil’s stiffness is overestimated, the actual pile reactions could be significantly underestimated. Use caution. Question: Does the area spring support have to match the mesh? Answer: No. Question: Can the soil stiffness vary? Answer: Yes. You can vary the stiffness in two directions. See Area spring properties (on page 168). Question: Where do I select the allowable soil bearing pressure? Answer: This is not an input parameter. You need to look at soil bearing pressure plans (which have a maxima / minima legend) to assess the maximum pressures. Also, see the FAQ on Soil bearing (on page 463). Question: Does Concept iterate to remove tension in a point or line spring?
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Answer: No, only for area springs.
43.8 Tendons Question: Why are some tendons shown at the wrong elevation in the tendon perspective? Answer: The soffit elevation at each profile point is determined during the Analyze All and Calculate All commands. If one of these commands is not performed since the drawing (or moving, etc.) of a tendon, or since a change in the mesh, the tendon elevations in perspectives are not accurate. The same is true for elevations optionally shown as text on the plans. It is quicker to analyze (but not using “Calculate All”) with Process > Analyze All. This avoids processing the design calculations. Question: What do Latitude and Longitude Tendons mean? Answer: In the USA, Britain and other countries it is typical practice to place all the tendons in one direction in a concentrated band over column lines. If the designer is using another practice then we recommend that you still use the Latitude and Longitude tendon layers because it makes editing the PT easier. i.e. Put the tendons in the X direction on one layer and the Y tendons on the other. Latitude and Longitude are just layer names. Question: Do I have to draw the tendons for a post-tensioned slab? Answer: Yes. It is not difficult, and encourages you to address detailing issues before they become field problems. Question: How do I draw tendons? Answer: See About drawing individual tendons (on page 322), Drawing single tendons (on page 322) and Drawing multiple tendons (on page 323). You double click the tendon tool to change default tendon properties and then draw tendons span by span, or panel by panel. You can select a specific tendon segment and right-click to change that segment’s properties. You can seek and change profile points that have the same value in one operation. See Change profiles tool (on page 328). Question: Can I harp tendons? Answer: Yes. Any tendon segment can be declared to be harped. The “half-span” tendon tool is useful for any harp point (or any low point) that is not at mid-span. Multiple harp points can be located in any span by using multiple tendon segments. Question: Does it matter how I draw half tendons? Answer: Yes. The inflection point is measured from the first point clicked and the profiles are specified in the order of the points clicked. To be compatible with the tendons created using the Full Span Tendon tool, we strongly recommend that you always start at the high point. Question: Can I terminate some strands past a column? Answer: This can be done with one of two methods. 1. The tendon can be “forked” such that the number of strands decreases. As shown in the following figure, if the transition is from 15S (15 strands) to 10S (because an adjacent span does not require that many strands) then terminate 5S using a half span tendon. It is common to terminate strands at quarter span and at the slab centroid.
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Note: You should only use this method for tendons with no jacks attached. This is because a jack attached to tendons of different lengths has inaccurate seating (wedge draw-in) loss calculations.
Figure 189: Termination of strands (no jacks) 2. The second method can be used when jacks are modeled. If the total number of strands is 15S then one tendon with 10S needs to be continuous with an additional tendon with 5S alongside. It is common to terminate tendons at quarter span and at the slab centroid.
Figure 190: Termination of strands / tendons (jacked). Plan alignment of tendons is subjective. Question: Does Concept check to make sure the number of strands in connected tendon segments is consistent? Answer: Yes. See An error has occurred while assembling the load vector. A tendon is not totally on the slab. Revise the tendon at #a. (on page 468). Question: How does Concept calculate friction losses? Answer: RAM Concept only calculates friction losses if jacks are specified. RAM Concept performs friction loss calculations considering the (elevation view) curvature of the tendons, the (plan view) horizontal kinks in the tendon and the jacking and friction parameters. The stress in the tendon is assumed to vary linearly along each tendon segment. Along each tendon the following formula used is: P2 = P1 × e-(μ×θ + k×L) where P1 P2 μ θ k L
= = = = = =
the known stress at one end of a tendon segment the unknown stress at the other end of a tendon segment the angular friction coefficient (in units of 1/radians) the total angular change along the tendon segment the wobble coefficient (in units of 1/length) the tendon segment length
Note: Some engineering communities (Australia in particular) use a definition of wobble coefficient that is the accidental angular change per unit length. These communities can calculate the wobble coefficient that RAM Concept uses, k, with the following relationship: k = AngularWobbleCoefficient × μ. At the joints between tendon segments RAM Concept uses the following formula: P4 = P3 * e-(μ × ɑ) where P4 P3 μ ɑ
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the unknown stress in the next tendon segment the known stress in the previous tendon segment (or the jack stress) the same angular friction coefficient as above the total angle change at the tendon profile point (includes both horizontal and vertical kinks)
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RAM Concept incorporates seating loss (wedge draw-in loss) into the losses using the standard strain integration formulation. The equations above are still used, but the known and unknown values are swapped. RAM Concept adjusts the tendon stresses iteratively until the integration of the strain change in the tendon equals the specified anchorage seat loss. Long term losses are input by the user as a jack parameter. See About jacks (on page 329) and Jack properties (on page 329) for more information. Question: Do I have to specify jacks? Answer: No. RAM Concept uses the relevant value of fse (specified in the Materials criteria page) as the effective stress for any tendon without a jack. Question: Does Concept calculate elongations (extensions)? Answer: Yes, if jacks are specified. Use the Visible Objects dialog to view Jack Elongation on a plan. Question: Do the elongations (extensions) include the effect of the seating distance (wedge draw-in)? Answer: Yes. The elongation reported includes the deduction of the seating distance. Question: Where are tendon profiles measured from? Answer: See discussion on Profile in Drawing banded tendon polylines (on page 313). Question: It's much easier to take all the strands and put them into one tendon bundle instead of having to lay them all out. Is there much difference to the model whether you distribute tendons over the tributary or not? Answer: This is a matter of engineering judgment. There is certainly no need to lay out individual strands and it is usually satisfactory to group strands in larger tendon groups than that installed in the field. Keep in mind that design strip cross sections consider only the tendons that they cut through to calculate strength etc. There could be instances where you want to model banded tendons in multiple groups (if the band is very wide). Question: I have laid out the longitude tendons but want to change the number of strands per group. Do I have to lay them out again? Answer: No. The number of strands in a tendon does not have to be an integer, so you can change it by any increment. Question: Can I determine the force in a tendon? Answer: Yes. Use the Visible Objects dialog to view the Tendon Forces on a plan. Question: Does Concept check for tendons being outside of the concrete? Answer: Yes. See discussion in Cannot auto-position profile point at (x,y) due to profile point value (on page 470) and Cannot auto-position the profile elevation for tendon (a) at (b) because the tendon represents a partial half span (on page 470). Question: Do I need to do a load balancing calculation with all the tendons? Answer: No. The load balance tool is available to help you calculate low points, but is not mandatory. Question: The load balancing percentage shown on the design strips plan does not make sense. How is this calculated? Answer: RAM Concept’s balanced load percentage calculation assumes that what you define as a span, actually behaves like a span. Sometimes this is not the case. To calculate the effective dead load applied, RAM Concept uses: D = 8 Md / L2 where D Md
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the dead load to be calculated the total dead load span moment (calculated from the moments at the first, middle and last cross sections of the span)
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L
=
the span length (as determined from the span segments, support conditions, etc.)
The calculation for the effective balance load is similar: B = 8 Mb / L2 The percentage balanced is 100 . (-B/D) If, for example, the dead load moments at the start, middle and end cross sections are not negative, positive and negative then percentage balance calculation will not be useful. This does not mean your strips are wrong, but it might mean that your tendon layout is not doing what you think it is doing. Look at the DL (or DL + LL) deflections (without balance loading) and try to get a better feeling for how the structure is working and from there determine where to add and remove tendons.
43.9 Loadings Question: Is pattern loading possible? Answer: Yes. See Creating Pattern Loading (on page 203). Question: For an irregular structure it is very time consuming to draw the area loads to match the structure. Is there a faster way? Answer: It is not necessary for area loads to match the structure. Area loads can overlap each other and they can “overhang” the floor. This is shown in the PT tutorial. Question: Are area loads additive or does the maximum govern? Answer: Loads are additive. Question: Can I input thermal loads into Concept? Answer: Yes, see Drawing Loads (on page 195) for more information on temperature and shrinkage area loads. Question: How do Lateral Self Equilibrium loadings work? Answer: Refer to Self-equilibrium analysis (on page 797). However, the best way to understand Lateral SE could be this simple example:
43.9.1 Lateral Self Equilibrium Example Consider the structure with two elevated floors shown in the following figure. Each level is 3m high and the structure is 10m wide.
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Figure 191: Example with two elevated floors Assume the following: • a frame analysis has been performed on the building for this 100kN loading and the column forces are known • a very simple distribution of forces (reasonable for beams much stiffer than columns) The forces on the top level slab (including column reactions) are:
Figure 192: Forces on top level slab Fx0 = 100kN Fx1 = -50kN
Fx2 = -50kN
Fz1 = -15kN
Fz2 = 15kN
My1 = 75kN-m
My2 = 75kN-m
These forces are in equilibrium and are applied directly to the slab in a lateral SE loading. RAM Concept then calculates the correct forces in the slab, design strips and punching checks. For the intermediate level there are more forces to consider (all of these are from the frame analysis). The forces that the columns apply to the slab are:
Figure 193: Forces on intermediate level slab Fx3 = 50kN
Fx4 = -50kN
Fx5 = 50kN
Fx6 = -50kN
Fz3 = 15kN
Fz4 = -45kN
Fz5 = -15kN
Fz6 = 45kN
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My4 = 75kN-m
My5 = 75kN-m
My6 = 75kN-m
These forces are in equilibrium and are applied directly to the slab in a lateral SE loading. Since the “3” and “4” forces occur at the same location, they can be added together and applied as a single load (same for “5” and “6”). RAM Concept then calculates the correct forces in the slab, design strips and punching checks. Note: There is one simplification - if you do not care about diaphragm forces, then you can ignore all the Fx and Fy forces. This assumes that the Fx and Fy forces act at the center of your slab and that the centroid elevation of your slab is constant. When these two assumptions are not true, the effects of these forces are typically still not large, but you may need to use some judgment before you ignore them.
43.10 Analysis Question: Should I use Auto-stabilize structure in X and Y directions in the Calc Options? Answer: This is only necessary if your structure has no lateral stability, such as an elevated floor with columns on rollers, or a mat (raft) with no X or Y direction springs. Auto-stabilize does not work if there are lateral loads.
43.11 Design Issues Question: What support width is used for round columns? Answer: RAM Concept calculates the support width for an equivalent (in area) square column. Question: What is the relevance of the Include Detailed Section Analysis box in Criteria > Design Rules? Answer: That box instructs RAM Concept to do a cracked section analysis even if one is not required for the code criteria. The only reason to check the box is if you want to see cracked section stresses even when they are not used for code checking / design. The only reason not to check the box is that cracked section analyses can be slow. See Decreasing calculation time (on page 361).
43.12 Results
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43.12.1 Reactions Question: Does Concept include the weight of columns and walls in self weight calculations? Answer: RAM Concept never includes the weight of supports below. You decide if the weight of supports above is included. This is a choice you can make in the Calculation Options. Question: Can I choose which column and wall reactions are shown? Answer: Yes - you can change what RAM Concept plots. See Reaction (on page 382). If there are columns (and or walls) above and below an elevated slab you can select (through the Plot dialog) which reactions are shown. The choices are: • the total reaction on the slab (below and above) • the reaction below • the reaction above Question: The reaction plans show many small values for Fx and Fy which makes the plan difficult to read. Can I look at just Fz? Answer: You can control this in two ways. The simplest way is to turn off Fx and Fy with the plot settings. See Changing which results plot (on page 369). Alternatively, you can filter out small reactions and moments through the Units window. See Specifying report as zero (on page 82). Question: The wall reactions are shown per straight section of wall. Can I see the reaction per wall element? Answer: No. This is not available because there would be too much information shown. Question: I have modeled columns at the end of walls. The column reactions are huge and the wall reaction is negative. Is this realistic? Answer: The huge result is mathematically correct but may not be realistic. Try modeling the column and walls in question as vertically compressible. This may reduce the column reaction to a more realistic value. Question: How can I determine the reaction at the end of a wall? Answer: Reactions are reported for continuous walls, so if you need discrete reactions leave a gap in the wall or specify a column at the end of a wall.
43.12.2 Plots Question: Why is there moment shown at a free edge about an axis parallel to the edge? Answer:
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Figure 194: Plan of moment about Y-Y axis at opening. The circled moment is displayed as non-zero. The plotted moments are smoothed curves of the element center moments. A slab element at a free edge may have a small moment at it center. The values shown between element centers are interpolated, but since there is no element outside the edge, there is no way for that value to ever reach zero. For better visual results (values closer to zero at the edge), you should use smaller elements at the edge. The distance from the edge to the edge element center is the most important parameter. Question: I have a pinned column at the edge of the slab. Why is there moment shown at the edge about an axis parallel to the edge? Answer:
The explanation is the same as the preceding question. Question: Why are there two lines for deflection in the strip plots? Answer: The two plots for maximum and minimum differ if you have one of the following conditions: • Alternate envelope factors that are not the same as the load factors (see About alternate envelope factors (on page 107) ). For example, for the service load combination, the load factor on live load could be 1.0 and the alternate envelope factor could be 0.0. This would produce differing maximum and minimum values. • Pattern loadings • More than one load combination using the same rule set. The default plot shows the maximum and minimum deflections. You could choose to show just the maximum values via the plot dialog, but remember that the absolute of minimum could be more than the maximum. It would be possible that minimum governs if you have upward deflection.
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Note: This also applies for plots of demand for resultants such as moment or shear.
43.12.3 Torsion Question: I have set the Behavior of a beam to No-torsion. Why is there still torsion in the beam? Answer: When you set your beams to have “no torsion”, you are really setting them to have no “twist” (Mxy). Twist is only one component of torsion. Torsion is a moment that in RAM Concept is measured about the centroid point of the cross section. The z-coordinate of this centroid is the mathematical centroid elevation of the cross section, the x- and y- coordinates of the centroid are the centre of the “core” portion of the centroid. The vertical shear in the cross section will create torsion unless it is centred upon the centroid. In an edge beam, the vertical shear at the ends must be centered on the column, or there must be torsion to maintain equilibrium.
43.12.4 Envelopes Question: What is the significance of Envelopes in the Audit? Answer: An envelope is a resultant (set of forces) in which one of the force values is a maximum or minimum for an item (such as a cross section) under consideration. All of the force values within a single envelope occur simultaneously. Audit envelopes are created by the following process: • for each rule set, 6 envelopes are added to a list (Max M, Min M, Max V, Min V, Max P, Min P) • duplicates are removed (if Max M and Max V are identical, one of them will be removed) • torsion conversion is performed (this can modify the torsion values, it can also create additional envelopes) The result is a list of envelopes (possibly just one, but also possibly up to 12). Note: Some “torsion conversions” (such as modifying the bending moment due to the torsion) can double the number of envelopes in effect.
43.12.5 Reinforcement Question: Can I determine the reinforcement spacing? Answer: Yes.
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1. Choose the appropriate reinforcement plan. 2. Choose View > Visible Objects ( ). 3. Check Bar Spacings under the Span Designs or Section Designs columns. Note: Plotted reinforcement quantities cannot show bar spacing. Question: Why is the Minimum Reinforcing required placed on the wrong slab face? Answer: This sometimes happens for an ACI318 or BS8110 / TR43 design. RAM Concept locates the minimum reinforcing required by certain design criteria on the tension face of the slab (or the face with the least amount of compression); this normally works well for both elevated slabs and mat foundations. However, in certain cases the moment at a design strip cross section is of the opposite sign of what would be expected given the location. For an elevated slab this can lead to reinforcing at columns being at the bottom of the slab and reinforcing at mid-span being at the top of the slab. For example, for ACI318 or TR43 if there is no tension at a slab location under service conditions, then RAM Concept places the minimum support rebar on the face with the least amount of compression. This could be the bottom face at a column. You can overrule this by choosing Elevated Slab for the design strip property CS Min. Reinforcement Location. See Span segment properties (on page 214). Question: I am getting more reinforcement than expected. Why is this? Answer: This can be for a number of reasons. The common ones are: 1. The floor is post-tensioned and yet you have not checked the Consider as Post-Tensioned option. RAM Concept is ignoring the tendons. See the description in Span segment properties (on page 214). 2. The depth of the span segment strip cross section contributes to a large amount of minimum reinforcement. This may be because the cross section depth is based upon a thickened area. 3. The bonded tendons are not in the tensile zone. Question: Why are the reinforcement results on the Design Status layer in different colors? Answer: The default Appearance scheme uses different colors for “Failed Span Design” and “OK Span Design”. Related Links • Span segment properties (on page 214)
43.12.6 AS3600 specific reinforcement questions Question: I am getting more reinforcement than expected. Why is this?
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Answer: The default setting for design strip Environment is Normal. Changing to Protected can reduce the amount of reinforcement. See Section 9.4.3.2 Shrinkage and Temperature (on page 1028) for further clarification.
43.12.7 BS8110 / TR43 specific reinforcement questions Question: Why is there bottom steel at the column? Answer: There are a couple of possibilities: 1. See “Why is the Minimum Reinforcing required placed on the wrong slab face?” (on page 0 ). 2. TR43 (1st Edition) clause 6.10.5 states that “additional un-tensioned reinforcement shall be designed to cater for the full tension force generated by the assumed flexural tensile stresses in the concrete” for “Support zones in all flat slabs”. The note under TR43 table 2 states that “the support zone shall be considered as any part of the span under consideration within 0.2 x L of the support, where L is the effective span”. This often means that there is tension on the bottom face near the “edge” of the support zone, beyond contraflexure. Per 6.10.5, RAM Concept adds reinforcement to the bottom face in such instances. Note: • Concept might draw reinforcement bars to the column, but a plot could reveal that is only required over a limited zone. • Using column and middle strips for a TR43 PT flat plate tends to increase the likelihood of this situation. Question: Why is there mild service reinforcement near midspan of a bonded post-tensioned flat plate? Answer: When designing to TR43 (BS8110) with bonded tendons, many designers are surprised to see bottom service reinforcement. TR43 (1st Edition) clause 6.10.5 states that “…additional un-tensioned reinforcement shall be designed to cater for the full tension force generated by the assumed flexural tensile stresses in the concrete for … span zones in flat slabs using unbonded tendons where the tensile stress exceeds 0.15 f cu ”. Many designers consider that they do not have to provide un-tensioned reinforcement if they use bonded tendons. However, what they miss is that the reinforcement “shall be placed in the tensile zone, as near as practicable to the outer fibre”. RAM Concept examines the location of the bonded tendons and determines if it is effective. See Calculation of Supplemental Reinforcement Per TR 43, 6.10.5 (on page 1090) for further explanation. The following figures show where bonded tendons would not provide serviceability crack control.
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Figure 195: Assumed stress distribution
Figure 196: Example 1: tendons in compression zone (not effective)
Figure 197: Example 2: ineffective tendons in tension zone: (i) small number of strands (ii) near neutral axis
43.12.8 Punching Shear Question: How does Concept check punching shear? Answer: See Punching Shear Design Notes (on page 1188). Question: Does Concept check punching shear at the ends of the walls? Answer: No. Question: What is the stress ratio? Answer: The ratio of maximum stress to allowable stress. Question: Does Concept use redistributed moments in punching shear checks? Answer: No. The biaxial moments are factored elastic moments. Question: Is the design insufficient if the stress ratio exceeds 1.0? Answer: The punching shear at such a column is either: 1. sufficient if provided with design punching shear reinforcement, or 2. insufficient (reinforcement cannot solve the problem and the concrete form needs revision). Question: Why is there a punching failure at a beam? I thought that punching shear failures occur only in flat slabs.
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Answer: The code provides formula for calculating punching shear. This does not apply any logic as to whether a punching failure can occur. RAM Concept is only doing a punching check at a column supporting a beam because the user drew a punching check there. You should decide the nature of the potential failure mechanism and thus whether punching check is appropriate. Shallow beams could certainly have punching failure. Deep beams are less likely to have punching failure, and one-way shear failure would be the likely failure mechanism. For example, column A in the following two figures is satisfactory for one-way shear (with reinforcement in the beam) but the code equation determines that there is a punching failure. You need to decide if this is appropriate. It would be possible, but very rare, for a punching failure at column B since it is satisfactory for one-way shear in the beam (with reinforcement).
Figure 198: Mixed form: flat slab with column capitals and beams
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Figure 199: Shear results
43.12.9 Shear reinforcement (one-way) Question: Why does my flat slab (or flat plate) model have one-way shear reinforcement results? I would expect punching shear to govern, not one-way shear. [Similarly: Why does my flat slab (or flat plate) model have one-way shear failures?] Answer: When engineers design flat slabs by hand, they often ignore the one-way checks. They decide that punching is all that is appropriate. (This is often decided without much consideration – it just “seems right”). RAM Concept does not make this decision, as nowhere does the code advise to ignore one-way shear checks in a flat slab or flat plate. Nonetheless, you should decide what the possible failure mechanism is and so what is appropriate. It may, or may not, be appropriate to ignore the one-way shear results. For example, columns C in the previous two figures are satisfactory for punching shear (without reinforcement) but the mathematics of the code requires one-way shear reinforcement. It is up to you to decide if this is appropriate. Note: In fact, ACI 318-02 rule 11.12.1.1 specifically requires a one-way shear check in flat plates. Question: The results have a lot more shear reinforcement than expected. Answer: This is likely to be a shear core issue. Refer to About shear core (on page 234) and Shear core in slabs (on page 236). For a post-tensioned beam, the reason could be that RAM Concept is deducting a fraction of the (bonded) duct from the web width per the appropriate code rules.
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RAM Concept calculates the number of duct by dividing the Strands per tendon by the Max strands per duct (as specified in the Materials) and rounding up to the next integer. Refer to the following sections for an explanation of RAM Concept’s shear web calculation: • • • • •
For AS 3600, Section 8.2 Shear Design (on page 1024) For BS 8110, Section 3.4.5 Design shear resistance of beams (on page 1084). For IS 456, Section 22.4 Design shear resistance of beams (on page 1117). For EC2, Section 6.2 Design shear resistance (on page 1143). For CSA A23.3, Section 11.3 Shear Resistance of Beams (on page 1170)
Note: There is no ACI318 rule concerning deduction of ducts. Question: What does this audit text mean: Depth d is zero - replacing with column effective depth. Depth is still zero - giving up.? Answer: The is likely a combination of two things: • there is net compression force and a small moment, and as such the bending designer does not provide any reinforcement • the minimum designer has been turned off If this is the case, you should consider turning the minimum designer back on.
43.12.10 Deflection Question: Is cracking taken into account for deflection? Answer: Not all deflection results consider creep and cracking. It is very important that you understand which ones do and which do not. See Load History Deflections (on page 1176). Question: Does Concept warn if deflection is too high? Answer: No. Allowable deflection is a very subjective issue and RAM Concept does not warn if deflections exceed conventional limits. Note: RAM Concept does display a warning when deflections are so large that the analysis itself may no longer be valid. This typically happens for structures that are unstable or nearly unstable. Often the instability is related to unrestrained lateral displacements.
43.12.11 Soil bearing Question: There are many soil bearing pressure plans. Is there a summary? Answer: The “Soil Bearing Design” rule set envelopes the maximum and minimum bearing pressures for all load combinations.
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Choose Layers > Rule Set Designs > Soil Bearing Design > Max Soil Bearing Pressure Plan
43.13 Performance Question: What are the graphics cards requirements? Answer: It is recommended that you use a graphics card supported by DirectX 9.0. See the graphics card manufacturer for latest information on DirectX drivers. If no graphics card supported by DirectX can be found, RAM Concept attempts to use software emulation under Windows XP SP2 ,Vista and Windows 7. At least 128 MB of video RAM is recommended, but 256 MB is more desirable. For optimal performance, graphics display color depth should be set to 24-bit or higher. When using a color depth setting of 16-bit, some inconsistencies will be noted.
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44
Warnings and Errors RAM Concept has many error and warning messages that can be triggered during modeling and analysis. Some messages are self-explanatory and do not warrant further explanation. This chapter explains some of the more complicated warning and error messages that commonly arise. Most errors and warnings advise of a coordinate (x,y) or an object number. RAM Concept shows coordinates at the bottom of the workspace (see the first figure in Chapter 2). You can turn on object numbers with the Visible Objects (
) dialog box.
44.1 To show an object number 1. Choose Layers > Plan. 2. Choose View > Visible Objects (
).
Note: You can also right click to see a popup menu that includes the Visible Objects command. 3. Check the Numbers box under the appropriate object’s column, then click OK.
44.2 Meshing RAM Concept can generate several different errors and warnings for meshing. A general description of meshing limitations is in Limitations of the automatic meshing (on page 179). It is strongly advised that you heed such errors and warnings and fix the problems. Otherwise, RAM Concept generates the mesh every time you do a “Calc All”. Note: Nearly all meshing problems are due to the user’s failure to use snapping properly.
44.2.1 Two or more slab areas or beams with the same priority overlap at (x,y) Overlapping slabs and beams should have different priorities. This is explained in “The priority method”.
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Warnings and Errors Meshing The error is generated when two or more overlapping slab or beam objects have the same priority. To fix this error 1. Choose Layers > Mesh Input Layer > Standard Plan. 2. Choose View > Visible Objects ( ). Note: You can also right click to see a popup menu that includes the Visible Objects command. 3. Check the Priorities boxes under Beams and Slab Areas, then click OK. 4. Use the coordinates in the error dialog box to find the location of the problem, and revise the assigned priorities. Usually this requires making sure that the thickest slab or beam have the higher priority (the lowest priority is 1). Note: The highest priority is not always assigned to the thickest element. For example, where a standard slab area overlaps a depressed slab area.
44.2.2 Two or more beam areas overlap with conflicting stiffnesses at (x,y) Overlapping beams have different material properties that affect their rigidity. In this case their properties should be similar.
44.2.3 Vertical gaps in beam elevation at (x,y) Vertical gaps have been detected in the defined beams at the given coordinate. Vertical gaps can drastically reduce the strength of a beam.
44.2.4 Different concrete mixes specified at (x,y) It is not recommended to have different material properties in the same member. Thus this warning is triggered to notice this problem.
44.2.5 Line is too short at (x,y) RAM Concept has a minimum element size of 50 mm (approximately 2 inches). This is effectively a “snap” distance. When an object such as a slab area has two nodes closer than this distance the line between them is too short. In such cases, RAM Concept merges the two nodes together and reports the coordinates of this occurrence in the dialog box. You can view the resulting elements and nodes in the element standard plan.
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44.2.6 Feature eliminated at (x,y) This warning is a result of one of two things: • A feature is too small to model (for example, a 1" (25mm) wide slab area), or • Failure to use snapping, causing small overlaps.
44.2.7 Recursion too deep If the mesh ends up with 3 nodes at a tight angle, RAM Concept attempts to use recursion numerous times to adjust the nodes and make the minimum angle larger. In such a case, the standard number of recursions did not solve the tight angle, so the warning message reported that the recursion was too “deep”. This does not generally cause a problem, although it is indicative that there is a “pointy” element which can affect the contour plots. Generally, it is best to avoid this situation. See “Feature eliminated at (x,y)”. Note: You should investigate the meshing / modeling of the problem area to ensure that Concept's elements are reasonable for the area. Note: This error is usually caused by a failure to use snapping while drawing: two lines that are supposed to be in the same place are instead slightly off parallel and intersect.
44.2.8 An error has been found. Two column elements below the slab are at the same location. Delete column element #a or #b. This error occurs when you inadvertently draw a column at the same location twice, or copy and paste a column and do not change the Support Set (above or below). To fix this error 1. Choose Layers > Mesh Input Layer > Standard Plan. 2. Choose View > Visible Objects ( ). 3. Check the Column numbers box. 4. Place the cursor at the appropriate column, double click and delete.
44.2.9 An error has been found. A column element below the slab is not attached to the slab. Revise column element #a (below the slab) This error occurs when a column is outside the slab boundary (or within an opening). To fix the problem you should move the column or edit the slab such that the column is within the slab boundary.
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44.2.10 It is good modeling practice to connect wall centerlines. Click on the Fix button to move wall endpoints to a nearby centerline This warning occurs when the end of a wall is drawn within close proximity, but not coincident with another wall centerline. Walls should be modeled this way in order to create the best analytical finite element mesh. The dialog box offers an automatic fix (Click on the Fix button). If you click this button, RAM Concept moves the wall endpoint to the centerline of the nearby wall.
44.3 Loads 44.3.1 An error has occurred while assembling the load vector. A point load is not on the slab. Revise point load #a. A point load that is not on a finite element is considered an error. Apart from generating the error, RAM Concept essentially ignores the load.
44.3.2 An error has occurred while assembling the load vector. A line load is not totally on the slab. Revise line load #a. A line load that is not completely on finite elements generates this error. There may be times you ignore the error, such as when a line load crosses an opening. RAM Concept ignores the part of the load crossing the opening. Note: You should closely investigate such an error. A line load may appear to be on a slab edge, but actually be outside it. If you believe you have a line load across an opening and ignore the error, you may miss a real problem.
44.3.3 An error has occurred while assembling the load vector. A tendon is not totally on the slab. Revise the tendon at #a. A tendon that is not completely on finite elements generates this error.
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Warnings and Errors Tendons Note: You should closely investigate such an error. A tendon may appear to be on a slab edge when it is actually outside the slab boundary.
44.3.4 An error has occurred while assembling the load vector. An area load is not on the slab. Revise area load #a. An area load that is not completely on finite elements generates this error.
44.4 Tendons 44.4.1 Tendon #a has a radius (b) that is less than the minimum allowable (c). Parabolic tendons with a large drape relative to their length have a small radius. A warning is triggered when the tendon segment radius is less than the minimum radius for that tendon system. A tendon’s minimum (vertical) radius is specified in the Materials section. RAM Concept does not check horizontal radii as tendon segments are straight in plan. The radii shown are suggestions based on industry standards. You can change them based on advice from prestress companies. Note: The warning can be indicative of an overbalanced condition (too much uplift) for parabolic tendons. To remove the warning, you can adjust the tendon profile or change the minimum radius in the Material section. To edit the minimum radius 1. Choose Criteria > Materials. 2. Edit the minimum radius for the PT system.
44.4.2 Tendon #a is harped, and hence violates the minimum allowable radius (b) A harped tendon has (vertically) straight segments. There is thus a zero radius at the profile point(s). To avoid the harped tendon warning 1. 2. 3. 4.
Choose Criteria > Materials. Create a new PT system (possibly called “Harped”). Set the minimum radius for the new PT system to zero. Use the new system for the harped tendons.
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44.4.3 Tendon #a is a simple parabola, and hence violates the minimum allowable radius (b) A simple parabola is violating the minimum ratio. • To avoid this warning, set the minimum ratio to zero.
44.4.4 Cannot auto-position profile point at (x,y) due to profile point value This warning occurs when both of the following are true for two tendon segments that share a Profile Point 2: 1. The tendon segments have the Position Profile Point 2 for equal balance loads option checked, and 2. One, and only one, of the tendon segments is flat (that is, the values for Profile Point 1 and Profile Point 2 produce a flat tendon segment: this usually occurs when the two values are equal). The Position Profile Point 2 for equal balance loads option is intended to move the plan position of Profile Point 2 so that the uplift is equal for both tendon segments. This is not possible when one tendon segment is flat (zero drape) as there is no uplift in that tendon segment.
44.4.5 Cannot auto-position the profile elevation for tendon (a) at (b) because the tendon represents a partial half span A node on a single half-span tendon cannot be auto-positioned.
44.4.6 An error has occurred while trying to calculate a profile. A profile point is not on the slab. Click on the Fix button to correct the profile point at (x,y). This occurs when a tendon extends beyond the slab edge. To fix this error, stretch the profile point so its end is on the edge or slightly inside the slab edge. The dialog box offers an automatic fix (Click on the Fix button). If you click this button, RAM Concept moves the profile point to the nearest concrete element.
44.4.7 Tendon is not on slab at (a). A point along the tendon has been detected out of the slab.
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44.4.8 Tendon elevation conflict at (a) (Profile Point above slab soffit step?) The start or end point of a tendon is located in a place where the slab has a change step and there is a conflict in determining the elevation of the tendon. Place the point out of this threshold change.
44.4.9 An error has occurred while trying to calculate a profile. A profile point is not within the slab (vertically). Adjust the profile at (x,y). This occurs when a tendon profile point is not within the slab thickness. Profile values are always relative to the slab or beam soffit at the location of the profile point. The easiest way to find these problems is to look at a tendon perspective. If a profile point is at a top or bottom surface step, RAM Concept moves the profile point so that there is no ambiguity. You should check that the profile point is within the expected slab area.
44.4.10 An error has occurred while trying to calculate the tendon profiles. A tendon is out of the slab at (x,y). This is different to the previous error in that the profile points are within the slab, but the tendon is out of the slab somewhere between the profile points. This usually occurs when there is a top or bottom surface step.
44.4.11 An error has occurred while trying to calculate the tendon effective stresses. A tendon has a different number of strands than an adjacent tendon. Investigate tendon #a. You can vary the number of strands along a continuous tendon, but it is discouraged. This warning alerts you that the number of strands within the tendon is variable. To avoid the warning go to the appropriate tendon layer (the dialog box indicates on which layer the tendon is located) and change the number of strands in the tendon. Note: It is usually best to use the Select Connected Tendons tool. See “Can I terminate some strands past a column?” in Chapter 39, “Frequently Asked Questions” for more advice.
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44.4.12 An error has occurred while trying to calculate the tendon effective stresses. Two connected tendons have inconsistent half span ratios. Revise tendon #a. The orientation of two consecutive half span ratios is wrong and not compatible to the other.
44.4.13 An error has occurred while trying to calculate the tendon effective stresses. Two connected tendons have different post-tensioning systems. Revise tendon #a. The prestressed systems of two consecutive tendons are different.
44.4.14 An error has occurred while trying to calculate the tendon effective stresses. A tendon is not connected to any jacks. Investigate tendon #a. [If any tendons are stressed then all tendons must be stressed.] RAM Concept calculates losses in tendons that have one or two jacks attached. RAM Concept does not allow a (latitude or longitude) tendon layer to have some tendons with jacks but other tendons with no jacks. You can have one tendon layer (say, latitude) with jacked tendons and the other tendon layer with no jacks. When you encounter this error, find the tendon (from the number given) and draw at least one jack on the tendon.
44.4.15 An error has occurred while trying to calculate the tendon effective stresses. A tendon is stressed by two jacks with different wobble friction coefficients/with different angular friction coefficients/with different long-term losses. Some characteristics of the two jacks are incompatible. Revise one of the jacks and set it like the other.
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44.4.16 An error has occurred while trying to calculate the tendon effective stresses. A tendon is connected with other tendons in a circular fashion. Revise tendon (a) The path of a tendon returns to the same point and this is not allowed.
44.4.17 An error has occurred while trying to calculate the tendon effective stresses. A tendon is jacked to a stress higher than its yield stress. Revise the jack connected to tendon #a The jack force is too high. Reduce the force or increment the number of tendons.
44.4.18 An error has occurred while trying to stress a tendon. There are no tendons at a jack/There are multiple tendons at a jack. Investigate jack #a The jack is either not connected or connected to several tendons.
44.5 Load History Deflections 44.5.1 An error has been found while calculating load history deflections. The floor may have incomplete design strip/cross section coverage to accurately calculate load history deflections. The slab coverages are a and b in orthogonal directions In order to accurately calculate load history deflections, RAM Concept needs each element containing significant forces to be covered by the tributary of a design strip cross section or design section tributary. In order to make sure the user hasn’t forgotten to define strips over a large portion of the slab, RAM Concept performs some rudimentary checks to make sure a large portion of the slab is covered by cross section tributaries in two perpendicular directions. This warning can be safely ignored in one-way slab regions where the spanning direction is appropriately covered by cross sections.
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44.6 Optimization 44.6.1 CONNECTION Client Sign In This means that the CONNECTION Client is not running or the user has not signed in. The CONNECTION Client that was installed with RAM Concept should be running and the user should be signed in to the CONNECTION Client. The user should also be already registered with Bentley Cloud Services. Currently, only one sign on session is allowed per user.
44.6.1 Cloud Services initialization error. Optimization configuration error. A problem with the environment or the application ID and/or cluster ID was encountered.
44.6.1 Manual tendons cannot be optimized. The program displays this error when manual tendons are detected within the optimization regions. The program gives an option to delete them or to keep them. Either way, the manual tendons will not be part of the optimization process.
44.6.1 The minimum optimizable property count of (a) is less than the permitted minimum of 1. The number of optimizable objects in a single region (or in the whole model) is zero. At least one optimizable object should be considered in one optimizable region.
44.6.1 The maximum optimizable property count of (a) is greater than the permitted maximum of 75. The number of optimizable objects in a single region (or in the whole model) is over the maximum value of 75. Reduce the region size, reduce the number of optimizable objects or combine like objects into one. This limit has been used to avoid problems in the optimization to guarantee the finding of good solutions. The maximum recommended value to use in a region is 50.
44.6.1 The maximum number of iterations of (a) is greater than the permitted maximum value of 500. The maximum number of iterations of 500 has been reached. Most models converge normally in less than 100 iterations. The program is having problems in finding a solution. An option would be to reduce the number of optimizable objects or use more optimizable regions to simplify the problem. This limit was set to avoid long optimization processes that may not have good results.
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44.6.1 Running scenarios must be stopped before the file can be closed. Stop (a) running scenarios? You cannot save and close the file if there are running optimization scenarios. If required, the user can run another instance of RAM Concept to continue working with another file.
44.7 Miscellaneous 44.7.1 An error has occurred while triangularizing the stiffness matrix. The structure is unstable at (a). Revise the structure. This means that the structure has no lateral stability. You need to either provide some lateral stability (e.g. shear walls, columns with sufficient moment connections, lateral springs etc.) or auto-stabilize the structure when the Skyline solver is used. To auto-stabilize the structure 1. Choose Criteria > Calc Options 2. Choose the General tab 3. Check the Auto-stabilize structure in X and Y directions box. Note: This does not work if there are lateral loads.
44.7.2 An error has occurred: (a) has horizontal loads, but the structure is automatically stabilized in the X and Y directions You cannot auto-stabilize the structure if there are horizontal loads (other than tendons). 1. Uncheck the Auto-stabilize structure in X and Y directions box in the General tab of the Calc Options. 2. Provide some lateral stability (e.g. shear walls, columns with sufficient moment connections, lateral springs, etc.).
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44.7.3 The code rules selected in Rule Set “Service” (Sustained Service / Max Service) do not appear compatible with the load factors in the load combinations using the rule set. This is likely an error. Any load combination that uses the Service (and Sustained Service / Max Service) rule sets should logically have a load factor of 1 for the Balance Loading (regardless of the presence of tendons) and load factors of no more than 1 for dead and live loadings. RAM Concept provides the warning when this is violated. The warning usually occurs when you have added load combinations and forgotten to enter the Balance Loading load factors. To avoid the warning change all load factors for the Balance Loading to 1 for all of the load combinations that utilize the service (sustained service / max service) rule sets.
44.7.4 Load Combination “Service” (Sustained Service / Max Service) has unusual balance and / or hyperstatic load factors. This is likely an error. Any load combination that uses the Service (and Sustained Service / Max Service) rule sets should logically have a load factor of 1 for the Balance Loading (regardless of the presence of tendons) and a load factor (and alternate envelope factor) of zero for the Hyperstatic Loading. RAM Concept provides the warning when this is violated. The warning usually occurs when you have added load combinations and forgotten to enter the Balance Loading load factors. To avoid the warning change all load factors for the Balance Loading to 1 for all of the load combinations that utilize the service (sustained service / max service) rule sets.
44.7.5 Rule Set “Strength Design” is being used by load combinations that appear to have load factors set for different purposes. This is likely an error. Any load combination that uses the Strength (or Ductility) rule sets should logically have a load factor (and alternate envelope factor) of 1 for the Hyperstatic Loading (regardless of the presence of tendons). RAM Concept provides the warning when this is violated. The warning usually occurs when you have added load combinations and forgotten to enter the Hyperstatic Loading load factors. To avoid the warning change all load factors (and alternate envelope factors) for the Hyperstatic Loading to 1 for all of the load combinations that utilize the strength or ductility rule sets.
44.7.6 The mat / raft is likely unstable. There is less that 25% contact area. When the mat (raft) has a significantly reduced bearing area it is likely that bearing pressures are very high and there could be instability.
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44.7.7 Punching Check #a is not located at a column This error occurs when a column is relocated after the punching checks have been drawn and the punching check is no longer centered on the column. You need to remove and redraw the punching check. It usually helps to show the punching check number. To display the punching check number (as opposed to column number) 1. Choose Layers > Design Strips > Punching Checks Plan. 2. Choose View > Visible Objects ( ). 3. Check the Punching Shear Checks numbers box.
44.7.8 Too many slab shapes intersecting the column shape at (x,y) RAM Concept uses very sophisticated algorithms to find the critical sections around the column and slab irregularities. If the column intersects a large number of slab thickness changes (such as where beams frame in on each side), the run time could be very long. In this instance, RAM Concept just reports this error. This error can be resolved by making the punch check smaller, simplifying the slab geometry around the column, or deleting the punch check.
44.7.9 An error has been found. The cross section trimming for strip ab-c has caused there to be no concrete remaining at one or more locations. This error is typically reported at steps in the slabs. The inter cross section slope limit is trimming the entire cross section away at the step. See “Inter Cross Section Slope Limit Trimming” for more information. You can avoid the problem by setting the inter cross section slope limit to a large value in spans containing large steps. You should, however, consider the underlying reason for the error.
44.7.10 An error has been found. [Design strip] ab-c has reinforcing bars with too much cover (the bottom bar is closer to the top than the top bar). The trimmed cross section has a thickness and covers such that the location of the bars is illogical. This is likely to happen with thin slabs, or steps.
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44.7.11 A cross section in design strip ab-c has no shear core Due to generated cross section geometry, no part of the cross section extends from the top most elevation in the cross section to the bottom most elevation. This will usually result in shear/torsion failures. This can normally be avoided by rearranging the span segments and design sections to make sure each cross section contains a shear core.
44.7.12 A cross section in design strip ab-c has a very small shear core This normally occurs at small steps in the slab or changes in geometry in the slab. If a design cross section clips a small change in slab thickness it can result in a small part of the cross section comprising the shear core. This can normally be avoided by utilizing cross section trimming.
44.7.13 ab-c contains user transverse reinforcement but has multiple shear cores. Shear/torsion calculations may be approximate If user reinforcement is drawn in a cross section that contains multiple separate shear cores, the distribution of the reinforcement between the cores is not known. The distribution of the transverse reinforcement within the cores can significantly affect the strength. The calculations for this situation may therefore be approximate. To eliminate this approximation, the span segment strips and design sections should be refined such that each cross section only contains a single shear core.
44.7.14 ab-c contains user reinforcement that is not within the primary (largest) shear core. This transverse reinforcement will be ignored If user transverse reinforcement is drawn within a design cross section, but is not contained in the shear core (or in the case of multiple shear cores, the largest shear core), it will be ignored. This error can be resolved by moving the user transverse reinforcement to a plan location that will intersect the shear core of the cross section.
44.7.15 An error has been found. ab-c contains multiple user transverse rebar regions Each cross section shear core can only contain a single user transverse reinforcement region. This error occurs when more than one user transverse rebar has been drawn through a single cross section shear core. The error can be resolved by deleting or moving the extraneous user transverse rebar.
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Warnings and Errors Management Tool The warning and error dialogs in RAM Concept normally report object numbers and/or coordinates where the issue occurs. RAM Concept also provides an interactive tool to aid in finding and resolving calculation warnings and errors that occur.
45.1 To launch the warnings and errors management tool To show the warnings and errors dialog following a meshing or calculation operation choose Process > Display ) or select the Display Warnings tool on the toolbar. The Warnings and Errors dialog opens to Warnings ( display each warning or error in each row of the table. Each warning or error is categorized by severity: • Performance This item doesn’t represent a calculation error, but can cause increased model run time. • Warning This item may represent an input or calculation error and should be evaluated. The calculations can continue after the warning. • Error This item represents an error in the input or calculations and should be fixed. The calculations can continue after this type of error. • Fatal This item represents an error that is severe and the calculations cannot continue. Calculations will stop immediately and no subsequent errors or warnings will be logged during this calculation. The warnings and errors dialog can be set to display automatically in the event that at least one warning or error at the minimum severity specified is experienced. For example, if the Automatic display severity drop-down is set to “Warning” then if a warning, error, or fatal error is experienced the warnings and errors dialog will display automatically at the end of the calculation. The automatic display severity can also be set to “Never” in which case the warnings and errors dialog will never display automatically. The dialog can always be launched manually after the completion of a calculation.
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Warnings and Errors Management Tool Using the warning and error tool to find and resolve problems
45.2 Using the warning and error tool to find and resolve problems Warnings and errors can be sorted by severity by clicking on the Severity column header. The Layer column shows the layer that the warning or error is associated with, and the Type column provides a short description
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Warnings and Errors Management Tool Hiding and Unhiding Individual Warnings or Errors of the warning or error. Hovering the mouse over the short description in the Type column will provide a more detailed description.
45.2.1 Highlighting error geometry Selecting one or more warning or error in the table will highlight any geometry associated with that warning or error. The geometry is shown on the active plan regardless of the layer that contains the error object. There must be an active plan displayed in order to view the geometry.
45.2.2 Selecting objects associated with warnings and errors If there is an object associated with the warning or error, click Select to open a plan that displays the object's plot layer and selects the appropriate object. This makes it easy to change the object's properties and either revise or delete the object in order to resolve the issue. Double-clicking on an individual warning or error row is equivalent to choosing that row and clicking Select.
45.2.3 Zooming the view to highlighted error extent Click Zoom to change the current plan view zoom to the extent of the highlighted error and warning objects.
45.3 Hiding and Unhiding Individual Warnings or Errors Once a warning or error has been resolved, you may wish to hide it from view in the table. Click Hide to hide all selected warnings and errors. Click Unhide All to show all previously hidden warnings and errors.
45.4 Filtering Warnings and Errors by Type Errors and warnings can be filtered by their type. Click Filter by Type to select and unselect the types of warnings and errors that are shown in the list. The pulldown will allow you to select “Show All” which will remove all current filters and show all rows that are not hidden, and the “Filter All” selection will filter all types, temporarily removing everything from the table. After using the “Filter All” command it would then be easy to target an individual error or warning type from the pulldown to show.
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Simple RC Slab Tutorial This chapter describes the steps for modeling a single panel two-way flat plate with uniform loads. The objective of the tutorial is to help you learn some basic modeling skills and expose you to a number of tools and methods that should prove useful for real projects. The codes used are ACI 318-02, AS3600-2001, BS8110:1997, EC2 - 2004, IS 456 : 2000, and CSA A23.3-04. The instructions show “US units” for an ACI 318 design, with metric values and units in square brackets for AS3600, BS8110, EC2, IS 456, and CSA A23.3. The metric values are not exact conversions. For information on creating a new file, see Creating and opening files (on page 51).
46.1 Defining the structure You start by drawing the structure and generating the element mesh.
46.1.1 Define the column locations and properties 1. Choose Layers > Mesh Input > Standard Plan. 2. Double click the Column tool ( ). 3. In the Default Column Properties dialog box: a. Choose a Concrete Strength of 5000 psi [32 MPa for AS3600; C32/40 for BS8110 & EC2, M40 for IS 456; 30 MPa for CSA A23.3]. b. Set Width to 24 inches [600 mm]. c. Set Depth to 24 inches [600 mm]. 4. Click OK. Define the column locations by one of the following three methods. We strongly recommend you try all of them for the purpose of learning different procedures. 5. Enter the following coordinates (x, y) and press return after each: a. 0, 0 ft. [0, 0 m] b. 24, 0 ft. [7.25, 0 m] c. 24, 20 ft. [7.25, 6 m] d. 0, 20 ft. [0, 6 m]
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Simple RC Slab Tutorial Defining the structure Note: The coordinates will appear in the command line, see the first figure in Chapter 2. Note: Do not enter the actual units (ft., m) 6. Go to “ Draw the slab area: ”, or select and delete the four columns and try the next method. 7. Right click over the plan and choose Grid. 8. In the Grid Setup dialog box: a. Set x and y to 1 foot [0.25 meters]. b. Click OK. 9. Turn on Snap to Grid ( ). 10. Click the Column tool ( ). 11. Place the cursor near the following coordinates and click (the cursor will snap to the grid and the coordinates appear in the command line): a. 0, 0 ft. [0, 0 m] b. 24, 0 ft. [7.25, 0 m] c. 24, 20 ft. [7.25, 6 m] d. 0, 20 ft. [0, 6 m] 12. Go to “ Draw the slab area: ”, or select and delete the four columns and try the next method. 13. Draw the two columns at 0, 0 ft. [0, 0 m] and 24, 0 ft. [7.25, 0 m] by one of the previous two methods. 14. Select the two columns. 15. Click the move tool ( ). 16. Hold down and click anywhere on the workspace. 17. Type r0,20 [r0, 6], and press . Note: This copies the two columns using the relative command. See “Using relative coordinates” for further explanation.
46.1.2 Draw the slab area 1. Turn on Snap to Intersection ( ). 2. If previously turned on, turn off Snap to Grid ( ). 3. Double click the Slab Area tool ( ) to edit the default properties. 4. In the Default Slab Area Properties dialog box: a. Choose a Concrete Strength of 5000 psi [32 MPa for AS3600; C32/40 for BS8110 & EC2, M40 for IS 456; 30 MPa for CSA A23.3]. b. Set Thickness to 12 inches [300 mm]. c. Leave Surface Elevation as 0 and Priority as 1. d. Click OK. 5. ) selected, define the four corners of the slab by snapping at the “outside” corner With the Slab Area tool ( of each column. 6. Complete the rectangle by clicking at your starting point (or type “c” in the command line and press ).
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46.1.3 Hatch the slab area 1.
Choose View > Visible Objects ( ). The Visible Objects dialog box will appear. 2. Check “Hatching” under “Slab Areas”, and then click OK. Note: You can also right click to see a popup menu that includes the Visible Objects command. You have now defined the slab but the element mesh does not yet exist.
Figure 200: After defining the slab, the Mesh Input: Standard Plan shows the slab area (hatched), and the columns.
46.1.4 Generate the mesh 1.
Click Generate Mesh ( ). 2. In the Generate Mesh dialog box set the Element Size to 2 feet [0.6 m]. 3. Click Generate.
46.1.5 View the mesh 1. Choose Layers > Element > Standard Plan. You will now see a somewhat random mesh. This produces reasonable results, but a regular mesh is better. You can regenerate a significantly improved mesh once you have defined design strips. This mesh is shown in the third figure.
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Figure 201: Element: Standard Plan (ACI318 example dimensions).
Figure 202: Element: Standard Plan (AS3600, BS8110, EC2, IS 456 and CSA A23.3 example).
Figure 203: Element: Standard Plan after regeneration (for ACI318 example; the metric codes produce a similar mesh)
46.1.6 View the structure 1. Choose Layers > Element > Structure Summary Perspective. 2. Use the Rotate about x- and y-axes tool ( ) to rotate the floor. 3. Click the Set Print Viewpoint tool ( ). Upon returning to this perspective, you can look at the saved view by clicking Show Set Viewpoint (
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Figure 204: Element: Structure Summary Perspective.
46.2 Drawing the loads RAM Concept calculates the concrete self-weight automatically. There is no limit to the number of loadings than can be specified but this example defines only Live Loading. 1. Choose Layers > Loadings > Live (Reducible) Loading > All Loads Plan. 2. Double click the Area Load tool ( ). 3. In the Default Area Load Properties dialog box: a. Change Fz to 50 psf [2.5 kN/m2]. b. Click OK. This tool will now draw area loads of 50 psf [2.5 kN/ m2]. 4. Define an area load over the entire slab by clicking four corners of a quadrilateral and then typing “c”. This shape need not match the slab’s exact dimensions, but should cover the slab.
Figure 205: Live (Reducible) Loading: All Loads Plan (with area loads hatching turned on): ACI318 example.
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Figure 206: Live (Reducible) Loading: All Loads Plan (with area loads hatching turned on): AS3600, BS8110, EC2, IS 456, & CSA A23.3 example.
46.3 Defining the design strips Design strips are an essential part of RAM Concept because they link finite element analysis with concrete design. Their properties include reinforcement bar sizes, cover, and parameters that RAM Concept uses to determine which code rules are applicable for cross-section design. There are two directions named Latitude and Longitude. It is normal practice to design two-way RC flat plates with column and middle strips in two orthogonal directions, and that practice is used here.
46.3.1 Draw latitude design strips 1. Choose Layers > Design Strip > Latitude Design Spans Plan. 2. Double click the Span Segment tool ( ). 3. The Default Span Properties dialog box opens to the Strip Generation properties. a. Set Column Strip Width Calc to Code Slab (this is the default for the AS3600 and IS 456 templates). b. Click the General tab. c. Uncheck the Consider as Post-Tensioned box. d. Click the Column Strip tab. e. Change CS Top Bar to #6 [N20 for AS3600; T20 for BS8110; H20 for EC2; T20 for IS 456; 20M for CSA A23.3]. f. Change CS Bottom Bar to #5 [N16 for AS3600; T16 for BS8110; H16 for EC2; T16 for IS 456]. g. Click the Middle Strip tab. h. Check the Middle Strip uses Column Strip Properties box. i. Click OK. 4. ), or choose Process > Generate Spans. Click the Generate Spans tool ( 5. The Generate Spans dialog box opens with Spans to Generate set to Latitude (as shown in the following figure): a. Set Minimum Span Length to 2 feet [0.6 meters]. b. Click OK.
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Figure 207: Generate spans dialog box The latitude spans appear, as shown in the following figure. 6. Click the Generate Strips tool ( ), or choose Process > Generate Strips. The latitude design strips appear, as shown in the second figure.
Figure 208: Latitude direction spans
Figure 209: Latitude direction design strips (with hatching turned on)
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46.3.2 Draw longitude design strips 1. Choose Layers > Design Strip > Longitude Design Spans Plan. 2. Double click the Span Segment tool ( ). 3. Click the Column Strip tab in the Default Span Properties dialog box. The defaults set up in the Latitude Design Spans Plan will have remained the same. Since the cover cannot be the same for both directions, change it for the longitudinal direction. a. Change CS Top Cover to 2.25 inches [60 mm]. b. Change CS Bottom Cover to 1.38 inches [41 mm]. c. Click OK. 4. Click the Generate Spans tool ( ), or choose Process > Generate Spans. 5. In the Generate Spans dialog box: a. Set Spans to Generate to Longitude. b. Click the “up-down” orientation button, and click OK.
Figure 210: Generate spans dialog box The longitude spans appear, as shown in the following figure. 6. Click the Generate Strips tool ( ), or choose Process > Generate Strips. The longitude design strips appear, as shown in the second figure.
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Figure 211: Longitude direction spans
Figure 212: Longitude direction design strips (with hatching turned on) Now that there are design strips, you can generate a much more regular mesh.
46.3.3 Regenerate the mesh 1.
Click Generate Mesh ( ). 2. Click Generate. 3. There is now a better mesh. View the mesh on the Element Standard Plan.
46.4 Drawing punching shear checks Drawing the punching checks is very straightforward. 1. Choose Layers > Design Strip > Punching Checks Plan. 2. ). Double click the Punching Shear Check tool ( 3. In the Default Punching Shear Check Properties dialog box: a. Change Cover to CGS to 2.25 inches [60 mm] (the average top cover) b. Click OK. 4. Fence the slab with the Punching Shear Check tool. See the following figure to view the punching checks.
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Figure 213: Design Strip: Punching Checks Plan
46.5 Calculate and view the results You can “run” the file at any time during modeling to analyze and check for errors. After you have drawn design strips, RAM Concept can analyze and design. You can then view the results. 1. Click Calc All (
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46.5.1 Design status The purpose of status plans is to indicate whether there are any violations of code limits for ductility, one-way shear, and punching shear. View Status 1. Select Layers > Design Status > Status Plan. For ACI318, AS3600 and IS 456, the status plan shows OK for all design strips and punching shear checks. See first following figure. The BS8110 status plan shows punching shear failure. See second following figure. The EC2 and CSA A23.3 status plan show OK for all design strips and OK with SSR for all punching shear checks. Note: Status does not flag excessive deflections.
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Figure 214: Design Status: Status Plan for ACI318, AS3600 & IS 456
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Figure 215: Design Status: Status Plan for BS8110 (Amd #1 & #2)
46.5.2 Design reinforcement You can view reinforcement results as bar drawings or plots.
View Reinforcement 1. Choose Layers > Design Status > Reinforcement Plan. This shows all the code-determined reinforcement for each of the eight design strips. See the following figures.
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Figure 216: Design Status: Reinforcement Plan for ACI318
Figure 217: Design Status: Reinforcement Plan for AS3600
Figure 218: Design Status: Reinforcement Plan for BS8110 (Amd #1 & #2)
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Figure 219: Design Status: Reinforcement Plan for IS 456 Such plans often suffer from “information overload” with congested results. For this reason, you can access plans in the Design Status layer that separate reinforcement according to: face (top or bottom), direction (latitude or longitude), and type (flexural or shear). You should decide which plans best convey the results without too much clutter.
View Specific Reinforcement 1. Choose Layers > Design Status > Latitude Bottom Reinforcement Plan. See the four following figures. Concept provides you with the code clause numbers that control the maximum top and bottom reinforcement at any design strip cross section. The following uses latitude bottom reinforcement as an example.
View Reinforcement Controlling Criteria 1. Choose Layers > Design Status > Latitude Bottom Reinforcement Plan. 2. Choose View > Visible Objects ( ). 3. In the span designs (not section designs) column: uncheck Bar Descriptions and check Controlling Criteria, and click OK. See the last four of the following figures for latitude bottom reinforcement controlling criteria.
Figure 220: Design Status: Latitude Bottom Reinforcement Plan for ACI318.
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Figure 221: Design Status: Latitude Bottom Reinforcement Plan for AS3600.
Figure 222: Design Status: Latitude Bottom Reinforcement Plan for BS8110 (Amd #1 & #2).
Figure 223: Design Status: Latitude Bottom Reinforcement Plan for IS 456.
Figure 224: Design Status: Latitude Bottom Reinforcement Plan for ACI318 with Bar Descriptions unchecked and controlling Criteria checked.
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Figure 225: Design Status: Latitude Bottom Reinforcement Plan for AS3600 with Bar Descriptions unchecked and Controlling Criteria checked.
Figure 226: Design Status: Latitude Bottom Reinforcement Plan for BS8110 with Bar Descriptions unchecked and Controlling Criteria checked.
Figure 227: Design Status: Latitude Bottom Reinforcement Plan for IS 456 with Bar Descriptions unchecked and Controlling Criteria checked.
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46.5.3 Design reinforcement plots RAM Concept has plotting options that you can use to view various strip-based results such as moment, shear, precompression, reinforcement and crack width. This section steps you through setting up a reinforcement plot. You can bypass this section, but there are steps that help you learn the more powerful aspects of the program. To create a new plan that plots latitude bottom reinforcement 1. Choose Layers > New Plan. 2. Enter a name for the plan, such as “Plot: Latitude Bottom Reinforcement”. (RAM Concept automatically prepends the layer name and appends the word “Plan”). 3. Select the Design Status layer, and click OK. The Visible Objects dialog box appears. 4. Click Show Nothing and click OK. 5. Choose View > Plot ( ). The Plot dialog box appears with the Section Design dialog. 6. Check the Active box. 7. Select the Bottom radio button. 8. Change Max Frame Number to 2, and click OK. See the following figures for the reinforcement plots.
Figure 228: Design Status: Plot: Latitude Bottom Reinforcement Plan for ACI318.
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Figure 229: Design Status: Plot: Latitude Bottom Reinforcement Plan for AS3600
Figure 230: Design Status: Plot: Latitude Bottom Reinforcement Plan for BS8110 (Amd #1 & #2).
Figure 231: Design Status: Plot: Latitude Bottom Reinforcement Plan for IS 456
46.5.4 Punching shear You can view punching shear results on dedicated plans.
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View Punching Shear 1. Select Layers > Design Status > Punching Shear Status Plan. You can see that, for ACI318, AS3600 and IS 456, the unreinforced stress ratio (USR) is less than 1.0 and hence punching shear capacity is satisfactory. The USR for BS8110 is 1.17. Since the stress ratio exceeds 1.0, shear reinforcement is required. RAM Concept designs stud shear reinforcement (SSR) for such situations.
View SSR 1. Choose Layers > Design Status > SSR Plan. The result for BS8110 is shown in the fourth figure.
Figure 232: Design Status: Punching Shear Status Plan for ACI318.
Figure 233: Design Status: Punching Shear Status Plan for AS3600
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Figure 234: Design Status: Punching Shear Status Plan for BS8110 (Amd #1 & #2).
Figure 235: Design Status: SSR Plan for BS8110 (Amd #1 & #2).
Figure 236: Design Status: Punching Shear Status Plan for IS 456
46.5.5 Deflection Usually you are interested in deflections for Service (Dead and Live Load plus PT if applicable) and Long Term. RAM Concept uses gross section inertia for deflection contours. You can investigate the effects of creep, shrinkage and cracking with Load History Deflections. See Chapter 65, “Load History Deflections” for more information. Note: The following deflection plans DO NOT consider cracking, creep or shrinkage.
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View service deflection 1. Select Layers > Load Combinations > Service LC > Deflection Plan The service deflection contours should be visible, as shown in the following figures. Note: These models use compressible columns and hence the deflection includes column deflection. Note: The AS3600 template uses 70% of live load for the Service LC.
Figure 237: Service LC: Deflection Plan for ACI318.
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Figure 238: Service LC: Deflection Plan for AS3600.
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Figure 239: Service LC: Deflection Plan for BS8110.
Figure 240: Service LC: Deflection Plan for IS 456.
View service deflection without colors 1. Choose Layers > Load Combinations > Service LC > Deflection Plan. 2. Right click over the plan and choose Plot ( ) to change Plot Type from Color Contour to Contour.
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46.5.6 Bending Moments While it is not necessary to view bending moments, it can be useful, especially for irregular structures. Even though principal moments are important, the default moment contours plans are for Mx (moment about the xaxis) and My. This is because most designers detail reinforcement orthogonally, and the directions are usually the x- and y-axes. You can view moments about any axes, including the principal axes. It is not particularly easy to assess the moment contours. This is why Plot Distribution Tools are so useful. Note: Plot Distribution Tools are useful for qualitative results but not quantitative results. Refer to “Section distribution plots” and, in particular, the “Summary” View Moments 1. Choose Layers > Load Combinations > Code Specific Load Combination > Mx Plan. For ACI318, use Factored LC: 1.4D. For AS3600, use Ultimate LC: 1.2D + 1.5 L. For BS8110, use Ultimate LC: 1.4D + 1.6L + 1.6S. For IS 456, use Ultimate LC: 1.5D + 1.5 L + 1.6S. For EC2, use Ultimate LC: 1.25D + 0.9H + 1.5L + 0.75S For CSA A23.3, use Factored LC: 1.4D. The contours are moment per unit length about the global x-axis. 2. Turn on Snap Orthogonal ( ) 3. Click the Selected Plot Distribution tool ( ). 4. Click first at the top of the structure and again on the bottom side. This shows the bending moment shape, about the x-axis, along the line you have drawn. See the following figures. 5. Now click from left to right across the structure. This shows how Mx varies along the span. If you do it through the column centers, you will see how the column strip has large negative moments and a small positive moment near midspan. If you do it in the middle strip, you will see only positive moments. See “About plot sign convention” in Chapter 8, “Choosing Sign Convention” for further information.
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Figure 241: Factored LC: 1.4D: Mx Plan showing use of Plot Distribution tool for ACI318.
Figure 242: Ultimate LC: 1.2D+1.5L: Mx Plan showing use of Plot Distribution tool for AS3600.
Figure 243: Ultimate LC: 1.4D+1.6L: Mx Plan showing use of Plot Distribution tool for BS8110.
Figure 244: Ultimate LC: 1.5D+1.5L: Mx Plan showing use of Plot Distribution tool for IS 456.
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46.6 Drawing reinforcement Version 3.0 introduces vastly improved tools for drawing reinforcement bars.
46.6.1 Drawing a bottom reinforcement mat In this section you are shown how to draw a bottom reinforcement mat and see the ramifications. 1. Choose Layers > Reinforcement > Bottom Bars Plan. 2. Double click the Distributed Reinf. Cross in Perimeter tool ( ). 3. The Default Distributed Reinforcement Properties dialog box opens. a. Note that Elevation Reference is set to Bottom Cover. b. Change Elevation to 0.75 inches [25 mm for AS3600, BS8110, IS 456, EC2, and CSA A23.3]. c. Change Bar Type to #5 [N16 for AS3600; T16 for BS8110; T16 for IS 456; H16 for EC2; 15M for CSA A23.3]. d. Change Spacing to 12 inches [225 mm for AS3600; BS8110, IS 456, EC2, and CSA A23.3]. 4. Turn on Snap Orthogonal ( ). 5. Click somewhere on the slab. 6. Click at another point to the left or right to define the orientation of the (primary) reinforcement. A polygon appears that is the shape of the slab. Once the file is run you can view the individual bars via the Visible Objects dialog box. Note: This creates three objects: a polygon matching the slab outline, a reinforcement object that belongs to the latitude reinforcement layer and a reinforcement object that belongs to the longitude reinforcement layer. 7. Using the Stretch tool, you can adjust the bar grip postilions for a better appearance.
Figure 245: ACI 318: Reinforcement > Bottom Bars Plan
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Figure 246: Bottom mat defined by clicking at points A and B. Point C appears such that AC = AB. The bars are shown to points A and B but the symbol indicates the reinforcement continues to the slab edges.
Figure 247: Bottom mat modified by stretching grip points at B and C.
Figure 248: AS3600, BS8110, IS456: Reinforcement > Bottom Bars Plan
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Figure 249: Bottom mat defined by clicking at points A and B. Point C appears such that AC = AB. The bars are shown to points A and B but the symbol indicates the reinforcement continues to the slab edges.
Figure 250: Bottom mat modified by stretching grip points at B and C.
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PT Flat Plate Tutorial: ACI 318-08 This chapter describes the steps for modeling a post-tensioned two-way flat plate with uniform loads. The objective of this tutorial is to build on the skills learned in the Chapter 41 RC tutorial and introduce new steps, such as using a CAD drawing and post-tensioning. Some tools and methods described in the RC tutorial are not used here. As such, it is highly recommended that you first do the RC tutorial. This is not a particularly “aggressive” design. After you have completed the tutorial, you may wish to make the slab thinner to investigate the ramifications. You could also use this as a reinforced concrete tutorial by making a few adjustments (for example, a thicker slab).
47.1 For information on creating a new file, see Creating and opening files (on page 51).
47.2 Import the CAD drawing The CAD file you import is located in your RAM Concept program directory. 1. Choose File > Import Drawing. 2. Select the CAD drawing file flat_plate.dwg. The File Units dialog box appears. 3. Select Inches (the units used in the CAD file) and click OK.
47.3 Define the structure To use the CAD file you need to make it visible on the Mesh Input layer.
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47.3.1 Show the drawing on the mesh input layer 1. Choose Layers > Mesh Input > Standard Plan. 2. Choose View > Visible Objects ( ). Note: You can also right click to see a popup menu that includes the Visible Objects command. 3. Click the Drawing Import tab. 4. Click Show All, and then click OK.
47.3.2 Draw the slab area 1. Turn on Snap to Intersection ( ) and Snap to Point ( ). 2. Double click the Slab Area tool ( ) to edit the default properties. 3. In the Default Slab Area Properties dialog box: a. Choose a Concrete Strength of 5000 psi. b. Set Thickness to 10 inches. c. Leave Surface Elevation as 0 and Priority as 1. d. Click OK. 4. With the Slab Area tool ( ) selected, define the 10 vertices of the slab outline by snapping to the imported drawing’s slab corners. Note: There are two vertices near each other near B-5 at 86, 27 ft and 86, 29 ft. Cursor plan coordinates display next to the command prompt. 5. Complete the polygon by clicking at your starting point (or type “c” in the command line and press ).
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Figure 251: The slab outline on the Mesh Input: Standard Plan.
47.3.3 Draw the balcony slab area 1.
) to edit the default properties. Double click the Slab Area tool ( 2. In the Default Slab Area Properties dialog box:
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With the Slab Area tool ( ) selected, define the six vertices of the balcony outline by clicking at each vertex, and then click at your starting point (or type “c” in the command line and press ).
Figure 252: The balcony slab on the Mesh Input: Standard Plan.
47.3.4 Draw the drop caps 1.
Double click the Slab Area tool ( ) to edit the default properties. 2. In the Default Slab Area Properties dialog box: a. Change Thickness to 20 inches. b. Change Surface Elevation to 0, and leave the Priority as 2. c. Click OK. 3. With the Slab Area tool ( ) selected, define the four drop caps with four or five vertices as appropriate. 4. Go to “ Draw the opening ”:, or try the next method 5. With the Selection tool ( ), select (by double-clicking) and delete the drop cap at B-2.
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).
Some tool button icons have a small triangle in the lower right corner ( ). This indicates that there are other similar tools available for this button. 7. 8. 9. 10. 11.
Place the mouse over the Slab Area tool ( ) and press down on the left mouse button for one second. A pop-up menu appears. Select the Drop Cap tool from the menu. The selected tool becomes current for that button. Click at the column at B-2. A Drop Cap Tool dialog box appears. Enter an angle of zero degrees. Enter a side dimension of 3.75 feet and click OK.
47.3.5 Draw the opening 1.
). Select the Slab Opening tool ( 2. Define the four corners of the opening by clicking at each location, and then click at your starting point.
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Figure 253: The opening on the Mesh Input: Standard Plan.
47.3.6 Hatch the slab areas 1.
Choose View > Visible Objects ( ). The Visible Objects dialog box will appear. 2. Check “Hatching” under “Slab Areas”. 3. Check “Hatching” under “Slab Openings”, and click OK. Note: You can also right click to see a popup menu that includes the Visible Objects command.
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47.3.7 Define the column locations and properties 1.
Double click on the Column tool ( ). 2. In the Default Column Properties dialog box: a. Choose a Concrete Strength of 5000 psi. b. Set Width to 24 inches. c. Set Depth/Diameter to 24 inches. 3. Click OK. 4. Click at the center of all 13 column locations shown on the imported drawing.
47.3.8 Define the wall location and properties 1. Turn on Snap Orthogonal ( ). 2. Double click on the Wall tool ( ). 3. In the Default Wall Properties dialog box: a. Choose a Concrete Strength of 3000 psi. 4. Click OK. 5. Define the wall by clicking at the start and end points, on the centerline. a. Place the cursor near 29.5, 87 ft and it will snap to where the center of the wall intersects the edge of the slab, and click. b. Place the cursor at the center of the column at C-2 (it will snap orthogonally) and click. You have now defined the structure but the element mesh does not yet exist. 6. Go to “ Generate the mesh ”:, or try the next method. 7. The wall should be highlighted as it is the current selection. If not, select it by double-clicking and press . 8. Click Redraw ( ). 9. Place the mouse over the Wall tool ( ) and press down on the left mouse button for one second. A pop-up menu appears. 10. Select the Left Wall tool from the menu. 11. Click at the extreme corner of the slab near D-2. 12. Click at Grid C, near C-2.
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Figure 254: After defining the slab, the Mesh Input: Standard Plan shows the slab areas and opening (hatched), the columns and the wall.
47.3.9 Generate the mesh 1.
). Click Generate Mesh ( 2. In the Generate Mesh dialog box set the Element Size to 3 feet.
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47.3.10 View the mesh 1. Choose Layers > Element Standard Plan. You will now see a somewhat random mesh. This will still produce reasonable results, but will significantly improve when you regenerate it later on.
Figure 255: Element: Standard Plan.
47.3.11 View the structure 1. Choose Layers > Element > Structure Summary Perspective. 2. ) to rotate the floor. Use the Rotate about x- and y-axes tool ( 3. Click the Set Print Viewpoint tool ( ). Upon returning to this perspective, you can look at the saved view by clicking Show Set Viewpoint (
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Figure 256: Element: Structure Summary Perspective.
47.4 Define the loads RAM Concept calculates the concrete self-weight automatically. RAM Concept uses superposition of loads. The easiest way to define areas with increased area loads is to draw a “blanket” area load over the entire floor, and then draw the additional loads. There is no limit to the number of loadings than can be specified.
47.4.1 Define the typical live load 1. Choose Layers > Loadings > Live (Reducible) Loading > All Loads Plan. 2. Double click the Area Load tool ( ). 3. In the Default Area Load Properties dialog box: a. Change Fz to 40 psf and click OK. This tool will now draw area loads of 40 psf. 4. Define an area load over the entire slab by clicking four corners of a quadrilateral and then typing “c”. This shape need not match the slab’s exact dimensions, but should cover the slab.
47.4.2 Define the balcony live load 1. Turn on Snap to Intersection ( ). 2. Define an area load by snapping to the six vertices of the balcony (and then type c). In this situation, it is best for the load to match the balcony’s dimensions.
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PT Flat Plate Tutorial: ACI 318-08 Define the loads You have drawn another 40 psf load. This load should be highlighted as it is the current selection. If not, select it before proceeding by double-clicking with the selection tool. 3. Do either of the following: Select Edit > Selection Properties or right-click and choose Selection Properties 4. In the dialog box, change Fz to 60 psf and click OK. There is now a total live load on the balcony of 100 psf. Note: You could have drawn the 60 psf load by first changing the area load default properties and then using the tool.
Figure 257: Live (Reducible) Loading: All Loads Plan (showing the balcony area load).
Figure 258: Live (Reducible) Loading: All Loads Plan (with area loads hatching turned on).
47.4.3 Define the other dead loading 1. Choose Layers > Loadings > Live (Reducible) Loading > All Loads Plan. 2. With the Selection tool ( ), select both area loads (fencing the balcony load selects both loads). 3. Choose Edit > Copy. 4. Choose Layers > Loadings > Other Dead Loading > All Loads Plan. 5. Choose Edit > Paste. This pastes the live loads onto the Other Dead Loading: All Loads Plan, ready for editing.
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With the Selection tool ( ), select the “blanket” load by double clicking in the center of the floor. Right click on the plan and choose Selection Properties from the popup menu. In the Properties dialog box, change Fz to 20 psf, and click OK. Double-click the balcony load. The balcony load should be the only selected load. Right click on the plan and choose Selection Properties from the popup menu. In the Properties dialog box, change Fz to -20 psf, and click OK.
The balcony other dead load is now effectively zero.
Figure 259: Other Dead Loading: All Loads Plan (with area loads hatching turned on).
47.5 Define the post-tensioning Post-tensioning methodology varies from country to country. In the USA it is common to use the “banding” technique for detailing tendons in two-way slabs. Banding means concentrating the tendons over support points in one direction, and distributing them uniformly in the orthogonal direction. This method is generally used in conjunction with full-panel design strips. That is, column and middle strips are not used. Note: RAM Concept has two layers for tendons called latitude and longitude. Refer to “Using the latitude and longitude prestressing folders” for more information. Note: The tutorial in Chapter 49 explains the use of Strip Wizard to establish an estimate of the number of strands required for the critical band.
47.5.1 Define the manual latitude tendons Pt. 1 1. Choose Layers > Latitude Prestressing > Manual Latitude Tendon > Standard Plan. 2. Choose View > Visible Objects ( ). 3. Click the Drawing Import tab. 4. Click Show All, and click OK.
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Double click the Tendon Polyline tool ( ) to edit its default properties. 6. In the Default Tendon Properties dialog box: a. Set Strands per Tendon to 9. b. Set Profile at end 1 to 8.75 inches. c. Set Profile at end 2 to 1.25 inches, and click OK. Note: The one-inch cover to the half-inch diameter strand determines these profiles. 7. Turn on Snap to Intersection (
).
Proceed immediately to “Define the manual latitdue tendons Pt. 2”.
47.5.2 Define the manual latitude tendons Pt. 2 Complete the steps in “Define the manual latitude tendons Pt. 1” before proceeding. 1.
With the Tendon Polyline tool ( ) selected, draw a tendon along grid A: a. Click at the center of the column at grid intersection A-1. b. Click at the center of the column at A-2. c. Click at the center of the column at A-3. d. Right click, and then click Enter.
2.
Double click the Tendon Polyline tool ( ) to edit its default properties. 3. In the Default Tendon Properties dialog box: a. Set Strands per Tendon to 21, and click OK. 4. With the Tendon Polyline tool ( ) selected, draw a tendon along grid B: a. Click at the center of the column at grid intersection B-1. b. Click at the center of the column at B-2. c. Click at the center of the column at B-3. d. Click at the center of the column at B-5. e. Right click, and then click Enter. 5. With the Tendon Polyline tool ( ) selected, draw a tendon along grid C: a. Click at the center of the column at grid intersection B.8-1. b. Click at the center of the column at C-2. c. Click at the center of the column at C-3. d. Click at the center of the column at C-4. e. Right click, and then click Enter. The latitude tendons are drawn but you need to adjust a number of profile points. Any profile point at the end of a tendon should be at the mid-depth of the 10-inch slab.
Proceed immediately to “Define the namual latitdue tendons Pt. 3”.
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47.5.3 Define the manual latitude tendons Pt. 3 Complete the steps in “Define the manual latitude tendons Pt. 2” before proceeding. 1.
With the Selection tool ( ), select all of the terminated tendon segments, other than those over a drop cap, by: a. Double clicking at grid intersection B-1. b. Hold the key down and double click at B.8-1. c. Hold the key down and double click at C-4. d. Hold the key down and double click at D-2. e. Hold the key down and double click at D-4. 2. Right click on the plan and choose Selection Properties from the popup menu. 3. In the Properties dialog box, set Profile at end 1 to 5 inches and click OK. 4. With the Selection tool ( ), select all of the terminated tendon segments over a drop cap, by: a. Double clicking at grid intersection A-1. b. Hold the key down and double click at A-3. c. Hold the key down and double click at B-5. 5. Right click on the plan and choose Selection Properties from the popup menu. 6. In the Properties dialog box, set Profile at end 1 to 15 inches and click OK. Note: This sets the tendon anchorage profile to the centroid of the 10-inch slab, rather than the centroid of the drop cap. 7.
With the Selection tool ( ), double click the tendon segment at B-2. 8. Right click on the plan and choose Selection Properties from the popup menu. 9. In the Properties dialog box, set Profile at end 1 to 18.75 inches and click OK. 10. With the Selection tool ( ), double click the tendon segment at C-2. 11. Right click on the plan and choose Selection Properties from the popup menu. 12. In the Properties dialog box, set Profile at end 1 to 6.75 inches, and click OK. Note: This accounts for the step near this location. 13.
With the Selection tool (
), select the tendon segments between C-2 and C-3.
14.
Click the Calc Profile tool ( ). The Calc Tendon Profile dialog box appears and reports the current balance load is -2.58 kips/ft. If this is not the number then you probably selected only one tendon segment. 15. Click Cancel. Proceed immediately to “Define the namual latitdue tendons Pt. 4”.
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47.5.4 Define the manual latitude tendons Pt. 4 Complete the steps in “Define the manual latitude tendons Pt. 3” before proceeding. 1.
With the Selection tool (
), select the tendon between C-3 and C-4.
2.
Click the Calc Profile tool ( ). 3. Input the desired balance load as -2.6 kips/ft in the Calc Tendon Profile dialog box and click Calc. The low point (end 2) adjusts to 5.01 inches. 4. ), select all the end span tendons between grids 3 and 5. With the Selection tool ( 5. Right click on the plan and choose Selection Properties from the popup menu. 6. In the Properties dialog box, set Profile at end 2 to 5 inches, and click OK. Note: These steps first used the Calc Profile tool to determine a low point that produces a similar average uplift in an end span as the adjacent span, and then manually changed the low points for practical reasons.
Figure 260: Manual Latitude Tendon: Standard Plan
47.5.5 Define a latitude tendon polyline This example shows that the tendon generation can be mixed between the tendon parameters and manual tendon layers. In most cases you would use exclusively one or the other to work with tendons. 1. Choose Layers > Latitude Prestressing > Latitude Tendon Parameters. 2. Turn on Snap Orthogonal ( ). 3. Turn on Snap to Intersection ( ). 4. Double click the Banded Tendon Polyline tool ( ) to edit its default properties. 5. In the Default Banded Tendon Polyline Properties dialog box: a. Set Number of Strands to 9, and click OK. 6. With the Banded Tendon Polyline tool ( ) selected, draw a banded tendon polyline: a. Click at the center of the column at D-4.
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47.5.6 Define the latitude profile polylines 1. 2. 3.
4.
5.
6. 7. 8.
Double click the Profile Polyline tool ( ) to edit its default properties. In the Default Profile Polyline Properties dialog box: a. Set Elevation to 5 inches. Draw a profile polyline: a. Click at the top of the column intersection with column line 4 at D-4. b. Click at the bottom of the column intersection with line 4 at D-4. c. Right click and select Enter. Draw a profile polyline: a. Click at the top of the column intersection with column line 3 at D-3. b. Click at the bottom of the column intersection with line 3 at D-3. c. Right click and select Enter. Draw a profile polyline: a. Click at the corner of the slab at D-2. b. Type r0,-2. c. Right click and select Enter Select the profile polyline at D-3, right click and choose Selection Properties. Change the elevation to 1.25 inches. Select all 3 drawn profile polylines.
Choose the Generate Span Polylines tool ( ). 9. Set the Elevation to 1.25 inches, and click OK.
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Figure 261: Latitude Tendon Parameters: Standard Plan
47.5.7 Define the manual longitude tendons Pt. 1 1. Choose Layers > Longitude Prestressing > Manual Longitude Tendon > Standard Plan. 2. Turn on Snap to Intersection ( ). 3. Double click the Full-Span Tendon Panel tool ( ) to edit its default properties. 4. In the Default Tendon Properties dialog box: a. Set Strands per Tendon to 4. b. Set Profile at end 1 to 8.75 inches. c. Set Profile at end 2 to 1.25 inches, and click OK.
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With the Full-Span Tendon Panel tool ( ) selected, draw tendons in the bottom left panel: a. Click at the center of the column at grid intersection A-1. b. Click at the center of the column at B-1. c. Click at the center of the column at B-2. d. Click at the center of the column at A-2. 6. In the Tendon Panel dialog box: a. Set Tendon Spacing to Equal. b. Set Spacing to 6 feet, and click OK. Note: This spacing exceeds some code maxima, but the tendon layout is for design purposes and not necessarily for detailing. 7.
With the Full-Span Tendon Panel tool ( ) selected, draw tendons in the next panel: a. Click at the center of the column at grid intersection B-1. b. Click at the center of the column at B.8-1. c. Click at the center of the column at C-2. d. Click at the center of the column at B-2. 8. In the Tendon Panel dialog box: a. Set Auto Connect, and click OK. 9. Turn on Snap Nearest Snapable Point () and Snap Orthogonal ( ). Proceed immediately to “Define the manual longitude tendons Pt. 2”.
47.5.8 Define the manual longitude tendons Pt. 2 Complete the steps in “Define the manual longitude tendons Pt. 1” before proceeding. 1.
With the Half Span Tendon Panel tool ( ) selected, draw tendons in the balcony: a. Click at the center of the column at grid intersection B.8-1. b. Click at the edge of the slab at 0, 59 ft. c. Click at the tendon profile point at 24, 56.6 ft. Note: The snap orthogonal snaps the cursor to 24, 59 ft.
a. Click at the tendon profile point at 24, 56.6 ft. 2. In the Tendon Panel dialog box: a. Set Auto Connect, and click OK. 3. Right click on the plan and choose Selection Properties from the popup menu. 4. In the Properties dialog box, set Profile at end 1 to 6 inches and Profile at end 2 to 4 inches, and click OK. 5. With the Selection tool ( ), select the two shortest of the half-span (cantilever) tendon segments. 6. Right click on the plan and choose Selection Properties from the popup menu.
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With the Full-Span Tendon Panel tool ( ) selected, draw tendons in the next panel: a. Click at the center of the column at grid intersection A-2. b. Click at the center of the column at B-2. c. Click at the center of the column at B-3. d. Click at the center of the column at A-3. 9. In the Tendon Panel dialog box: a. Set Tendon Spacing to Equal. b. Set Spacing to 6 feet. c. Check Skip start tendon, and click OK. 10. With the Full-Span Tendon Panel tool ( ) selected, draw tendons in the next panel: a. Click at the center of the column at grid intersection B-2. b. Click at the center of the column at C-2. c. Click at the center of the column at C-3. d. Click at the center of the column at B-3. 11. In the Tendon Panel dialog box, click OK to accept the last choices. Alternatively, you could select Auto Connect, but you would have to uncheck Skip Start Tendon. Proceed immediately to “Define the manual longitude tendons Pt. 3”.
47.5.9 Define the manual longitude tendons Pt. 3 Complete the steps in “Define the manual longitude tendons Pt. 2” before proceeding. 1.
With the Full-Span Tendon Panel tool ( ) selected, draw tendons in the next panel: This sequence is counterclockwise. a. Click at the center of the column at grid intersection C-3. b. Click at the center of the column at D-3. c. Enter 31, 86 (feet). d. Turn off Snap Orthogonal ( ). e. Click at the center of the column at C-2. 2. In the Tendon Panel dialog box: a. Set Auto Connect. b. Uncheck Skip start tendon, and click OK. 3. With the Full-Span Tendon Panel tool ( ) selected, draw tendons in the next panel: a. Click at the center of the column at grid intersection B-3. b. Click at the center of the column at C-3. c. Click at the center of the column at C-4. d. Click at the center of the column at B-5. 4. In the Tendon Panel dialog box:
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PT Flat Plate Tutorial: ACI 318-08 Define the post-tensioning a. Set Layout to Splayed. b. Set Tendon Spacing to Equal. c. Set Spacing to 6 feet. d. Check Skip start tendon, and click OK. 5.
With the Full-Span Tendon Panel tool ( ) selected, draw tendons in the next panel: a. Click at the center of the column at grid intersection C-3. b. Click at the center of the column at D-3. c. Click at the center of the column at D-4. d. Click at the center of the column at C-4. 6. In the Tendon Panel dialog box: a. Set Auto Connect. b. Uncheck Skip start tendon, and click OK. Note: Auto-connect will ignore the tendons at the first click because there are already two tendon segments connected at that point.
The panel in the top right has too many tendons and some should be deleted. 7. Select the second tendon in this panel. 8. Hold down and select the fifth tendon in this panel, and press . 9. With the Half Span Tendon Panel tool ( ) selected, draw tendons that terminate in this panel: a. Turn on Snap Orthogonal ( ). b. Click at the profile point at 63.2, 58 ft. c. Type r0,7. d. Click at the last tendon profile point at 72.8, 58 ft. Note: The snap orthogonal snaps the cursor to 72.8, 65 ft. a. Click at the last tendon profile point at 72.8, 58 ft. Proceed immediately to “Define the manual longitude tendons Pt. 4”.
47.5.10 Define the manual longitude tendons Pt. 4 Complete the steps in “Define the manual longitude tendons Pt. 3” before proceeding. 1. In the Tendon Panel dialog box: a. Set Auto Connect, and click OK. 2. Right click on the plan and choose Selection Properties from the popup menu. 3. In the Properties dialog box, set Profile at end 2 to 5 inches, and click OK. The longitude tendons are drawn but you need to adjust a number of profile points. Any profile point at the end of a tendon should be at the mid-depth of the 10-inch slab. 4. With the Selection tool ( ), select all of the terminated tendon segments, other than those over a drop cap or within the balcony slab: a. Fence the tendon segments that end on grid A.
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PT Flat Plate Tutorial: ACI 318-08 Define the post-tensioning b. Hold the key down and repeat the procedure until you have selected all applicable end tendon segments (tendon segments terminating at grids B and D). 5. Right click on the plan and choose Selection Properties from the popup menu. 6. In the Properties dialog box, set Profile at end 1 to 5 inches and click OK. 7. With the Selection tool ( ), select all of the terminated tendon segments over a drop cap, by: a. Double clicking at grid intersection A-1. b. Hold the key down and double click at A-3. c. Hold the key down and double click at B-5. 8. Right click on the plan and choose Selection Properties from the popup menu. 9. In the Properties dialog box, set Profile at end 1 to 15 inches, and click OK. Note: This sets the tendon anchorage profile to the centroid of the 10-inch slab, rather than the centroid of the drop cap. 10.
With the Selection tool ( ), double click the tendon segment at B-2. 11. Right click on the plan and choose Selection Properties from the popup menu. 12. In the Properties dialog box, set Profile at end 1 to 18.75 inches and click OK. Finally, you need to move the tendon that goes through the opening. Proceed immediately to “Define the manual longitude tendons Pt. 5”.
47.5.11 Define the manual longitude tendons Pt. 5 Complete the steps in “Define the manual longitude tendons Pt. 4” before proceeding. 1.
With the Selection tool ( ), select the tendon segment that passes through the opening. 2. Choose the Move tool ( ). 3. Click anywhere on the plan, and type r-1.5,0. 4. With the Selection tool ( ), select the tendon segment above the moved tendon. 5. Choose the Stretch tool ( ). 6. Stretch the end of the tendon segment to meet the end of the moved tendon. 7. Repeat for the tendon segment below the moved tendon. Note: You could cut down the number of steps in moving the tendon from the opening by using the Utility tool. This combines the selection tool with move and stretch. Refer to “Expanding tool buttons” and “Using the Utility tool to move and stretch” for further information.
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Figure 262: Longitude Tendon: Standard Plan.
47.5.12 Replace some manual longitude tendons with a distributed tendon quadrilateral 1.
With the Selection tool ( ), select the tendons between lines 1 and 2, and press the delete button. 2. Choose Layers > Longitude Prestressing > Longitude Tendon Parameters. 3. Turn on Snap Orthogonal ( ). 4. Turn on Snap to Intersection ( ). 5. Double click the Distributed Tendon Quadrilateral tool ( ). a. Change the Tendon Orientation Angle to 90 degrees. b. Change the Number of Strands to 0.6667 /feet, and click OK. 6.
With the Distributed Tendon Quadrilateral tool (
) selected:
a. Click the corner of the slab at A-1. b. Click the corner of the slab at C-1. c. Click the center of the column at C-2. d. Click the edge of the slab at A-2.
47.5.13 Define the longitude profile polylines Pt. 1 1.
Double click the Profile Polyline tool ( ) to edit its default properties. 2. In the Default Profile Polyline Properties dialog box: a. Set Elevation to 5 inches. 3. Turn off Snap Orthogonal ( ). 4. Draw a profile polyline: a. Click at the intersection of the slab edge with line B.8 near line 1. b. Click at the center of the column at B.8-1. c. Click at the center of the column at C-2.
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PT Flat Plate Tutorial: ACI 318-08 Define the post-tensioning d. Right click and select Enter. 5. Draw a profile polyline: a. Click at the intersection of the slab edge with line B near line 1. b. Click at the center of the column at B-2. c. Right click and select Enter. 6. Draw a profile polyline: a. Click at the intersection of the slab edge with line A near line 1. b. Click at the center of the column at A-2. c. Right click and select Enter. Proceed immediately to “Define the longitude profile polylines Pt. 2”.
47.5.14 Define the longitude profile polylines Pt. 2 Complete the steps in “Define the longitude profile polylines Pt. 1” before proceeding. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12.
Choose the Move tool ( ). Hold down the key, click anywhere on the plan, and type r0,-0.75. Select the profile polyline between B-1 and B-2. Right click and choose Selection Properties. Change the elevation to 1.25 inches. Select the profile polyline between B.8-1 and C-2. Turn on Snap Nearest Snapable Point ( ) . Choose the Stretch tool ( ). Stretch the end of the profile polyline at C-2 to approximatley mid way between lines 1 and 2. Right click and choose Selection Properties. Change the Elevation Reference to Above Soffit and the Elevation to 6 inches, and click OK.
Choose the Profile Polyline tool ( ). 13. Turn off Snap Nearest Snapable Point ( 14. Turn on Snap to Point ( ).
).
Proceed immediately to “Define the longitude profile polylines Pt. 3”.
47.5.15 Define the longitude profile polylines Pt. 3 Complete the steps in “Define the longitude profile polylines Pt. 2” before proceeding. 1. Draw a profile polyline: a. Click at the end of the profile polyline point stretched to mid way between lines 1 and 2. b. Click at the center of the column at C-2. c. Right click and select Enter. 2. Right click and choose Selection Properties. 3. Change the Elevation Reference to Above Soffit and the Elevation to 4 inches, and click OK.
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PT Flat Plate Tutorial: ACI 318-08 Create the design strips 4. Select all four profile polylines on the longitude tendon parameters layer along lines C/B.8, B, and A. 5. Choose the Generate Span Polylines tool ( ). 6. Set the Elevation to 1.25 inches and the Span Orientation Angle to 90 degrees, and click OK. 7. Choose the Generate Tendons tool ( ) and inspect the generated tendons on the Generated Latitude Tendon and Generated Longitude Tendon layers.
Figure 263: Longitude Tendon Parameters: Standard Plan
47.6 Create the design strips Design strips are an essential part of RAM Concept because they link finite element analysis with concrete design. Their properties include reinforcement bar sizes, cover, and parameters that RAM Concept uses to determine which code rules are applicable for section design. There are two directions called Latitude and Longitude.
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47.6.1 Generate the latitude spans 1. Choose Layers > Design Strips > Latitude Design Spans Plan. 2. Double click the Span Segment tool ( ). The Default Span Properties dialog box opens to the Strip Generation properties. 3. Click the General tab. 4. Change Environment to Class U (corrosive). Note: This actually has no effect because ACI 318 requires two-way post-tensioned slabs to be designed as class U. Note: The Consider as Post-Tensioned box is already checked in the ACI 318 template. 5. 6. 7. 8. 9. 10.
Click the Column Strip tab. Set Cross Section Trimming to Max Rectangle. Change CS Top Cover to 1 inch. Change CS Code Min. Reinforcement Location to Elevated Slab. Click OK.
Click the Generate Spans tool ( ), or choose Process > Generate Spans. The Generate Spans dialog box opens with Spans to Generate set to Latitude. 11. Set Minimum Span Length to 2 feet and click OK. The span segments appear in the latitude direction.
Figure 264: Design Strip: Latitude Design Spans Plan. Two span segments are skewed. How you treat skewed strips is often a subjective matter, but in this tutorial we suggest one strip is straightened and the other edited in a different manner.
47.6.2 Generate the latitude strips 1. Click the Generate Strips tool ( ), or choose Process > Generate Strips. The design strips appear in the latitude direction.
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Figure 265: Latitude design strips (with hatching turned on). Some editing is now required. RAM Concept uses imperfect algorithms that do not always produce acceptable span segments and span segment strips, as shown in the following three figures. You can make corrections with a number of tools You can see this more easily if the strip hatching is turned on.
47.6.3 Hatch the strips 1.
Choose View > Visible Objects ( ). The Visible Objects dialog box will appear. 2. Check Hatching under Latitude Span Segment Strips, and click OK. Note: You can also right click to see a popup menu that includes the Visible Objects command.
Figure 266: Skewed span segment that snapped to end of wall
47.6.4 Straighten a span segment 1. 2. 3. 4. 5.
Select span segment 4-2 (between the wall and grid D3), as shown in the previous figure. Turn on Snap to Intersection ( ). Select the Rotate tool ( ). Click at the end of the span segment at grid D3. Click at the end of the span segment at the wall. The command line prompts Enter rotation end angle. 6. Enter 180 and press . The selected span segment is now horizontal.
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Figure 267: Diagonal strip that warrants manual improvement.
47.6.5 Edit the span cross section orientation 1. 2. 3. 4.
Select span segment 3-1 as shown in the previous figure. Select the Orient Span Cross Section tool ( ). Turn on Snap Orthogonal ( ). Click near the diagonal span strip and then again above or below the first click.
The orientation line half way along the span strip is now “vertical”.
Figure 268: Design strip with excessive width.
47.6.6 Draw a Span Boundary Polyline 1. 2. 3. 4.
Select the Span Boundary Polyline tool ( ). Click at the intersection of Grid B and Grid C design strips near Grid 3 (point A in the previous figure). Click to the right of the slab edge (point B). Right-click, and click enter.
47.6.7 Regenerate the latitude span strips 1. Click the Generate Strips tool (
).
The two edited spans produce improved span strips, as shown in the following figure.
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Figure 269: Design Strip: Latitude Design Strips Plan after strip regeneration.
47.6.8 Generate the longitude spans 1. Choose Layers > Design Strips > Longitude Design Spans Plan. 2. Double click the Span Segment tool ( ). 3. Click the Column Strip tab. The defaults set up in the Latitude Design Spans Plan will have remained the same. Since the cover cannot be the same for both directions, change it for the longitudinal direction. a. Change CS Top Cover to 1.63 inches. b. Change CS Bottom Cover to 1.25. c. Click OK. 4. Click the Generate Spans tool ( ), or choose Process > Generate Spans. 5. In the Generate Spans dialog box: a. Set Spans to Generate to Longitude. b. Click the “up-down” orientation button tool ( ). c. Click OK. The spans appear in the longitude direction, as shown in the following figure. One span segment on grid 2 is slightly skewed due to the column wall detail at C2. Another span segment overlays a wall and is unnecessary since the slab is continuously supported (see “Drawing design strips near walls” for discussion).
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Figure 270: Design Strip: Longitude Design Spans Plan. Related Links • Drawing design strips near walls (on page 263)
47.6.9 Straighten a span segment 1. 2. 3. 4. 5.
Select the span segment between grid B2 and C2 (the highlighted span segment in the previous figure). Turn on Snap to Intersection ( ). Select the Rotate tool ( ). Click at the end of the span segment at grid B2. Click at the end of the span segment at the wall. The command line prompts Enter rotation end angle. 6. Enter 90 and press . The selected span segment is now vertical.
47.6.10 Delete the span segment over the wall 1. Select the span segment that overlays the wall, and press .
47.6.11 Edit the span cross section orientation 1. 2. 3. 4.
Select the diagonal span segment between B-5 and C-4. Select the Orient Span Cross Section tool ( ). Turn on Snap Orthogonal ( ). Click near the diagonal span strip and then again to the left or right of the first click.
The orientation line half way along the span strip is now “horizontal”.
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47.6.12 Generate the longitude strips 1. Click the Generate Strips tool (
), or choose Process > Generate Strips.
The design strips appear in the longitude direction.
Figure 271: Design Strip: Longitude Design Spans Plan after strip generation.
47.6.13 Check for punching shear 1. Choose Layers > Design Strip > Punching Checks Plan. 2. Double click the Punching Shear Check tool ( ). 3. In the Default Punching Shear Check Properties dialog box: a. Change Cover to CGS to 1.63 inches (cover to centroid of top reinforcement). b. Click OK. 4. Fence the slab with the Punching Shear Check tool.
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Figure 272: Design Strip: Punching Checks Plan.
47.7 Regenerate the mesh The presence of design strips can significantly improve the regularity of the finite element mesh. We recommend that once you have completed the design strips, you regenerate the mesh. 1.
). Click Generate Mesh ( 2. Enter Element Size of 2.5 feet and click Generate.
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PT Flat Plate Tutorial: ACI 318-08 Calculate and view the results There is now a better mesh. View the mesh on the Element: Standard Plan.
Figure 273: Element: Standard Plan after regeneration.
47.8 Calculate and view the results After you run the model, you can view the results of the analysis and design calculations.
47.8.1 Review Calc Options 1. Choose Criteria > Calc Options. 2. Review the options, and click OK. Note: See “ Calculating the results (on page 350) ” for more information. Related Links • Calculating the results (on page 350)
47.8.2 Calculate 1. Click Calc All ( ), or choose Process > Calc All. An error message appears concerning a problem with a tendon out of the slab in strip 6C-2. 2. Click Continue three times to clear the error message. The source of the error messages must be investigated.
47.8.3 View the design strips with tendons 1. Choose Layers > Design Strips > Longitude Cross Sections Perspective.
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Choose View > Visible Objects ( ). 3. Click the Tendons tab. 4. Select the Longitude Tendons layer, check Tendons, and click OK. 5. Use the Rotate about X and Y axes tool ( ) and the Zoom Rectangle ( shown in the following two figures.
) tool to view the problem location
Figure 274: Longitude Cross Sections Perspective with longitude tendons visible.
Figure 275: Rotation and zoom-in of the problem location in the previous figure. The problem is that the cross sections are trimmed with the Max Rectangle setting. For span segment 6-2, that setting is causing a problem because of the combination of the drop cap and thinner balcony slab.
47.8.4 Edit span segment 6-2 1. Choose Layers > Design Strips > Longitude Design Spans Plan. 2. Choose View > Visible Objects ( ). 3. Check the Numbers box under Longitude Span Segments, and click OK. 4. Select span segment 6-2. 5. Right click on the plan and choose Selection Properties from the popup menu. 6. Click the Column Strip tab. 7. Change CS Cross Section Trimming to Inverted T or L, and click OK.
47.8.5 Recalculate 1. Click Calc All ( ), or choose Process > Calc All. RAM Concept completes the calculations without errors.
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PT Flat Plate Tutorial: ACI 318-08 Calculate and view the results See “Cross Section Trimming” for a thorough explanation of Cross Section trimming. Related Links • Cross Section Trimming (on page 233)
47.8.6 Design status Look at design status 1. Choose Layers > Design Status > Status Plan.
Figure 276: Design Status: Status Plan. This shows OK for all design strips. This means that there are no violations of code limits for ductility, flexural stress and one-way shear. Note that status does not flag excessive deflections. There are punching shear status results at each column. You can see these more easily on the dedicated punching plan. 2. Choose Layers > Design Status > Punching Shear Status Plan.
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PT Flat Plate Tutorial: ACI 318-08 Calculate and view the results RAM Concept has noted “Non-standard section” at six column locations and “OK with SSR” at one column. “Non-standard Section” is a warning, not an error. What it means is that at least one of the critical sections that RAM Concept is investigating for that column does not perfectly fit one of the three ACI 318-05 cases: interior, edge and corner. RAM Concept still calculates a stress ratio for non-standard sections. Refer to “NonStandard Sections: ACI 318 and CSA A23.3” in Chapter 29 for more information. Where the unreinforced stress ratio (USR) is less than 1.0, the column’s punching shear is satisfactory without any reinforcement (subject to the comments above concerning “Non-standard section”)). Stud shear reinforcement is required where RAM Concept reports “OK with SSR”. If RAM Concept reports “Failed” then SSR does not solve the problem and a thickening is required. Note: Choose Layers > Design Status > SSR Plan to view the stud shear reinforcement.
Figure 277: Design Status: Punching Shear Status Plan.
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47.8.7 Design reinforcement Look at design reinforcement 1. Choose Layers > Design Status > Reinforcement Plan.
Figure 278: Design Status: Reinforcement Plan. This shows all the code-determined reinforcement for each of the design strips. Since the slab is posttensioned, there is not much reinforcement. You might choose to view all design reinforcement on the one plan, or you can access plans in the Design Status layer that separate reinforcement according to: face (top or bottom) and direction (latitude or longitude). 2. Choose the plans that best convey the results without too much clutter.
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Figure 279: Design Status: Latitude Bottom Reinforcement Plan. The Reinforcement layer plans show detailed reinforcement. In particular, the top bars are rationalized so that the number is consistent each side of columns.
Look at detailed top reinforcement 1. Choose Layers > Reinforcement > Top Bars Plan.
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Figure 280: Reinforcement: Top Bars Plan
47.8.8 Concrete stresses ACI 318-05 has limits for the hypothetical stresses due to flexure and axial loads. The code bases the rules upon “averaging” rather than peak values. Stress contour plots of the net flexural stresses are available in RAM Concept. Most designers will not be interested in these plots because, in following the code, RAM Concept does not use the contours directly in design. What will likely be of interest are the plans that show the concrete stresses plotted along the design strips. These are the average stresses based upon the design strip widths. View top stress plan 1. Choose Layers > Rule Set Designs > Service Design > Top Stress Plan.
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Right click over the plan and choose Plot ( 3. In the Plot Settings dialog box: a. Change Max Frame # to 4. b. Click OK
).
Figure 281: Service Design: Top Stress Plan. To view the Max Demand more easily you can uncheck Max Capacity in the plot options. Similarly, you can view the bottom stress plan at Layers > Rule Set Designs > Service Design > Bottom Stress Plan.
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47.8.9 Deflection Usually you are interested in short-term and long-term deflections. Load history deflections can be used to evaluate both.
Calculate Load History Deflections 1. Click Calc Load History Deflections (
), or choose Process > Calc Load History Deflections.
The Maximum Short Term Load, Sustained Load, and Final Instantaneous Load History Deflection Layers provide contour plans for deflection.
View maximum short term load deflection 1. Choose Layers > Load History Deflections > Maximum Short Term Load > Std Deflection Plan.
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Figure 282: Maximum Short Term Load: Deflection Plan. 2.
Right click over the plan and choose Plot (
) to change Plot Type from Color Contour to Contour.
View sustained deflection 1. Choose Layers > Load History Deflections > Sustained Load > Std Deflection Plan.
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Figure 283: Sustained Load: Deflection Plan.
47.8.10 Bending Moments While it is not necessary to view bending moments, it can be useful, especially for irregular structures. Even though principal moments are important, the default moment contours plans are for Mx (moment about the xaxis) and My. This is because most designers detail reinforcement orthogonally, and the directions are usually the x- and y-axes. You can view moments about any axes, including the principal axes. It is not particularly easy to assess the moment contours. This is why Plot Distribution Tools are so useful.
View Factored LC Moments 1. Choose Layers > Load Combinations > Factored LC: 1.2D + 1.6L + 0.5Lr > Mx Plan. The Mx contours should be visible. 2. Turn on Snap Orthogonal ( ) 3. Click the Selected Plot Distribution tool ( ).
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PT Flat Plate Tutorial: ACI 318-08 Calculate and view the results 4. Click first at grid intersection B-3, and then click at grid intersection D-3. This shows the bending moment shape along the line you have drawn. 5. While pressing the key, click at grid intersection B-1, and then click at grid intersection B-3. This shows how Mx varies across the panel, and highlights the approximate nature of the ACI318-05 posttension design method. See “Section distribution plots” for more information.
Figure 284: Factored LC: 1.2D + 1.6L + 0.5Lr: Mx Plan showing use of Plot Distribution tool. Related Links • Section distribution plots (on page 372)
View the balanced load percentages 1. Choose Layers > Design Strips > Latitude Design Strips Plan. 2. Choose View > Visible Objects ( ). 3. Choose “Balanced Load Percentages” in the Visible Objects dialog box and click OK. See “Calculating the balanced load percentages” for more information. Related Links • Calculating the balanced load percentages (on page 801)
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PT Flat Plate Tutorial: AS3600-2001 This chapter describes the steps for modeling a post-tensioned two-way flat plate with uniform loads. The objective of this tutorial is to build on the skills learned in the Chapter 41 RC tutorial and introduce new steps, such as using a CAD drawing and post-tensioning. Some tools and methods described in the RC tutorial are not used here. As such, it is highly recommended that you first do the RC tutorial. This is not a particularly “aggressive” design. After you have completed the tutorial, you may wish to make the slab thinner to investigate the ramifications. You could also use this as a reinforced concrete tutorial by making a few adjustments (for example, a thicker slab).
48.1 For information on creating a new file, see Creating and opening files (on page 51).
48.2 Import the CAD drawing The CAD file you import is located in your RAM Concept program directory. Import the CAD file 1. Choose File > Import Drawing. 2. Select the CAD drawing file flat_plate_metric.dwg. The File Units dialog box appears. 3. Select Millimeters (the units used in the CAD file) and click OK.
48.3 Define the structure To use the CAD file you need to make it visible on the Mesh Input layer.
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48.3.1 Show the drawing on the mesh input layer 1. Choose Layers > Mesh Input > Standard Plan. 2. Choose View > Visible Objects ( ). Note: You can also right click to see a popup menu that includes the Visible Objects command. 3. Click the Drawing Import tab. 4. Click Show All, and then click OK.
48.3.2 Draw the slab area 1. Turn on Snap to Intersection ( ) and Snap to Point ( ). 2. Double click the Slab Area tool ( ) to edit the default properties. 3. In the Default Slab Area Properties dialog box: a. Choose a Concrete Strength of 32 MPa. b. Set Thickness to 250 mm. c. Leave Surface Elevation as 0 and Priority as 1. d. Click OK. 4. With the Slab Area tool ( ) selected, define the 10 vertices of the slab outline by snapping to the imported drawing’s slab corners. There are two vertices near each other near B-5 at 26.05, 8.2 m and 26.05, 8.8 m. Cursor plan coordinates display next to the command prompt. 5. Complete the polygon by clicking at your starting point (or type “c” in the command line and press ).
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Figure 285: The slab outline on the Mesh Input: Standard Plan.
48.3.3 Draw the balcony slab area 1.
) to edit the default properties. Double click the Slab Area tool ( 2. In the Default Slab Area Properties dialog box:
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PT Flat Plate Tutorial: AS3600-2001 Define the structure a. Change Thickness to 200 mm. b. Change Surface Elevation to -50 mm. c. Change the Priority to 2, and click OK. 3.
With the Slab Area tool ( ) selected, define the six vertices of the balcony outline by clicking at each vertex, and then click at your starting point (or type “c” in the command line and press ).
Figure 286: The balcony slab on the Mesh Input: Standard Plan.
48.3.4 Draw the drop caps 1.
Double click the Slab Area tool ( ) to edit the default properties. 2. In the Default Slab Area Properties dialog box: a. Change Thickness to 500 mm. b. Change Surface Elevation to 0, and leave the Priority as 2. c. Click OK. 3. With the Slab Area tool ( ) selected, define the four drop caps with four or five vertices as appropriate. 4. Go to “Draw the opening:”, or try the next method 5. With the Selection tool ( ), select (by double-clicking) and delete the drop cap at B-2.
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).
Some tool button icons have a small triangle in the lower right corner ( ). This indicates that there are other similar tools available for this button. 7. 8. 9. 10. 11.
Place the mouse over the Slab Area tool ( ) and press down on the left mouse button for one second. A pop-up menu appears. Select the Drop Cap tool from the menu. The selected tool becomes current for that button. Click at the column at B-2. A Drop Cap Tool dialog box appears. Enter an angle of zero degrees. Enter a side dimension of 1.2 m and click OK.
48.3.5 Draw the opening 1.
). Select the Slab Opening tool ( 2. Define the four corners of the opening by clicking at each location, and then click at your starting point.
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Figure 287: The opening on the Mesh Input: Standard Plan.
48.3.6 Hatch the slab areas 1.
Choose View > Visible Objects ( ). The Visible Objects dialog box will appear. 2. Check “Hatching” under “Slab Areas”. 3. Check “Hatching” under “Slab Openings”, and then click OK. Note: You can also right click to see a popup menu that includes the Visible Objects command.
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48.3.7 Define the column locations and properties 1.
Double click on the Column tool ( ). 2. In the Default Column Properties dialog box: a. Choose a Concrete Strength of 32 MPa. b. Set Width to 600 mm. c. Set Depth/Diameter to 600 mm. 3. Click OK. 4. Click at the center of all 13 column locations shown on the imported drawing.
48.3.8 Define the wall location and properties 1. Turn on Snap Orthogonal ( ). 2. Double click on the Wall tool ( ). 3. In the Default Wall Properties dialog box: a. Choose a Concrete Strength of 20 MPa. 4. Click OK. 5. Define the wall by clicking at the start and end points, on the centerline: a. Place the cursor near 8.825, 26.3 m and it will snap to where the center of the wall intersects the edge of the slab, and click. b. Place the cursor at the center of the column at C-2 (it will snap orthogonally) and click. You have now defined the structure but the element mesh does not yet exist. 6. Go to “ Generate the mesh: ”, or try the next method. 7. The wall should be highlighted as it is the current selection. If not, select it by double-clicking and press . 8. Click Redraw ( ). 9. Place the mouse over the Wall tool ( ) and press down on the left mouse button for one second. A pop-up menu appears. 10. Select the Left Wall tool from the menu. 11. Click at the extreme corner of the slab near D-2. 12. Click at Grid C, near C-2.
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Figure 288: After defining the slab, the Mesh Input: Standard Plan shows the slab areas and opening (hatched), the columns and the wall.
48.3.9 Generate the mesh 1.
). Click Generate Mesh ( 2. In the Generate Mesh dialog box set the Element Size to 1 m.
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48.3.10 View the mesh 1. Choose Layers > Element > Standard Plan. You will now see a somewhat random mesh. This will still produce reasonable results, but will significantly improve when you regenerate it later on.
Figure 289: Element: Standard Plan.
48.3.11 View the structure 1. Choose Layers > Element > Structure Summary Perspective. 2. Use the Rotate about x- and y-axes tool ( ) to rotate the floor. 3. Click the Set Print Viewpoint tool ( ). Upon returning to this perspective, you can look at the saved view by clicking Show Set Viewpoint (
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Figure 290: Element: Structure Summary Perspective.
48.4 Define the loads RAM Concept calculates the concrete self-weight automatically. RAM Concept uses superposition of loads. The easiest way to define areas with increased area loads is to draw a “blanket” area load over the entire floor, and then draw the additional loads. There is no limit to the number of loadings than can be specified.
48.4.1 Define the typical live load 1. Choose Layers > Loadings > Live (Reducible) Loading > All Loads Plan. 2. Double click the Area Load tool ( ). 3. In the Default Area Load Properties dialog box: a. Change Fz to 2 kN/m2 and click OK. This tool will now draw area loads of 2 kN/m2. 4. Define an area load over the entire slab by clicking four corners of a quadrilateral and then typing “c”. This shape need not match the slab’s exact dimensions, but should cover the slab.
48.4.2 Define the balcony live load 1. Turn on Snap to Intersection ( ). 2. Define an area load by snapping to the six vertices of the balcony (and then type “c”). In this situation, it is best for the load to match the balcony’s dimensions.
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PT Flat Plate Tutorial: AS3600-2001 Define the loads You have drawn another 2 kN/m2 load. This load should be highlighted as it is the current selection. If not, select it before proceeding by double-clicking with the selection tool. 3. Choose Edit > Selection Properties, or right-click and choose Selection Properties. 4. In the dialog box, change Fz to 3 kN/ m2 and click OK. There is now a total live load on the balcony of 5 kN/ m2. Note: You could have drawn the 3 kN/ m2 load by first changing the area load default properties and then using the tool.
Figure 291: Live (Reducible) Loading: All Loads Plan (showing the balcony area load).
Figure 292: Live (Reducible) Loading: All Loads Plan (with area loads hatching turned on).
48.4.3 Define the other dead loading 1. Choose Layers > Loadings > Live (Reducible) Loading > All Loads Plan. 2. With the Selection tool ( ), select both area loads (fencing the balcony load selects both loads). 3. Choose Edit > Copy. 4. Choose Layers > Loadings > Other Dead Loading > All Loads Plan. 5. Choose Edit > Paste. This pastes the live loads onto the Other Dead Loading: All Loads Plan, ready for editing. 6. With the Selection tool ( ), select the “blanket” load by fencing the entire area. 7. Right click on the plan and choose Selection Properties from the popup menu. 8. In the Properties dialog box, change Fz to 1 kN/ m2, and click OK. 9. Double-click the balcony load.
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PT Flat Plate Tutorial: AS3600-2001 Define the post-tensioning The balcony load should be the only selected load. 10. Right click on the plan and choose Selection Properties from the popup menu. 11. In the Properties dialog box, change Fz to -1 kN/ m2, and click OK. The balcony other dead load is now effectively zero.
Figure 293: Other Dead Loading: All Loads Plan (with area loads hatching turned on).
48.5 Define the post-tensioning Post-tensioning methodology varies from country to country. In Australia, engineers use column and middle strips for post-tensioned flat plate design, and, generally, detail (bonded) tendons in both the column and middle strips. Note: RAM Concept has two layers for tendons called latitude and longitude. Refer to “Using the latitude and longitude prestressing folders” for more information. Note: The tutorial in Chapter 49 explains the use of Strip Wizard to establish an estimate of the number of strands required for the critical band. Note: For use of the tendon parameters layers as an alternative and perhaps quicker means of defining prestressing, please refer to “PT Flat Plate Tutorial: ACI 318-08”.
48.5.1 Define the manual latitude tendons Pt. 1 1. Choose Layers > Latitude Prestressing > Latitude Tendon > Standard Plan. 2. Choose View > Visible Objects ( ). 3. Click the Drawing Import tab. 4. Click Show All, and then click OK. Showing the CAD file makes the following instructions easier to follow. 5. Double click the Full Span Tendon Panel tool ( ) to edit its default properties.
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PT Flat Plate Tutorial: AS3600-2001 Define the post-tensioning 6. In the Default Tendon Properties dialog box: a. Set Strands per Tendon to 4. b. Set Profile at end 1 to 212 mm. c. Set Profile at end 2 to 38 mm, and click OK. Note: The 25 mm cover to the 19 mm high duct (containing 12.7 mm diameter strand) determines these profiles. 7. Turn on Snap to Intersection (
) and Snap Orthogonal (
).
Proceed immediately to “Define the manual latitude tendons Pt. 2”.
48.5.2 Define the manual latitude tendons Pt. 2 Complete the steps in “Define the manual latitude tendons Pt. 1” before proceeding. 1.
With the Full Span Tendon Panel tool ( ) selected, draw tendons in the bottom left panel: a. Click at the center of the column at grid intersection A-1. b. Click at the center of the column at A-2. c. Click at the center of the column at B-2. d. Click at the center of the column at B-1. 2. In the Tendon Panel dialog box: a. Set Tendon Spacing to Equal. b. Set Spacing to 2 m, and click OK. 3. With the Full Span Tendon Panel tool ( ) selected, draw tendons in the next panel: a. Click at the center of the column at grid intersection B-1. b. Click at the center of the column at B-2. c. Click at the center of the column at C-2. d. Click at the grid intersection C-1. 4. In the Tendon Panel dialog box: a. Set Tendon Spacing to Equal. b. Set Spacing to 2 m, c. Check Skip start tendon, and click OK. 5. ) selected, draw tendons in the next two panels: With the Full-Span Tendon Panel tool ( a. Click at the center of the column at grid intersection A-2. b. Click at the center of the column at A-3. c. Click at the center of the column at C-3. d. Click at the center of the column at C-2. 6. In the Tendon Panel dialog box: a. Set Auto Connect. b. Uncheck Skip start tendon, and click OK. 7. Turn off Snap Orthogonal ( ). 8. ) selected, draw tendons in the next panel: With the Full-Span Tendon Panel tool (
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PT Flat Plate Tutorial: AS3600-2001 Define the post-tensioning a. Click at the center of the column at grid intersection B-3. b. Click at the center of the column at B-5. c. Click at the center of the column at C-4. d. Click at the center of the column at C-3. 9. In the Tendon Panel dialog box: a. Set Auto Connect, and click OK. 10. With the Full-Span Tendon Panel tool ( ) selected, draw tendons in the next panel: a. Click at the center of the column at grid intersection C-2. b. Click at the center of the column at C-3. c. Click at the center of the column at D-3. d. Click at grid intersection D-2. 11. In the Tendon Panel dialog box: a. Set Tendon Spacing to Equal. b. Set Spacing to 2 m. c. Check Skip start tendon, and click OK. 12. With the Full-Span Tendon Panel tool ( ) selected, draw tendons in the next panel: a. Click at the center of the column at grid intersection C-3. b. Click at the center of the column at C-4. c. Click at the center of the column at D-4. d. Click at the center of the column at D-3. 13. In the Tendon Panel dialog box: a. Set Auto Connect. b. Uncheck Skip start tendon, and click OK. Note: Auto-connect will ignore the tendons at the first click because there are already two tendon segments connected at that point. Proceed immediately to “Define the manual latitude tendons Pt. 3”.
48.5.3 Define the manual latitude tendons Pt. 3 Complete the steps in “Define the manual latitude tendons Pt. 2” before proceeding. 1. 2. 3. 4. 5. 6. 7.
With the Select Connected Tendons tool ( ) selected, double-click the tendon on grid B. Right click on the plan and choose Selection Properties from the popup menu. In the Properties dialog box, change Strands Per Tendon to 10, and click OK. With the Select Connected Tendons tool ( ) selected, double-click the tendon directly above grid B. Hold down and double-click the tendon directly below grid B. Right click on the plan and choose Selection Properties from the popup menu. In the Properties dialog box, change Strands Per Tendon to 5, and click OK. The latitude tendons are drawn but you need to adjust a number of profile points. Any profile point at the end of a tendon should be at the mid-depth of the 250 mm slab.
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With the Selection tool ( ), select all of the terminated tendon segments, other than those over a drop cap or within the balcony slab: a. Fence the tendon segments that end on grid 1. b. Hold the key down and repeat the procedure until you have selected all applicable end tendon segments (tendon segments terminating at grids 2, 3, 4 and 5).
Proceed immediately to “Define the manual latitude tendons Pt. 4”.
48.5.4 Define the manual latitude tendons Pt. 4 Complete the steps in “Define the manual latitude tendons Pt. 3” before proceeding. 1. Right click on the plan and choose Selection Properties from the popup menu. 2. In the Properties dialog box, set Profile at end 1 to 125 mm and click OK. 3. With the Selection tool ( ), double click the tendon segment above B.8-1 that terminates within the 200 mm balcony slab. 4. Right click on the plan and choose Selection Properties from the popup menu. 5. In the Properties dialog box, set Profile at end 1 to 100 mm and click OK. 6. ), select all of the tendon segments that terminate over a drop cap, by: With the Selection tool ( a. Double clicking at grid intersection A-1. b. Hold the key down and double click at A-3. c. Hold the key down and double click at B-5. 7. Right click on the plan and choose Selection Properties from the popup menu. 8. In the Properties dialog box, set Profile at end 1 to 375 mm and click OK. Note: This sets the tendon anchorage profile to the centroid of the 250 mm slab, rather than the centroid of the drop cap. Proceed immediately to “Define the manual latitude tendons Pt. 5”.
48.5.5 Define the manual latitude tendons Pt. 5 Complete the steps in “Define the manual latitude tendons Pt. 4” before proceeding. 1.
With the Selection tool ( ), double click the tendon segment at B-2. 2. Right click on the plan and choose Selection Properties from the popup menu. 3. In the Properties dialog box, set Profile at end 1 to 462 mm and click OK. 4. ), double click the tendon segment at C-2. With the Selection tool ( 5. Hold down the key, and double click the tendon segment immediately below (profile point at (9,15.7)). 6. Right click on the plan and choose Selection Properties from the popup menu. 7. In the Properties dialog box, set Profile at end 1 to 162 mm and click OK.
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With the Selection tool (
), select the tendon segments between D-2 and D-3.
9.
Click the Calc Profile tool ( ). The Calc Tendon Profile dialog box appears and reports the current balance load is -5.67 kN/m. If this is not the number then you probably selected only one tendon segment. 10. Click Cancel. Proceed immediately to “Define the manual latitude tendons Pt. 6”.
48.5.6 Define the manual latitude tendons Pt. 6 Complete the steps in “Define the manual latitude tendons Pt. 5” before proceeding. 1.
With the Selection tool (
), select the tendon between C-3 and C-4.
2.
Click the Calc Profile tool ( ). 3. Input the desired balance load as -6 kN/m in the Calc Tendon Profile dialog box and click Calc. The low point (end 2) adjusts to 126 mm. 4. With the Selection tool ( ), select all the end span tendons between grids 3 and 5. 5. Right click on the plan and choose Selection Properties from the popup menu. 6. In the Properties dialog box, set Profile at end 2 to 125 mm and click OK. Note: These steps first used the Calc Profile tool to determine a low point that produces a similar average uplift in an end span as the adjacent span, and then manually changed the low points for practical reasons. Finally, you need to adjust the tendon that goes through the opening. 7. Turn on Snap Nearest Snapable Point ( ) and Snap Orthogonal ( ). 8. ), select the tendon segment that passes through the opening. With the Selection tool ( 9. Right click on the plan and choose Selection Properties from the popup menu. 10. In the Properties dialog box, set Profile at end 1 to 125 mm and click OK. 11. Choose the Stretch tool ( ). 12. With the one tendon segment selected, stretch the profile point at grid 3 to the other side of the opening. Note: The Snap Nearest Snapable Point snaps the cursor to the edge of the opening.
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Figure 294: Manual Latitude Tendon: Standard Plan.
48.5.7 Define the longitude tendons Pt. 1 1. Choose Layers > Longitude Prestressing > Manual Longitude Tendon > Standard Plan. Note: The defaults set up in the Latitude Tendon Plan remain the same. Strictly speaking, you should adjust Profile at end 1 at columns (to avoid a clash with latitude tendons) but you can ignore for this tutorial. 2. Turn on Snap to Intersection ( ). 3. ) selected, draw tendons in the bottom left panel: With the Full-Span Tendon Panel tool ( a. Click at the center of the column at grid intersection A-1. b. Click at the center of the column at B-1. c. Click at the center of the column at B-2. d. Click at the center of the column at A-2. 4. In the Tendon Panel dialog box: a. Set Tendon Spacing to Equal. b. Set Spacing to 2 m, and click OK. 5. With the Full-Span Tendon Panel tool ( ) selected, draw tendons in the next panel: a. Click at the center of the column at grid intersection B-1. b. Click at the center of the column at B.8-1. c. Click at the center of the column at C-2. d. Click at the center of the column at B-2. 6. In the Tendon Panel dialog box: a. Set Auto Connect, and click OK. 7. Turn on Snap Nearest Snapable Point ( ) and Snap Orthogonal ( ). 8. With the Half Span Tendon Panel tool ( ) selected, draw tendons in the balcony: a. Click at the center of the column at grid intersection B.8-1. b. Click at the edge of the slab at 0, 17.8 m. c. Click at the tendon profile point at 7.2, 17.1 m. Note: The snap orthogonal snaps the cursor to 7.2, 17.8 m.
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PT Flat Plate Tutorial: AS3600-2001 Define the post-tensioning a. Click at the tendon profile point at 7.2, 17.1 m. 9. In the Tendon Panel dialog box: a. Set Auto Connect, and click OK. Proceed immediately to “Define the longitude tendons Pt. 2”.
48.5.8 Define the longitude tendons Pt. 2 Complete the steps in “Define the longitude tendons Pt. 1” before proceeding. 1. Right click on the plan and choose Selection Properties from the popup menu. 2. In the Properties dialog box, set Profile at end 1 to 150 mm and Profile at end 2 to 100 mm, and click OK. 3. With the Selection tool ( ), select the two shortest of the half-span (cantilever) tendon segments. 4. Right click on the plan and choose Selection Properties from the popup menu. 5. In the Properties dialog box, set Profile at end 1 to 100 mm, and click OK. Note: This makes the short tendon segments flat. 6.
With the Full-Span Tendon Panel tool ( ) selected, draw tendons in the next panel: a. Click at the center of the column at grid intersection A-2. b. Click at the center of the column at B-2. c. Click at the center of the column at B-3. d. Click at the center of the column at A-3. 7. In the Tendon Panel dialog box: a. Set Tendon Spacing to Equal. b. Set Spacing to 2 m. c. Check Skip start tendon, and click OK. 8. With the Full-Span Tendon Panel tool ( ) selected, draw tendons in the next panel: a. Click at the center of the column at grid intersection B-2. b. Click at the center of the column at C-2. c. Click at the center of the column at C-3. d. Click at the center of the column at B-3. 9. In the Tendon Panel dialog box, click OK to accept the last choices. Alternatively, you could select Auto Connect, but you would have to uncheck Skip Start Tendon. Proceed immediately to “Define the longitude tendons Pt. 3”.
48.5.9 Define the longitude tendons Pt. 3 Complete the steps in “Define the longitude tendons Pt. 2” before proceeding. 1.
With the Full-Span Tendon Panel tool (
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PT Flat Plate Tutorial: AS3600-2001 Define the post-tensioning Note: This sequence is anti-clockwise. a. Click at the center of the column at grid intersection C-3. b. Click at the center of the column at D-3. c. Enter 9.25, 26, and press . d. Turn off Snap Orthogonal ( ). e. Click at the center of the column at C-2. 2. In the Tendon Panel dialog box: a. Set Auto Connect. b. Uncheck Skip Start Tendon, and click OK. 3. ) selected, draw tendons in the next panel: With the Full-Span Tendon Panel tool ( a. Click at the center of the column at grid intersection B-3. b. Click at the center of the column at C-3. c. Click at the center of the column at C-4. d. Click at the center of the column at B-5. 4. In the Tendon Panel dialog box: a. Set Layout to Splayed. b. Set Tendon Spacing to Equal. c. Set Spacing to 1.8 m. d. Check Skip start tendon, and click OK. 5. With the Full-Span Tendon Panel tool ( ) selected, draw tendons in the next panel: a. Click at the center of the column at grid intersection C-3. b. Click at the center of the column at D-3. c. Click at the center of the column at D-4. d. Click at the center of the column at C-4. 6. In the Tendon Panel dialog box: a. Set Auto Connect. b. Uncheck Skip start tendon, and click OK. Note: Auto-connect will ignore the tendons at the first click because there are already two tendon segments connected at that point. The panel in the top right has too many tendons and some should be deleted. 7.
With the Selection tool ( ), select the second tendon in this panel. 8. Hold down and select the fifth tendon, and press . Proceed immediately to “Define the longitude tendons Pt. 4”.
48.5.10 Define the longitude tendons Pt. 4 Complete the steps in “Define the longitude tendons Pt. 3” before proceeding. 1.
With the Half Span Tendon Panel tool (
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PT Flat Plate Tutorial: AS3600-2001 Define the post-tensioning a. Turn on Snap Orthogonal ( ). b. Click at the profile point at 19, 17.5 m. c. Type r0,2.1. d. Click at the last tendon profile point at 22, 17.5 m. Note: The snap orthogonal snaps the cursor to 22, 19.6 m. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.
a. Click at the last tendon profile point at 22, 17.5 m. In the Tendon Panel dialog box: a. Set Auto Connect, and click OK. Right click on the plan and choose Selection Properties from the popup menu. In the Properties dialog box, set Profile at end 2 to 125 mm, and click OK. With the Select Connected Tendons tool ( ) selected, double-click the tendon on grid 2. Right click on the plan and choose Selection Properties from the popup menu. In the Properties dialog box, change Strands Per Tendon to 10, and click OK. With the Select Connected Tendons tool ( ) selected, double-click the tendon directly to the left of grid 2. Hold down and double-click the tendon directly to the right of grid 2. Right click on the plan and choose Selection Properties from the popup menu. In the Properties dialog box, change Strands Per Tendon to 5, and click OK. The longitude tendons are drawn but you need to adjust a number of profile points. Any profile point at the end of a tendon should be at the mid-depth of the 250 mm slab.
Proceed immediately to “Define the longitude tendons Pt. 5”.
48.5.11 Define the longitude tendons Pt. 5 Complete the steps in “Define the longitude tendons Pt. 4” before proceeding. 1.
With the Selection tool ( ), select all of the terminated tendon segments, other than those over a drop cap or within the balcony slab: a. Fence the tendon segments that end on grid A. b. Hold the key down and repeat the procedure until you have selected all applicable end tendon segments (tendon segments terminating at grids B and D). 2. Right click on the plan and choose Selection Properties from the popup menu. 3. In the Properties dialog box, set Profile at end 1 to 125 mm and click OK. 4. With the Selection tool ( ), select all of the terminated tendon segments over a drop cap, by: a. Double clicking at grid intersection A-1. b. Hold the key down and double click at A-3. c. Hold the key down and double click at B-5. 5. Right click on the plan and choose Selection Properties from the popup menu. 6. In the Properties dialog box, set Profile at end 1 to 375 mm, and click OK. This sets the tendon anchorage profile to the centroid of the 250 mm slab, rather than the centroid of the drop cap. 7. With the Selection tool ( ), double click the tendon segment at B-2.
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PT Flat Plate Tutorial: AS3600-2001 Create the