Method Statement For Taxiway Edge Lights & Manholes [PDF]

Zitiervorschau

EMPLOYER :

SUPERVISION CONSULTANT : The Royal Estates Royal Court Affairs Sultanate of Oman

CONTRACT No. : DPN/22/14

CONTRACTOR : Al Watanyiah United Engineering & Contracting Co. LLC

COWI & Partners LLC

PROJECT : ROYAL FLIGHT, SEEB – REHABILITATION OF APRONS

METHOD STATEMENT FOR RELOCATION OF TAXIWAY EDGE LIGHTS & MANHOLES (Reference Number: RFSRA/MS/018, Rev. 0)

Revision Status:

Date

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Initial issue.

Rev. No.

Description

Prepared by

Reviewed by

Approved by Page 1 of 7

Relocation of Taxiway Edge Lights and Manholes

RFSRA/MS/017,R0

1. Purpose: The purpose of this method statement is to outline the procedures to be followed for the Relocation of existing Edge Lights and Manholes, and the measures to be adopted for the safe and systematic completion of the activity.

2. Scope: The scope of the work includes the Relocation of existing Edge Lights and Manholes in Taxi ways R1, R2, R3 & R4 as per approved construction drawings.

3. References: The following documents shall be referred: o

Project specification

o

Approved construction/ shop drawings

4. Responsibilities Site Engineer 

Managing the execution of construction plans using the specified resources and equipment, planning and following up day-to-day activities and programs.

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Supervising all on-site operations and ensuring its implementation in alignment with the project plans and within the specified budget.

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Ensuring that all operations are being held as per the standard construction methods and procedures and complies with standards and regulations, and taking all safety precautions, permits and licenses prior to work execution.

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Leading the completion of all required tasks on time and requesting modifications in plans and schedules when needed. Making sure that all discrepancies and nonconformities are being resolved and reporting any obstacles or conflicts to the concerned parties.

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Managing the implementation of construction method statements, reviewing all correspondence and ensuring that all construction related documents are being properly maintained and available when needed.

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Responsible to ensure that all people at site adhere with HSE requirement.

QA/QC Engineer 

Liaison with Consultants, Project Manager, Site Engineers and Supervisors for inspection and work progress.

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Implementation of QA/QC activities in accordance with approved QCP/ITPs and Procedures, method statements and other contract documents.

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Provide sufficient feedback to Project Manager on the day to day quality issues.

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Initiate timely corrective action and preventive actions on NCR/Client complaints.

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Ensure the materials used are approved by Engineer and satisfy the requirements and specifications.

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Performing regular inspections on activities engaged in quality control testing of materials and/ or finished work in an efficient and cost conscious manner for the purpose of ensuring their compliance with the set quality standards.

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Relocation of Taxiway Edge Lights and Manholes

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RFSRA/MS/017,R0

Co-ordinate with execution team during testing of materials/works and recommend necessary corrective and preventive action to control the non-conforming products/works.

HSE Officer 

Assist Project Manager in all aspect of HSE compliance as per contract.

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Advising and ensuring that the safety procedures for all works are according to contract HSE requirement.

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Conducting tool box meeting / talk at the work front.

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Investigating and reporting of any accidents / risk involving occurrence at site.

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Identify safety training needs.

5. Procedure

5.1. Preparatory works.   Setting out survey shall be carried out to mark the new Manhole locations and duct bank routs.   Shop drawings of new Manholes and duct bank shall be prepared and submitted to the consultant for approval.  Initial testing on Taxiway Edge lights to assess the working condition shall be carried out by competent person.   The working perimeter shall be secured well with proper hard barricades. 5.2. Edge Lights and Transformer Removal.   All the electrical connections to the existing Taxiway Edge lights and transformer (inside manhole) shall be disconnected after obtaining shutdown to the specified areas.   All electrical activities shall be carried out by trained technicians in competent person’s supervision.   Interlock tiles in the affected area shall be removed and stored for re-use.   Existing Taxiway Edge lights shall be removed carefully by un-screwing the connections to the base.   All power cables to the lights were then removed by pulling back.    Light base shall be removed by asphalt coring.   For the Manhole transformer removal, all the primary and secondary cable connections to it shall be removed first.   All the removed Taxiway Edge lights & transformers shall be stored in site stores. 5.3. Existing duct bank & Manhole demolition.   After removing the lights and transformer safely, the existing duct banks and manholes shall be demolished using breaker/Excavator.    All demolition debris shall be removed from site as a part of housekeeping.    Pits thus formed shall be filled with suitable backfill material in layers (not exceeding 150mm of compacted depth) and compacted well using plate/roller compactor. 5.4. New Manhole works. Page 3 of 7

Relocation of Taxiway Edge Lights and Manholes

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RFSRA/MS/017,R0

Excavation for the new manholes and the duct banks shall be carried out based on the ground markups and the approved shop drawings. Bottom of the excavations shall be compacted well and debris if any shall be removed. Preventive measures shall be taken for excavation side collapse based on the site condition. Side forms for blinding concrete shall be fixed over 500 g polythene sheets (overlapping if any, shall be more than 50cm) as per approved shop drawings. Blinding concrete (75mm thick ) for the work shall conform to the approved mix design ( C16 grade) and transported to site through transit mixers and poured using chute / pump Immediately after pouring, approved curing compound shall be sprayed all over the surface for proper curing. PCC Side shutter removal can carried out after 30hrs. Concreting shall be carried out in two stages as, (i) Base Slab shall be concreted in the first stage and (ii) Full height Walls shall be casted in the second stage.

Pre-pour Activities for Base Slab     

Manhole Base slab markups on blinding shall be carried out based on approved shop drawings. Cutting, Bending and fixing of rebars shall be as per the approved shop drawings. Reinforcement works for the base slab shall be carried out after fixing the side shutters. 50mm cover blocks shall be used. Finish the formwork side supports and concreting can be carried out after getting consultant’s clearance.

Pre-pour Activities for Walls      

Reinforcement works for the walls shall be finished (After De-shuttering base slab) as per approved shop drawings. Manhole cover angles shall be welded/ Tied to the wall reinforcement, strictly based on the shop drawing. 50mm cover blocks shall be used. While shuttering of walls, provision of cutouts shall be strictly as per the approved shop drawings. Side formworks shall be fixed and align for the plumb and level. Finish the formwork side supports and concreting can be carried out after getting consultant’s clearance.

Pouring Stages and de-shuttering 

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Ready mix structural concrete , having min. cylinder strength 3000psi as per the approved mix design shall be transported to site using transit Mixers and poured using concrete pump. All Insitu test requirements shall be fulfilled prior to starting the pouring process and 6 nos. of cylinder samples shall be casted (3 for 7days and 3 for 28 days) compressive strength determination of concrete. Ensure that, during pouring operation, the height of fall of concrete shall not be more than 1.5m. Page 4 of 7

Relocation of Taxiway Edge Lights and Manholes

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RFSRA/MS/017,R0

Immediately after finishing the pour, the exposed face of fresh concrete shall be sprayed with approved curing compound ( Polycure AC) to ensure proper curing. De-shuttering for the vertical forms can be carried out after 30 hrs of pouring, and shall be sprayed with approved curing compound( Polycure AC) immediately after the de-shuttering to ensure proper curing All concrete surfaces which may contact with soil shall be painted with 2 coats of bitumen emulsion. Side backfill shall be carried out with suitable backfill material in layers (not exceeding 150mm of compacted depth) and compact well using plate/roller compactor.

5.3. Duct bank concrete works.    

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For the duct bank work, trench shall be excavated using barker /backhoe loader as per approved shop drawings. Preventive measures shall be taken for excavation side collapse based on the site conditions. Bottom of the excavations shall be compacted well using plate compactor and debris if any shall be removed. 500 g polythene sheets (overlapping if any, shall be more than 50cm) shall be fixed bottom of the excavation as well as the sides to isolate duct bank lean concrete from surrounding soil. For cable trench between manholes and lights, 1 x 50mm uPVC duct pipes with cable rope inside shall be fixed with proper cover and level as per approved shop drawings. For cable trench between manholes, 2 x 110mm uPVC duct pipes with cable rope inside shall be fixed with proper cover and level as per approved shop drawings. Duct bank shall be casted by mass concreting up to required height as per approved shop drawings. Concrete for the work shall conform to the approved mix design ( C16 grade) and transported to site through transit mixers and poured using chute / pump Ensure that, during pouring operation the height of fall of concrete shall not be more than 1.5m. Immediately after pouring, approved curing compound shall be sprayed all over the surface for proper curing.

5.3. Trench Backfilling. 

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Trench backfill shall be started after 7 days of pouring using suitable backfill material in layers (not exceeding 150mm of compacted depth) and compact well using plate compactor. For cable trench between manholes, Counter Poise wire (#6 AWG bare copper earth wire) shall be fixed at required depth as per approved shop drawing. Approved Detectable Cable Warning Tape shall be fixed at required depth as per approved shop drawing. After reaching the backfill up to required level, top surface shall be finished with interlock/ Asphalt tiles (which removed from the existing sign board area)

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Relocation of Taxiway Edge Lights and Manholes

RFSRA/MS/017,R0

5.3. Cable pulling, Transformer and lights fixing, termination, testing & commissioning. 

For cable trench between manholes and lights, 1 x 2 core 4sqmm H07RNF 600/1000V rated secondary cable shall be pulled manually through the duct bank using cable ropes. For cable trench between manholes, 1 x Single core 6sqmm 5KV rated primary cable shall be pulled manually through the duct bank using cable ropes. Extreme care shall be taken to protect the cable from wear & tear damage during pulling. Excess cable length of 1.5 meters in manhole side shall be pulled for termination works in both ends. Continuity and Insulation resistance test shall be conducted for cables after the pulling. Transformer shall be fixed in manholes. Light base shall be fixed in new location by coring the asphalt layer and using approved sealant. Edge lights shall be fixed over the base. Cable Termination shall be carried out by well experienced technicians in the presence of competent electrical engineer. Cable end in the Transformer side shall be terminated first. After finishing of cable termination, testing and commissioning of the relocated sign boards shall be carried out by competent person. After finishing the testing, manhole opening shall be covered with Heavy Duty manhole Cover.

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6. Resources Manpower Site Engineer (Civil/ Electrical) Surveyor QA/QC Engineer HSE Supervisor Supervisor / Foreman Operators & drivers Carpenters, Masons & Steel fixers Technicians

Should be deployed as required.

Equipment / Machinery Back Hoe Loader-– 1Nos Megger – 1No. Excavator-– 1Nos Trucks – 1Nos Air compressor – 1 No. Water tanker – 1No. Concrete Vibrator– 3Nos Rebar Cutting/Bending Machine – 1Nos Roller Compactor / Plate compactor – 1No.

Should be deployed as required.

7. Safety Page 6 of 7

Relocation of Taxiway Edge Lights and Manholes

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RFSRA/MS/017,R0

Ensure Proper use of hard barricades to secure the work area Ensure that all PPEs are available with the crew involved in the job. All equipment and tools should be checked before starting of the activity for suitability and integrity. Ensure that housekeeping is being carried out before and after work on a daily basis.

8. Documents / Records  Request for inspection.  Checklist.

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