Block Type Machine Foundation Design by Barkan's Method: 1. Available Data [PDF]

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Block type Machine foundation design by Barkan's Method 1. Available Data: Length of footing, Lf =

2.90

m

Breadth of footing, Bf =

1.70

m

Depth of footing, Df =

0.75

m

Mass of machine, m =

1000.00

Kg

rpm of machine =

1450.00

rpm

Safe bearing capacity of soil, q =

250.00

KN/m2

Subgrade Modulus, k =

25000

Total mass, M =

1376.91

Kg

2. Check for Resonance: Natural frequency, fn = (1/2π)√(cuLfBf/M) where, cu =

200

q=

∴ fn =

67.34

Hz

=

4040

rpm

And, operational frequency, fm =

24.17

Hz

50000

Frequency ratio, r = fm/fn = 0.36 ∴ Natural frequency is sufficiently away from the operating frequency. revise the size of footing 3. Check for Maximum Amplitude: az = Q0/cuLfBf(1-r2) =

0.06

mm

∴ The amplitude of vibration is within the tolerable limits 4. Check for Base Pressure: qb = M/LfBf = 2.76 KN/m2 ∴ The base pressure does not exceeds the dynamic bearing capacity i.e. half the static allowable soil pressure.

an's Method

evise the size of footing

owable soil pressure.