Foundation Engineering

Bearing capacity is the maximum pressure a foundation can safely transfer to soil without shear failure or excessive settlement — Terzaghi and IS code methods used in India.

Add the immediate elastic settlement (dominant in sands) to the consolidation settlement from the compression index C_c (dominant in clays), and check the total against the allowable limit of around 40 mm.

Size the plan area from the service load divided by the safe bearing capacity, then fix the depth from the two-way punching-shear check and detail the flexural steel for the cantilever moment about the column face.

Add the skin-friction capacity along the shaft to the end-bearing capacity at the tip, apply a factor of safety of about 2.5, and reduce the group capacity by the group efficiency for closely spaced piles.

Compute the natural frequency of the soil-foundation-machine system and keep the operating frequency well away from it (frequency ratio outside 0.7–1.4) to avoid resonance and excessive amplitude.