The most commonly used formula to determine the allowable static load on a pile is the Engineering News formula.
Case-1 The allowable load for piles driven by a drop hammer
Case-2 The allowable load for piles driven by a steam hammer
Pa=allowable pile load, tons (kg)
W= weight of hammer, tons (kg)
H= height of drop, ft (m)
p= penetration of pile per blow, in (mm)