Engineering news formula

A formula proposed by the late A. M. Wellington, C.E., for determining the safe load on piles.

Safe Load = ${\frac {2WH}{s+1}}$

where

W denotes the weight of the drop or steam hammer

H denotes the fall in feet or the stroke in a steam hammer

s denotes the average penetration of the pile per blow in inches under the last few blows

For steam hammer work this formula is modified by substituting 0.1 in place of unity in the denominator