Hiley Formula calculator for pile foundation

Hiley Formula - Pile Driving Calculator

Units: weight = tonne, drop height h = mm, c = mm, Ru in tonne (same units as used in your image).

Working load (tonne) — used to compute Ru = 2 × working load

Or enter Ultimate driving resistance R_u (tonne)

Hammer weight W_h (tonne)

Pile weight W_p (tonne)

Hammer drop height h (mm)

Temporary compression (helmet+packing) c (mm)

Friction constant k (winch/other losses)

Coefficient of restitution e

Formula reference (Hiley): \( \displaystyle R_u = \frac{W_h\,h\,\eta}{S + \tfrac{1}{2}c} \). Rearranged for set per blow \(S\): \( \displaystyle S = \frac{W_h h \eta}{R_u} - \frac{c}{2} \).