Analytical Solutions for Active Lateral Earth Force

Analytical solutions are presented for the active force on a retaining wall from a single wedge of unreinforced soil, as obtained from a general Coulomb-type limit equilibrium analysis. The solutions can accommodate variable wedge geometry, pore pressure, shear-strength parameters, surcharge stress, applied loads, pseudostatic seismic coefficients, and a tension crack zone. Closed-form expressions are derived for the critical angle of the base failure plane and corresponding maximum effective normal force on the wall for a triangular soil wedge. Verification checks show exact agreement with existing analytical solutions for simplified conditions, including Coulomb and Mononobe-Okabe active earth force. A numerical example is provided to demonstrate the method for a gravity retaining wall.