Energy-Based Solutions for Nondisplacement Piles Subjected to Lateral Loads

Abstract

This paper reviews the energy-based solutions that have been proposed for boundary value problems involving pile foundations subjected to lateral loads and presents semianalytical solutions that are applicable to both elastic and elastoplastic soils. Generally, the displacements in the soil are directly linked to the pile deflections through formulations in either Cartesian or cylindrical coordinates. A system of differential equations for the pile deflection and soil displacements can be derived based on the principle of minimum total potential energy or the principle of virtual work in a total or incremental form. The system of equations can be solved analytically or numerically using an iterative algorithm, producing profiles of pile deflections, shear forces, and bending moments for the pile(s) and displacements within the soil domain. Comparisons between results from energy-based analyses using various combinations of the energy principles and displacement formulations show that a stiffer pile response is observed when degrees of freedom in certain directions are constrained in the soil. By adopting suitable displacement formulations and appropriate constitutive models for the soil, the method produces realistic predictions of laterally loaded pile response at an affordable computational cost.