Nonlinear analyses of laterally loaded piles – A semi-analytical approach

Abstract

This paper describes a semi-analytical, continuum mechanics-based method of calculating the non-linear response of pile foundations subjected to lateral loads. The displacement field in the soil is obtained as the product of a pile deflection function and displacement decay functions. Based on the incremental form of the virtual work, a system of coupled differential equations for the pile deflection and decay functions is derived and then solved by using the finite difference method, producing pile deflections, shear forces and bending moments, as well as displacements within the soil domain. The soil is modeled as an elasto-plastic material. The analysis is computationally efficient and produces results that are in good agreement with those from 3D finite element modeling with the same constitutive model for the soil. The method models laterally loaded pile response more realistically than the traditional p–y method at a comparable computational cost. The method is substantially more efficient than 3D finite element simulations. The proposed method offers a good alternative to the p–y method in contexts in which fast calculation of lateral pile response is required, such as in the design of piles for offshore wind farms.