Linear analysis of a circular pile under vertical load in layered soils

Abstract

This paper presents a new simple method for analyzing the linear response of a single pile with circular cross-section under vertical load in layered soils. The properties of each soil layer are assumed to be constant but can vary from layer to layer. The method is based on energy principles and variational approach with an explicit solution by using the finite element method in pile displacement approximation. Bar elements models the pile and soil column below the pile tip while a series of independent springs distributed along the pile shaft models the surrounding layered soils. Properties of the corresponding soil layer determine the spring stiffness. The iterative solutions provide vertical displacement along the pile, vertical displacement of soil as a function of the radial distance at any depth, and equivalent stiffness of the pile-soil system. Validation of the proposed method is conducted by comparing its results to analytical solutions, three-dimensional finite element analyses, and a field load test.