Simplified Approach for Pile and Foundation Interaction Analysis

Abstract

A simple approach is described for the analysis of soil‐pile interactions under static and dynamic lateral loadings. The method uses variational calculus to obtain the governing differential equations of motion for the soil‐pile system under a harmonic concentrated load at the pile head with intensity P0 and frequency ω. The pile is treated as a shear beam and the soil is assumed to be a linear elastic material. The solutions are based on a semianalytical and seminumerical approach, and are brought to a form that makes it possible to predict the dynamic displacements, stiffness, and damping for different soils and end conditions of the pile. Two cases are investigated: (1) A pile clamped to a rigid bottom underlying an elastic soil layer; and (2) a floating pile in an elastic half‐space. Numerical results are presented to illustrate the method and investigate the dynamic stiffness and damping of the soil‐pile system. The complex frequency responses of the soil‐pile system for typical values of the stiffness and hysteretic material damping of the soil are also presented. The numerical computations required for all solutions are modest.