Cyclic Response of Axially Loaded Pile Groups

Abstract

This paper presents a total stress hybrid load‐transfer analysis for the response of pile groups in clay under either uniform or irregular cyclic loading. The soil mass may be arbitrarily layered and the nonlinear pile response is represented by a simple cyclic hyperbolic interface soil model. The reduction of shaft stress and accumulation of displacement are considered using the degradation of the soil secant modulus and shaft limiting stress. The shaft‐stress‐degradation factor is related to the cyclic strain in a hyperbolic form. The formulation of the analysis is relatively simple and the soil parameters required are relatively few and have physical meaning. The method is used to analyze the response of model pile‐group tests in soft clay under cyclic loading. In addition, a repeated monotonic loading on a full‐scale pile‐group field test in stiff overconsolidated clay is analyzed. The measured and computed results are in reasonably good agreement.