Ultimate Lateral Pressure of Circular Pile in Undrained Clay Considering the Strength Reduction Induced by Pile Installation

Abstract

This study analyses the classical problem of the ultimate lateral pressure (ULP) of a circular pile in undrained clay considering the undrained strength reduction induced by pile installation. A modified Tresca model considering strain softening proposed by Einav and Randolph is used to describe the variation in soil strength. The pile installation effect is evaluated through the cylindrical cavity expansion model (CEM). An analytical solution for CEM considering the undrained strength reduction is derived by introducing the modified Tresca model. The analytical solution is validated by comparison with the theoretical prediction and the three-dimensional (3D) large deformation finite-element results through CEL in ABAQUS. Subsequently, the obtained analytical solution for the radially nonuniform distribution of undrained strength is read into Optum G2 to conduct a two-dimensional plane strain finite-element limit analysis (FELA). A series of parametric studies are performed to investigate the influence of strain softening on the ULP. A closed-form solution for ULP considering the pile installation effect is given through the regression analysis of FELA data. The present analysis first considers the pile installation effect on ULP and could provide a basis for constructing the p–y model of a laterally loaded pile considering the pile installation.