Analysis of Time-Dependent Bearing Capacity of a Driven Pile in Clayey Soils by Total Stress Method

Abstract

This paper proposes an analytical approach to evaluate the time-dependent bearing capacity of a driven pile in clayey soils by taking the pile installation and subsequent reconsolidation effects into consideration. The process of pile installation is modeled by undrained expansion of a spherical cavity at the pile tip and a cylindrical cavity around the pile shaft. The cavity expansion solution, which is based on a K0-consolidated anisotropic modified Cam-clay model (K0-AMCC), is used to capture the pile installation effects. After pile installation, the dissipation of the excess pore water and the increase of the effective stress in the surrounding soil are evaluated by the radial consolidation theory. Based on the effective stress, the strength of the remolded soil is quantified by the modified Cam-clay (MCC) model and the spatially mobilized plane (SMP) criterion. With the three-dimensional strength of the surrounding soil, the time-dependent bearing capacity of the driven pile is evaluated by the total stress (α) method. To verify the proposed analytical approach, three groups of centrifuge model tests were performed, and the proposed approach was applied to predict the time-dependent bearing capacity of the tested piles. It is shown that reasonable predictions can be made by the method proposed in this paper.