Plasticity solution for the limit vertical pressure of a single rigid pile with a pile cap in soft soil

Abstract

This paper presents an analysis of the limit vertical capacity of a pile with a cap in soft soil and evaluates the influence of the cap on the limit vertical pressure (LVP) through finite element limit analysis methods based on OptumG2 and OptumG3. Rigorous upper and lower bound plastic solutions for the LVP are given. Subsequently, the effect of the pile-soil interface adhesion factor α, the ratio between the pile length and diameter L/d and the ratio between the pile cap diameter and pile length D/d on the LVP are investigated through parametric analysis. Moreover, a simple empirical equation for LVP is proposed by conducting nonlinear regression analysis with the least squares method. The presented equation for LVP can be used to construct a simple load-displacement relation for a single pile with a cap in the future.