Lateral Response of Hollow Circular Caisson Embedded in Nonlinear Soils

Abstract

This paper presents the numerical analysis of the lateral response of hollow circular caisson embedded in nonlinear soils. The caisson–soil system is modeled by a three-dimensional nonlinear finite-element method. The caisson is considered as a linear elastic body, whereas the nonlinear behavior of the adjoining soil is defined by kinematic hardening-based multiyield surface plasticity model. The interface between the caisson and adjoining soil is modeled by a zero thickness contact element which is defined by the constitutive relationships capable of describing the relative sliding and the separation at the interface. The present study discusses the lateral response of the hollow caisson, which consists of the lateral load versus lateral displacement (P–Y) curves, mechanism of deformation of the caisson–soil system, and deformation profile of the hollow caisson. It also presents the effect of the D/B ratio, relative stiffness of the caisson–soil system, and the effect of the vertical load on the lateral response of the hollow caisson embedded in nonlinear soils. The present study indicates that the D/B ratio, relative stiffness of the caisson–soil system, and the vertical load have a significant effect on the lateral response of the caisson–soil system. This study reveals that there occurs elastoplastic deformation during the lateral loading of the caisson–soil system. Further, a simplified transitional plasticity-based constitutive law is proposed to model the lateral response of a caisson–soil system. The proposed model requires only three parameters, which can be calibrated using the lateral load versus lateral displacement curve obtained from the finite-element analysis or the field test. Furthermore, mathematical relationships between the model parameters and the material parameters defining the caisson–soil system are established using the least-squares regression analysis.