Abstract:Contact element is employed to simulate the nonlinear behaviour of interaction of pile,raft and soil. And Drucker-Prager elastoplastic constitutive model is used to represent nonlinear and inelastic characteristics of soils. Based on these models,the three-dimensional numerical analyses by finite element method are conducted to examine the interaction and bearing behaviour of raft-pile foundation. According to the distributions of normal and friction stresses along the contact surface and the plastic deformations in subsoil computed by the finite element methods,the relative ratios of loads respectively carried by pile and raft are investigated. It has been shown that with the increasing of the applied loads,the bearing ratio of pile increases slightly while the bearing ratio of shaft decreases slightly.