筏板-桩-土相互作用的三维弹塑性有限元分析

通过无厚度的接触面单元模拟筏板–桩–土之间的非线性接触特性,同时采用Drucker-Prager弹塑性本构模型描述土的非线性特性,对桩筏基础进行了三维弹塑性有限元分析,得到了筏板–桩–土接触表面上法向应力和摩擦应力的分布以及桩周土体塑性变形发展情况。在此基础上,对筏形基础中筏板和桩的承载力分担比进行了分析。计算结果表明,随外荷载的增大,桩的承载力分担比增大,筏板的承载力分担比减小,但两者的变化幅度不大。

3D ELASTOPLASTIC FINITE ELEMENT ANALYSIS OF BEARING CAPACITY BEHAVIOUR OF INTERACTION OF RAFT-PILE AND SOIL

Contact element is employed to simulate the nonlinear behaviour of interaction of piler,aft 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.