土与结构间接触面的非线性弹性-理想塑性模型及其应用

将非线性弹性理论与弹塑性理论相结合，对于土与结构间接触面提出了一种非线性弹性-理想塑性模型，用于模拟土与结构相互作用体系的变形与破坏机理。推导建立了这种接触面单元的应力-应变关系和弹塑性系数矩阵，并且讨论了这种模型在基坑开挖与支护分析应用中所面临的数值计算问题。最后针对某一基坑工程实例，应用这种接触面模型进行了数值计算与分析，结果表明，该模型能够较合理地模拟接触面上的变形机理与受力状态。

A nonlinear elasto-perfectly plastic model of interface element for soil-structure interaction and its applications

A nonlinear elasto-perfect plastic model of interface element is presented. The proposed model can simulate behavior of soil and structure interaction. The stress-strain relationship and nonlinear elasto-perfect plastic matrix of interface element are established based on elastoplasticity theory. The computational procedure for implementing this-type of nonlinear and inelastic interface element in the finite element methods is developed and numerical scheme is presented. Then the method is applied to numerical analyses of foundation pit excavation. Through numerical computations for an example of the foundation pit excavation and bracing, the distributions of earth pressures behind and in the front of pile wall along the depth and their variations during the excavation of foundation pit are examined. It is indicated that the proposed model can rationally simulate the stress-strain relationship of interface element and will be practically applicable.