土的三维应力再分配方法和非线性地震反应分析

A Procedure for Redistribution of Soil Stresses in Three Dimensional Analysis and its Application to Nonlinear Earthquake Response Analysis

摘要: 倘若用有限单元法来分析上-结构系统,单元的数量可达几百个甚至上千个。这样,要每一步用不同的刚度重新组成新的刚度矩阵来求解运动方程的话,即使在大型计算机上也很难实现非线性地震反应分析。本文提出上的三维应力再分配方法,找出非线性和线性分析之间的不平衡应力;然后,应用荷载转移法对三维上-结构系统作地震反应分析。在整个计算过程中,只需要对刚度矩阵进行一次逆运算,节省了大量的CPU时间。计算结果表明本文提出的再分配方法具有良好的收敛性。

Abstract: In this paper, a procedure was proposed for stresses redistribution after soil yielding in three dimensional analysis and nonlinear seismic responses of a 3D soil-structure system was analyzed by using this procedure combined with the load transfer method. It appeared the procedure suggested here is more realistic than that used in 2D analysis, because σ2, together with σ1 and σ3 was taken account of in stresses redistribution after soil yielding. Good convergence was founded in computation.