有限元强度折减法边坡失稳判据

Study on Criteria for Evaluating Stability of Slope with FEM Based on Shear Strength Reduction Methods

有限元强度折减法分析边坡稳定性的一个关键问题是根据有限元计算结果来判别边坡是否处于整体破坏状态。目前,判别失稳的依据主要有三个,即依据计算的收敛性、特征部位位移的突变性和塑性区的贯通性。为考查目前各种失稳判据的合理性及其适用性,借助ADINA有限元软件分别用三种失稳判别标准对二个典型算例进行了稳定分析,并将安全系数与Spencer极限平衡法所得到的总体安全系数进行了对比,进而对三者的适用性、一致性等进行了分析研究。

How to judge the slope＇s state with FEM based on shear strength reduction methods, stability or instability based on the results of FEM is a key problem. There are three main criteria for evaluating instability： the convergence of equation＇s solution, the abruptness of the displacement or deformation at a certain characteristic location and the connectivity of plastic zone. In order to examine the reasonability and applicability of these criteria, in the presence of FEM software ADINA, two example slopes are analyzed by using three instability criteria, and the computed results are compared with the solution of Spencer＇s procedure of limit equilibrium. And then the applicability, consistency and the condition of the application of these criteria are studied.