强度折减有限元法土坡失稳判据分析均质土坡

Discussion on criteria for evaluating stability of slope in elastoplastic FEM based on SSR technique

目前强度折减法分析土坡稳定一般有三种判断依据:位移突变法、求解过程中计算的不收敛、塑性区的贯通情况。针对典型均质土坡算例,采用强度折减有限元方法进行稳定分析,并与极限平衡方法所得到的安全系数进行对比。对比分析表明,三种判别法得到的安全系数与极限平衡法计算的结果接近,说明对均质土坡有适用性。

At present, there are three criteria for evaluating stability of slope in elastoplastic FEM based on SSR technique including the abruptness of the displacement, the convergence of numerical computations or deformation at a certain characteristic location and connectivity of plastic zone. An example homogenous soil slope is analyzed by using the elastoplastic FEM based on the SSR technique and their computed resuits are compared with the solution of limit equilibrium. It is shown that the safety factors computed by using the three criteria are almost identical to the solution of limit equilibrium method. It is also proven that the three criteria are feasibility to analyze the homogenous soil slope.