基于强度折减法的边坡稳定性分析

Stability Analysis of Slope Based on Strength-reduction Method

将有限元强度折减法应用于边坡稳定分析中,探讨了该方法的基本原理、安全系数的定义、屈服准则和失稳判据等。采用强度折减法对某边坡进行稳定性分析,并与传统极限平衡法求得的安全系数进行对比。计算结果表明,采用塑性区贯通或特征点位移突变为失稳判据确定的安全系数与传统极限平衡法的计算结果很接近,表明有限元强度折减法能够满足工程应用。建议在有限元强度折减法中联合采用塑性区贯通和特征点位移突变作为边坡的失稳判据。

The strength reduction FEM is applied to the stability analysis of slope. The basic principle of this method and the definition of safety factor, yield rule and instability criterion are discussed. An example slope is analysised by using the strength reduction FEM. The computed results are compared with the solution of the traditional limit equilibrium method. It shows that safety factors computed by using the criteria respectively based on connectivity of plastic zone and the abruptness of the displacement or deformation at a certain characteristic location are almost identical to the solution of the traditional limit equilibrium method, so the strength reduction FEM can meet the demand of projects. Both criterias based on connectivity of plastic zone and the abruptness of the displacement or deformation at a certain characteristic location are suggested to be jointly used in the strength reduction FEM analysis of slope stability.