基于容重增加与强度折减法的边坡稳定性对比分析

为了研究容重增加法在边坡稳定分析中的适用性及计算精度,针对一算例边坡采用非线性的有限元法进行数值模拟,基

ContrastAnalysis of Slope Stability based on GravityIncrease and Strength Reduction Method

In order to study on the application and calculation precision of gravity increase method in the analysis of slope stability, the example slope is numerically simulated using nonlinear FEM, with employment of non-associated flow rule and circumcircle Drucker-Prager (D-P) yield criterion provided by the ANSYS programme. The safety factor of slope stability is calculated by using gravity increase method according to the horizontal deformation catastrophe of slope top and the connectivity of equivalent plastic strain zone. Then the safety factor could be obtained under different D-P yield criterion based on the conversion formula. Through comparing with the calculation results of limit equilibrium and strength reduction method, it is found that safety factor obtained by using gravity increase method is larger than that obtained by strength reduction method and limit equilibrium. On this basis, the factors affecting calculation precision such as slope ratio, cohesion, internal friction angle and size of computational grid, are analyzed. The results indicated that effect of calculation precision by various factors, with gravity increase method is higher than that strength reduction method and the calculation results using gravity increase method are more reliable when soil shear strength index values of steep slope are small. By comparison, the results calculated by strength reduction method is reasonable and practical, while the application of gravity increase method has certain limitations in evaluating slope stability.