中文摘要：

基于Phase2有限元软件强度折减法，根据塑性区贯通以及特征点位移突变两个判据分析土质边坡的稳定性。依据地基塑性区开展深度和数值模型下部边界深度之间的关系，根据模拟塑性区的贯通情况确定土质边坡边界的范围。采用Mohr-Coulomb模型和Duncan-Chang模型模拟不同折减系数下监测点的位移，结果表明：Mohr-Coulomb模型强度折减法得到的安全系数与极限平衡法得到的安全系数相同，建议采用Mohr-Coulomb模型强度折减法确定安全系数；当折减系数在一定范围内时Duncan-Chang模型计算得到的位移值比Mohr-Coulomb模型计算得到的位移值更符合工程实际，建议采用Duncan-Chang模型强度折减法确定变形场。

英文摘要：

Based on Phase2 strength reduction method,according to the breakthrough of the plastic zone and feature point displacement mutation two criterion,it analyzed the stability of soil slope. On the basis of the foundation to carry out the depth of the plastic zone and the relationship be-tween the numerical model for the lower boundary depth and according to the simulation of plastic zone,it determined the extent of soil slope bound-ary condition. Using the Mohr-Coulomb nonlinear constitutive model and the Duncan-Chang model to simulate the displacement of monitoring points under different reduction factor,the results show that the safety factor of the Mohr-Coulomb strength subtraction model and the safety factor of the limit equilibrium method are the same,we recommend using Mohr-Coulomb strength subtraction model to determine the safety factor;when the re-duction factor within a certain range,the calculated displacement value of Duncan-Chang model is more in line with the engineering practice compa-ring with Mohr-Coulomb model. Therefore,it suggests using the Duncan-Chang model strength subtraction to determine the deformation field.