用局部强度折减法进行边坡稳定性分析

边坡的变形与其稳定性具有内在的必然联系，因而可以通过变形场来对边坡的稳定性进行判断。传统的强度折减法基于理想弹塑性模型对所有单元进行强度折减，所求解出来的变形场并不能很好地反映出边坡失稳时的真实变形。实际上，边坡的失稳是由于局部土体的强度降低所致的，因此提出只对局部土体单元进行强度折减、其他土体单元保持原有强度不变的局部强度折减法，本构模型采用变模量弹塑性模型。工程实例计算分析表明，基于变模量弹塑性模型的局部强度折减法对边坡进行稳定性分析是可行的。

Slope stability analysis by local strength reduction method

There is an inherent relationship between deformation and stability of slope, so it is possible to identify the stability of slope by deformation field. Based on ideal elastoplastic model, the typical strength reduction method reduces strength of all elements of slope. Therefore, the deformation field by the typical method can not reflect real deformation when slope is close to instability. In fact, slope failure occurs when strengths of some regional soils are sufficiently weakened; so local strength reduction method is proposed here. According to local strength reduction method, only local soils strengths are reduced; and strength of the other soils keep unchanged. Moreover, this paper uses variable modulus elastoplastic model instead of ideal elastoplastic model. Actual engineering example shows that the slope stability analysis, which is based on local strength reduction method and variable modulus elastoplastic model, is feasible and rational.