非均质土体稳定性分析的广义极限平衡法及其应用

Generalized limit equilibrium method with applications for stability analysis of non-homogeneous soil structures and foundations

非均质土体稳定性分析是岩土工程中十分重要且非常复杂的课题，目前既缺乏严密的理论公式，也无统一的实用方法。本文运用拉格朗日乘子法，有机地将传统的极限平衡法与极限分析上限定理相结合，建立了一种既能考虑土料强度非线性特征，又适用于非均质剖面等的土建筑物及地基稳定性统一分析方法即广义极限平衡法，并比较严密地阐明了方法的物理基础与解答的性质。最后简要介绍了这种方法在非均质土坡稳定性、层状地基承载力与挡土墙土压力等方面应用所取得的一些数值结果与结论。

An unified approach to stability ana1ysis of soil structures and foundations is deve1oped, according to the genera1ized limit equilibrium method which intimately combines the conventional limit equilibrium method with the upper bound theorem of 1imit ana1ysis by emp1oying the variationa1 technique and Lagrangian mu1tiplier procedure. It is characterized by its flexibi1ity of application to access the soil materials possessing nonlinear strength criterion and adaptabi1ity to simulate the non-homogeneities of soi1 profiles. As another attractive feature of this method, no assumptions on the failure mechanisms are made before hand. In addition,the physica1 fundamental and solution nature are examined. Finally, this unified method is successful1y utilized to assess the earthquake-resistant capacity of non-homogeneous soil slopes, bearing capacity of layered foundations and lateral earth pressures of cohesive backfills on retaining walls. Some important results and conc1usions are brief1y presented.