多层土质边坡抗滑稳定的可靠性分析

Reliability Analysis of the Slipping Stability of Complex Multi-layered Soil Slopes

对于多层土组成的天然边坡或人工开挖边坡极限平衡分析法计算边坡滑动稳定可靠性问题，采用给定滑动范围，在该范围内据精度要求进行分割，并用给定曲线连接分割线上分段交点（或随机抽样交点），判断所连接曲线是否组成一合理滑面，再对选定的合理滑面计算其可靠指标（失效概率），比较所有合理滑面计算结果，从而获得该边坡最小可靠指标（最大失效概率）．本文的方法克服了优化法或随机搜索法往往不能获得边坡最危险的整体滑动面位置及其相应最大破坏概率的缺陷。

o solve the stability problem of a multi-layered soil slope with the method of the limiting equilibrium theory,the method of giving a slipping range is used,The given slipping range is cut by several lines,which are divided into many line segments.The intersection points are connected with general arcs.By repeating the same process a series of cambered surfaces are forms.Then whether every cambered surface is a probable slipping arc is determined,and the reliability index for probable arcs is calculated.The minimum reliability index(the maximum failure probability)of the slope can be obtained by comparing the values for all probable slipping arcs-The method used in this paper has surmounted the difficulty that the minimum reliability index(the maximum failure probability ) can not be found by using the methods of optimization or random sampling.