边坡整体稳定的可靠性分析方法

RELIABILITY ANALYSIS METHOD OF SLOPE STABILITY

边坡整体滑动稳定性的可靠性分析是建立在土体具有的抗力大于荷载效应的概率基础上进行设计和校验的。在条分法的基础上推导出了进行边坡稳定可靠性分析的统一极限状态方程 ,将土的容重γ、内摩擦角φ、粘聚力 c作为随机变量 ,当其为非正态分布时 ,进行当量正态化 ,考虑变量相关的情况 ,用简化相关法对随机变量进行统计分析 ,并以 Bishop圆弧滑动法为例 ,用 JC法求解边坡的可靠性指标及失效概率 ,给出计算安全系数和可靠性指标的算法程序。并就影响可靠性指标的因素如抗剪强度指标、变量分布形式、土性参数的变异性等进行了讨论。

The reliability analysis of slope sliding stability is based on the probability of having the soil resistance greater than the soil sliding force. A united ultimate state equation is introduced for making the slope stability reliability analysis in this paper. The soil parameters, including unit weight γ , internal friction angle φ and coherence c are regarded as radom variables, and their equivalents are normalized when these parameters are not normally distributed. By taking the correlation between these variables into account, the simplified correlation method is used for making the statistical analysis of random variables, and Bishop method is taken as an example to use JC method to derive the reliability indexes of slope stability and the failure probability, and to give the algorithmic procedures for computing the safety factor and the reliability index. The factors to influence the reliability index, such as the shear strength of soil, the distribution type of random variable and the variabilities of soil parameter are also discussed.