以破坏概率为目标的岩质边坡平面滑动破坏反分析

Back Analysis of Plane Sliding Failure of Rock Slope Aiming at Failure Probability

把可靠性理论和反分析方法相结合,对岩质边坡平面滑动破坏进行了反分析,讨论了分别以稳定系数和破坏概率为目标的反算方法,阐述了平面滑动破坏反分析的计算过程,根据无后缘张裂缝的岩质边坡平面滑动极限状态函数,运用Monte Carlo方法对某核电工程基坑边坡平面滑动破坏进行了反分析。指出了基于稳定系数的常规定值反分析中的不足,讨论了变异系数、截尾位置、相关系数对计算结果的影响。认为抗剪强度指标的变异系数和相关系数对反算结果影响不大,截尾位置按照“3σ”原则兼顾变异系数经验范围的设置方法可以满足要求。

By combining reliability theory with back analysis method,the plane sliding failure of rock slope was analyzed.The back calculation method aiming at stability coefficient and failure probability was discussed,and the calculation process of the plane sliding failure was expounded.According to the limit state function of plane sliding of rock slope with no posterior edge tension crack,Monte Carlo method was used to analyze the plane sliding failure of foundation pit slope in a nuclear power project.The shortcomings in the analysis of the normal values based on the stability coefficient was pointed out,and the influence of the variable coefficient,the truncation position,and the correlation coefficient on the calculation results was discussed.It is believed that the variation coefficient and correlation coefficient of the shear strength index have little effect on the back calculation results,and the truncation position could meet the requirements in accordance with the“3σ”principle and the setting method of the empirical range of the variation coefficient.