为了给危岩崩塌灾害的预测提供理论依据,以主控结构面贯通长度、危岩断裂韧度和裂隙水深为随机变量,基于断裂力学和可靠度理论对危岩稳定可靠度进行了研究,建立了危岩稳定可靠度的优化求解方法并考察了危岩可靠指标和失稳概率与随机变量之间的变化规律,最后以三峡库区万州太白岩南坡危岩为例对该方法进行了验证。结果表明:危岩可靠指标随主控结构面贯通长度、主控结构面倾角、主控结构面贯通长度标准差、裂隙水深标准差和断裂韧度标准差的增加而减小,而危岩的失稳概率除了随断裂韧度的增大而减小外,均随其余各变量的增大而增大;在各变量的改变中断裂韧度标准差的改变对危岩可靠指标和失稳概率的影响较小;且该方法与规范法计算结果基本吻合。
In order to provide theoretical basis for the prediction of perilous rock collapse, the length of perilous rock control fissure, the fracture toughness and the depth of fissure water weretreated as random variables. Through the fracture mechanics and reliability theory, the perilous rock reliability was studied. An optimization approach for perilous rock reliability analysis wasthen proposed. And the variation law between the perilous rock reliability index, instability probability and random variables was analyzed. The method established in this paper was verifiedby the perilous rock on the south cliff of Wanzhou in the Three Gorges reservoir area. The results show that with the increase of the length, dip and standard deviation of the length of controlfissure, standard deviation of fracture toughness and fissure water depth, the perilous rock reliability index decreases. The instability probability increases when the variables increase,except the fracture toughness. In all of the variables, the standard deviation of fracture toughness has little influence on the perilous rock reliability index and instability probability. The method isconsistent with the results from the criteria.