摘要
岩体的非均质性使得传统确定性分析方法在复杂岩层的边坡的风险评估中存在较大的偶然性和不确定性。针对岩性复杂的三峡库区泄滩边坡,利用蒙特卡洛方法,采用不同岩体参数的随机分布,自动搜索滑动面,计算其失效概率。结合边坡的渗流场,综合评价泄滩边坡稳定性并对其进行支护。结果表明:岩土体参数近似服从韦伯分布;渗流场的分布决定了边坡的破坏机制;泄滩边坡素填土的强度参数对边坡失效概率的影响较为显著;泄滩失效概率为12%,最小安全系数为0. 758。针对素填土进行喷锚支护,安全系数提高到1. 395,失效概率降为0,支护方式有效。结合渗流场分布,利用不确定性分析方法可以更全面的描述工程边坡稳定性,将边坡失效概率与破坏机理结合,快速为工程提供可靠的描述及风险评估,并为边坡破坏的预测及采取支护方式提供了依据。
Crucial problems relating to the contingency and uncertainty depend on the discontinuity of rock and soil materials,increasing the difficulties in estimating stability of slope.Aiming at Xietan slope with complicated lithology in the area of Three Gorges Reservoir,its failure probability is calculated through automatic search of the sliding plane with the random distribution of different parameters of rock mass by Monte-Carlo method.Combined with the seepage field of the slope,the stability of Xietan slope is comprehensively evaluated,and then it is supported.The result shows that the parameters of the rock-soil mass therein are approximately subjected to Weibull distribution and the failure mechanism is depended on the distribution of the seepage field,while the influence from the strength parameter of the plain fill of Xietan slope on the slope failure probability is more significant and the failure probability of the slope is 12%with the minimum safety factor of 0.758.If shotcrete-bolt support is made for the plain fill therein,the safety factor is to be enhanced to 1.395 and the failure probability is to be lowered to 0,thus the supporting mode is effective.Combined with the distribution of seepage field,the engineering slope stability can be more fully described,and then the failure probability of slope can be combined with the failure mechanism by means of the uncertainty analysis method,thus not only reliable description and risk assessment can be quickly provided for the relevant project,but a basis can be also laid for the prediction of the slope failure and its support mode.
作者
朱瑜劼
刘晓丽
王恩志
王思敬
钟建文
ZHU Yujie;LIU Xiaoli;WANG Enzhi;WANG Sijing;ZHONG Jianwen(State Key Laboratory of Hydroscience and Engineering,Tsinghua University,Beijing100084,China)
出处
《水利水电技术》
CSCD
北大核心
2018年第12期154-161,共8页
Water Resources and Hydropower Engineering
基金
国家自然科学基金项目(41772246
51479094)
国家自然科学基金青年基金项目(51522903)
水沙科学与水利水电工程国家重点试验室自主课题资助(2015-KY-04
2016-KY-05
2016-KY-02)
科技部973重大专项(2013CB035903)
关键词
滑坡
蒙特卡洛法
失效概率
敏感性
稳定性分析
岩体空间变异性
土体抗剪强度
极限平衡法
landslides
Monte-Carlo method
failure probability
sensibility
stability analysis
spatial variability of rock mass
shear strength of soil
limit equilibrium method
