考虑参数不确定性的红砂岩边坡可靠性分析研究  

Study on Reliability Analysis of Red Sandstone Slope Considering Parameter Uncertainty

作　　者：樊长刚 盛焰正 陈双庆 FAN Changgang;SHENG Yanzheng;CHEN Shuangqing(China Municipal Engineering Southwest Design and Research Institute Co., Ltd., Chengdu, Sichuan 610081,China;China Communications Second Highway Survey and Design Institute Co., Ltd., Wuhan,Hubei 430000,China;School of Civil Engineering, Central South University, Changsha, Hunan 410018,China)

机构地区：[1]中国市政工程西南设计研究总院有限公司,四川成都610081 [2]中交第二公路勘察设计研究院有限公司,湖北武汉430000 [3]中南大学土木工程学院,湖南长沙410018

出　　处：《公路工程》2022年第2期103-108,160,共7页Highway Engineering

基　　金：国家重点基础研究发展规划项目(2015CB057706)。

摘　　要：为解决传统边坡稳定性分析需要明确岩土参数定值的困难,针对湖南省某高速公路红砂岩边坡开展了考虑参数不确定性的可靠性分析,首先对边坡沿线范围内的风化红砂岩样品进行了抗剪强度参数统计分析,建立了正态分布模型,并基于此开展了利用蒙特卡洛法和罗森布鲁斯法的边坡可靠性分析,研究了支护前后可靠性指标的变化规律,并将可靠性方法分析结果与传统定值方法进行了对比。研究表明:红砂岩的抗剪强度具有明显的不确定性,这是由矿物成分、含水率等因素的不均匀所造成的,黏聚力和内摩擦角都具有正态分布的特征;根据蒙特卡洛法,支护前红砂岩边坡失效概率P_(f)=22.6%,处于欠稳定状态,与现场出现失稳的情况相符,进行支护后,边坡失效概率P_(f)=4.6%,表明支护后边坡处于稳定状态,出现失稳的概率很小,而支护后采用罗森布鲁斯法计算得出失效概率P_(f)=6.3%,偏于保守。In order to solve the problem in acquiring geo-technical parameters during traditional slope stability analysis,the reliability analysis considering the parameter uncertainty of red sandstone slope at an expressway in Hunan province was carried out.Relative normal distribution modelswere established.The Monte-Carlo Method and Rosenbluth Method were used to calculate the slope reliability,and the variation rule of the reliability index before and after the support was studied.The results of the reliability method were compared with the traditional value determination method.The results show that the shear strength of red sandstone is obviously uncertain,which is caused by the inhomogeneity of mineral composition,water contentand other factors.The cohesion and internal friction angle are normally distributed.According to the Monte Carlo method,the failure probability of the red sandstone slope before support is 22.6%,which is in an understable state.It is consistent with the situation of instability in-site.After support,the failure probability of the slope is 4.6%,which indicates that the slope is in a stable state after support,and the probability of instability is very small.The failure probability P_(f)=6.3%is calculated by Rosenbluth Method after support,which is more conservative.

关 键 词：边坡 红砂岩 可靠性 蒙特卡洛法 不确定性 

分 类 号：U416.14[交通运输工程—道路与铁道工程]