库水位升降联合降雨作用下白家包滑坡稳定性评价  

Stability analysis of Baijiabao landslide under reservoir water level fluctuation and rainfall

作　　者：杨背背 殷坤龙[1] 黄发明[2] 周超[1] 

机构地区：[1]中国地质大学(武汉)工程学院,湖北武汉430074 [2]中国地质大学(武汉)地质调查研究院,湖北武汉430074

出　　处：《中国水利水电科学研究院学报》2016年第6期460-467,共8页Journal of China Institute of Water Resources and Hydropower Research

基　　金：国家自然科学基金项目(41572292;41572289)

摘　　要：库水位升降和降雨通过改变三峡库区库岸滑坡岩土体的抗剪强度和应力状态,影响库岸滑坡的稳定性.为探讨白家包滑坡在库水位升降和降雨联合作用下的稳定性变化特征,本文首先根据GPS监测数据定性分析白家包滑坡变形规律,再采用Geo一studio软件计算4种工况下滑坡的稳定性系数,最后采用R/S分析法计算各GPS监测点累积位移的Hurst指数,并将Hurst指数值与Geo一studio数值模拟结果进行对比分析.结果表明：白家包滑坡累积位移曲线呈 “阶跃状” 特征;滑坡稳定性受库水位升降和降雨的综合影响,库水位下降时稳定性系数减小,上升时稳定性系数增大,降雨也能在一定程度上降低滑坡稳定性;175~145m加降雨工况下滑坡最小稳定性系数为1.034,处于欠稳定状态;各监测点Hurst指数均介于0.5~1之间,表明未来滑坡变形将持续加剧,与滑坡变形定性分析及稳定性数值模拟结果一致.Reservoir water level fluctuation and rainfall can influence landslides stability by changing theshear strength and stress state. In order to explore the landslide stability characteristics under the combination effect of water level fluctuation and rainfall,the paper analyzes the deformation features of Baijiabaolandslide based on GPS monitoring displacement data. Then Geo- studio software is used to calculate thesafety factor of Baijiabao landslide in four working conditions. Finally,R/S method is used to calculate theHurst index of four GPS monitoring points and is compared with stability analysis result. The results showthat Baijiabao landslide with step-style displacement characteristic is affected by reservoir water level fluctuation and rainfall. The landslide safety factor decreases with water level drawdown and increases with waterlevel rise. Rainfall can also reduce the landslide stability to a certain extent. In the condition of 175-145mwater level and rainfall,the minimum safety factor of Baijibao landslide is 1.034 and means that the land-slide lacks stability. Besides,the Hurst index of four GPS monitoring point are all between 0.5 and1,suggesting that the landslide deformation will be continuous,which is consistent with the results of stabilityanalysis.

关 键 词：白家包滑坡 库水位升降 降雨 R/S分析 滑坡稳定性 

分 类 号：P642.22[天文地球—工程地质学]