库水位下降对滑坡稳定性的影响  

EFFECTS OF DRAWDOWN OF RESERVOIR WATER LEVEL ON LANDSLIDE STABILITY

作　　者：刘新喜[1] 夏元友[1] 张显书[2] 郭瑞清[2] 

机构地区：[1]武汉理工大学土木工程与建筑学院,湖北武汉430070 [2]中国地质大学工程学院,湖北武汉430074

出　　处：《岩石力学与工程学报》2005年第8期1439-1444,共6页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(49902022);教育部科学技术研究重点项目(104135);湖北省自然科学基金资助项目(2004ABA058)

摘　　要：三峡水库2003年蓄水后,滑坡将可能成为三峡库区最严重的地质灾害之一,库水位下降和暴雨是导致滑坡的主要因素。根据三峡库水位调控方案考虑库区极端暴雨情况,利用有限元模拟库水位在175～145m波动和降雨时红石包滑坡Ⅲ的暂态渗流场,将计算得到的暂态孔隙水压力分布用于滑坡的极限平衡分析,并考虑基吸力对非饱和土抗剪强度的影响。探讨不同降雨速度、降雨条件对滑坡稳定性的影响。研究表明:库水位下降对滑坡稳定性的影响受控于滑坡土的入渗能力和滑坡结构形态,当暴雨强度为300mm/d时,红石包滑坡Ⅲ的临界降速1m/d。其成果将为库区滑坡治理提供科学依据。Landslide is one of the most serious geological hazards in the Three Gorges reservoir regions. Since the reservoir was in operation in 2003, both reservoir water level descending and rainstorm infiltration have become major factors that affect the stability of landslide. According to the water level operation options considering the case of extreme rainfall in the Three Gorges reservoir region, transient seepage due to the descending of reservoir water level from 175 to 145 m and rainstorm infiltration is calculated using the finite element method. The transient pore water pressures are then used for limit equilibrium analyses of landslides considering the effects of suction on shear strength of unsaturated soils. The effects of different rainfall speed, various rainfall events on landslide stability are discussed. The results of stability analysis show that the stability of landslides by the drawdown of reservoir water level depends on permeability coefficient of landslides and the structure of landslide. The critical declining velocity of Hongshibao landslide III is 1 m/d when the rainstorm intensity is 100 mm/d, which will provide scientific basis for the treatment of landslide in Three Gorges reservoir.

关 键 词：岩土力学 库水位下降 饱和与非饱渗流 滑坡 稳定性评价 

分 类 号：TU457[建筑科学—岩土工程]