库水位降落与降雨耦合作用下鸡脑壳包滑坡变形分析  

Deformation Analysis of Jinaokebao Landslide under the Coupling of Reservoir Water Level Drop and Rainfall

作　　者：江俊杰 刘东泽 卢应发 JIANG Jun-jie;LIU Dong-ze;LU Ying-fa(School of Civil Architecture and Environment,Hubei University of Technology,Wuhan 430068,Hubei Province,China;WSGRI Engineering and Surveying Incorporation Limited,Wuhan 430080,Hubei Province,China)

机构地区：[1]湖北工业大学土木建筑与环境学院,湖北武汉430068 [2]中冶武勘工程技术有限公司,湖北武汉430080

出　　处：《中国农村水利水电》2023年第9期236-243,共8页China Rural Water and Hydropower

基　　金：国家自然科学基金面上项目(41372363,41641027);三峡后续工作地质灾害防治项目(0001212015CC0005)。

摘　　要：为研究三峡库区水位降落与降雨对沿岸涉水边坡的影响,以鸡脑壳包滑坡为例,采用数值模拟方法对鸡脑壳包滑坡在库水位降落、降雨以及二者耦合作用工况下的变形破坏进行分析。首先在二维模型中通过MorgensternPrince法对滑坡在不同工况下的稳定性进行计算,同时利用三维滑坡模型监测滑坡孔隙水压力、应力以及位移的变化,从而分析涉水滑坡破坏机理。在此基础上分析库水位下降速率、降雨强度单一指标对滑坡的稳定性影响。结果表明:在二维计算中库水位从175 m水位缓降至145 m同时叠加50年一遇暴雨时鸡脑壳包滑坡最危险,此时滑坡的稳定系数为1.032,滑坡处于欠稳定状态。在三维模型监测中坡体内的渗透力和位移发生很大变化,其中库水位从175 m缓降至145m且遭遇50年一遇暴雨时,滑坡出现最大位移,其中水平位移达到31.38 mm,垂直位移为31.13 mm。表明滑坡的位移主要发生在中后部,所以在库水位下降且伴有强降雨时要着重观察滑坡后缘的变形。对单一因子分析可知,滑坡在仅调整库水位下降速率时,随着库水位下降速率增大,滑坡的稳定性随之降低,当水位下降速率4.2 m/d时,滑坡出现失稳。在分析降雨因子影响时,降雨强度越大、降雨时长越长,滑坡越容易失稳,50年一遇暴雨持续4天滑坡稳定系数达到0.968,进入失稳状态,因此在库水位快速下降与持续性强降雨期间要做好对滑坡的监测预警。In order to study the effects of water level drop and rainfall on the coastal wading slope in the Three Gorges Reservoir area,this pa⁃per takes the Chicken Brain Shell Landslide as an example,and uses the numerical simulation method to analyze the deformation and failure of the Chicken Brain Shell Landslide under the conditions of reservoir water level fall,rainfall and coupling between the two.Firstly,the sta⁃bility of landslides under different working conditions is calculated by Morgenstern-Prince method in the two-dimensional model,and the three-dimensional landslide model is used to monitor the changes of pore water pressure,stress and displacement of the landslide,so as to analyze the failure mechanism of the waterslide landslide.On this basis,the influence of single indicators of reservoir water level decline rate and rainfall intensity on the stability of landslide is analyzed.The results show that in the two-dimensional calculation,the reservoir water level slowly drops from 175 m to 145 m,and the landslide is the most dangerous when the chicken brain shell is the most dangerous in the event of heavy rainfall in 50 years,and the stability coefficient of the landslide is 1.032,and the landslide is in an unstable state.In the 3D model,the permeability and displacement of the slope body change greatly,in which the reservoir water level slowly decreases from 175 m to 145 m and encountered heavy rainfall in 50 years,the landslide had the maximum displacement,of which the horizontal displacement reached 31.38mm and the vertical displacement is 31.13 mm.The numerical prediction model shows that the displacement of the landslide mainly occurs in the middle and rear part,so when the reservoir water level drops and is accompanied by heavy rainfall,the deformation of the trailing edge of the landslide should be observed.The analysis of single factor shows that when the landslide only adjusts the reservoir wa⁃ter level decline rate,the stability of the landslide decreases as the reservoir water level decline r

关 键 词：三峡库区 滑坡 水位降落 耦合 数值模拟 下降速率 

分 类 号：P642.22[天文地球—工程地质学]