清江流域覃家田滑坡成因机制及稳定性分析

Formation Mechanism and Stability Analysis of QinJiatian Landslide of Qingjiang River Basin

覃家田滑坡位于清江流域隔河岩库区,是灰岩顺向岸坡区沿软弱夹层滑移的代表。水库(区)蓄水后前缘塌岸变形明显,其稳定性直接关系到3户共12人的生命财产安全及隔河岩水库的正常运行。通过野外调查,采用工程地质测绘、钻探、槽探等工程勘查手段,查明滑坡形成条件,分析滑坡形成演化历史和成因机制,并应用极限平衡分析法对滑坡进行了稳定性计算。滑坡稳定性主要受暴雨、水库水位涨落等外动力因素的影响;稳定性计算表明,该滑坡整体稳定性较好,但在暴雨加库水位骤降工况条件下稳定系数有所降低,局部存在滑塌的可能。

Qinjiatian landslide,located in Geheyan Reservoir area of Qing River basin,is a representative of the slip of limestone along the soft interlayer in the slope area.The deformation of leading edge of the bank is obvious after water storage,and its stability is directly related to the safety of 12 people from 3 families and the normal operation of the Geheyan reservoir.By means of field investigation,engineering geological surveying,drilling and trenching,the formation conditions of the landslide are found out,the formation evolution and mechanism of the landslide are analyzed,and the stability of the landslide is calculated by using the limit equilibrium analysis method.The results show that the stability of the landslide is relatively well and mainly affected by external dynamic factors such as rainstorm,fluctuation of reservoir water level,etc.,however,under the condition of heavy rainfall and sudden drawdown of reservoir water level,the stability coefficient decreases and local collapse may occur.