湖北姚家平水利枢纽工程木贡滑坡稳定性分析及加固建议

Stability Analysis and Mitigation Measures of Mugong Landslide in Yaojiaping Water Conservancy Project in Hubei Province

依托湖北姚家平水利枢纽工程库区左岸木贡滑坡可研阶段勘测分析,采用极限平衡法分析该边坡在水库蓄水后不同骤降下的稳定性。研究结果表明:滑坡整体稳定,工程蓄水对滑坡800.0 m高程以上没有影响,且有助于近坡脚处滑坡的稳定;对于东侧次生滑坡(M1)方向,723.0 m~746.5 m高程在正常蓄水位745.0 m骤降至死水位710.0 m工况下浅层处于基本稳定,建议采用抗滑桩进行加固;对于矮楼门次生滑坡(M3)方向,806.0 m~875.0 m高程斜坡均处于基本稳定状态,由于处于工程非影响区域,工程蓄水对这些部位没有影响。建议地方加强观测,实时注意这些滑体的变形动态;700.0 m高程以下滑体位于死水位以下,考虑失稳形成稳定斜坡,不会对滑坡稳定性造成影响。

This paper presents the slope stability analysis of Mugong landslide on the left bank of the reservoir area of Yaojiaping water control project in Hubei Province.The limit equilibrium method was used in the analysis of the reservoir under different rapid drawdown conditions after pooling.The results show that the potential landslide body is in the stable state in general.The proposed water pooling would not trigger the landslides at locations with elevation above 800.0m.In the direction of potential secondary landslide(M1) on the east side,the surficial soil layer is marginally stable under the condition that the elevation of 723.0m ~ 746.5m with a rapid drawdown from the normal pool level of 745.0m to the dead water level of 710.0m.For the surficial soil layer within this zone,it is recommended that the anti-slide caisson could be used as the mitigation method.For the potential secondary landslide of in the direction of Aimenlow(M3),the slopes within the zone between elevation 806.0m and 875.0m are basically stable.As this area in in the non-affected area of the project,the water storage of the project has no impact.The real-time slope deformation monitoring tools should be adopted.The potential sliding bodies below the elevation of 700.0m are below the dead water level,so it is considered that instability is not likely.