库水下降条件下靠椅形滑坡的变形规律和稳定性

Deformation Law and Stability of Chair Shaped Landslide Under Reservoir Water Lowering Conditions

分析靠椅形滑坡在库水下降条件下的变形规律与稳定性意义重大。以三峡库区典型靠椅形滑坡-麻柳林滑坡为例,基于FLAC3D和Geostudio分别分析该滑坡在库水下降条件下的变形规律和稳定性。结果表明:滑坡在库水位快速下降阶段位移变化量大于缓慢下降阶段,且随着库水位的下降,坡体最大变形位置由高程220 m处变至175 m处,最大位移量为0.12 m;滑坡整体破坏以拉张为主;滑坡稳定性随库水位下降速率增加而显著降低,当组合工况为1.2 m/d下降速率+50年一遇暴雨时,滑坡处于欠稳定状态,此时应增加巡查次数。

It is significant to analyze the deformation regularity and stability of chair shaped landslides under the condition of reservoir water decline.Take Maliulin landslide,a typical chair shaped landslide in the Three Gorges reservoir area,as an example.Based on FLAC3D and Geostudio,the deformation law and stability of the landslide under the condition of reservoir water decline were analyzed.The results show that the displacement variation of landslide during the rapid decline stage of reservoir water level is greater than that during the slow decline stage.With the decline of the reservoir water level,the maximum deformation position of the slope changes from an elevation of 220 m to 175 m.The maximum displacement is 0.12 m;The overall failure of landslide is mainly caused by tension;The stability of the landslide decreases significantly with the increase of the drawdown rate of the reservoir water level.When the combined working condition is 1.2 m/d decline rate+50 year return period rainstorm,the landslide is in an unstable state,and the number of inspections should be increased.