库水下降联合降雨作用下树坪滑坡流固耦合分析

Coupling of Seepage and Stress of Shuping Landslide under the Combined Action of Reservoir Water Decline and Rainfall

三峡水库蓄水将显著改变库岸的地质条件,特别是库水的周期性涨落将极大地影响到滑坡体的稳定性,由于防洪等需求,目前库水位在175～145 m之间波动,若滑坡在库水下降时遭遇到强降雨,将可能失稳.树坪滑坡属巨型古堆积体滑坡,距三峡大坝坝址约47 km,若失稳将造成重大损失.应用ABAQUS软件对树坪滑坡进行库水下降联合降雨作用下三维流固耦合分析,研究了树坪滑坡在几种工况下的变形及破坏规律,并与监测结果进行对比.结果表明：库水下降及降雨作用对树坪滑坡的稳定性有很大影响,特别是在库水下降后期时遭遇到强降雨,滑坡极易失稳.

The impoundment of Three Gorges reservoir would remarkably change the reservoir area. In particular, the periodic fluctuation of reservoir water level the hydrogeological conditions in will greatly affect the stability of landslide. As a result of flood control requirements, the water level fluctuates between 145 m to 175 m, but if land- slide encounters heavy rainfall when reservoir water declines, landslide instability would happen. Shuping landslide is a giant old accretions landslide about 47km away from the Three Gorges Dam, its instability would cause signifi- cant losses. Software ABAQUS was employed to research the three-dimensional coupling of seepage and stress of Shuping landslide under the combined action of water level decline and rainfall. The deformation and failure of Shuping landslide under several conditions were analyzed and were compared with monitoring results. Results show that reservoir water level decline combined with rainfall has great influence on Shuping landslide. The stress field of landslide together with the physico-mechanical properties of soil changes greatly. Heavy rainfall in the end of reservoir water decline would very much likely lead to landslide failure.