Abstract: The impoundment of Three Gorges reservoir would remarkably change the hydrogeological conditions in the reservoir area. In particular, the periodic fluctuation of reservoir water level 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 landslide 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 significant 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.

Key words: Three Gorges reservoir area, reservoir water decline, coupling of seepage and stress, landslide monitoring