Deformation response regularity of Liujiaba landslide under fluctuating reservoir water level condition

Abstract

Due to the periodic rising and falling of the reservoir water level, the rock–soil body of bank slope is constantly changing between the saturated and unsaturated status, which changes the limit equilibrium condition of the slope body, resulting in a large number of dormant landslide reactivation and new landslide generation after water impounding operation of the three gorges reservoir. Based on the long-term monitoring data of pore-water pressure, water content, reservoir water level, rainfall and landslide deformation, the deformation response regularity of Liujiaba landslide under the fluctuating reservoir level combined scenario is studied in this paper. The results show that the landslide deformation is mainly in the lower section affected by the fluctuation of the reservoir water. The slide deformation appears in the mid-early stage of the water level declining and during the running of 175 m water level. The deformation is gradually increasing from a slowly to rapidly stage, then slows down and gradually reduces to a relative stopped state. Considering that the variation of the saturation line in the landslide will be influenced by the water level fluctuation rate, the SEEP and SLOPE modules are used with Geo-studio software for the fluctuant reservoir level and response pattern of landslide deformation analysis. The study can be provided as a reference for landslides study of debris aggradational landslide.