Dynamic Response and Deformation Behavior of Kadui-2 Landslide Influenced by Reservoir Impoundment and Rainfall, Baoxing, China

This study focuses on the deformation characteristics of Kadui-2 Landslide by the influence of reservoir filling-drawdown and precipitation. A three-year monitoring project was implemented in order to observe the short/long-term deformation. The slide mass experienced consistent deformation with a maximum cumulative displacement of 331.34 cm. Based on the recorded data of reservoir water level and precipitation during this period, a two-dimensional (2-D) finite element model using Geostudio software was set up for deformation simulation under different conditions to understand the real influence of these triggering factors on landslide. The numerical simulation results are in consistent with monitoring field data. Both numerical simulation and field monitoring results exhibit that the maximum deformation occurred at the foreside of slumping mass. The slip surface shows significant creep characteristics decreasing as long-term shear strength reducing gradually. Reservoir water level fluctuation is the primary triggering factor to reactivate the landslide mass and has a negative correlation with deformation rate. Displacement rate increases with the reservoir drawdown and decreases with impoundment rise. Compared with reservoir filling-drawdown operation, rainfall has no significant effect on the slide motion of landslide due to limited penetration from the ground surface.