Influence of water level drawdown on landslide movement in reservoir

Abstract

Water level variation is one of the main triggering factors of landslides in reservoirs. In the Three Gorges Reservoir, China, the field monitoring data of the Shuping landslide shows that the sliding deformation accelerates during water level drawdown. In order to study the influence of water level drawdown on landslide movements in the reservoir, series of slope model tests were conducted to simulate the response of water level drawdown on the slope. The movement of slopes with different soil permeability is presented along with the generation and dissipation of pore water pressure in the slopes under water level variation. Experimental results show that the permeability of slope material controls the dissipation of pore water pressure in the slope under water level drawdown. However, if the permeability is high enough, the effect of the permeability change on the dissipation time of pore water pressure will not be obvious. During the mitigation and prevention of landslide with low permeability soil in reservoir, more attention should be focused on the drainage of ground water to quickly reduce the pore water pressure after water level drawdown in reservoir.