Unsaturated seepage analysis of the influence of water level fluctuation on pore water pressure of landslide in reservoir area

Iandslide in a certain reservoir area is chosen as the engineering background. According to the saturated-unsaturated seepage equation, the dynamic response of pore water pressure in the landslide influenced by the fluctuation of water level is studied when considering the infiltration characteristics and the fluctuation velocity of water level. The analysis results show that (1) when the water level fluctuates, the saturated permeability coefficient has great impact on the initial water level under the same infiltration condition; with the increase of the saturated permeability coefficient, the water level becomes lower, and the water level line becomes more smooth, which has smaller impact on the dynamic and static pore water pressure, and is good to the slope stability; (2) with the increase of fluctuation velocity of water level, the response of water level lags behind, the water level line becomes steeper, which causes greater dynamic pore water pressure to the slope, and is worse to the slope stability.