Abstract: Since the impoundment of the Three Gorges Reservoir, many landslides and other geological hazards have occurred in the reservoir area. Based on the analysis of the relationship between the GPS monitoring data and the reservoir pool water level, the Sunjiazhuang landslide in the three Gorges Reservoir area was selected to evaluate the stability. It is concluded that the sliding belonged to the buoyancy weight loss landslide type. The SEEP/W and SLOPE/W modules in geo-studio software were used and the seepage field under different pool water level rising rate conditions was evaluated. The variation of the stability coefficients was analyzed in detail. The results show that in the process of reservoir water rising, the sliding resistance section at the leading edge of the landslide body is continuously submerged, the anti-sliding force decreases, and the stability coefficient decreases. The smaller the rising rate of reservoir pool water, the smaller the stability coefficient.

Key words: buoyancy weight loss landslide, rate of rise of reservoir water pool level, seepage field, slope stability