Stability Analysis of Qianchanggou Landslide Mass under Fluctuation of Reservoir Water Level

Stability of the Qianchanggou landslide mass on the right bank of the Guanyinyan hydropower station in Yunnan province is analyzed. Physical and mechanical parameters of the rock and soil in the landslide mass are determined through in-situ geological investigation,laboratory experiments and back calculation. Geo-Studio software is adopted to calculate the safety factors of the slope under different conditions. Results show that the Qianchanggou landslide slope is stable in the original riverbed water level condition. After impoundment of the reservoir,stability of the slope reduces with the water level rises. When the water level drops suddenly,the stability of the slope will decline slightly. While under extreme adverse conditions such as a storm or earthquake,the slope stability will be greatly reduced. Then,a treatment measure of slope cutting is proposed. It shows that the stability of the slope improves greatly after the cutting and meets the safety requirement.