Deterministic and Uncertainty Analysis of a Reservoir Slope Stability and Failure Mechanism Under Combined Action of Multi-hazards

Influenced by continuous rainfall and water level fluctuation, a large number of landslide disasters occur in the reservoir areas in China every year, causing serious property losses and casualties. Based on the unsaturated seepage theory, the deterministic method and Monte-Carlo method are used to simulate the safety state of a reservoir bank slope under combined action of continuous rainfall and fluctuation of water level. Besides, the variation trend of safety factor, failure probability and reliability index of the slope under different working conditions are also obtained. By revealing the instantaneous variation characteristics of the equivalent plastic zone, the progressive failure mechanism of the slope is analyzed. The most dangerous condition is the time when the water level drops by 3 m/d and the rainfall changes at 30 mm/d simultaneously. This study provides a reference for risk analysis and emergency management of reservoir slope under extreme conditions.