Abstract: Deposit slope, which widely distributes in southeast Tibet with complex climate condition and harsh geological condition, poses large potential risk due to multiple extreme factors. To investigate into the effect of complex environment on slope failure, a hazard evaluation method in consideration of coupled multiple triggering factors is proposed. The probability and return period of triggered events of different hazard levels are analyzed, and on this basis, the failure probability corresponding to different events is calculated by Monte Carlo simulation techniques. In the meantime, the stochastic characteristic of triggering factors and the uncertainty involved in the inducing process are considered. Furthermore, multiple factors are coupled with the law of total probability, thus the hazard degree and potential risk of deposit slope can be comprehensively assessed. Earthquake and rainfall, as two explicit scenarios, are incorporated into a real engineering case as an example. The results suggest that the hazard level of the case is moderate; and in general, when the combination of triggering factors gets more extreme, the comprehensive hazard level is smaller.

Key words: deposit slope, return period, probability of failure, rainfall-induced landslide, earthquake-induced landslide, Monte Carlo simulation