Abstract: The detailed process to calculate risk probability of earth-rock dam overtopping caused by floods based on Monte-Carlo Method was presented in this paper. Factors affecting the risk probability, inclusive of flood, wind wave, reservoir scheduling and reservoir features were deeply analyzed and sensitivity analysis for these factors was conducted. An earth-rock dam in south China was taken for example. Results reveal that the mean value of peak flow, the coefficient of variation, as well as the mean value of maximum wind speed have large impact on the risk probability; whereas the coefficient of skewness and the mean wind speed variance have little effect. Besides, the reservoir characteristics and the initial water level before flood also have considerable influence on the risk probability. By comparing the calculated results with engineering analysis results, we conclude that it’s reliable to calculate the risk probability of earth-rock dam overtopping by using Monte-Carlo method.

Key words: earth-rock dam, overtopping risk probability, uncertain factors, Monte-Carlo method, sensitivity analysis