土石坝建设期漫坝风险分析

Risk analysis of overtopping during the construction period of earth-rock dam

结合土石坝建设期挡水建筑物及其顶部高程不断变化的实际,基于Monte-Carlo计算机模拟方法,通过分析水文、水力因素的不确定性,确定洪水位的分布;分析施工进度的不确定性,确定挡水建筑物顶部高程的分布。在此基础上建立漫坝风险数学模型,并根据建设期导流阶段的划分,计算各阶段漫坝风险以及综合漫坝风险。实例分析表明,施工进度的不确定性对土石坝建设期的漫坝风险有显著影响,计算方法和研究模型具有较好的实用性。

Risk of overtopping during the construction period of earth-rock dam is not only controlled by flood level, but also by the top elevation of water retaining structure. With these two factors simulated by Monte-Carlo simulation, their distributions have been determined via analysis on the uncertainties in hydrologic and hydraulic factors and the uncertainties of construction progresses, the overtopping risk for each stage and the integrated overtopping risk have been calculated using a mathematical model that was developed for calculation of different water diversion stages. The case study shows that the uncertainties of construction progresses have significant effects on overtopping risk during the construction period of earth-rock dam, the calculation methods and models are practicable.