基于大坝脆弱度与溃坝后果系数的群坝风险排序方法再研究

A Modified Ranking Method for Dam Portfolio Risks Based on Dam Fragility and Dam-Break Consequence Coefficient

我国水库数量世界第一,大坝安全涉及公共安全,安全管理成本巨大,如何在大坝安全管理中体现差别化,被各级政府所重视,随着党和国家对水库安全要求越来越高,现有大坝安全管理方式已经逐渐无法满足各级政府对水库大坝安全实施差别化管理的需求,研究提出体现大坝差别化管理的方法十分必要。在大坝脆弱度和溃坝后果系数概念基础上,对大坝风险指数计算方法进行再研究,对大坝风险指数法的内涵作了深入分析,对溃坝后果系数作了改进,重新将该方法用于20座震损水库上,获得大坝风险指数排序的有益认知。结果表明,脆弱度并非大坝风险指数的唯一因变量,需将脆弱度和溃坝后果结合起来考虑才能确定大坝风险指数的高低,风险指数大的水库大坝应优先安排加固。

China has the largest number of dams in the world.Reservoir and dam safety involves the public safety with high cost for safety management.Governments at all levels have paid increasing attentions to differentiated dam safety management,which is worthy of research as current safety management no longer meets governments’requirements in reservoir and dam safety.Based on the concepts of dam fragility and dam-break consequence coefficient,we analyzed the method of calculating dam risk index,modified the dam-break consequence coefficient,and apllied the modified method to 20 earthquake-damaged reservoirs to obtain the ranking of dam risk index.Results show that the risk index of highly vulnerable reservoir is not necessarily high,and vise versa.Fragility is not the only dependent variable in determining the risk index.Fragility and dam-break consequence coefficient must be combined to determine the risk index.Dams with high risk index should be reinforced in priority.