基于结构可靠度理论的溃口范围确定方法研究

Dam-breach range determination based on structural reliability theory

当前水工设计中常用的单个单元点的安全系数很难表征工程结构整体的安全性,更不利于判断具有贯穿性破坏特点的溃口问题。对此,提出了选取贯穿大坝上下游面且距离最短的所有单元组成一个单元组,并用概率理论分析大坝整体溃口失效与单元组的串并联关系,进而提出了用可靠度定量确定溃口范围的新方法。据此对某碾压混凝土双曲拱坝进行了计算分析,结果表明该计算方法科学、可行,由失效概率确定的溃口范围比传统点安全系数的表达更直观、客观。

The safety coefficient of single element normally used in hydraulic engineering design is difficult to representing the overall structure safety, especially unqualified to analyze the penetrative dam-breach problem. A reliability theory to determine dam-breach range is proposed, in this method,the single element that penetrates dam body with the nearest distance is incorpo-rated into an element group;furthermore, the series-parallel relation between dam-break overall failure and the element group is analyzed by probability theory. The proposed method is applied to a roller concrete arch dam, the results show that the presen-ted method has advantages of rationality and applicability and its dam-breach range is more intuitive and objective to traditional point safety coefficient method.