含概率与区间混合不确定性的重力坝可靠性分析

Reliability Analysis of Gravity Dams with Probability and Interval Mixed Uncertainty

针对重力坝可靠度分析中由于数据缺乏或监测条件限制难以得到各变量精确的概率分布的情况,提出了含概率与区间混合不确定性的结构可靠性分析方法,对于可得到精确概率分布的变量用随机变量进行考虑,对于无精确概率分布的变量用区间表示,并结合响应面法计算了广西红水河龙滩重力坝坝踵抗拉可靠度。结果表明,该方法只需少量的不确定信息就可对结构进行可靠性分析,更适合结构复杂、不确定性较高的水工建筑物结构。

In the reliability analysis of gravity dams,it is often difficult to get the precise probability distribution function with limited data or limited test conditions.Therefore,in this paper,a structure reliability analysis method with probability and interval mixed uncertainties is proposed,in which those variables with precise probability distributions are taken as random variables,while others without precise probability distribution can only be given variation intervals.Then a case study of Longtan Gravity Dam is presented,and the tensile reliability of dam heel is calculated using the response surface.The results show that the method can be used for the dam reliability calculation with limited information.Thus,it is more suitable for hydraulic structures with high uncertainty.