基于反应谱法的RCC重力坝动力可靠度分析

A Reliability Analysis of RCC Dam Based on the Response Spectrum Theory

在反应谱理论的基础上结合响应面法显式表达了RCC重力坝的功能函数,解决了在动力分析中弹性抗拉和抗压的功能函数不能显示表达的困难,再运用JC法求解可靠度指标。以铅厂水电站RCC重力坝为例,计算了其结构可靠度指标。结果表明,整个坝体的抗压强度可靠度指标均比较高,均满足规范要求。坝踵、上游坝坡转折处、坝基面、坝趾部位的抗拉可靠度指标较小,甚至小于1,表明这些地方的拉应力超过混凝土的允许抗拉强度,甚至被破坏。这从动力特性分析的结果中能够得到印证。可见,运用这种方法计算可靠度指标效率高,实用性强。

Based on the response spectrum theory and the response surface method, this paper expresses explicitly the reliability function. Therefore, the tensile and compressive function can not show the function explicitly. Then reliable index can be solved by using JC method. Taking Qianchang RCC dam as an example, this paper solves the reliable index. The results show that the compressive strength is higher than the standard value in the entire dam. But tensile reliable index is small in the dana heel, turning of the upper slope, foundation face and the dam toe, even less than 1. It indicates that these areas of stress over the concrete allow the tensile strength. This can be confirmed by an analysis of the dynamic behavior. It is clear that the method can get good precision,high performance and practicability.