水工混凝土结构分项系数设计法可靠度研究

On reliability of concrete hydraulic structures

本文对《水工混凝土结构设计规范》修订搞承载能力极限状态设计表达式中分项系数的确定方法及取值方案进行了分析计算和探讨，提出了相应的分项系数取值建议。文中提出的确定分项系数的方法可概括为：根据各基本变量变异性的大小，事先选定合适的作用与材料性能分项系数，然后由给定的目标可靠指标，用概率方法确定设计表达式中的结构系数。这种分项系数设置体系和方法，不仅物理意义明确，而且由于作用与材料性能分项系数可事先选定，仅结构系数的确定才需作概率运算，因而使确定分项系数的工作得到简化。可靠度分析结果表明，按本文建议的分项系数取值方案进行设计，可使水工混凝土结构构件在不同设计条件下均具有较佳的可靠度一致性。

This paper investigates the evaluation of term-separated coefficients in a limit state expression of structual bearing capacity in Design Norms for Concrete Hydraulic Structures (revised draft). The method proposed in this paper for evaluating these coefficients may be summarized:according to the range of variation of basic variables. appropriate values of respective coefficients of both actions (loads) and material properties can be selected in advance; based on given reliable objective indices,the values of structural coefficients in the limit state expression are then determined using probabilistic method.This method not only has definitely physical meaning,but also makes the whole evaluation of various coefficients much simplified due to that coefficients of both actions (loads )and material properties may be selected in advance and only the structural coefficients need to be determined probabilisticly. The reliability analysis shows that with different design conditions,the reliabilities of elements of hydraulic structures designed by this method are in good agreement with each other.