混凝土拱坝的多轴强度与安全指标

为便于推算混凝土多轴强度,开展混凝土结构的多轴强度设计,本文针对任意的多参数强度准则,给出了用等比超载系数K_(OL)计算多轴强度的通用方法。以某已建成的拱坝为例,分别计算坝体的等比超载系数K_(OL)和失效距离系数K_(FD),并与单轴强度安全系数进行比较,指出混凝土拱坝按多轴强度设计的必要性。基于K_(FD)的定义和算例分析,建议将K_(FD)作为拱坝多轴强度安全设计和校核的指标。

Multi-axial strength and safety index of concrete arch dams

In order to calculate the multi-axial strength of concrete and design a concrete structure considering the multi-axial strength of concrete, a general method for calculating the multi-axial strength under an arbitrary multi-parameter strength criteria is presented in this paper by using the overload factor of equivalent ratio, K_OL. Taking a completed arch dam as an example, the equal proportional overload factor, K_OL, and the failure distance factor, K_FD, are calculated, respectively, and compared with the safety factor of uniaxial strength. Then, the necessity of designing a concrete arch dam according to the multi-axial strength is pointed out. Based on the definition of K_FD and the analysis of an example, it is suggested that K_FD should be consideredas an index for the safety design and the checking of multi-axial strength of arch dams.