Abstract: In the analyses of concrete structures, the strength criterion for concrete under biaxial stresses is applied frequently. But in fact, there is some discordance in accuracy among some existing strength criteria and their expressions are relatively fussy. Refering to code for design of concrete structures (GB50010-2002), the paper gains a unilateral Bernoulli’s lemniscate through fitting of a curve on the basis of analysis of document .In comparison with other strength criteria for concrete under

Key words: concrete, biaxial stress, strength criterion

摘要： 在砼结构分析中，常用到砼二轴应力状态下的强度准则.针对已有的一些砼强度准则取值不尽一致，且表达 式相对繁琐，在分析文献[1]试验结果的基础上，笔者结合《混凝土结构设计规范》(GB50010-2002)，按照曲线拟合的 方法，拟合成一条单侧贝努利双纽线，经与其他砼二轴应力状态下的强度准则进行了比较，本文提出的砼二轴应力 状态下的简化强度准则既能满足实际要求，又具有确定参数少、表达式简单、在不同的受力区具有统一的表达式的 特点.

关键词: 砼, 二轴应力状态, 强度准则