对于钢筋混凝土弯扭构件的配筋设计,我国《混凝土结构设计规范》(GBJ 10—89,GB 50010—2002和GB50010—2010)基本沿用了相同的思路,常称为"简化实用算法",即忽略弯扭相关性,受弯扭构件纵向钢筋截面面积分别按受弯构件的正截面受弯承载力和剪扭构件的受扭承载力计算确定,并叠加配置在相应的位置。但现行混凝土规范(GB 50010—2010)没有给出弯扭承载能力验算公式,有人错误地混淆设计和验算的关系,认为按现行混凝土规范(GB 50010—2010)设计的弯扭构件承载能力严重偏低且对应的可靠指标远不能满足《建筑结构可靠度设计统一标准》(GB 50068—2001)的目标可靠指标。基于弯扭相关性,提出钢筋混凝土弯扭构件承载能力简化验算方法,并对其安全性进行探讨,得出的结论具有指导意义,有助读者正确和深入地理解我国《混凝土结构设计规范》。
In order to design the RC member under torsion and bending, Chinese Codes for design of concrete structures( GBJ 10--89, GB 50010--2002 and GB 50010--2010) always carry out the same way. The method generally is named "Simplified Practical Method", that is, ignoring the bearing capacity correlation between torsion and bending, the longitudinal reinforcement of RC member under torsion and bending depend upon the reinforcement calculating on the same RC member under torsion and bending individually. Two different types of reinforcement are superimposed on each other in the corresponding position according to the section area of reinforcement. Chinese current Codes for design of concrete structures ( GB 50010--2010) do not prescribe the bearing capacity check method of RC member under torsion and bending. Someone mistakes the relationship between design method and check method, and thinks that the real bearing capacity designed by Chinese current Codes for design of concrete structures (GB 50010--2010)is below the real expected demand severely and the corresponding reliability can not meet the minimal requirements of Unified standard for reliability design of building structures (GB 50068--2001 ). Based on the correlation between torsion capacity and bending capacity, a simplified calculation method for bearing capacity of RC member was put forward, and the safety of the simplified calculation method was discussed. The conclusions have directive significance and can help readers understand Chinese Codes for design of concrete structures rightly and further.