对钢筋混凝土弯扭构件承载力计算公式的修正

GB50010-2002《混凝土结构设计规范》(以下简称“规范”)分别按纯弯和纯扭进行弯扭构件承载力计算。基于国内外大量试验数据的分析表明,该设计计算方法与试验结论相矛盾,未能正确反映构件的受力状态,使得计算值与试验数据拟合较差且偏于不安全,可靠指标偏低,不能满足GB50068-2001《建筑结构可靠度设计统一标准》(以下简称《统一标准》)的要求,配筋需要较大幅度地提高。通过对现有试验数据的分析,给出了基于1/4圆弧模型的建议修正公式和其相应的计算方法,该公式考虑了构件的整体受力相关性,具有明确的物理意义,配筋能返回公式验算。分析结果表明:该文建议的修正公式比规范公式的计算模式准确,可靠指标满足《统一标准》的要求。

MODIFICATION OF THE BEARING CAPACITY FORMULA OF RC MEMBERS UNDER TORSION AND BENDING

The torsion and bending capacity of RC torsion-bending components are calculated separately according to the methods of pure torsion and bending in GB50010-2002,which is contrary to test results and cannot reflect a force state.Therefore,the computing model of the code formula is inaccurate,which causes low reliability and the demand of GB50068-2001 cannot be satisfied.Through the analysis of existing test data,a modified formula based on 1/4 arc and its calculation method are proposed.The overall force correlation of torsion and bending is considered in this formula,with a definite physical meaning.The calculated reinforcement area can be returned to this formula for checking.Computational results show that the computing model of the modified formula is more accurate and its reliability can meet the demand of GB50068-2001.