钢筋混凝土剪扭构件承载力计算公式的研究

《混凝土结构设计规范》(GB 50010-2010)(以下简称《规范》)在剪扭复合作用构件承载力计算中采用三段折线关系,将1/4圆弧外扩,导致设计偏于危险;丁大钧建议公式使用1/4圆弧模型,但在选取混凝土剪力项折减系数时低估了混凝土部分的抗剪能力;黄靓建议公式使用内缩的直线模型,设计偏于保守.在1/4圆弧相关关系的基础上提出两种修正公式.实例对比表明,两种修正公式安全于《规范》公式.算例分析表明,两种修正公式既能完全满足1/4圆弧相关关系,又较好地满足了黄靓提出的直线相关关系且两种修正公式计算结果相当接近.

Study on the Calculation Formula of Reinforced Concrete Members under Shear and Torsion

It is pointed out that the Tri-linear Model in Concrete Structure Design Code GB 50010-2010 for calculating the bearing capacity of reinforced concrete members under the combined action of shear and torsion enlarges the 1/4 Circular Arc Model and leads to an unsafe design. The formula proposed by Ding Dajun using the 1/4 Circular Arc Model understates the bearing capacity of concrete in choosing the reduction factor of concrete shear capacity. The formula proposed by Huang Liang using the Linear Model makes the design conservative. On the basis of the 1/4 Circular Arc Model, two modified formulas were provided. Practical examples show that Formula 1 and Formula 2 are more secure than the Code formula. Numerical examples show that Formula 1 and Formula 2 not only totally conform to the 1/4 Circular Arc Model , but also approximately conform to the Linear proposed by Huang Liang, and their calculation results are quite similar.