基于力学机制的钢筋混凝土柱抗剪承载力模型∗

为了兼顾钢筋混凝土(RC)柱抗剪承载力分析的计算精度和简便性,研究建立了一种基于力学机制的RC柱抗剪承载力简化模型。首先基于变角桁架-拱模型理论,结合变角桁架模型的力平衡条件以及变角桁架模型和拱模型之间的变形协调条件,建立了RC柱抗剪承载力分析的理论模型;然后利用38组试验数据进行统计分析,分别确定了混凝土、箍筋和拱模型的抗剪承载力贡献系数近似取值,在此基础上建立了R C柱抗剪承载力分析的简化模型;最后通过与试验数据进行对比分析,验证了该模型的计算精度和适用性。分析结果表明,该模型不仅可以合理分析混凝土、箍筋和拱作用的抗剪承载力贡献,具有较高的计算精度,而且计算公式较为简洁。

Shear Strength Model of Reinforced Concrete Columns based on Me-chanical Mechanism

In order to balance the accuracy and convenience of shear strength analysis of reinforced concrete(RC) columns,a simplified model for shear strength of RC columns was established based on mechanical mechanism.A theoretical shear strength model for RC columns was established first based on the theory of variable angle truss-arch model,by taking into account the equilibrium condition for forces of the variable angle truss model as well as the deformation compatibility condition between the variable angle truss model and the arch model.Then a simplified model for shear strength of RC columns was developed by simplifying the shear strength contribution coefficients of concrete,transverse reinforcement and arch action based on statistical analysis of 38 sets of experimental data.Finally,the accuracy and applicability of the simplified model were validated by comparing with 58 sets of experimental data.The analysis results show that the simplified model not only can rationally describe the shear strength contributions of concrete,transverse reinforcement and arch action,but also has high accuracy and convenience.