论文部分内容阅读
准确计算节点核心区剪力设计值是节点核心区抗剪设计的关键。GB 50010—2010《混凝土结构设计规范》(简称《混凝土规范》)和GB 50011—2010《建筑抗震设计规范》(简称《抗震规范》)中给出了不同的节点核心区水平剪力计算公式。基于受力平衡条件,对这两部规范中的节点核心区水平剪力计算公式进行讨论,并给出改进建议。结果表明:《混凝土规范》中对不同位置节点受剪计算应采取不同的计算公式,但顶层节点公式未考虑单侧柱端剪力对节点核心区水平剪力的贡献,而《抗震规范》中的建议公式可考虑这一贡献。《混凝土规范》和《抗震规范》中的公式均采用梁端弯矩之和等于柱端弯矩之和的假定,主要适用于节点核心区几何尺寸远小于梁跨或柱高的情况。建议公式中考虑了单侧柱端剪力对节点核心区水平剪力的贡献,其适用范围更大。
Accurately calculating the core shear strength of the node is the key to the shear resistance design in the core of the node. The formulas for calculating the horizontal shear force in different core regions are given in GB 50010-2010 Code for Design of Concrete Structures (“Concrete Code”) and GB 50011-2010 “Seismic Design Code for Buildings” (“Seismic Specifications” for short). Based on the stress equilibrium condition, the calculation formulas of the horizontal shear force in the core of these two specifications are discussed and the suggestions for improvement are given. The results show that different formulas should be adopted for the calculation of shear at different positions in Concrete Code, but the formula of top node does not consider the contribution of end shear of unilateral columns to the horizontal shear force in the core of the node. However, The proposed formula can consider this contribution. The formulas in Concrete Code and Seismic Code both adopt the assumption that the sum of bending moment at beam end equals to the sum of bending moment at column end, which is mainly applied to the case where the geometric size of the core area of a node is much smaller than the beam span or column height. The proposed formula takes into account the contribution of the shear force of the unilateral column to the horizontal shear force of the core region of the node, which is more applicable.