论文部分内容阅读
梁柱新旧混凝土结合面是框架结构托换节点的薄弱部位。为了提高梁柱结合面承载能力,进行了配置不同界面钢筋的14组托换节点试件的静力加载试验研究。结果表明:托换节点的破坏由两种形式控制,托换节点界面滑移破坏或托换梁受剪破坏。当梁柱结合面不设置界面钢筋或界面钢筋配筋特征值(钢筋屈服强度设计值与其面积的乘积)小于2 MPa时,托换节点发生界面滑移破坏;当界面钢筋配筋特征值大于2 MPa时,托换节点的破坏形式由界面破坏转变为托换梁的受剪破坏。提出考虑界面钢筋的摩擦剪切公式,并确定了其中的参数。在托换节点设计时,可以根据托换梁的受剪承载力及界面承载力计算公式确定界面钢筋的配置量,确保托换节点的结合面不发生破坏,实现托换节点的优化设计。
The new-to-old concrete joint surface of the beam column is the weak part of the frame support node. In order to improve the bearing capacity of the beam-column joint, static loading experiments were carried out on 14 specimens of underpinning nodes with different interface reinforcement. The results show that the damage of the underpinning node is controlled by two forms, the interface of the underpinning node slips or the sheared damage of the underpinning beam. When the interface between the beam and the column is not set interface reinforcement or the value of interface reinforcement reinforcement (the product of the design value of reinforcement yield strength and its area) is less than 2 MPa, the interface slip failure occurs at the underpinning node. When the characteristic value of interface reinforcement reinforcement is greater than 2 MPa, the damage form of underpinning node changes from interface damage to shear damage of underpinning beam. The friction shear formula considering the interface reinforcement is proposed and the parameters are determined. When designing the underpinning node, the configuration of the interface reinforcement can be determined according to the shear bearing capacity of the underpinning beam and the calculation formula of bearing capacity of the interface, so as to ensure the joint surface of the underpinning node will not be damaged and the optimal design of the underpinning node will be realized.