框架柱托换体系抗冲剪承载力预计模型研究

为了能够准确进行框架柱托换体系抗冲剪承载力的预计，通过试验研究了托换体系的受力机理以及托换界面不同的连接构造、托换梁配筋对框架柱抗冲剪承载力和破坏形态的影响．结果表明：设置新老混凝土界面连接钢筋和增大托换梁中部和上部配筋可提高框架柱托换体系的抗冲剪承载力和延性．在此基础上通过理论分析将破坏过程分为界面滑移前和滑移后2个阶段并分别提出了托换体系抗冲剪承载力的预计模型和设计建议．

Prediction Model of Antipunching Shear Bearing Capacity for Frame Columns Underpin System

In order to predict the antipunching shear bearing capacity of the frame column underpin system, the stress mechanism of underpin system and the influences of different coupling construction of underpinning interface and the bar of underpinning beam on the an- tipunching shear bearing capacity and failure form of frame column underpin system were studied experimentally. The results show that the antipunching shear bearing capacity and ductility of frame column underpin system are improved by installing coupling bar at the interface of the new-to-old concrete and enlarging the reinforcing bars at the centre and upper position in the underpinning beam. Based on the experimental results, the failure process is divided into two stages which are before and after interface slip by theoretical analysis, and the prediction mod- els and design advices of antipunching shear bearing capacity of the underpin system for the two stages were presented.