高强箍筋高强混凝土Z形截面柱框架节点抗震性能试验研究

Experimental research on seismic behavior of high-strength concrete Z-shaped column frame joints with high-strength stirrups

为了研究高强箍筋约束高强混凝土Z形截面柱框架节点在地震作用下的抗震性能,对缩尺比为1∶2的5榀配置高强箍筋和1榀配置普通强度箍筋的高强混凝土Z形截面柱框架节点试件进行拟静力试验。研究了高强箍筋约束高强混凝土节点的破坏形态、滞回性能、骨架曲线、延性、耗能能力、刚度退化、受剪承载力以及高强箍筋应力发挥水平等。分析了剪压比、轴压比、箍筋的体积配箍率等参数对Z形截面柱框架节点破坏形态、滞回性能和受剪承载力的影响。结果表明：Z形截面柱节点的破坏形态受设计参数的影响,有弯曲破坏和弯剪破坏两类;与普通强度箍筋高强混凝土Z形截面柱框架节点相比,高强箍筋高强混凝土Z形截面柱框架节点在显著提高节点最大剪压比控制值的同时具有优越的抗震性能。给出了高强箍筋应力的取值,采用JGJ 149—2017《混凝土异形柱结构技术规程》公式计算高强箍筋高强混凝土Z形截面柱框架节点的受剪承载力是可行的,将其计算结果与试验结果进行了比较,两者吻合较好。

To research the seismic behavior of high-strength concrete （ HSC ） Z-shaped column frame joints confined with high-strength stirrups, quasi-static tests were carried out on five 1/2-scale HSC Z-shaped column frame joint specimens with high-strength stirrups and one with normal strength stirrups. Failure patterns, hysteretic performance, skeleton curve, ductility, energy dissipation capacity, stiffness degradation, shear bearing capacity and stress magnitude of high-strength stirrups were studied. The influences of shear compression ratio, axial compression ratio, stirrup volume ratio and other parameters of Z-shaped column frame joints on the failure mode, hysteretic behavior and shear bearing capacity were analyzed. The results show that the failure modes of Z-shaped column frame joint specimens are flexural failure or flexural-shear failure influenced by design parameters. Compared with HSC Z-shaped column frame joints with ordinary strength stirrups, HSC Z-shaped column frame joints with high-strength stirrups not only have significantly improved maximum shear compression ratio control value, but also have good seismic behavior. The values of high-strength stirrup stress are given. The shear capacity of HSC Z-shaped column frame joints with high- strength stirrups can be calculated using normal formula in the JGJ 149--2017 ＇Technical specification for concrete structures with specially shaped columns＇, and the solutions agree well with the experimental results.