混凝土框架顶部钢结构加层连接节点抗震性能试验研究

Experimental study on seismic behavior of joints between concrete frame and added top steel stories

通过对锚栓生根、焊接生根、增大截面生根等三类共5个加层连接节点进行低周反复荷载作用下的足尺模型试验,对混凝土框架顶部直接加层钢结构连接节点的破坏形态、滞回曲线、位移延性、耗能能力等进行研究。试验结果表明:三类加层节点的破坏形态均为混凝土梁端受弯破坏,混凝土与钢结构之间的螺栓及焊缝连接性能良好,连接过渡钢板未出现明显变形;增大截面生根节点的滞回曲线较为饱满,抗震性能优于锚栓生根节点和焊接生根节点;锚栓生根节点和焊接生根节点的施工工艺相对简单,可操作性较强。

The seismic behavior of three types of joints（bolted joint,welded joint and expanded section joint） between a concrete frame and the added top steel stories was investigated under low cycle load reversals.Performance of the test specimens was evaluated in terms of failure mode,joint shear deformation,energy dissipation capacity and ductility,etc.The test results reveal that all joints fail due to concrete crushing and rupture of longitudinal bars as a result of plastic hinges formed at the fixed beam end.The performance of bolted and welded joints are favorable.The transfer steel plate has no visible deformation.The energy dissipation capacity of the increased section joint is better than that of the bolted and welded joints.The construction technique of bolted and welede joint are simple.The results in this paper are useful to the design and construction of steel adding stories on top of the concrete frame.