现浇柱叠合梁框架节点抗震性能试验研究

以一幢六层现浇柱叠合梁框架实际工程为背景,按照强柱弱梁、强节点弱构件等原则进行设计,取4个不同位置的现浇柱叠合梁框架节点进行低周反复荷载下的足尺模型试验,对现浇柱叠合梁框架节点的破坏形态、滞回曲线、位移延性、刚度退化、耗能能力、预制梁与预制板之间和预制板与现浇板之间的滑移等进行了较系统的研究。结果表明:4个现浇柱叠合梁框架节点均实现了强柱弱梁、强节点弱构件的设计目标,破坏形态均为梁端受弯破坏形式,节点核心区仅有少量细小裂缝;边节点、中节点和平节点的初裂位置为梁中新旧混凝土界面处,而角节点的初裂发生在柱上;与其他2个节点相比,中节点和边节点的滞回曲线饱满;中节点、边节点和平节点的位移延性高于角节点;4个节点的刚度退化规律基本一致。研究成果可为现浇柱叠合梁框架在地震区的推广应用提供技术依据和基础数据。

Experimental study on seismic behavior of different type of frame connections with composite beams and cast-in-place columns

An experimental program consisting of the tests of selected connections with composite beams and cast-in-place(CIP) columns under cyclic loading,which were from the bottom story and the top story of a six story prototype residential building,was conducted to evaluate the seismic behavior of connections with composite beams and CIP columns.Performance of the test specimens was evaluated in terms of failure mode,stiffness degradation,energy dissipation capacity,ductility,joint shear deformation,etc.The test results revealed that both the test specimens exhibited a strong column-weak beam failure mechanism.All connections failed due to concrete crushing and rupture of longitudinal bars as a result of plastic hinges at the fixed beam end;the initial crack occurred at the interface between precast concrete and cast-in-place concrete in beam for the interior and exterior and T connections,but occurred in column for the knee connection;the hysteretic curves of both the interior and the exterior connections were full and showed good energy dissipation,and the energy dissipation capacity of the interior and exterior connections were better than that of the T and knee connections;the displacement ductility of the interior and exterior and T connections were better than that of the knee connection,and the stiffness degradation rules were similar to each other.The results in this paper are useful to expand the application of precast concrete structures in seismic zones.