施工缝及现浇楼板对混凝土平面框架“强柱弱梁”影响的试验研究

EXPERIMENTAL RESEARCH ON INFLUENCE OF CONSTRUCTION JOINTS AND CAST-IN-PLACE FLOORS ON “STRONG COLUMN AND WEAK BEAM” FOR PLANE FRAMES

为研究施工缝及现浇楼板对混凝土平面框架"强柱弱梁"的影响,对3个一榀两跨混凝土平面框架进行水平低周反复试验,分析各试件的破坏形态、滞回曲线。结果表明:在梁端设置施工缝的平面框架为梁铰破坏机制,带有现浇楼板的平面框架为柱铰破坏机制;梁端设置施工缝会降低框架的整体性,更易出现"强柱弱梁"破坏机制,结构整体抗震性能较差;现浇楼板的存在增强了框架梁的承载力,提高了结构的屈服荷载、极限荷载、极限位移,增加了结构耗能。

To study influence of construction joints and cast-in-place floors on the “strong column and weak beam” for RC plane frames,horizontal low-cycle repeated tests were conducted on three RC plane frames with one story and two spans,the failure modes and hysteresis curves of each specimen were analyzed.The results showed the plane frame with construction joints at beam ends failed due to plastic hinges at beam ends,and the plane frame with the cast-in-place floors failed due to plastic hinges at column ends;the construction joints at beam ends reduced the integrity of frames,which were more prone to the “strong column weak beam”.The aseismic performances of structures were poorer;cast-in-place floors could enhanced the bearing capacity of frame beams,including the yield loads,ultimate loads and corresponding displacement of structures,and increased the structural energy consumption.