钢支撑-钢筋混凝土掉层框架结构抗震性能试验研究  

EXPERIMENTAL STUDY ON SEISMIC PERFORMANCE OF REINFORCED CONCRETE SPLIT-FOUNDATION FRAME STRUCTURES WITH STEEL BRACES

作　　者：刘立平[1,2] 李瑞锋 殷尧日 李英民[1,2] 邓飞 LIU Li-ping;LI Rui-feng;YIN Yao-ri;LI Ying-min;DENG Fei(College of Civil Engineering,Chongqing University,Chongqing 400045,China;Key Laboratory of earthquake resistance and disaster prevention for engineering structures,Chongqing University,Chongqing 400045,China;Anhui Design Institute,Hefei 230601,China)

机构地区：[1]重庆大学土木工程学院,重庆400045 [2]重庆大学工程结构抗震防灾重庆市重点实验室,重庆400045 [3]安徽省建筑设计院,合肥230601

出　　处：《工程力学》2024年第1期182-192,共11页Engineering Mechanics

基　　金：国家自然科学基金面上项目(51878101,51638002);重庆市研究生科研创新项目(CYB22030)。

摘　　要：为改善坡地钢筋混凝土(RC)掉层框架结构抗侧刚度分布的不均匀性,设计了一栋在上接地层设置钢支撑的RC掉层框架结构,按1/4比例提取其顺坡向中榀框架下部5层子结构为试验对象,开展钢支撑-RC掉层框架拟静力试验,观测试件的破坏过程,并对比RC掉层框架试验所得试件的破坏形态,分析试件滞回性能、延性和刚度退化等抗震性能指标。结果表明:试件的最终破坏是以第4层柱底混凝土压溃,梁端混凝土剥落、底部钢筋断裂,顶层柱顶混凝土剥落为标志。与RC掉层框架试验结果相比,钢支撑-RC掉层框架试件上接地柱的破坏明显减轻,柱端破坏分布也更为均匀,避免了掉层框架结构“半层破坏模式”的出现,改善了结构的耗能和抗地震倒塌能力。但试件上接地层相邻上一层的变形和破坏程度较大,应对该楼层的柱端进行适当的抗震加强;设置钢支撑后,试件的滞回曲线较为饱满,并具有良好的延性(正、负向加载的位移延性系数分别可达5.13、5.69),正负向加载的刚度退化曲线也趋于对称。In order to improve the non-uniformity of lateral stiffness distribution of reinforced concrete(RC)split-foundation frame structures,an RC split-foundation frame structure with steel braces was designed.According to the ratio of 1/4,the substructure of the lower 5 floors of the middle frame along the slope was extracted as the test object.A quasi-static test of RC split-foundation frame specimen with steel braces was carried out to investigate the failure process.And the failure mode of the specimen was compared with those obtained from the RC split-foundation frame tests,and then the seismic performance indexes such as hysteretic performance,ductility and stiffness degradation were analyzed.The results show that the final failure of the specimen was marked by the crushing of the concrete at the bottom of the column at the forth story,the spalling of the concrete at the beam end,the fracture of the bottom reinforcement and the spalling of the concrete at the column top of the top story.Compared with the test results of RC split-foundation frames,the damage of grounding columns of RC split-foundation frame specimen with steel braces was significantly reduced,and the damage distribution at the column ends was more uniform,which avoids the occurrence of"half floor failure mode",thus improving the energy consumption and seismic collapse resistance of the structure.However,the deformation and damage degree of the adjacent upper story of the upper ground story of the specimen was large,so the column ends on that story should be properly strengthened;The overall seismic performance of the RC frame specimen with steel braces is excellent,its hysteretic curve is relatively full,and it has good ductility(the displacement ductility coefficient under positive and negative loading can reach 5.13 and 5.69 respectively).The stiffness degradation curves of positive and negative loading tend to be symmetrical.

关 键 词：掉层框架结构 钢支撑 拟静力试验 抗震性能 破坏模式 

分 类 号：TU352.11[建筑科学—结构工程] TU375