【作者】 王婷；

【导师】 杨勇；

【作者基本信息】 西安建筑科技大学 ， 防灾减灾工程及防护工程， 2016， 硕士

【摘要】 钢筋混凝土框架结构是我国常用的建筑结构类型之一,在我国地震区的城镇中大量存在。钢筋混凝土框架结构在经历较大地震后,会出现混凝土开裂、局部破坏和残余变形,但是多数建筑仅会在局部楼层出现较严重破坏,而在多数楼层破坏不是很严重。对这种震后钢筋混凝土框架结构全部进行拆除会带来较大的经济损失,而且拆除后的建筑垃圾处理问题也较为突出。鉴于此,论文提出“防屈曲支撑补强+预应力钢带加固”相结合的加固设计思路,对此类震后钢筋混凝土框架结构进行加固,使其达到甚至超过震前抗震性能,并满足新建结构抗震性能要求,以充分利用震后结构,减小经济损失、建筑垃圾和资源消耗,加快震后恢复重建进程。本项目对一榀单跨三层1:2比例的钢筋混凝土框架分别进行了地震和震后加固试验研究,对采用防屈曲支撑和预应力钢带加固的震损钢筋混凝土框架的抗震性能进行了分析研究。首先,对一榀缩尺比例1:2的单跨三层钢筋混凝土框架进行低周往复加载,试验结束后在原框架每层分别设置防屈曲支撑,以模拟震后加固框架。对该框架再次进行拟静力试验,以考察防屈曲支撑加固震后框架的抗震性能。结合对比试验,对加固试件的破坏过程、屈服机制、破坏形态进行了详细观察,并结合试验研究结果,详细分析对比了采用防屈曲支撑加固的震后框架和对比框架试件的滞回曲线、骨架曲线、承载能力、变形能力、延性、耗能、刚度退化等抗震性能指标。研究结果表明,在加固框架中,作为第一道抗震防线,防屈曲支撑早于主体结构屈服,耗散大量的地震能量,有效保护主体结构,采用防屈曲支撑可以对震后钢筋混凝土框架进行有效加固。本文进一步对采用防屈曲支撑加固框架的梁柱节点的核心区水平剪力进行了理论分析,并对震后框架结构的梁柱节点抗剪承载能力的影响因素进行了分析,提出了震后加固框架梁柱节点抗剪承载能力的计算公式,并提出了相应的设计建议和方法。更多还原

【Abstract】 Reinforced concrete frame(RC frame)is the most commonly adopted structure system,which existed substantially in the area subjected to seismic activities.Some phenomena caused by seismic excitation can be seen,such as concrete cracking,local damage as well as residual deformation.However,not whole structure are damaged severely,since that only some stories are damaged badly.It will cost greatly to dismantle the whole structure after earthquake and highlight the problem of construction refuse disposal.Consequently,in this paper,the retrofitting design method of “combination of buckling-restrained braces(BRB)for strengthening and prestressed steel strip for retrofitting” is proposed,the earthquake-damaged RC frame structure retrofitted with this method can recover or even exceed the previous seismic performance and meet the requirement of seismic design.This retrofitting method can employ full benefits of structural components,reduce economic loss,construction refuse and resource waste,and accelerate recovery procedure after earthquake.In this paper,two experimental researches on the scaled RC frame of 1:2,one undamaged and the other earthquake-damaged,were conducted.First at all,low-cyclic pseudo static test of the reinforced concrete frame with single span and three stories was conducted and then retrofitted the damaged structure with BRBs to simulate the earthquake-damaged structure.The test on the earthquake-damaged structure was conducted again to investigate the seismic performance.Compared with the contrast test,the failure process,yield mechanism,failure mode were observed and seismic index such as hysteretic curve,skeleton curve,bearing capacity,deformability,ductility,energy-dissipation capacity,stiffness degradation and so on,were analyzed in detail.when the bearing capacity was dropped to 85% of the ultimate load bearing capacity,test ended.The results indicated that,of earthquake-damaged structure,BRBs served as the first seismic defensive line and could yielded prior to the main structure to dissipate a great deal of input energy,protecting the main structure,so the installation of BRBs could retrofit earthquake-damaged RC frame effectively.Furthermore,the shear force of beam-column joint of RC frame with BRBs was analyzed theoretically,and the influence factors of earthquake-damaged beam-column joint’s shear capacity were analyzed.Then,the calculation formula of shear capacity and relative design recommendation and method of beam-column joint of retrofitted earthquake-damaged frame were proposed.更多还原