利用BRB实现桥梁排架基于保险丝理念的抗震设计  

Seismic design of bridge bents with BRB as a structural fuse

作　　者：孙治国[1,2] 华承俊 石岩[1,2] 王东升[1,2] 

机构地区：[1]大连海事大学道路与桥梁工程研究所,辽宁大连116026 [2]辽宁省公路工程重点实验室,辽宁大连116026

出　　处：《振动与冲击》2015年第22期199-205,共7页Journal of Vibration and Shock

基　　金：国家自然科学基金(51008041;51178071);教育部新世纪优秀人才支持计划(NCET-12-0751);中国博士后科学基金(2013M540226;2014T70250);中央高校基本科研业务费专项资金资助项目(3132014073;3132014326)

摘　　要：由于防屈曲支撑(Buckling-restrained brace,BRB)利用低屈服点芯材轴向受压、受拉屈服耗能,若置于钢筋混凝土桥梁排架中,通过合理设计使其先于排架屈服并耗能,可减少排架本身的地震损伤,且其破坏后易于更换、起保险丝的作用。为此,初步发展利用BRB实现桥梁排架基于保险丝理念的抗震设计方法,通过拟静力、增量动力分析手段对BRB减小排架地震损伤效果进行验证。结果表明,BRB核心段长度为影响排架屈服顺序关键,BRB先于桥梁排架构件发生屈服并消耗地震能量,因此能提高桥梁排架强度及刚度,延缓排架本身屈服过程,减少变形。Buckling-restrained brace （BRB） made of low yield strength steel is an energy dissipation damper,which can yield in tension and compression without buckling.BRB added to an RC bridge bent will yield and dissipate seismic energy prior to the bent itself with reasonable design,and the seismic risk to the bent will be decreased.The damaged BRB can be easily replaced and is designed as a structural fuse.A preliminary seismic design method based on the structural fuse concept was proposed,and the seismic damage control effect of BRB on the bent was verified by quasi-static and incremental dynamic analysis.It is found that the length of the BRB core is the key influencing factor on the yield sequence of the bent.A properly designed BRB would yield before the bent and dissipate most of the seismic energy through hysteretic behavior of the fuse while avoiding damage to the bent itself.The strength and lateral stiffness of the bent are improved,and the yielding of the transverse beam and pier is delayed.Also,the deformation demand of the bent is decreased by using BRB.

关 键 词：桥梁排架 防屈曲支撑(BRB) 可替换耗能元件 保险丝 拟静力分析 增量动力分析 

分 类 号：U448[建筑科学—桥梁与隧道工程]