脉冲型地震动对CFST拱桥抗震性能的影响分析  

Effect of Pule-Like Ground Motion on Seismic Performance of Concrete-Filled Steel Tubular Arch Bridge

作　　者：李晰[1,2] 何澜 李倩[1,2] 潘毅[1,2] LI Xi;HE Lan;LI Qian;PAN Yi(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;National Engineering Laboratory for Technology of Geological Disaster Prevention in Land Transportation,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]西南交通大学土木工程学院,四川成都610031 [2]西南交通大学陆地交通地质灾害防治技术国家工程实验室,四川成都610031

出　　处：《西南交通大学学报》2019年第4期731-740,共10页Journal of Southwest Jiaotong University

基　　金：国家自然科学基金资助项目(51508473)

摘　　要：为了研究脉冲型地震作用下钢管混凝土拱桥的抗震性能,以一座钢管混凝土拱桥的实际工程为例,采用时程分析方法系统分析了其在非脉冲和脉冲型地震作用下的抗震性能.首先,基于PEER地震衰减模型并采用谱兼容的方法选取了符合不同场地条件且具有不同脉冲周期的天然地震记录;其次,在综合考虑有无脉冲、脉冲周期以及地震动多维性的基础上,对钢管混凝土拱桥的抗震性能进行了对比分析.研究结果表明:脉冲型地震动会对结构响应产生较为明显的影响,脉冲效应对结构响应的放大作用在0.96~19.88倍之间,桥梁修建处的场地条件越好放大作用越明显;脉冲周期的不同也会对结构响应产生不可忽略的影响,结构响应的改变率在10~133%之间,脉冲周期越小脉冲效应对结构响应的放大作用就越明显;与非脉冲型地震动相比,地震动多维性对脉冲型地震作用下的结构响应影响较小,但随着脉冲周期的减小,地震动多维性对结构响应的影响变大.因此,在对断层附近的钢管混凝土拱桥进行抗震设计时不但要考虑有无脉冲的影响,还需要考虑脉冲周期、地震动多维性以及桥梁修建处场地条件的影响,以免错误地估计结构响应.To study the seismic performance of a concrete-filled steel tubular(CFST)arch bridge under pulse-like ground motions,a comprehensive theoretical analysis is made of an actual CFST arch bridge under the action of non-pulse-like and pulse-like ground motions using time history analysis.The actual ground motion records with different pulse periods are first selected for each site condition based on the PEER(pacific earthquake engineering research center)ground motion models using the spectrum match method.Then,a comparative seismic analysis of the CFST arch bridge is conducted with and without consideration of pulse,different pulse periods and the dimensionality of ground motions.Results show that the pulse-like ground motions can significantly affect structural responses;a better bridge site condition results in a larger structural responses,and the amplification factor is between 0.96–19.88.Meanwhile,the difference of pulse periods induces significant variations in structural responses,the change rate is between 10%–133%;the smaller the pulse period is,the more obvious the amplification effect on the structural response is.In addition,the dimensionality of ground motions has smaller effect on structural responses under pulse-like motions than the one under non-pulse-like ground motions,but the effect intensifies as the pulse period decreases.Therefore,it is suggested that not only the pulse effect but also the influence of pulse period,dimensionality of ground motions and site conditions for the location of the bridge should be considered in the seismic design phase of a CFST bridge to avoid erroneous response predictions.

关 键 词：脉冲型地震动 钢管混凝土拱桥 脉冲周期 场地条件 多维性 

分 类 号：TU317.1[建筑科学—结构工程] TU352.1