人工主余震作用下桥墩结构损伤预测评估分析  

Damage prediction and evaluation of bridge pier structures under artificial mainshock-aftershock sequences

作　　者：李喜梅[1,2] 李明睿 母渤海 LI Ximei;LI Mingrui;MU Bohai(Western Engineering Research Center of Disaster Mitigation in Civil Engineering,Lanzhou Univ. of Tech., Lanzhou 730050, Gansu, China;Institute of Earthquake Protection and Disaster Mitigation, Lanzhou Univ. of Tech., Lanzhou 730050, Gansu, China;China Municipal Engineering Northwest Design & Research Institute Co., Ltd., Lanzhou 730000, Gansu, China)

机构地区：[1]兰州理工大学西部土木工程防灾减灾教育部工程研究中心,甘肃兰州730050 [2]兰州理工大学防震减灾研究所,甘肃兰州730050 [3]中国市政工程西北设计研究院有限公司,甘肃兰州730000

出　　处：《地震工程学报》2021年第6期1402-1408,共7页China Earthquake Engineering Journal

基　　金：国家自然科学基金资助项目(51778276)。

摘　　要：主余震作用下,断层距(RJB)和余震次数的不同对结构造成的损伤也大不相同,进行主余震序列下桥梁损伤评估时需要考虑断层距、余震次数等影响因素。基于OpenSees平台,以一座连续梁桥为例,根据人工主余震构造时不同的影响因素,选用余震衰减和PGA调幅的人工主余震构造法构造主余震序列进行结构损伤分析,并与实际主余震事件的损伤结果作对比,研究人工构造主余震序列预测结构损伤的可行性。结果表明:基于PGA调幅构造主余震的方法,当考虑余震衰减时,能够较好模拟出结构在实际主余震地震作用下造成的最终损伤,能够较合理的预测结构在实际主余震序列中的损伤指标;对区域主余震作用下的桥梁进行损伤评估时,需要考虑断层距和余震次数影响因素,桥梁距断层距RJB越近时结构的损伤状态越严重,余震发生次数越多则结构的损伤增量就越大,并且结构在人工主余震作用下RJB越大的地方,结构损伤增量误差程度越小,预测的损伤状态就越接近实际的损伤状态。Under mainshock-aftershock sequences,the structural damage caused by different fault distance(RJB)and aftershock times are obviously different,so these influencing factors should be considered when evaluating the bridge damage under mainshock-aftershock sequences.Based on OpenSees platform,a continuous girder bridge was taken as an example in this paper.According to different influencing factors,the artificial main-aftershock sequences were selected to carry out the structural damage analysis.The damage results were compared with those of real main-aftershock events to study the feasibility of predicting structural damage by artificial main-aftershock sequences.The analysis results showed that:when considering the aftershock attenuation,the method based on modified PGA amplitude can well simulate the final damage of the structure under real main-aftershock sequences,and can reasonably predict the damage index of the structure.The influencing factors of fault distance and aftershock times should be considered when evaluating the damage of bridge under regional mainshock-aftershock sequences.The damage state of the bridge structure becomes more and more serious with the decrease in fault distance,and the structural damage increment increases with the increase in the number of aftershocks.Under artificial mainshock-aftershock sequences,the larger the fault distance,the smaller the error of incremental damage,and the closer the predicted damage state is to the actual state.

关 键 词：主余震序列 损伤增量分析 连续梁桥 区域震害预测 

分 类 号：TU352.1[建筑科学—结构工程] U4413[建筑科学—桥梁与隧道工程]