铅芯温度效应对隔震桥梁地震反应影响研究  

Lead Core Heating Effects on Seismic Response of Isolated Bridges

作　　者：王东升 安正汉 孙治国[2] 徐婷婷 WANG Dongsheng;AN Zhenghan;SUN Zhiguo;XU Tingting(School of Civil engineering and Transportation,Hebei University of Technology,Tianjin 300400,China;Institute of Disaster Prevention,Yanjiao 065201,China)

机构地区：[1]河北工业大学土木与交通学院,天津300400 [2]防灾科技学院,河北燕郊065201

出　　处：《应用基础与工程科学学报》2020年第5期1172-1186,共15页Journal of Basic Science and Engineering

基　　金：国家自然科学基金项目(51478074);教育部新世纪优秀人才支持计划资助项目(NCET-12-0751)。

摘　　要：地震作用下铅芯橡胶支座(LRB)中铅芯因机械能转化热能导致温度变化,力学性能随之改变,进而影响隔震桥梁反应过程.本文利用OpenSees数值模拟平台和时程分析方法,研究了远断层与近断层地震波输入下铅芯温度效应对隔震连续梁桥地震反应的影响.结果表明:地震作用下铅芯温度可升高15~50℃,导致屈服力下降10%~30%,同时支座地震剪切变形反应增加可达8%~20%,而主梁最大位移与桥墩最大侧移角变化不大;相比远断层地震动作用,铅芯温度效应在近断层地震动作用下更为显著.在结构能量反应方面,铅芯温度效应对桥梁总输入能影响不大,但会使得支座总滞回耗能及单个支座的滞回耗能增加.考虑铅芯温度效应后单个支座滞回能增加值的大小随总输入能增加呈现先减后增的变化趋势,其受控于桥墩是否进入弹塑性反应阶段.The temperature of lead rubber bearings(LRBs)change induced by the internal energy conversion of lead core under seismic loading,which will make a difference to the mechanical properties of bearings and further influence the seismic responses of isolated bridges.To study this heating effect of lead core on the seismic response of isolated bridges,the finite element model of an isolated bridge was built for time history analyses based on OpenSees software,and both far-fault and near-fault ground motions were input to the model.The results show that the temperature of the lead core can increase by 15~50℃under seismic loading,then,the yield forces of LRBs decrease by 10%~30%and the shear deformations of the LRBs increase by 8%~20%.However,the maximum displacement responses of the girders and the maximum drift ratios of the columns change little.Besides,the lead core heating effect is more significant when the isolated bridge is subjected to the near fault ground motions.According to the analysis of structural seismic energy responses,it is found that the total input energy almost remains the same whether considering the lead core heating effect or not,while the hysteretic energy of the LRBs will increase.The increase values of the hysteretic energy for the single LRB with heating effect will decrease firstly,and then increase with the increase of the total seismic input energy for the bridge,which mainly determined by that the columns are inelastic or elastic responses during the earthquake.

关 键 词：隔震桥梁 铅芯橡胶支座 铅芯温度效应 修正双线性模型 近断层地震动 地震反应 能量反应 

分 类 号：TU311.3[建筑科学—结构工程] TU352.1