近断层地震下梁式桥考虑SSI效应的能力谱法  

Capacity Spectrum Method Considering SSI Effects for Beam Bridges under Near-fault Ground motion

作　　者：李宇[1] 董世杰 乔云强 赖亚平 薛晓锋[1] LI Yu;DONG Shijie;QIAO Yunqiang;LAI Yaping;XUE Xiaofeng(School of Highway,Chang’an University,Xi’an 710064,China;TY.Lin International Engineering Consulting(China)Co.Ltd.,Chongqing 401121,China)

机构地区：[1]长安大学公路学院,陕西西安710064 [2]林同棪国际工程咨询(中国)有限公司,重庆401121

出　　处：《湖南大学学报（自然科学版）》2022年第9期71-79,共9页Journal of Hunan University:Natural Sciences

基　　金：国家自然科学基金资助项目(51408042);陕西省自然科学基础研究计划资助项目(2021JM168,2022JQ-507);重庆市技术创新与应用示范项目(cstc2018jscx-mszd0430)。

摘　　要：合理地选取215条典型近断层地震动记录,并根据我国桥梁抗震设计规范的场地标准进行分类后,统计了适用于我国桥梁抗震设计的近断层地震弹塑性加速度和位移反应谱,并拟合了阻尼比对近断层地震弹塑性反应谱的影响关系式,进而得到近断层地震的弹塑性需求谱.再将其与FEMA440的考虑土-结构相互作用(SSI效应)的方法、Chopra改进能力谱法相结合,完善了近断层地震下适用于我国梁式桥且能考虑SSI效应的能力谱法.最后,将本文方法应用于某梁式桥的抗震性能评估中,结果表明:对于近断层地震下考虑SSI效应的我国梁式桥,FEMA440的计算结果偏于保守,而本文方法的计算结果则较为合理,可以应用于我国梁式桥的抗震性能评估中.A total of 215 typical near-fault ground motion(GM)records were selected reasonably and classified according to the Chinese seismic design code for bridges.Then,the near-fault elastoplastic acceleration and displace⁃ment spectra were counted,and the relationship between damping ratio and near-fault elastoplastic spectra was fit⁃ted,so as to obtain near-fault elastoplastic demand spectra.By combining the FEMA440 and Chopra capacity spec⁃trum method with the established near-fault elastoplastic demand spectra,a capacity spectrum method considering soil-structure interaction(SSI)effects for Chinese beam bridges was suggested and applied in the seismic perfor⁃mance assessment for a beam bridge under near-fault GMs.The results show that,for the Chinese beam bridge con⁃sidering SSI effects under near-fault GMs,the results calculated by FEMA440 are conservative,while the results cal⁃culated by the proposed method in this study are more reasonable,which can be applied to the seismic performance evaluation for Chinese beam bridges.

关 键 词：地震 桥梁 能力谱法 土-结构相互作用 弹塑性反应谱 

分 类 号：U448.27[建筑科学—桥梁与隧道工程]