Near-fault directivity pulse-like ground motion effect on high-speed railway bridge  

作　　者：陈令坤 张楠 蒋丽忠 曾志平 陈格威 国巍 

机构地区：[1]School of Civil Engineering,Beijing Jiaotong University [2]College of Civil Science and Engineering,Yangzhou University [3]School of Civil Engineering,Central South University [4]National Engineering Laboratory for High-Speed Railway Construction(Central South University) [5]Department of Civil and Environment Engineering,University of Auckland

出　　处：《Journal of Central South University》2014年第6期2425-2436,共12页中南大学学报（英文版）

基　　金：Project(2013CB036203)supported by the National Basic Research Program of China;Project(2013M530022)supported by China Postdoctoral Science Foundation;Project(2013-K5-31)supported by Science and Technology Plan of Ministry of Housing and Urban-Rural Development of China;Project supported by High-level Scientific Research Foundation for the Introduction of Talent of Yangzhou University,China;Project supported by the Open Fund of the National Engineering Laboratory for High Speed Railway Construction,China;Project(IRT1296)supported by the Program for Changjiang Scholars and Innovative Research Team in University,China;Project(50908236)supported by the National Natural Science Foundation of China

摘　　要：The vehicle-track-bridge(VTB)element was used to investigate how a high-speed railway bridge reacted when it was subjected to near-fault directivity pulse-like ground motions.Based on the PEER NAG Strong Ground Motion Database,the spatial analysis model of a vehicle-bridge system was developed,the VTB element was derived to simulate the interaction of train and bridge,and the elasto-plastic seismic responses of the bridge were calculated.The calculation results show that girder and pier top displacement,and bending moment of the pier base increase subjected to near-fault directivity pulse-like ground motion compared to far-field earthquakes,and the greater deformation responses in near-fault shaking are associated with fewer reversed cycles of loading.The hysteretic characteristics of the pier subjected to a near-fault directivity pulse-like earthquake should be explicitly expressed as the bending moment-rotation relationship of the pier base,which is characterized by the centrally strengthened hysteretic cycles at some point of the loading time-history curve.The results show that there is an amplification of the vertical deflection in the girder's mid-span owing to the high vertical ground motion.In light of these findings,the effect of the vertical ground motion should be used to adjust the unconservative amplification constant 2/3 of the vertical-to-horizontal peak ground motion ratio in the seismic design of bridge.The vehicle-track-bridge （VTB） element was used to investigate how a high-speed railway bridge reacted when it was subjected to near-fault directivity pulse-like ground motions. Based on the PEER NAG Strong Ground Motion Database, the spatial analysis model of a vehicle-bridge system was developed, the VTB element was derived to simulate the interaction of train and bridge, and the elasto-plastic seismic responses of the bridge were calculated. The calculation results show that girder and pier top displacement, and bending moment of the pier base increase subjected to near-fault directivity pulse-like ground motion compared to far-field earthquakes, and the greater deformation responses in near-fault shaking are associated with fewer reversed cycles of loading. The hysteretic characteristics of the pier subjected to a near-fault directivity pulse-like earthquake should be explicitly expressed as the bending moment-rotation relationship of the pier base, which is characterized by the centrally strengthened hysteretic cycles at some point of the loading time-history curve. The results show that there is an amplification of the vertical deflection in the girder＇s mid-span owing to the high vertical ground motion. In light of these findings, the effect of the vertical ground motion should be used to adjust the unconservative amplification constant 2/3 of the vertical-to-horizontal peak ground motion ratio in the seismic design of bridge.

关 键 词：ELEMENT near-fault ground motion directivity pulse high-speed railway bridge earthquake response 

分 类 号：U448.13[建筑科学—桥梁与隧道工程] P315.9[交通运输工程—道路与铁道工程]