高速铁路大跨矮塔斜拉桥地震主导振型识别  

Identification of Seismic Dominant Modes for Long-span Low-pylon Cable-stayed Bridge of High Speed Railway

作　　者：谢明志[1] 杨永清[1] 张明[1] 赵金钢[2] 李晓斌[1] 郑克川 XIE Mingzhi;YANG Yongqing;ZHANG Ming;ZHAO Jjingang;LI Xiaobin;ZHENG Kechuan(Southwest Jiaotong University,Chengdu,Sichuan 610031,China;Guizhou University,Guiyang,Guizhou 550025,China;China Railway 24th Bureau Group Co.Ltd,Shanghai 200071,China)

机构地区：[1]西南交通大学,成都610031 [2]贵州大学,贵阳550025 [3]中铁二十四局集团有限公司,上海200071

出　　处：《铁道工程学报》2020年第7期50-56,共7页Journal of Railway Engineering Society

基　　金：四川省科技计划资助(2020YJ0081);国家自然科学基金项目(51508474,51978589).

摘　　要：研究目的:为探明高速铁路矮塔斜拉桥地震响应特性,以某主跨(90+180+90)m矮塔斜拉桥为工程背景,基于理论推导及非线性有限元分析,采用平均模态应变能系数为指标,开展该桥型地震作用下主导振型识别,研究其动力特性.研究结论:(1)平均模态应变能系数能同时考虑结构及地震动特性,可作为矮塔斜拉桥振型识别指标,具有高效、精确等特点;(2)梁式体系矮塔斜拉桥在x和z方向主导振型较y方向敏感,反映出结构在这两个方向的动力效应更显著;(3)振型分解反应谱法和时程分析对比可得出,考虑主导振型组合能满足实际工程需求,桥梁主导振型识别对掌握结构地震响应特性具有重要意义,可为地震损伤分析、桥梁减隔震设计等提供依据.Research purposes:In order to prove the seismic response characteristics of low-pylon cable-stayed bridge of high speed railway,the(90+180+90)m low-pylon cable-stayed bridge was taken as a case study.Based on theoretical derivation and nonlinear finite element analysis,the average modal strain energy ratio was used as an indicator to identify the dominant modes of the bridge under earthquake,and its dynamic characteristics were also studied.Research conclusions:(1)The average modal strain energy ratio can consider both the structure and ground motion characteristics.It can be used as an index for identifying the vibration mode of low-pylon cable-stayed bridge during seismic analysis with high efficiency and accuracy.(2)The dominant modes of the bridge with support system in x and z directions are more sensitive than that in y direction,which shows that the dynamic effect of the structure in these two directions is more obvious.(3)By comparing the mode response spectrum method and time history analysis,it can be concluded that the combination of dominant modes can meet the actual engineering needs,and the identification of dominant modes of bridges is of great significance for mastering the seismic response characteristics of structures,which can provide the basis for earthquake damage analysis and bridge seismic isolation design.

关 键 词：桥梁工程 大跨矮塔斜拉桥 高速铁路 主导振型 平均模态应变能系数 

分 类 号：U24[交通运输工程—道路与铁道工程] U448.27[建筑科学—桥梁与隧道工程]