跨线钢箱梁斜拉桥列车风荷载及风致振动  

Train Wind Loads Applied on a Fly-over Steel Box Girder Cable-stayed Bridge and Wind-induced Bridge Vibrations

作　　者：周小刚 张迅 陈韬 邱敏捷 罗实 ZHOU Xiaogang;ZHANG Xun;CHEN Tao;QIU Minjie;LUO Shi(Department of Bridge Engineering,Southwest Jiaotong University,Chengdu 610031,China;Chengdu Survey and Design Research Institute of China Railway Eryuan Engineering Group Co.,Ltd.,Chengdu 610031,China)

机构地区：[1]西南交通大学桥梁工程系,成都610031 [2]中铁二院成都勘察设计研究院有限责任公司,成都610031

出　　处：《铁道标准设计》2022年第1期94-100,共7页Railway Standard Design

基　　金：国家自然科学基金项目(51978580,51778534);中铁二院工程集团有限责任公司科技开发项目(KYY2020009(20-21))。

摘　　要：为获得高速列车下穿时的列车风和桥梁振动响应特性,以某独塔无背索钢箱梁斜拉桥为工程背景,采用CFD仿真获得钢箱梁不同部位的列车风荷载,并基于桥梁动力模型研究施工阶段和运营阶段的风致振动响应。结果表明:高速列车下穿时,钢箱梁翼缘板、腹板及底板的表面风压均表现出明显的“头波”“尾波”特性;随着车-桥间距和距轨道中心线距离的增加,风压极值逐渐衰减,底板和腹板处的衰减速率较翼缘板处更快;在距轨道中心线20 m处,梁体受到的升力、阻力及扭矩极值分别下降为轨道中心线处的28%,23%和11%;当车速为350 km/h、轨面距梁底为7.25 m时,合龙前梁端最大竖桥向位移为9.89 mm、最大竖桥向加速度为164.58 mm/s^(2),运营阶段跨中最大竖桥向位移为3.24 mm、最大竖桥向加速度为91.95 mm/s^(2)。In order to obtain the characteristics of train winds and wind-induced bridge vibrations during the under-passing of high-speed trains,a fly-over steel box girder cable-stayed bridge with a single tower and no back cable is selected as the background engineering.The CFD simulation is used to analyze the train wind loads applied on different panels of the steel box girder.Furthermore,the bridge dynamic analysis models are built to explore wind-induced vibrations in the construction and operation stages.Results show that the surface wind pressures applied on the flange plate,web and bottom plate of the steel box girder exhibit obvious“head wave”and“tail wave”characteristics due to the under-passing of high-speed trains.With the increase of train-bridge distance and the distance to track centerline,the extreme wind pressures decrease continuously,and the attenuation rates at the bottom plate and the web are faster than that at the flange plate.At the location that is 20 m away from the track centerline,the lift force,drag force and torque force applied on the steel box girder are about 28%,23%and 11%of those at the track centerline.When the train speed is 350 km/h and the distance between track surface and bridge bottom is 7.25 m,the maximal displacement and acceleration at the beam-end are 9.89 mm and 164.58 mm/s ^( 2) respectively before the bridge closure;while during the operation stage,the maximal displacement and acceleration at mid-span are 3.24 mm and 91.95 mm/s^( 2) respectively.

关 键 词：高速列车 铁路桥 跨线桥 斜拉桥 钢箱梁 列车风 风致振动 数值仿真 

分 类 号：U441.2[建筑科学—桥梁与隧道工程] U448.27[交通运输工程—道路与铁道工程]