摘要
钢桁梁断面形式的不同可能会改变桥上列车的气动力,进而影响桥上列车运行安全性和舒适性。为此,以某千米级公铁两用悬索桥为工程为背景,通过风洞试验对三种常用钢桁梁断面形式的桥上列车进行测力、测压试验。研究结果表明,当单列车位于三种钢桁梁断面形式上的上游时,列车的阻力、升力系数无明显差异,而单列车位于下游时,列车的阻力、升力系数有较大的区别;在双车状态下,由于迎风侧列车的遮挡作用,改变了不同钢桁梁断面形式下列车的流场,使得钢桁梁断面形式对背风侧列车影响较小。无论列车位于上游、下游,其三种钢桁梁断面形式下列车的阻力系数、升力系数随风攻角的变化趋势一致。当列车位于上游时,其三种钢桁梁断面形式上列车顶部和底部圆弧过渡段都出现不同程度的流动分离,使得其列车平均风压系数不同;当列车位于下游时,三种钢桁梁断面形式上列车平均风压系数变化趋势一致,说明钢桁梁断面形式对下游列车的平均风压影响较小。列车位于上、下游时,其脉动风压系数会有显著的差异,其脉动风压系数的大小受腹杆布置形式的影响要比梁高的不同更为显著。本文研究结果可为大跨钢桁梁桥的断面形式选取提供参考和依据。
Different steel truss girder section types may change the aerodynamic forces of trains on the bridge,which in turn affect the safety and comfort of the train operation on the bridge.To this end,based on a kilometer class rail-cum-road suspension bridge,this paper conducted force and pressure tests on trains running on the bridge with three common steel truss girder section types through wind tunnel tests.The results show that when a single train is located upstream of the three types of steel truss girder sections,no significant difference exists in the drag and lift coefficients of the train,while when a single train is located downstream,there is great difference in the drag and lift coefficients of the train.In the double-train state,due to the blocking effect of the train on the windward side,the flow field of the train under different steel truss girder cross-section types is changed,causing minor impact of steel truss girder section type on the train on the leeward side.Whatever the train is located upstream or downstream,the variation trend of drag coefficient and lift coefficient of the train under the three steel truss section types is the same with the change of wind angle of attack.When the train is in the upstream,different levels of flow separation appear on the top of the train on the three steel truss girder sections and the bottom arc transition section,resulting in different mean wind pressure coefficients of the train.When the train is located downstream,the variation trend of the mean wind pressure coefficients of the train on the three steel truss girder section types is the same,indicating that the steel truss girder section type has little impact on the mean wind pressure coefficients of the downstream train.When the train is located upstream or downstream,a significant difference may exist in the fluctuating wind pressure coefficients,with the coefficients more significantly affected by the steel truss girder layout form than by the height of the girder.The results of the study can provide
作者
何旭辉
肖海珠
高宿平
邹云峰
刘路路
HE Xuhui;XIAO Haizhu;GAO Suping;ZOU Yunfeng;LIU Lulu(School of Civil Engineering,Central South University,Changsha 410075,China;Hunan Key Laboratory of Disaster Prevention and Mitigation of Rail Transit Engineering Structures,Changsha 410075,China;National Engineering Research Centre,Changsha 410075,China;China Railway Major Bridge Reconnaissance&Design Institute Company,Wuhan 430000,China)
出处
《铁道学报》
EI
CAS
CSCD
北大核心
2024年第4期184-193,共10页
Journal of the China Railway Society
基金
国家自然科学基金(52078504,51925808)
湖南省自然科学基金(2022JJ10082)。
关键词
钢桁梁断面形式
车桥组合
三分力系数
平均风压
脉动风压
风洞试验
steel truss girder section type
vehicle-bridge combination
aerodynamic coefficients
mean wind pressure
fluctuating wind pressure
wind tunnel test
