摘要
钢桁架拱桥具有构件轻、易于加工、承载力强和运输架设方便的优点,已在公路、铁路设计中得到广泛应用。为了研究大跨度连续中承式钢桁架拱桥抗风性能,指导该类桥梁建造,以长沙市暮坪湘江特大桥为背景,通过桥址风环境分析、结构动力特性仿真分析及风洞试验,获取桥梁结构的抗风性能并检验大桥的抗风稳定性。针对中跨拱肋、中跨主梁及边跨桁架,采用弹簧悬挂二元刚体节段模型,通过风洞试验研究,获取了-12°~+14°不同风攻角下静力风荷载三分力系数,为桥梁风荷载取值提供了依据。同时根据试验结果曲线,中跨主梁、边跨桁梁断面在成桥状态各种风攻角下升力系数斜率均为正,判定主梁及边跨桁架结构均不会发生驰振。结合节段模型弹性悬挂试验,获取主梁结构在成桥阶段及施工阶段最大双悬臂状态,风攻角-3°、0°、3°情况下的竖向位移及扭转角,并依据相似关系将试验风速及所得响应换算至实桥值,以检验主梁的颤振稳定性及涡激共振特性。结果表明,当换算实桥风速高达100 m/s,远高于其颤振检验风速时,主梁均未发生颤振现象,表明该桥在成桥状态下与施工过程中均具有足够的颤振稳定性。在成桥状态或者最大单/双悬臂状态下,桥面设计基准风速34.8 m/s的范围内,各种风攻角情况下均未观察到明显的涡激振动现象。
Steel truss arch bridge has the advantages of lightweight components,ease of processing,high loadbearing capacity,and convenient transportation and installation.As a result,they have been widely used in highway and railroad design.In this study,the wind resistance of large span continuous steel truss arch bridges was investigated to guide the construction of such bridges.The main bridge of Muping Xiangjiang Special Bridge in Changsha was used to obtain the wind resistance of the bridge structure and test the wind stability of the bridge through wind environment analysis at the bridge site,structural dynamic characteristics simulation analysis,and wind tunnel testing.Wind tunnel tests were conducted on the mid-span arch ribs,main girders.The side span trusses to obtain the three-component force coefficient for wind attack angles ranged from−12°to+14°.The results can provide a basis for determining the wind load values of the bridge.Additionally,the test results show that the slope of the lift coefficients of the main girder and side span sections are positive,indicating that these components would not experience vibration.Moreover,segmental model elastic suspension tests are performed to obtain the vertical and torsional displacements of the main girder structure under wind attack angles of−3°,0°,and 3°during the bridge formation stage and the construction maximum double cantilever condition.The results show that,even when the wind speed of the real bridge reached 100 m/s,far higher than its chattering test wind speed,no chattering occurred in the main girder.This indicates that the bridge has sufficient chattering stability during the bridge formation state and construction process.Furthermore,in the bridge state or the maximum single/double cantilever state,no significant eddy vibration phenomenon is observed in all wind attack angle cases,and the design reference wind speed of the bridge deck is determined to be 34.8 m/s.
作者
常柱刚
魏标
蒋丽忠
李红利
CHANG Zhugang;WEI Biao;JIANG Lizhong;LI Hongli(School of Civil Engineering,Central South University,Changsha 410075,China;Changsha Planning&Design Institute Co.,Ltd.,Changsha 410007,China;Hunan Provincial Engineering Lab of Safety Control of Bridge Structure,Changsha University of Science&Technology,Changsha 410076,China)
出处
《铁道科学与工程学报》
EI
CAS
CSCD
北大核心
2024年第5期1898-1908,共11页
Journal of Railway Science and Engineering
基金
湖南省自然科学基金资助项目(2021JJ30840)
国家自然科学基金资助项目(51408070)
长沙理工大学桥梁工程领域开放基金项目(14KD14)。
关键词
钢桁架拱桥
风洞试验
气动特性
抗风性能
风致响应
steel truss arch bridge
wind tunnel test
aerodynamic characteristics
wind resistance
wind induced response
