大跨度中承式拱桥节段模型风洞试验

风致振动是大跨度中承式拱桥设计的主要控制因素之一,本文介绍了重庆菜园坝长江大桥风洞主桥节段模型静力三分力试验以及节段模型动态试验的主要内容及相应的结果,介绍了由于双拱干扰下的主拱静力三分力试验和涡振试验及其结论。试验表明,桥梁主桥具有良好的气动稳定性,主拱在风载下受力极为复杂。由于前榀拱尾流的影响,后拱阻力系数起伏较大。当两榀拱相距较近时,后拱的阻力系数为负数,随着间距的增大逐渐增大。试验结果将为大桥的抖振、涡振以及颤振分析提供依据。

Wind Tunnel Tests of Long Span Half - through Arch Bridge Section Model

Wind induced vibration is one of the main control factors in the Long span bridge structure design.The wind tunnel tests for measuring the static wind forces on the bridge girder and the section model wind tunnel dynamic testing for Caiyuanba Yangtze River Bridge in Chongqing are introduced in this paper.The wind tunnel testing for measuring static wind forces and vortex-induced vibration test on the arch are introduced taking account of the influence between two arches.The main contents and outcomes of testing are presented.It is indicated that the bridge girder has excellent wind stability and the arch mechanical characters are rather complicated.The drag force on the hind arch varied a lot because of the font arch interference on the wind flow.The drag force on the hind arch will be negative when two arches are close to each other.It increases with the space of two arches.The results of testing will give the data of buffeting and vortex-induced vibration and flutter analysis of the bridge.