以南京长江三桥为背景,通过均匀流场和紊流场刚体节段模型测压试验对扁平箱梁的抖振力频谱特性和沿桥跨方向相关性进行了研究。结果显示,由于特征紊流的影响,均匀流场中的扁平箱梁也存在抖振力;在10%紊流度的紊流场中,特征紊流对扁平箱梁的抖振力也有一定的影响,但来流紊流的贡献较大,特征紊流的影响不起主要作用;实测的抖振力沿桥跨方向相关性要好于公路桥梁抗风设计规范以及其他一些规范中的取值。
Based on The 3rd Nanking Bridge over Yangtze River, spectral characteristics and spanwise coherence of buffeting forces on the fiat box-girder bridge deck have been investigated through pressuremeasurement wind tunnel test of section model in both uniform and turbulent flows. The testing results show that buffeting forces exist on a flat box-girder bridge deck in uniform flow resulting from signature turbulence. The signature turbulence also exerts some influence on buffeting forces on a fiat box-girder bridge deck in turbulent flows with a turbulent intensity of 10% , however the major contribution to the buffeting forces comes from the turbulence of incident flow in this case. The measured spanwise coherence of buffeting forces is found to be better than that specified in some wind load codes, such as Chinese Wind-Resistant Design Specification for Highway Bridges.