Effect of Maintenance Rail on Vortex-Induced Vibration of Narrow Streamlined Box Girder
An existing suspension bridge with a narrow stiffening girder consisting of streamlined steel boxes is used as a case to study the wind-resistant design of the bridge of this type.Sectional model wind tunnel test was conducted,considering wind attack angles,to analyze the effect of maintenance rail on the vortex-induced vibrations(VIVs)of the box girder.Numerical simulation was carried out to investigate the influential mechanism of maintenance rail and its proper locations on the circumfluence characteristics of the box girder and propose effective vibration suppressing measures.It is shown that the maximum amplitudes of vertical VIVs of the narrow steel box girder at+3°and 0°wind attack angles are increased by 348％and 189％,respectively,compared to that at-3°wind attack angle.At the 0°wind attack angle,when the maintenance rail is placed at the location of 1/6 point of the box girder soffit width,the maximum dimensionless amplitude of vertical VIVs is reduced by 60.8％.Furthermore,when the box girder is added with guide vanes,the maximum dimensionless amplitude of vertical VIVs is reduced by 79.9％.Compared with placing the maintenance rail on the inclined webs,the solution to place the maintenance rail on the box girder soffit and adding guide vanes leads to significant reduction of the maximum amplitude of vertical VIVs of box girder,and the flow structures around the box girder are more stable,indicating improved vortex-induced vibration responses of the box girder.An effective measure to suppress the maintenance rail induced VIVs of the narrow box girder is to install the maintenance rail a little bit close towards the centerline of the box girder or add guide vanes.
万方数据
维普
