The long-span suspension bridges are prone to vortex-induced vibrations(VIVs)at service stage.To ensure the safety of existing bridge structures as well as vehicle and passengers travelling safety in the VIVs events,a VIVs controlling index system that takes into account the human comfort,load bearing behaviors of the structure and driving alignment for the long-span suspension bridge with steel-concrete composite stiffening girder is presented.The system incorporates nine indexes,including the driver comfort,motion sickness,passenger comfort(Dieckmann index),as well as bending capacity,stresses,deflection,longitudinal slope and radius of vertical curve of stiffening girder,and stopping sight distance.In the Yingwuzhou Changjiang River Bridge in Wuhan,the limits of VIVs corresponding to the nine indexes were calculated,considering the two traffic control conditions of speed limitation and bridge closure,based on which,the minimum VIVs values were taken as the recommended values.It is shown that the deflection of stiffening girder is a control index in the events of lower-mode vertical vibrations(VS1 and VAS1),while motion sickness and passenger comfort will take charge in the case of VAS2 modes,and the passenger comfort is also an important control index in the cases of higher-mode vertical VIVs(VAS3 and VAS4).The VIVs control index system and the VIV limits computing framework are applicable to the calculations of VIV limits of different bridge types.
关键词
悬索桥/钢-混结合梁/涡激振动/控制指标体系/人员舒适性/结构受力/行车线形
Key words
suspension bridge/steel-concrete composite girder/vortex-induced vibration/control index system/passenger comfort/load bearing performance of structure/vehicle travelling alignment
维普
万方数据