Wind Induced Vibration Performance of Suspended Double-deck Flat Box Girder Bridge

The paper researches the wind vibration performance of suspended double-deck streamlined bridge deck using the wind tunnel test and numerical simulation. Studies shown that for suspended double- deck bridge, due to the aerodynamic interference of the upper deck, the lower deck is driven by a vertical vibration negative damping, and the vertical vibration is significantly changed. The pressure distribution of the upper deck and the upper edge of lower deck did not change. The wind load acts on the upper edge of lower deck, and the minus attack angle was generated. With the generation, migration and shedding of large-scale vortices at the lower edge of the lower deck, the lower deck occurs the bending-torsional coupling "soft flutter". Moreover, due to the structural static coupling between the upper deck and the lower deck, the bending-torsional soft flutter at the lower deck induces the bending-torsional soft flutter of the double-deck bridge deck.