Wind-Resistent Performance And Aeerodynamic Optimization Measures For Super-Long-Span Bridge With Three-Box Girder

The super-long-span bridge is an important development direction. At present, the construction of super-long-span bridges has entered into a vigorous development period at home and abroad. However, the increase of bridge span will cause the bridge structure to become more tender, and to reduce the damping and the vibration frequency of the structure. So destructive vibration will easily occurs with the action of natural wind. The wind-resistent preformance of the super-long-span bridge has already become a key factor in construction and service phases. As the main wind-bearing structure component, the wind-resistent performance of deck directly affects the wind-resistent ability of the whole bridge. It's very significant to make studies on new-type bridge deck sections for better aerodynamic characteristcs.Firstly, the involved research of long-span-bridge at home and abroad is reviewed, and cases of the deck sections and aerodynamic measures are collected. Then the effection the aerodynamic measures on the aerodynamic characteristics of deck are summarized, in order to provide some references for the aerodynamic characteristic and aerodynamic measures research of girder at the next step.Secondly, based on the existing method of girder flutter derivatives identification, the ideal flat chatter derivatives are simulated and identificated. Comparing the numerical solution and the theoretical solution of the flat chatter derivatives, it is proved that the numerical simulation method can be used to compare the aerodynamic characteristics of different bridge deck sections.Thirdly, the differernt girder's aerodynamic parameters of the super-long-span bridge are simulated and calculated by the CFD method. The aerodynamic characteristics, the static buckling critical wind speed and the flutter critical wind speed of the girders are calculated. After comparing the static stability performance and the flutter stability performance of different deck sections, the wind resistance ability of different girders are evaluated.Finally, six kinds of pneumatic measures for the three-box-girder with better wind resistance ability are designed. The static stability performance and the flutter stability performance of different deck sections are compared. The effection of the aerodynamic measures on the aerodynamic characteristics of the three-box-girder are discussed. And some conclusions are drawn to provide references for aerodynamic characteristics optimization of the bridge deck.