Test And Simulation Investigation On Wind-induced Vibration Of Long-span Steel Trussed Arch Bridge

Due to the advantages of superior load carrying papacy, lightness, fast construction and convenience in segment assembly, the steel truss arch bridges have widely adopted in the mountainous area of Southwest China and costal areas. The spanning across the river usually requires a length of over 300 m, wh ich lead to the overall stiffness of the arch bridge and small damping. Consequently the arch bridges may be easily affected by static and dynamic wind actions in particular during the construction stages. And the current "Highway Bridge Wind Specification " provisions, no to the steel truss arch bridge wind resistance of the relevant rules. Due to the large stiffness of the bridge, the flutter instability and vortex-induced vibration usually will not govern the wind-resistant design, however the truss girde rs have large area normal to wind, and the static wind loads and buffeting response may have an important role. By taking Guangzhou Nansha District Pearl Bay Bridge as research background, the static and dynamic buffeting wind effects are evaluated for bot h in-service and construction stages by using wind tunnel tests and theoretical studies. The main work and achievements of this paper are as follows:First, a review of historic development of arch bridge worldwide is made, and the emphasis have been placed on the wind resistance research of the large span arch bridgeSecondly, the theory for the dynamic characteristics of long span steel truss arch bridge is introduced. The dynamic characteristics of the in-service and critical construction stages for Pearl Bay bridge structure dynamic is analyzed and become state of the bridge and the construction state of basic vibration type.Then, wind tunnel tests on the bridge girder and arch rib section model are performed to determine the corresponding steady aerodynamic coefficients. The wind field for the bridge is digitally generated by using the traditional spectral decomposition method. The quasi-steady buffeting theory developed by professor Davenport is briefly introduced and is used to determine the wind-induced dynamic response in time domain. After taking into account the static wind response, the peak responses are obtained.Finally, the vortex-induced vibrations of the typical member of arch bridges are analyzed using CFD. The vibration equation of numeri cal calculation method for the preparation of UDF embedded in fluent software in predicted typical rod can generate vortex induced vibration of wind speed, and lead to the corresponding wind vortex induced vibration lock interval graphs and tables.