ABSTRACT
Vortex-induced vibration (VIV) is a commonly occurred limited amplitude vibration for long-span bridges which may cause serious comfort problems during operation period and even lead to fatigue damage of some key components. Based on a large scale sectional model test, this paper discussed the influence of damping ratio, various aerodynamic measures on a separated twin-box girder with large cantilever plate. The anti-lock-in phenomenon observed in the wind tunnel test was also described and analyzed in detail. Results show that the maximum amplitude of VIV decreases with the increase of the damping ratio. The guide plate, central stabilizer, and grille have limited effects to control the VIV while the proposed L-shaped windshield in this paper can almost completely suppress the occurrence of VIV in the lower turbulence wind field. Through wind pressure measuring test and data analysis, the mechanism of VIV was explained, as well as the mechanism of anti-lock-in phenomenon.
