Rapid Vibration Suppression Measures Research for Mitigating Vortex-Induced Vibration in Long-Span Steel Box Girder Suspension Bridges

Long-span steel box girder suspension bridges are prone to vortex-induced vibrations (VIVs) due to their light weight, flexible characteristics, and low structural damping. Traditional temporary aerodynamic measures, although effective in vibration suppression, involve prolonged construction periods and high costs, leading to traffic disruptions and considerable socio-economic losses. To address these limitations, this study implemented rapid vibration suppression by prescribing designated lanes and traveling speeds for vehicles with varying aerodynamic configurations, dynamically arranged on the bridge deck for efficient vibration control. Through CFD numerical simulations, the influence of vehicle placement on vibration suppression efficiency was systematically investigated. The results indicated that the strategic arrangement of vehicles could reduce the root-mean-square (RMS) amplitude of VIV of the main girder by more than 75%, with suppression efficiency significantly correlated with the spatial distribution of the vehicles. Moreover, the suppression mechanism was analyzed, revealing that resonance occurs when the vortex-shedding frequency matches the natural frequency of the main girder in the absence of suppression measures. Vehicle deployment alters the vortex-shedding frequency from the bridge surface, shifting it away from the structural natural frequency, while simultaneously weakening the periodic energy input from vortex shedding, thus effectively mitigating the vibration response.