Effects of turbulence and nonuniformly distributed mean wind on vortex-induced vibration of a long-span bridge

With the increase of span length, long-span bridges are more flexible and therefore more susceptible to vortex-induced vibrations (VIV). Accurate predictions of the structural responses caused by VIV are important as sometimes a certain degree of VIV is inevitable. Turbulence and the nonuniformly distributed wind speed are highly likely to affect the VIV responses but were never considered in the existing VIV analysis methods. A VIV analysis method is developed in this paper to involve the effects of turbulence, as well as the nonuniformly distributed mean wind speed along the bridge axis. The developed method is applied on a long-span suspension bridge with a twin-box deck that suffers VIV. The analytical results are compared with the on-site VIV responses recorded by the monitoring system on that bridge. Results show that both the turbulence and the nonuniform distribution of mean wind speed can notably reduce the VIV responses.