Influence of Girder Spacing on Vortex-Induced Vibration Performance and Flow Field Characteristics of Double-Layer Box Girder

Abstract

Through wind tunnel tests and computational fluid dynamics (CFD), the vortex vibration performance and flow field characteristics of double-layer box girder with different girder spacings were studied. The results showed that the double-layer box girder has vortex-induced vibration phenomena at 0 ° and positive wind angle of attack. Among them, at 0 ° wind angle of attack, the double-layer box girder’s vortex performance gradually became better with increasing girder spacing. Under the wind attack angles of +3° and +5°, the vertical bending vortex vibration performance of the double-layer box girder showed a trend of first optimizing and then worsening with the increase of the girder spacing, and the torsional vortex vibration performance of the double-layer box girder showed a tendency to deteriorate first and then improve with the increase of the girder spacing. The development of vortices caused by the enhancement of the flow separation between the upper surface of the upper girder and the lower surface of the lower girder caused by the aerodynamic interference between the upper and lower girders of the double-layer box girder, and the magnifying effect of the upper girder on the vortex in the wake area of the upper surface of the lower girder were the internal reasons for the influence of the girder spacing on the vortex vibration performance of the double-layer box girder.