Vortex-Induced Vibration Performance and Mechanism Analysis of a Suspension Bridge Affected by Water-Filled Barriers

Abstract

The existence of water-filled barriers alters the cross-sectional shape of the main girder, which may lead to vortex-induced vibrations (VIVs) in suspension bridges. However, the mechanism and occurrence conditions of VIVs in the main girder that is affected by water-filled barriers are still unclear. To this end, this study investigates the effect of water-filled barriers on the VIV performance of suspension bridges. The evolution of the vortex structure during one VIV cycle and the corresponding pressure variations, including the average and fluctuating values on the surface, were analyzed. Additionally, the spatiotemporal distribution of the surface pressure was studied using proper orthogonal decomposition (POD). The results show that VIV occurs in the main girder when the height of the water-filled barriers exceeds a threshold value of 0.317. Moreover, a significant negative pressure vortex occurred when the barriers were installed. The vortex underwent the following distinct phases in one VIV cycle: generation, separation, reattachment, and shedding. However, the negative pressure vortex behind the barrier did not vary substantially when the water-filled barriers were installed without VIV. Additionally, the average pressure on the surface of the main girder remained constant regardless of the occurrence of VIVs. In the presence of VIVs, the pressure fluctuations became much more pronounced and were mainly concentrated on the top surface and leading edge of the main girder. Additionally, the dominant modes of the pressure variations correlated with the evolution of the vortices and pressure distribution.