Vortex-Induced Vibration Performance of Wide Streamlined Box Girder and Aerodynamic Countermeasure Research

To suppress the vortex-induced vibration (VIV) of the wide streamlined box girder, the Qingshan Yangtze River Bridge (a long-span cable-stayed bridge with a wide streamlined box girder) was taken as an example. The study of the VIV performance was carried out through a 1:50 scale section model wind tunnel test. The VIV performance of the girder was studied in a low-damping condition, as well as the effects of various countermeasures on such performance, including wind fairing, inspection vehicle rail, guide vane, vibration mitigation plate, and maintenance way railing. The test results show that a sharp wind fairing is favourable to the VIV performance of the girder. The position of the inspection vehicle rail, the height of rail supporter, and the guide vane slightly suppress the VIV response. The vibration mitigation plate, which was installed behind the anti-collision railing such that five seals off one, can reduce the vertical VIV displacement by 45%. The circular maintenance way railing and the high ventilation rate can improve the VIV of the wide streamlined box girder significantly. In particular, the displacement was reduced by 63%. The recommended railing style does not affect the aesthetic of the bridge and is convenient to apply. A 1:27 scale section model test was conducted to verify the countermeasure. The test results show that the recommended maintenance way railing can suppress the VIV of the wide streamlined box girder effectively.