Despite the wind-resistant design performed during the design stage, an existing bridge may still experience severe vortex-induced vibrations (VIVs) because of the installation of new affiliated facilities during its operation period. Therefore, it is necessary to apply control measures to suppress the VIV induced by such changes in configuration. In this study, the VIV performance of a streamlined box girder bridge during the installation of new auxiliary piping system was investigated through a series of sectional model tests and flow visualization tests. Severe vertical VIVs of the bridge used in this study were observed at lower wind speed ranges during wind tunnel tests. Based on the flow pattern around the sectional model, it was inferred that the flow across the deck bottom surface was entirely separated by the new pipelines, which resulted in the periodic generation of shedding vortices in the wake zone and induced deck vibration. Twin downward vertical stabilizer plates (TDVS) were found to be an effective aerodynamic countermeasure for improving the VIV performance of the bridge and could significantly decrease the amplitude of the vertical VIV motion. Additional flow visualization investigations showed that after the TDVS were installed, the vortex shedding in the wake was mitigated, and the location of the vortex shedding was further away from the deck, and hence, considerably suppressed the vertical VIVs. It was found that the effectiveness of the TDVS in improving the aerodynamic performance was significantly dependent on the TDVS parameters, i.e., the plate height and spacing between plate elements. The optimal values of these parameters were correspondingly identified for the bridge deck used in this study after a comprehensive evaluation.

尽管在设计阶段进行了防风设计，但由于在运营期间安装了新的附属设施，因此现有桥梁可能仍会遭受剧烈的涡激振动（VIV）。因此，有必要采取控制措施来抑制由这种结构改变引起的VIV。在这项研究中，通过一系列截面模型测试和流量可视化测试，研究了流线型箱梁桥在安装新辅助管道系统期间的VIV性能。在风洞测试期间，在较低的风速范围内观察到了本研究中使用的桥梁的严重垂直VIV。根据截面模型周围的流动模式，可以推断出穿过甲板底面的流动完全被新管道分开，这导致在尾流区周期性产生脱落涡并引起甲板振动。发现双向下垂直稳定器板（TDVS）是改善桥梁VIV性能的有效空气动力学对策，并且可以显着降低垂直VIV运动的幅度。附加的流动可视化研究表明，安装TDVS后，尾流中的涡流脱落得到缓解，涡流脱落的位置离甲板更远，因此大大抑制了垂直VIV。已经发现，TDVS在改善空气动力学性能方面的有效性显着取决于TDVS参数，即，板高度和板元件之间的间距。