水平中央隔涡板透空形式对分体箱梁涡振响应的影响

Effects of horizontal central vortex isolation plates with different openings on VIV of twin-box girder

分体箱梁断面因其优异的颤振性能近年来在大跨度缆索承重桥梁中多有应用。对涡振问题比较严重的分体箱梁,采用气动措施削弱开槽处的大尺度漩涡是控制涡振的最有效手段。通过大比例节段模型风洞试验,对比了不同形式水平隔涡板对分体箱梁的涡振控制效果。比较结果显示:在透空率接近的情况下,采用两侧水平隔涡板比各种打孔板的涡振控制效果都要好,如果要采用打孔板达到两侧水平板近似的涡振效果,透空率需要再减小26%左右;如果采用打孔板,板上的孔越是不均匀,涡振控制效果越好,而孔的形状对涡振影响不大。

Twin-box girders are widely used in long-span cable-supported bridges for their excellent performance against flutter.Using aerodynamic counter-measures to weaken large size vortexes at slotting of two-box girder is the most effective way to control vortex-induced vibration(VIV).Here,effects of horizontal central vortex isolation plates with different openings on VIV of twin-box girder were compared through conducting wind tunnel tests for a large-scale segment model.The results showed that compared to various plates with different openings,twin-side horizontal vortex isolation plates have the best VIV control effect under a similar opening rate;plates with other types openings can reach the same level of VIV control effect as twin-side horizontal plate,the opening rate needs to decrease by about 26%;if adopting plates with openings,unevenly distributed openings have better VIV control effect,the shape of opening has a small impact on VIV.