中文摘要：

不同槽宽分体箱梁可以有效地提高大跨度桥梁的气动稳定性,但是其涡振性能还不够明确,研究了6种代表性开槽率分体箱梁的涡振性能随开槽率的变化规律,对比了4种控制措施（增大阻尼比、可调风障、导流板和隔涡板）的制振效果,并对其进行了综合评价。结果表明：闭口箱梁的涡振性能要优于开槽的分体箱梁;随着开槽率的增大,分体箱梁的竖弯涡振振幅先增后减,扭转涡振振幅表现较为敏感,其中,60%开槽率的竖弯涡振和80%开槽率的扭转涡振振幅最大。对比了60%和20%开槽率分体箱梁,增大结构阻尼比和增设小透风率的隔涡板可以明显的减小不同槽宽分体箱梁的竖弯涡振振幅,增大阻尼比和增设水平风障可以有效地提高不同槽宽分体箱梁的扭转涡振性能,而增设内置、外置导流板对的涡振控制效果取决于开槽率的大小。以上4种控制措施都可以满足分体箱梁的扭转涡振振幅要求,但只有增设0%透风率的隔涡板才能满足Sperling指标和抗风设计规范的竖弯涡振振幅要求。

英文摘要：

Although twin box girders with various slot ratios could improve the aerodynamic instability of long-span bridges, their vortex-induced vibration （VIV） performances are not explicit. The relationship of VIV performance of twin box girder with six resperentive slot ratios and slot ratio was investigated. The control effectiveness of four countermeasures including increasing structural damping ratio, installing wind barriers, installing guide vanes, and installing the grid plates were separately compared and then comprehensively evaluated. The results show that the VIV performance of a closed box girder is superior to those of twin box girders with various slot ratios. The vertical VIV amplitudes firstly increase and then decrease with the increasing of slot ratio, and torsional amplitudes are sensitive to the change of slot ratio, in which the 60% and 80% slot ratio has the largest vertical and torsional amplitude, respectively. As for the twin box girder with 60% and 20% slot ratios, increasing damping ratio and installing grid plates with small ventilation ratios could effectively decrease the verical VIV responses, while increasing damping ratio and installing the vertical and horizontal wind barriers are helpful to improve the torsional VIV performance. However, the control effect of a twin box girder with internalposition or extraposition guide vanes are depended on the slot ratio. Four countermeasures could be satisfied with the displacement requirement of torsional VIV of twin box girders, but only the grid plates with 0% ventilation ratio can be satisfied with the displacement requirement of vertical VIV according to Sperling＇s indicator and Wind-Resistance Specification of China.