间距比对叠合梁双幅桥涡振性能的影响

以工程中常用的双边工字钢式叠合梁平行双幅桥为对象,基于系列弹簧悬挂节段模型风洞试验,研究了不同间距比下叠合梁平行双幅桥涡振(VIV)干扰效应,并将上下游桥面涡振振幅、涡振风速锁定区间与单幅桥面进行了对比。结果表明:双幅桥与单幅桥相比,气动干扰效应使得双幅桥的最大涡振振幅和风速锁定区间都明显增加;双幅桥的最不利间距比为2～4,此时桥面最大涡振振幅最大且风速锁定区间更长;上下游桥面的振动存在一个相位差,受到折减风速、上游桥面振幅和间距比的共同影响。

Effect of Gap Distance Ratio on Vortex-induced Vibration Performance for Bridge with Twin Composite Girders

Based on a series of sectional model wind tunnel tests, the effects of gap distance ratio on aerodynamic interference and vortex-induced vibration (VIV) performance of parallel twin-deck bridge were studied. The results show that the maximum amplitude of VIV and the lock-in wind speeds increase significantly compared with a single-deck bridge due to the aerodynamic interference effect; the most unfavorable range of gap distance ratio is 2~4, with the largest maximum amplitudes of VIV and a wider lock-in wind speed range; there is a phase lag in the vibration of two decks, which is affected by reduced wind speed, the amplitude of upstream deck and gap distance ratio.