中央稳定板对大跨度开槽桁架梁悬索桥颤振稳定性的影响

Effect of Central Stabilizing Barriers on the Flutter Stability of a Long-Span Truss Girder Suspension Bridge with a Central-Slot Deck

以坝陵河大桥为背景,通过节段模型风洞试验研究了上下中央稳定板对具有中央开槽桥面板的大跨度桁架加劲梁悬索桥颤振性能的影响。结果表明,在桁架加劲梁横梁上弦杆上侧设置适当高度的上中央稳定板可以较大幅度地提高桥梁的颤振临界风速,并且在常规的稳定板高度范围,颤振临界风速基本上随上稳定板高度的增加而提高;在横梁上弦杆下侧的主桁架内设置适当高度的下中央稳定板也能在一定程度上改善桥梁颤振稳定性,但效果明显不如上稳定板,在某些高度情况下甚至会降低桥梁的颤振临界风速。

Taking the Baling River Bridge as a background, the effects of upper and lower central stabilizing barriers on the flutter stability of long-span truss girder suspension bridge with a central-slot deck have been investigated by a series of wind tunnel tests of sectional model. The results show that the flutter critical wind speed can be significantly increased by mounting an upper central stabilizing barrier on the top surface of the upper chords of the transverse frames of the truss girder, and the flutter critical wind speed increases with the increase of the height of upper central stabilizing barrier within a normal range. The flutter stability of the bridge can also be improved to some extent by using a lower central stabilizing barrier with proper heights beneath the top surface of the upper chords of the transverse frames, but the effect of the lower one is obviously not so good as that of the upper one. And the flutter critical wind speed may even decrease by the lower stabilizing barrier in some height cases.