中央稳定板对分体箱梁桥梁的涡振控制

Vortex-Induced Vibration Control for Twin Box Girder Bridges with Veritical Central Stabilzers

摘要:

以一座分体箱梁桥梁为背景，通过计算流体动力学 (CFD) 数值模拟和节段模型风洞试验，分别对上、下中央稳定板作用于分体箱梁的涡振控制效果展开研究.发现随着中央稳定板高度的增加，竖向涡振性能都是先变好再变差，分别在0.4倍梁高上稳定板时和0.2倍梁高下稳定板时竖向涡振振幅最小；增设上稳定板时加大了扭转涡振振幅，而下稳定板明显减小了扭转涡振振幅.CFD模拟的涡度场和压强场对比还表明，中央稳定板改变了槽中漩涡的运动方式和下风侧两端上下表面的压强，从而明显改变了竖向涡振的振幅.综合结果发现，0.2倍梁高下稳定板的涡振控制效果最好，而0.8倍梁高上稳定板的涡振控制效果最不利.

Abstract:

Taking a twinbox girder bridge with a slot width ratio of 20% as an example, the control effects of upward vertical central stabilizers (UVCS) and downward vertical central stabilizers (DVCS) on the bridge were investigated using CFD simulation and a series of wind tunnel tests, respectively. The results show that the amplitudes of heaving vortexinduced vibration(VIV) responses first increase and then decrease with the height increase of vertical central stabilizers, in which the amplitudes of heaving VIV responses for the UVCS with 0.4h/H and the DVCS with 0.2h/H were the smallest. The amplitudes of torsional VIV responses were enhanced by installing the UVCS while the DVCS are helpful to decrease the torsional responses. In addition, the results of the CFD numerical simulation show that VCS change the motion mode of vortex structures in the slotting and the pressure zones on the upper and bottom surface of the leeward side girder. It is found that the optimal control effective on the VIV performance is the DVCS with 0.2h/H, whereas the UVCS with 0.8h/H has the worst effective of all cases.