台湾后龙溪桥风洞试验研究与静风响应分析

摘 要：通过风洞试验研究了台湾后龙溪桥气动稳定性；获得了混凝土梁和钢梁两种断面发生涡振的条件、涡振锁定风速范围及涡振振幅；对自然界和风洞中的风轴和体轴异同进行了区分；实测了两种断面的静气动力系数；最后进行了非线性静风荷载响应分析。研究结果表明：实桥风速达到135m/s，不会发生气动失稳；钢梁和混凝土梁断面+3°攻角时在均匀流场中会发生竖向和扭转涡振，扭转涡振风速锁定风速很高，而且范围很宽；在紊流度约为10％风场中，攻角在-3°～+3°范围内，未观测到明显涡振；由静风荷载引起的主梁附加攻角很小，风荷载非线性对主梁扭转位移和侧向位移影响很小，而对竖向位移影响相对较大，原因是竖向风荷载引起主缆刚度改变。

Wind tunnel testing study and aerostatic response analysis of houlongxi bridge in taiwan

The aero-stability performance of Houlongxi Bridge in Taiwan was investigated via wind tunnel tests. The conditions for vortex induced vibration of concrete and steel deck sections, as well as the lock-in wind velocity regions and vibration amplitudes were obtained. The similarity and discrepancy between the wind-axis and the body-axis in natural field and wind tunnel were expounded and discriminated. Then the aerostatic force coefficients were measured. The non- linear aerostatic response analysis was conducted finally. The study results revealed that the real bridge will not diverge when the velocity attains13.5m/s; in smooth flows, vertical bending and torsional vortex vibration occur for two models with +3° attack angle; for torsional vortex vibration,the wind velocity is quite high and its lock-in region is wide; in flows with turbulence intensity of 10%, when attack angle varies form -3° to + 3°, no apparent vortex can be observed; the deck added attack angle incurred by static wind loads is very tiny; the wind load non-linearity plays negligible role on deck torsional and lateral displacement; as the vertical lift wind loads will cause the obvious change of main cable rigidity, the vertical displacement is more relevant with the wind load non-linearity.