悬浮隧道锚索流固耦合振动试验研究

悬浮隧道跨越长深水域的新型交通结构物。在水流的作用下，锚索将会发生涡激振动，以往的研究主要采用数值方法，而进行模型试验研究是探索悬浮隧道锚索涡激振动机理不可或缺的研究手段之一。本文利用风浪流多功能水槽，以千岛湖悬浮隧道锚索为原型，采用节段模型试验的方法，进行了均匀流作用下锚索涡激振动试验研究。通过试验发现，圆形锚索的Cm值约为0.94，线性流体阻尼比ξ’约为1.26%；锚索在约化速度U/fnD =5.8~10.1发生涡激锁定现象，产生涡激共振，此时横向振幅约化值（Ay/D）最大达到1.10，顺流向振动依旧较小，而升力系数CL和拖曳力系数CD均会显著的增大；参数分析发现，圆形锚索倾斜布置有利于降低涡激共振的不利影响，但当来流角度的变化后会对倾斜布置的锚索产生不利影响。

Experiment on Cable Dynamic Response of Submerged Floating Tunnel based on Fluid-Structure Interaction

Submerged floating tunnel(SFT) is a new traffic structure across long and deep waterway. The vortex-induced vibration of cables will occur under action of water current. Privious studies were done by using numerical methods, however, experiment is indispensable mean to explore VIV mechanism of cables in water. In this paper, taking cables of Qiandao Lake SFT for prototype, the experiments of VIV on cable were carried out under the action of current by using segment models in stormy stream integrated sink. The results show that inertial force coefficient Cm of circular cable is 0.94, linear fluid damping ratio ξ’ is 1.26%; when the reduced velocity is between 5.8~10.1, the vortex-induced resonance will occur, the maximum lateral amplitude Ay/D is 1.10, the in-line amplitude is still low, and the lift coefficient CL and drag coefficient CD will increase. The parametric analysis concluded that the diagonal arrangement of circular cables will be helpful to reduce the VIV effects and the changing of flow direction will adversely affect vibration of inclined cables.