波流作用下悬浮隧道运动响应纵向截断模型试验研究

A study on the wave-current-induced motion responses of submerged floating tunnels using longitudinal truncated model tests

利用波流水槽构建悬浮隧道纵向截断模型试验,分析了水流及波浪作用对悬浮隧道运动响应的影响,获得了管体结构的垂向及横向运动响应特性。研究结果表明:水流流速较小时,模型振幅随约化流速Vr增大而增大,而在约化流速为5.8附近,管体振幅达到最大并在这一临界值之后形成较为稳定的振幅值,产生明显的结构共振和涡激振动“锁定”现象。振幅稳定后垂向幅值约为管径的2倍,横向幅值与管径相当。对于波浪单独作用,在波浪较弱时,横向幅值与垂向几乎相等,随着特征KC_(n)数的增大,响应振幅先增后减。在特征KC_(n)数小于0.51范围内,垂向振幅大于横向振幅,其余范围则相反。垂向振幅和横向振幅分别在特征KC_(n)数为0.42和0.55时达到峰值,且两个方向的最大振幅值均与管体的管径相当。相对响应频率随着特征KC_(n)数的增大而减少,且垂向大于横向。

Using a wave-current flume,a truncated model of the submerged floating tunnels(SFT)was established for analyzing the wave-current-induced motion response.The vertical and horizontal response characteristics of the SFT tube structure were obtained.Experimental results are as follows:at low velocity,the model motion amplitude increases by increasing the reduced velocity of Vr.The vertical motion amplitude peaks when the reduced velocity equals 5.8,and maintains stable amplitude results when the reduced velocity is larger than this critical value,leading to structural resonance and vortex-induced vibration“lock-in”phenomenon.In the stable amplitude range,the vertical motion amplitude is two times of the SFT's diameter,and the horizontal motion gives a comparable amplitude to the SFT's diameter.When considering waves action solely,the horizontal motion amplitude is comparable to the vertical when wave is weak.The motion amplitude firstly increases and then decreases when increasing the characteristic KC_(n)number.In the range of KC_(n)<0.51,the vertical amplitude is greater than the horizontal amplitude,and if KC_(n)>0.51,an inverse relationship takes hold.The vertical and horizontal amplitude peaks at KC_(n)=0.42 and 0.55,respectively,and both the two peak values are comparable to the SFT's diameter.As the characteristic KC_(n)number increases,the relative response frequency deceases,and the vertical relative frequency is generally larger than the horizontal one.