轨道不平顺激励下悬浮隧道车隧耦合振动响应分析

Vehicle-tunnel coupled vibration responses of a submerged floating tunnel under excitation of track irregularities

悬浮隧道是悬浮在水下一定深度的新型封闭式交通结构物。为分析轨道不平顺激励下水中悬浮隧道车隧耦合振动特性,将行驶车辆和悬浮隧道分别抽象为弹簧-质量车和离散弹性支撑梁,并结合Morison方程考虑流体附加惯性效应和阻尼效应,建立悬浮隧道车隧耦合振动微分控制方程。基于MATLAB采用四阶龙格-库塔法求解悬浮隧道在轨道不平顺激励下的车隧耦合振动响应。计算结果表明:悬浮隧道车隧耦合振动同时受到轨道不平顺和流体作用效应的影响。基于数值计算结果,考虑流体作用效应的结构位移响应有3%左右的增加;而在轨道不平顺激励下,考虑耦合振动的结构位移响应平均有5%～10%的增加。其次,锚索刚度对在轨道不平顺激励下结构位移响应具有抑制作用。具有较大锚索刚度的悬浮隧道对轨道不平顺更敏感,局部振动更剧烈。再者,快速行驶车辆在高干扰轨道激励下使耦合系统发生更强烈的振动,可通过控制车辆行驶轨道的平顺度以降低高速通行要求下产生的车隧耦合振动影响。

Submerged floating tunnel(SFT)is a novel closed traffic structure suspended under water.Here,in order to analyze vehicle-tunnel coupled vibration responses of a SFT due to track irregularities,it was simplified as a spatial beam on discrete elastic supports with a spring-mass vehicle moving on it.Considering fluid added inertia effect and damping effect with Morison equation,the governing dynamic differential equations for vehicle-tunnel coupled vibration responses of the SFT due to track irregularities were established.Adopting the fourth-order Runge-Kutta method based on MATLAB,these dynamic differential equations were numerically solved.The results showed that the vehicle-tunnel coupled vibration responses of the SFT are affected by both track irregularities and fluid effects;the structure displacement responses due to fluid effects increase by about 3%;the structure displacement responses due to track irregularities increase by about 5%to 10%;besides,the tether stiffness can suppress the structure displacement responses under excitation of track irregularities,the SFT with larger tether stiffness is more sensitive to track irregularities,and its local vibration is more acute;furthermore,the fast moving vehicle may cause more intensive vibration of the coupled system under excitation of track with larger irregularities,to control track irregularities can reduce the effects of vehicle-tunnel coupled vibration of the SFT on moving vehicles with high velocity.