中低速磁浮诱发交通枢纽换乘中心振动响应研究OA北大核心CSTPCD

To address the vibration problem of the airport ground transportation center(GTC)induced by low-to-medium speed maglev train,a coupled vibration model of maglev train-guideway girder and a finite element model of guideway girder-GTC-soil are established,and then the two-step method is used to analyze the response characteristics,propagation laws,and vibration levels of the vibration problem.The maglev train is modeled using multi-body dynamics,and the guideway girder is modeled using finite element method.The coupled vibration model is formed by linear magnet-rail relationship between the two components,and the correctness of the model is verified by field measurement results.Based on the established coupled vibration model,the time history curves of the fastener force between the H-shaped rail sleeper and the rail support platform are obtained.The fastener force is applied to the guideway girder-GTC-soil model,and the dynamic response of typical observation points of GTC is obtained by transient analysis.The results show that when the vibration induced by maglev train propagates along the height direction,the vibration responses of structural columns and floors decrease first and then increase with the increase of height.When the vibration propagates along the horizontal direction,the vibration response decreases rapidly with the increase of distance.There is an obvious frequency doubling phenomenon in the vibration response of GTC,that is,there is an obvious peak value in the power spectral density curve of the vibration response at the frequency doubling of the main frequency of the fastener force.When the vehicle speed is 60 km/h,the main frequency of the vehicle excitation is close to the first-order vertical natural frequency of the guideway girder.At this time,the maximum vibration level of the 1/3 octave of the observation point is greater than other vehicle speeds.When the maglev train passes through the GTC at 60～120 km/h,the maximum Z vibration level of each floor does not exceed the standard limit,indicating that the airport GTC has good overall stiffness.