Vehicle-tunnel coupled vibration analysis of submerged floating tunnel due to tether parametric excitation

摘要

Submerged floating tunnel (SFT) is a novel type traffic structure for crossing the long straits. To analyze the vehicle-tunnel coupled vibration of SFT due to tether parametric excitation, Hamilton principle and D'Alembert's principle are applied to establish the theoretical model. The fourth order Runge-Kutta method is carried out to calculate the responses of the system. The proposed model is verified by the beam on the elastic foundation (BOEF) model without considering tether parametric excitation, and the relative difference is less than 2%. If the initial excitation can be controlled in a small range, the influence of the tether vibration on the vehicle-coupled vibration can be efficiently reduced. Meantime, the effects of some factors, such as the gravity-buoyance ratio (GBR), the inclined angle of the tether (IAT), and the vehicle velocity on the dynamic response are discussed. The results show that the dynamic amplification factors (DAFs) of the deflection and the bending moment decrease with the GBR increasing. Besides, the larger IAT results in larger tether tension fluctuation when the vehicle-tunnel coupled vibration of the SFT subjected to tether parametric excitation. And the slower vehicle is more affected by the tether vibration when the vehicle drives in the tunnel.