Fluid–Vehicle–Tunnel Coupled Vibration Analysis of a Submerged Floating Tunnel Based on a Wake Oscillator Model

The submerged floating tunnel (SFT) is a newly developed traffic structure for crossing the long waterway. On the basis of the vehicle–tunnel coupled vibration, the vortex-induced effect of the SFT in the water flow field is considered through a wake oscillator model. The tunnel is modeled as an Euler–Bernoulli beam supported by the continuous elastic foundation. The vehicle is regarded as a spring–mass block moving on the tube with a damping term. The finite-difference method is carried out to calculate the fluid–vehicle–tunnel coupled system vibration response evolution. The effects of the buoyancy weight ratio (BWR), the structural span, the vehicle weight, and the distributed flow field on the fluid–vehicle–tunnel coupled vibration are discussed. The results show that the vehicle moving in the SFT will aggravate the fluid–tunnel coupled vibration. The reverse displacement of the vehicle is driven by the coupled vibration. With an increase in the flow velocity, the short-span SFT will vibrate more intensively than the long-span SFT. The heavy-weight vehicle moves more stably during the fluid–vehicle–tunnel coupled vibration. The characteristics of the distributed flow field could be indirectly reflected by the vehicle vibration response.