The coupled tube-mooring system SFT hydrodynamic characteristics under wave excitations

Submerged floating tunnel (SFT) is a new type of promising traffic structure for the crossing of strait, ocean and fjord. This paper used a CFD method to investigate the hydrodynamic response of a 2D coupled tube-mooring system SFT under regular wave impacts. The influence of some key parameters was discussed, including submerged depth, buoyancy weight ratio (BWR), inclined mooring angle (IMA), mooring stiffness, mooring system arrangement, mooring pre-tension distribution andwave conditions. The results showthat themotion amplitudes and external forces of the SFT decrease with increasing submerged depth, but the SFT motion responses increase with increasing wave height and IMA. The influence of wave period is complicated, and the resonance of the SFT system must be avoided. Reasonable range of BWR exist, which leads to less motion response and more structural stability. Pre-tension distribution is not a key factor, and the mooring arrangement lacking vertical lines is not recommended. The influence factors on dynamic response was investigated, which provides references for the engineering practice.