- Copyright 2018 by the International Society of Offshore and Polar Engineers (ISOPE) Effects of moving loads and wave excitations on a 900-m-long SFT (submerged floating tunnel) are presented and discussed. Floater-mooring coupled dynamic analysis is done by a time-domain numerical simulation program. Hydro-elasticity of the tunnel and mooring lines are considered with the clamped-clamped end-boundary condition. The result of modal analysis is included to investigate natural frequencies of the entire structure. Effects of the BWR (buoyancy to weight ratio) and velocity of a moving vehicle are discussed. In addition, moving-load effects coupled with wave excitations are also analyzed. Finally, the effect of the same moving weight on smaller SFT is also assessed. Time histories of horizontal and vertical responses of the tunnel and mooring tensions at the middle span are presented with the corresponding spectra.