Effect of cable layout on hydrodynamic response of submerged floating tunnel under wave action

A submerged floating tunnel (SFT) is a new type of traffic-crossing scheme in relatively deep waters that realizes suspension fixation through gravity, buoyancy, and cable force. The cable mainly constrains the SFT, and its layout has a critical impact on the dynamic characteristics of the SFT. In this study, hydrodynamic experiments are conducted on a reduced-scale model of the SFT under regular waves. The acceleration of the SFT tunnel, cable force, wave height, and other data are collected. The dynamic response of the SFT with three cable layouts (parallel, inclined, and mixed) is analyzed. Results show that the dynamic response of the SFT with a parallel cable layout is considerably less than that of the other two cable layouts under the action of regular waves. The amplitude of cable force at the upstream side is generally less than that at the downstream side for the inclined cable of the SFT with inclined and mixed cable layouts. The cable slack phenomenon reduces the overall constraint stiffness of the SFT, and the dynamic response considerably exceeds that under non-slack conditions. Resonance zone and long-period waves are the main excitations causing the motion of SFTs when the submerged depth is at safe level.