Numerical Estimation of Static and Dynamic Response of Submerged Floating Tunnel Under Wave and Cable Breakage Conditions

Submerged floating tunnels (SFTs) are intricate structures influenced by a complex interplay of parameters such as buoyancy-weight ratio, immersion depth, water depth configuration, cable inclination, and tension distribution. To improve the assessment of SFT service performance, this paper introduces a computational model that evaluates the static behavior of SFTs, deriving a tension distribution formula aimed at minimizing deflection based on the interdependence of these parameters. Building on this model, the study further examines the hydrodynamic response of SFTs under wave conditions, analyzing variations in immersion depth, cable inclination angles, wave heights, and wavelengths. Furthermore, based on the static analysis, this study emulated the equivalent load of cable breakage and examined the subsequent dynamic response before and after under wave conditions. Finally, the response results were compared with the static analysis of the structure, mutually verifying the accuracy of the model. The results indicate that optimizing cable tension distribution can significantly reduce maximum deflection and bending moments, enhancing structural stability. Moreover, increased cable tension contributes to overall stiffness, thereby mitigating vortex-induced vibrations. Cable inclination also plays a crucial role; smaller inclination angles provide greater lateral constraints but reduce vertical constraints, with an optimal range identified between [Formula: see text] and [Formula: see text]. Additionally, higher wave heights and shallower immersion depths amplify the hydrodynamic response, with certain conditions exciting higher-order vibration modes. Overall, downstream cable tensions tend to surpass those upstream, except under specific wave periods and inclinations. Under the condition of cable breakage, the structural stiffness decreases, leading to an increase in dynamic response. Meanwhile, the cable tensions on the opposite side of the same cross-section slightly increase, whereas the cable forces on the same side of different cross-sections significantly increase. These insights are valuable for the design and maintenance of SFTs across diverse environmental conditions.