Global Dynamic Responses and Progressive Failure of Submerged Floating Tunnel Under Cable Breakage Conditions

The Submerged Floating Tunnel(SFT) relies on a tensioned mooring system for precise positioning. The sudden breakage of a single cable can trigger an immediate alteration in the constraint conditions of the tube, inducing a transient heave response within the structure along with a transient increase in cable tension experienced by adjacent cables. In more severe cases, this may even lead to a progressive failure culminating in the global destruction of the SFT. This study used ANSYS/AQWA to establish a numerical model of the entire length SFT for the hydrodynamic response analysis, and conducted a coupled calculation of the dynamic responses of the SFT-mooring line model based on Orca Flex to study the global dynamic responses of the SFT at the moment of cable breakage and the redistribution of cable internal forces. The most unfavorable position for SFT cable breakage was identified, the influence mechanism of cable breakage at different positions on the global dynamic response was revealed, and the progressive chain failure pattern caused by localized cable breakage are also clarified.