Dynamic interaction with travelling vehicles in a submerged floating tunnel

The work aims to investigating the effect of vehicle-bridge interaction (VBI) on a Submerged Floating Tunnel (SFT), a novel type of bridge still at the feasibility study phase. The case study is a prototype SFT designed to cross the Messina’s Strait, in Italy. Tethers guarantee the static equilibrium of the SFT subjected to Archimede’s forces and, due to their length, behave in a non-linear way. The VBI coupled problem is solved through an uncoupled iterative procedure, where bridge and crossing vehicle are analyzed separately for the whole duration of the time history: the vehicle is subjected, on its wheels, to roughness and bridge motion and the bridge is subjected to vehicle’s contact forces. The ANSYS code performs the non-linear analyses of the bridge, while a research code integrates the vehicle equation of motion and handles the data exchange between the two codes. The numerical procedure achieve convergence in a few iterations. Results show that the effect of crossing vehicle do not propagate on the tunnel, affecting only the nearby tethers.