Floating bridge response under combined ship collision, wind and wave loads

Abstract

ABSTRACT Floating bridges over navigable fjords with exposed substructures are at risk of accidental ship collisions. Other hazards such as extreme wind and wave loads are also critical for floating bridges. This study investigates the global dynamic responses of a floating bridge subjected to different combinations of ship collision, wind and wave loads. A numerical model of a floating bridge is developed using OrcaFlex. The ship-bridge interaction is modelled by defining a constraint element attached to the striking ship. The stiffness of the constraint is described by a nonlinear force-displacement curve. The full turbulent wind field is generated using TurbSim, and the bridge buffeting response is calculated in time domain based on the linear quasi-steady theory. The wind-bridge interaction is accounted for by considering the relative angle of attack and the relative wind velocity at each time step. The bridge responses under individual hazards are compared with those considering multi-hazards.