Response-based bridge deck limit state considering component-level failure under extreme wave

Coastal bridges are crucial components of transportation systems; however, they are susceptible to increasing failure risk from extreme waves due to climate change scenarios. Previously, most of the studies focused on the extreme wave forces on the bridge superstructure, while the effects of the overturning moment, bearing constraints, and local damage were seldom discussed. This research conducts an in-depth investigation on the wave-bridge interaction to explore the structural limit state of the coastal bridges subjected to extreme waves considering component failure. Firstly, a three-dimensional (3D) Computational Fluid Dynamics (CFD) model is established and validated to simulate the wave-bridge interaction under various wave scenarios. To lend confidence to the CFD model, laboratory experiments are conducted to improve and validate the simulation results. Subsequently, based on the numerical results, wave force prediction methods are proposed by considering the solitary wave characteristics. Accordingly, the time histories of wave forces are imported into a spatial Finite Element (FE) model of the investigated bridge FE model to compute dynamic structural responses, including bearing reaction forces, bridge displacements, and bearing working states. Then, based on the dynamic structural response, a novel structural limit state incorporating component damage is developed to prevent bearing damages under the wave impacts and corresponding structural demand is parametrically studied and quantified with different wave parameters. Such a study could help optimal and robust designs of coastal bridges and modifications of existing ones.