Probabilistic performance of coastal bridges under hurricane waves using experimental and 3D numerical investigations

This paper proposes a comprehensive framework for performance and reliability analyses of coastal bridges under hurricane surge and waves, including a three-dimensional (3D) Computational Fluid Dynamics (CFD) model to simulate the wave-structure interaction, laboratory experiments to improve the model accuracy, a 3D Finite Element Model (FEM) to evaluate bridge and component responses, surrogate models for performance prediction, as well as effects of uncertainties and climate changes in long-term vulnerability analyses. The experimental validation ensures the credibility of the established model and computational results. For accurate and efficient quantification of the structural responses under different surge and wave conditions, surrogate models are introduced for the investigated scenarios, which could not be well predicted by using existing methods. Based on the detailed 3D CFD and FEM results, a new component-level overturning failure mode of a bridge subjected to the hurricane is developed by considering wave forces, overturning moments, bearing damages, and uncertainties in structural and hazard parameters. Given fragility surface and potential changing climate scenario, long-term reliability analysis is performed. The established framework could be accurately and widely applied to other bridges and hurricane scenarios by adjusting the model and experimental parameters. This study could help in exploring the resistance of coastal bridges against natural hazards, and in developing specifications to mitigate future hurricane risk.