Performance-based fragility and resilience assessment of coastal bridges subjected to extreme wave loads

Abstract

Bridges are vulnerable to severe damage due to extreme wave-induced loads from natural disasters, including storm surges, tsunamis, and hurricanes. The frequency of these hazards has been increasing recently as a direct impact of global warming. Enhancing the resilience of coastal bridges toward extreme waves is very important and quantification of the vulnerability of these structures is the very first step in designing a resilient bridge system. Design of most bridges in earlier times had no particular focus on the failure mechanism due to wave-induced forces. Only recently, after the collapse of the major bridges around the world due to tsunamis and hurricanes, research is being conducted to identify the resulting force and response of the coastal bridge system. However, the majority of these researches are focused on superstructure behaviour only. Therefore, studies on the response of both substructure and superstructure members of the coastal bridges are still inadequate and need to be addressed. The primary objective of this study is to identify the resilience of coastal bridges under extreme wave loads via the development of component and system-level performance-based fragility assessment using nonlinear finite element modeling in OpenSees. This study is based on numerical analysis where the finite element model of the bridge is developed considering both material and geometric nonlinearities. The modeling technique is validated against existing experimental results of a single column under cyclic lateral loading. This study also presents a simplified wave load calculation method considering the dynamic nature of the wave. [...]