Resiliency Assessment of Coastal Bridges Under Extreme Wave Loads

Susceptibility of the transportation system, namely the coastal bridges, to wave-induced damages has been demonstrated in past hurricane and tsunami events. With the rapid change of climate, extreme weather events are becoming more frequent and intense. It is imperative now that the failure mechanism be assessed to propose retrofitting of existing coastal bridges as well as new designs. This paper presents a comprehensive framework for the fragility and resilience assessment of coastal bridges exposed to extreme wave-induced loads. The analysis is demonstrated on a three-span reinforced concrete I-girder coastal bridge with circular piers. Intensity parameters chosen for this study are wave period, wave height and still water elevation. This numerical study is done in OpenSees, where the component-level fragility curves are generated using the multiple stripe analysis method. The system resiliency generated via the assumption of a series connection between the bridge components reveals that the bearing elements are the most vulnerable among the other bridge components studied when the waves do not reach the deck level. The proposed framework could be applied to assess the resiliency of other bridge types by adjusting the model parameters. This paper could help in developing design guidelines to improve the resistance of coastal bridges toward future extreme weather events.