ABSTRACT
Coastal bridges are susceptible to the compounding effects of storm surge and waves in tropical cyclone-prone areas. Over the long term, the vulnerability and risk of bridges may increase due to the uncertain storm conditions under climate change. Thus, evaluating the long-term risk of these bridges can be significant for mitigating financial and societal losses and minimizing interruptions to transportation systems. However, previous studies mainly highlighted bridge reliability, neglecting loss assessment and long-term risk under the uncertain frequency and intensity of cyclones. Particularly, the potential extreme risk has not been investigated. This study aims to develop a framework to assess the extreme risk of coastal bridges subjected to storm waves and surge in a life-cycle context. Within the framework, risks of different failure modes will be investigated and compared. In addition to the conventional deck unseating failure, a failure mode that considers dynamic structural response will be analyzed by incorporating component damage, thereby comprehensively combining the effects of wave load time histories, bearing connections, and overturning moment. Given vulnerabilities to different failure modes, the long-term risk and the associated extreme loss can be calculated based on a stochastic non-homogeneous Poisson process considering the non-stationary frequency and intensity of cyclones. The developed framework will be applied to a coastal highway bridge to identify the extreme risk and long-term performance under cyclone hazards.
