Probabilistic Hazard Assessment of Bridges under Multihazard Actions during the Life-Cycle Period

Various hazards can have immediate or long-term impacts on the safety of bridges, and the interactions between them are complicated. This study examined the multihazard concerns in bridge engineering. Through a comprehensive literature review, 16 hazards that pose threats to bridges were identified and analyzed by considering their temporal-spatial characteristics. The interactions between hazards were described using a hazard correlation matrix, and specific chained hazards were identified based on the site-specific conditions. The methods of probability analysis were discussed in terms of the hazard correlation, and a generalized formula is proposed to illustrate the chained effect process by considering the uncertainty in both primary and secondary hazards. Additionally, a lifetime model was introduced to address the long-term effects. A case study was conducted using field investigation data to demonstrate the proposed method, with emphasis on the joint probability of the earthquake–landslide chained effect. Moreover, the lifetime model was also incorporated to account for the scour effects serving as a long-term hazard. This study is aiming to complement the types of critical hazards threatening bridges and to provide guidance for engineers to select design hazards in accordance with the site-specific conditions.