Over the past few decades, engineering research has increasingly focused on the reliability assessment of transport infrastructures and their critical components when faced with multiple natural hazards. This trend stems from recognizing the substantial direct and indirect economic losses associated with infrastructure damage and the resulting downtime. The increasing frequency of intense hazard occurrences, as a consequence of climate change, coupled with the time-intensive nature of post-event bridge inspections, highlights the need for an efficient approach to assess bridge fragility to hazards that occur either as single abrupt events or in compounds, i.e., multiple hazard perturbations or combined incremental deterioration. This approach should account for the order of hazards and the accumulation of damage to bridge components. Within this context, we introduce an analytical method for evaluating the fragility of bridges affected by independent or multiple successive and independent natural hazards. The proposed method is demonstrated through a case study in which a riverine bridge is evaluated considering different sequences of hazards. Initially, the fragility of the bridge under individual hazards, such as earthquakes or floods, is calculated. Subsequently, multi-hazard fragility curves are constructed to capture the combined effects of these events. This approach is a comprehensive method for generating fragility curves for bridges, considering all structural components involved in the resisting system of the structure. These curves are based on a detailed estimation of thresholds for different limit states, encompassing multiple failure modes and accounting for soil-structure interaction (SSI) effects. The method employs a probabilistic framework to manage uncertainties in both the demand on the structure and its capacity to withstand single hazards. The framework is extended to include scenarios involving multiple hazards that occur separately or in series, emphasizing how cumulative damage influences the overall bridge fragility. The findings indicate a significant increase in the probability of damage for all the limit states examined, underscoring the importance of considering the cumulative effect of multiple hazards in the fragility analysis of bridges. The fragility models can be used in life-cycle risk assessment of aging bridges exposed to multiple hazards to inform decision-making and prioritization of investments for risk mitigation and climate adaptation.

来源平台：STRUCTURES