Bridges are essential components of road networks, and their failure can lead to significant economic and social repercussions, as shown by many recent failures worldwide. In Italy, the dramatic collapse of the Morandi bridge prompted the introduction of improved management of its roadway infrastructure, leading to the issuing of multi-level multi-hazard assessment guidelines for bridge management, assessment and monitoring in 2020. Although these comprehensive guidelines marked a significant progress in standardising management practices, they do not facilitate detailed prioritisation of thousands of bridges due to their qualitative description of risk. To mitigate such a limitation, this study proposes an enhanced quantitative risk-based method for prioritising existing bridges for both structural/traffic and seismic hazards, built upon a recently proposed methodology settled on a simplified index-based evaluation of the three primary risk components: vulnerability, exposure, and hazard. The performance of the proposed enhanced approach, which includes hazard-dependent vulnerability parameters, is evaluated in different versions, when applied to a large case-study of 415 bridges in northern Italy. It is demonstrated that the proposed approach and indices can generate rankings that improve the differentiation among bridge priority, allowing for more nuanced prioritisation than most existing guidelines (e.g., within each risk class currently foreseen by the ones in Italy) for both traffic and seismic risk, thereby enhancing bridge management strategies.
Scattarreggia et al. (Sat,) studied this question.