A quantitative methodology for risk-based priority ranking of deteriorated bridges: Application to a bridge stock

Bridges play a crucial role in a nation’s infrastructure, facilitating connectivity in road networks. Recent global incidents of bridge failures have heightened concerns about the existing bridge structures, prompting the development of more effective bridge management techniques. Italy, among other countries, has addressed this concern by introducing national guidelines for the risk assessment and management of bridge portfolios. While these guidelines offer a detailed multi-level and multi-hazard approach, their qualitative nature limits enhance precision of risk classification for a specific bridge stock. This study addresses this limitation by presenting a quantitative approach to evaluate bridge risk conditions. The method provides quantifiable expressions for vulnerability, exposure, and hazard, considering both the general robustness of the bridge structure and the presence of defects and damages. Leveraging the Italian guidelines’ specifications, the priority ranking approach employs a refined scoring system to convert qualitative bridge characteristics into quantitative parameters. The study focuses on prioritizing 130 bridges in northern Italy through both the priority ranking method and the ITAGuidelines. It thoroughly assesses the ITA-Guidelines’ classes of attention for various risk parameters and compares the outcomes with the priority ranking method.