An index-based multi-hazard risk assessment method for prioritisation of existing bridge portfolios

This study develops and proposes a multi-hazard risk-based prioritisation methodology to be used at territorial scale on a large number of bridges, both in the case of a scarce level of knowledge (e.g. when visual inspections have not been caried out yet), and when data from visual inspections is available. In recent years, several catastrophic collapses of existing bridges have highlighted the need for rapid risk analysis methods aimed at supporting infrastructure managers in the prioritisation of detailed assessments and, if any, risk mitigation actions.

This study proposes a multi-hazard risk-based prioritisation methodology for application to a large number of bridges under limited level of knowledge. Specifically, the risk level is quantified through indices, accounting for uncertainties, that are used for comparative purposes among bridges. The methodology is applied to a highway bridge portfolio located in northern Italy, producing a risk-based ranking that is critically discussed.