Performance-based integrated assessment of earthquake-induced economic losses for reinforced concrete bridges

Bridges are vital elements in ‘lifeline’ routes required to transport goods and people effectively, thus, the failure of a bridge in a crucial location within a transportation road network can cause substantial consequences for society, especially in the aftermath of a catastrophic event. With the increasing number of both new and ageing bridge assets in national inventories, there is a growing interest within the governmental and bridge management entities to quantify the risk of bridge structures to aid retrofitting activities, enhancing the overall resilience of transportation networks. In this regard, annual economic loss estimations are particularly helpful as a risk measure, given their correlation with the asset’s economic value and ability to represent the overall seismic performance. Nonetheless, for objective seismic risk quantification, it is necessary to compute both direct losses, e.g., repair costs due to physical damage, and indirect ones related to the interruption of regular economic activities, such as traffic congestion due to non-functional bridges on a roadway. With this in mind, this paper presents an integrated and comprehensive component-based framework to evaluate both seismic loss components for reinforced concrete (RC) bridge structures as part of a specific road network, adopting a performance-based earthquake engineering rationale. Its application to a road network is showcased using proposed open-source software tools, and indirect loss estimates are compared with the direct counterpart, relating such ratio with the bridge’s strategic importance. Finally, utilising the case-study application results, recently introduced risk prioritisation guidelines in Italy are evaluated with a view to improve them.