Influence of strengthening interventions on the structural performance of a Maillart‐type arch bridge: the case of “Ciolo Bridge” in the South of Italy

Recent collapses of existing bridges occurred worldwide demonstrated the need of risk mitigation strategies. The failure of existing bridges can be attributed to many reasons: unexpected external actions due to both natural and anthropogenic catastrophes, materials degradation, increased traffic loads, inadequate original design or construction, lack of maintenance. In this context, it is remarkable that a significant percentage of the existing infrastructures has reached its nominal service life, requiring the allocation of relevant resources for their assessment, repair and upgrading. This study investigates the structural performance of a Maillart bridge built in 1960s in the South‐East of Italy. Due to its exposure close to the sea, the bridge has been subjected to a significant degradation, which asked strengthening interventions over the years. A detailed survey and tests were performed to investigate the mechanical properties of structural materials and detailing. A structural analysis was led by considering the original configuration and the retrofitted one. The results of the numerical analyses are shown and discussed in the paper, also by assessing the safety levels of the bridge and the effectiveness of the strengthening interventions occurred during the service life.