Failure analysis of ageing RC bridges: The cases of the Polcevera viaduct and the Caprigliola bridge

Many existing bridges now have a life of more than 50 years and the recently occurred failures underline the need for many of these structures to be assessed and, if required, retrofitted, in order to avoid catastrophic collapses. The Applied Element Method is herein used to show as advanced numerical modelling that accounts for as-built structural details, construction stages, material deterioration effects and structural modifications over time, have the potential to predict the failure mechanism and study the sensitivity of complex structural schemes to external actions. To this end, the collapse of the Polcevera viaduct in Genoa (August 2018), and of the historical multi-span arch bridge of Caprigliola (April 2020) are reproduced. Comparisons between numerical results and evidence, indicate that an accurate knowledge of the asbuilt structural details and conservation may permit to point out potential criticalities and analyse the robustness of existing bridges to avoid the premature end of their life.