La diagnostica a supporto delle verifiche di sicurezza strutturale del ponte della Badia

The Ponte della Badia bridge is a milestone in the Archaeological Park of Vulci. Its complex constructive framework, represented by different stone materials and geometries, is a result of several interventions during the centuries to solve the continuous effects of river floods, such as the loss of material, detachments, exfoliation, and deposition of concretions. In this work, we present the results of a multi-disciplinary approach to studying the bridge combining in-site tests with lab measurements, useful to model the actual behaviour of the bridge. We carried out ground penetrating radar measurements with core information in a few selected points. The use of the dynamic identification test allowed the achievement of an overall estimation of the whole dynamic behaviour. Several mechanical tests in the lab have been set and a series of mineralogical, microstructural and microchemical characterizations were performed, where radiocarbon dating provided other interesting information. The result of this study depicts a bridge built with squared blocks “opus quadratum” without mortar, mainly with yellow and grey tuffs, where the second one is significantly more resistant than the first one. The water action, by deposition of concretions on the interfaces, provides a efficient connection among blocks.