Nutcracker Deformation Of Arch Bridge In Consequence Of Slow Gravitational Slope Deformations

Italy is a geologically young territory and still subject to tectonic actions and orogenic thrusts, originating a significant and continuous geomorphological evolution. This is expressed both by landslides and by phenomena of slow deformation of the slopes. These are sometimes seemingly imperceptible deformations, which however can potentially lead to long-term damage to infrastructure, as for the case of the famous Lagonegro bridge. Very small deformations that modern technologies allow us to objectively document and monitor by satellite images. These images, when appropriately analyzed and elaborated, contribute to the understanding of the dynamics of territory. This work presents a set of cases related to arch bridges deformed by slow but continuous thrusts linked to gravitational phenomena which give rise to compressive deformations of the abutments which can give rise to deformations of the bridges which can be defined as "nutcracker". In this work, a roundup of Italian examples of how slow gravitational slope deformations can lead to the collapse of bridges is reported. It is also presented a preliminary investigation on bridge deformation based on satellite techniques. It is briefly presented the case of Albiano-Magra bridge in Tuscany, which collapsed in April 2020, and the case of the Lagonegro bridge which was dismissed since 1952. Other cases presented are the former FFSS 12-arch bridge of the old Paola Cosenza railway line, cases of masonry arch bridges in Basilicata along provincial roads 154 and 103 in the province of Matera and the case of the former FAL bridge of Cassano to the Ionian Sea in the province of Cosenza. These are all examples of how slow deformations can affect arch bridges creating the condition for the failure or for the final compromission of the bridge.