Preliminary Structural Assessment of a Multi-span Masonry Arch Bridge

The Olla bridge is a multi-span masonry arch bridge dating back to the second part of the 19th century. The structure, 117 m long, includes five arches of different span and crosses the Stura river close to the small town of Gaiola, about 16 km far from Cuneo (Piedmont, Northern Italy). The central span of the bridge was destroyed during the 2nd World War and rebuilt in 1945. Recently, damages (i.e., the opening of some cracks) have been reported on two arches and the structural assessment of the structure is ongoing. So far, no original drawings of the bridge have been found in the archives and a multidisciplinary research program started, including direct visual inspection, geomatic survey, ambient vibration tests, minor destructive tests, numerical simulations and full-scale load tests. The paper summarizes the experimental results obtained from direct inspection, geometric survey and dynamic tests as well as the development of a simplified numerical model.