Safety stabilization of the Ponte Scaligero in Sirmione
29 September 2023
The stabilization works on the Ponte Scaligero in Sirmione, designed, managed, and coordinated by Foppoli Moretta e Associati, have been completed. The works had to be carried out urgently due to significant settlements observed in the bridge piers and the riverside wall last winter, likely caused by the exceptionally low water level of the lake, which at that time was close to its historical minimum.
The work carried out included laser scanner surveys of the structure, diagnostic investigations (core sampling, endoscopies, and radar surveys) to assess its condition, and a stability assessment, which highlighted the immediate need to install a temporary steel bridge above the historic structure to ensure safety and maintain access. The bridge is, in fact, the only vehicular and pedestrian access to the historic center of Sirmione, and its closure would have caused an incalculable impact on the town’s tourism.
To avoid interrupting passage and to prevent interference with the numerous underground utilities beneath the pavement, which could not be disrupted, all work had to be performed from the intrados, i.e., from the lakebed. It was therefore necessary to partially enclose the area with sheet piling and pump out the water, carry out temporary safety measures (temporary wall tie-rods and provisional shoring) to protect both workers and users, and then proceed with the planned interventions, including underpinning, selective masonry stitching of degraded areas, and installation of permanent geotechnical tie-rods and transverse structural reinforcements anchored into the ground.
A complex intervention, a complex and challenging construction site, but ultimately an excellent organizational and execution outcome.
