L’USO DI RINFORZI IN ACCIAIO PER IL MIGLIORAMENTO SISMICO DI EDIFICI VINCOLATI IN MURATURA. IL CASO DELL’EX OSPEDALE DI FORLÍ.

The design of seismic improvement interventions on listed masonry buildings requires specific strategies, focused on the preservation of the original features and the integration of new elements able to restore their functionality. In this context, steel has a fundamental role, due to its characteristics, like lightness, reduced sections, rapid construction and reversibility. This paper illustrates this specific topic within the project of conservative restoration of the Sauli and Saffi pavilions in the complex of the old hospital of Forlì, built in 1907 with typical regional material choices for the contemporary buildings, such as masonry and brick vaults, wooden roof and floors. Despite the good quality of the construction, the pavilions present the vulnerability of the Twentieth century buildings having a masonry structure, such as the absence of connections between horizontal elements and masonry walls, poor stiffness of the floors and an inadequate conformation of the roof. Therefore, the reinforcement with supplementary steel elements can easily correct these shortcomings while increasing as a whole the general safety index of the buildings.