Interventi migliorativi in acciaio a tutela delle opere di interesse storico-monumentale dal rischio sismico

The research concerns the analysis of structural behaviour of some historic-monumental buildings in which steel structures are used for the seismic protection. A dynamic model has been made to individuate the macro-element with an high seismic risk, that is, for church studied, the drum-dome system. Then a scaled model has been tested to determinate the evolution of the lesions, the retrofitting works, that are constituted by steel frames, bare or braced, inserted inside door/window holes of the drum-dome system, and the variation structural ductility. An elastic linear analysis, with a FEM software, has been developed for other type of buildings, in which the vertical structures are made with squared blocks of calcarenite connected by mortar. These buildings have the plan of rectangular shapes and are characterized by flexible floors. A suitable upgrading technique consists in using horizontal braced steel frames connected to the walls in order to prevent local mechanisms and to limit the interstorey drift values.