Seismic Energy Upgrading of an Existing Brick Masonry Building by a Cold-Formed Steel Envelope System

Abstract

In recent years, new solutions have been studied in order to intervene on existing buildings made of load-bearing masonry or reinforced concrete, both from the seismic point of view and the energy one. In recent years, novel modern techniques using lightweight steel profiles made of steel or aluminium alloys, suitably coupled with heat-insulating panels, have been proposed for requalification of existing building stock. In this paper, the Resisto 5.9 system designed by the Progetto Sisma S.r.l. company was studied and applied as a retrofit system of an existing masonry building. First, this new system for seismic energy requalification of the build-up was presented, describing the basic components and the mounting phases. Subsequently, it has applied to a case study building made of full-brick masonry located in the municipality of Casalecchio di Reno, on the outskirts of Bologna in Northern Italy. Finally, the used coating system was designed for the examined building together with other seismic interventions applied to horizontal structures and foundations. The seismic benefits deriving from using the proposed envelope system and other seismic interventions were proved from the seismic viewpoint by linear dynamic and non-linear static analyses using the TreMuri analysis software. From modal analysis it was seen that the dynamic behaviour of the building with Resisto 5.9 is improved, with an increase of the participating mass (68% instead of 49% of the bare building) of the second mode in the longitudinal direction. Moreover, from pushover analysis it was noticed that the seismic safety factor has passed from 0.51 to 1.05 in the X-direction and from 0.78 to 1.27 in the Y-direction. In conclusion, it was demonstrated that Resisto 5.9, together with all the other planned interventions, is able to accomplish the seismic retrofitting of the studied building.