Seismic assessment of typical masonry historical residential buildings in Catania

The seismic vulnerability assessment of historical UnReinforced Masonry (URM) buildings is a very complex task being strongly related to the great variety of geometrical layouts and masonry mechanical characteristics which reflect the regional traditions in the art of building. In this paper some results of a Catania University research project (FIR 2014) on the “Seismic vulnerability of historical aggregate buildings” are presented. The project was focused on the analysis of the seismic vulnerability of Historical Aggregates by means of cost demanding nonlinear static analysis as well as simplified fast assessment strategies. As a first needed step a detailed typological analysis of the urban fabric of typical residential masonry buildings built in Catania in the XVIII century has been performed. The typical geometrical layouts, the basic structural units and their combinations as aggregates for a wide class of historical masonry residential building have been identified. The periodicity of the construction scheme has allowed recognizing a typical unit cell that has been analyzed individually and according to different combination schemes leading to several geometrical arrangements representative of larger buildings or aggregates of buildings. An innovative macro-element approach has been applied on 16 structural aggregates in five areas of the historical center of Catania. Nonlinear static analyses, consistent to the Italian building code (NTC2008), have allowed providing some results in terms of seismic assessments of these typical URM buildings for different geometrical layouts and material characteristics. The results obtained so far, although related to specific urban fabrics, could also be used for a better calibration of fast seismic assessment strategies, particularly useful for the evaluation of the seismic risk at urban scale as well as for risk management after seismic events.