Typological fragility analysis of masonry buildings in Emilia Romagna region (Italy)

UnReinforced Masonry (URM) buildings constitute the majority of the Italian building stock and represent one of the most vulnerable construction typologies, as emerged during the seismic events occurred in the last decades. The objective of the present work is the proposal of a methodology for the seismic vulnerability and fragility assessment of different typologies of URM buildings. Through the statistical analysis of post-earthquake damage survey forms and of census data, the most prevalent structural typologies were identified in the Emilia Romagna region (Italy), leading to the definition of two reference masonry buildings, built at the beginning of the XX century and representative of the building stock of the study area. These buildings were modeled according to the equivalent frame method and their seismic performance was studied by means of nonlinear static analyses, considering uncertainties on the mechanical properties of masonry, on the intensity of the seismic action and on the displacement demand calculation method. Through the definition of Response Surfaces, analytical fragility curves relative to the investigated structural typologies were determined for the different damage states.