Seismic fragility and risk of Italian residential masonry heritage

Seismic risk mitigation at national scale requires the vulnerability assessment of the built stock, along with seismic hazard and exposure evaluation. In this work, the fragilities of more than 500 Italian unreinforced masonry (URM) residential buildings, related to an intermediate damage state DS (between severe and moderate), were calculated based on a mechanical approach (through the Vulnus_4.0 software). The fragility results were then processed for calibrating a macro-seismic vulnerability model available in the literature, in order to propose a fragility model based on the five DSs of the EMS98 scale and on some URM building macro-typologies. The model was then validated using the damage observations of the 2009 L’Aquila earthquake, contained in DaDO (Database of Observed Damage). Lastly, the fragility model was used to derive seismic damage maps and to carry out risk analyses (economic losses) on a national scale.