Large-scale seismic vulnerability assessment of masonry buildings through a simplified methodology

Assessing the seismic vulnerability of existing building stocks is crucial for risk mitigation, especially in countries, like Italy, where historic masonry structures are prevalent and vulnerable to seismic events. This paper proposes a procedure for evaluating the seismic vulnerability of residential masonry buildings to support risk mitigation strategies at the territorial scale. The procedure relies on first-level data collection forms to characterize the building stock and applies an analytical simplified methodology that requires limited effort and knowledge of the structure. The vulnerability assessment is conducted by correlating the structural capacity, expressed in terms of Peak Ground Acceleration with key structural and geometric parameters. Based on these correlations, response surfaces are calibrated and fragility curves are derived through Monte Carlo simulations, enabling the evaluation of the overall vulnerability of the building stock in a given territory. In the paper, the procedure is applied to the municipality of Maranello (Italy): after a validation of the analytical simplified methodology, performed through a comparison with results of pushover analyses on selected masonry buildings, fragility curves are derived for masonry typologies considered representative of the building stock. Within the municipality, homogeneous territorial areas, called Sectors, are identified and, based on the presence of the different building types in these areas, typological fragility curves are combined to evaluate the seismic vulnerability of entire Sectors. The study highlights the effectiveness of the procedure in supporting stakeholders and decision-makers in prioritizing interventions to reduce seismic risk at municipal, regional and national levels.