PSI - Issue 44

Carolina Bazzani et al. / Procedia Structural Integrity 44 (2023) 171–178 Carolina Bazzani et al. / Structural Integrity Procedia 00 (2022) 000–000

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seismic events of Intensity equal to or greater than grade VIII on the Mercalli scale, that is in average one every four and a half years. Therefore, the need to increase knowledge of the seismicity and seismic risk of the Italian territory emerged increasingly over the years, so scientific research developed seismic risk mitigation strategies through different models that were developed over the years. Lagomarsino & Giovinazzi (2006) and Bernardini et al. (2007a, b) developed a vulnerability model that allows for the damage distribution associated with a given seismic intensity to be defined starting from the EMS-98 macroseismic scale and the observation of the damage suffered by buildings. The model originates from the numerical damage probability matrices derived from the EMS-98 scale through the use of fuzzy set theory. In 2004, several scientific papers about the S.A.V.E. project, which defines the vulnerability class of a set of buildings through a rapid methodology, were published (Zuccaro, 2004). The S.A.V.E. project is based on the analysis of observed damage data collected after some past Italian seismic events, such as the Irpinia 1980 and Abruzzo 1984 earthquakes, and defines a synthetic parameter of average damage (SPD) associated with the building vulnerability classes. Recently, within the National Risk Assessment (NRA, 2018) focused on seismic risk analysis at the territorial scale, vulnerability models proposed by Lagomarsino & Giovinazzi (2006) and Bernardini et al. (2007a, b), as well as the S.A.V.E. project, were updated. In this paper, a methodology of seismic risk analysis at the territorial scale in the Mugello area in Tuscany, with particular attention to the municipality of Barberino di Mugello, is proposed. It consists of the following steps: - classification of the building stock of the municipalities in the Mugello area (northeast area of Tuscany, Fig. 1a, b) into typological classes and then into building sectors (sub-municipal homogeneous areas) according to the CARTIS methodology (Zuccaro et al., 2014); - seismic vulnerability analysis at the territorial scale using the Macroseismic Method developed by Lagomarsino & Giovinazzi (2006) and Bernardini et al. (2007a, b); - comparison of the results obtained through: EMS98 method, Macroseismic and updated Macroseismic Method, and S.A.V.E. method. - estimation of hypothetical damage scenarios, through vulnerability curves processed for both building typologies and building sectors, and of unusable buildings by comparison with damage data collected after the moderate seismic event (Mw = 4.5) that hit the Mugello area on December 9, 2019. (a) (b)

Fig. 1. Mugello area (Nord Est Tuscany) (a) and Mugello Municipalities (b).

2. Typological analysis of the built environment

In this work, a database in a GIS environment was created for the characterization of the built environment. According to the CARTIS methodology, the main constructive characteristics - materials, total height, year of construction, irregularities, etc... - were assigned. The survey of the buildings was carried out through the analysis of cartographies, Google Maps - Street View, and by performing field surveys together with technicians and interviews of local construction companies. The processing of the database helped to identify the main building typologies and thus homogeneous areas of the built environment called sectors. The built-up area of the Barberino di Mugello