GNGTS 2018 - 37° Convegno Nazionale

388 GNGTS 2018 S essione 2.2 then subdivided based on the class of height (i.e. low-rise: 1-2 stories and mid-/ high-rise: >2 stories), see Fig. 1. On the other side, empirical damage data were classified into macro-typologies, based on the information of the national census data (i.e. construction material, class of height and construction age). The vulnerability model was defined by determining the fractions of each macro-typology belonging to the predefined vulnerability classes. To this aim, the fragility curve of a preselected macro-typology and of a given damage state was expressed as a linear combination of the fragility curves of the vulnerability classes. The coefficients of the linear combination, representing the fractions of each macro- typology belonging to the predefined vulnerability classes, were obtained by solving an optimization problem. Class fragility curves for RC buildings. Fragility curves for RC buildings were defined for two vulnerability classes, C2 and D, of decreasing vulnerability, and depending on the class of height. More specifically, buildings designed for gravity loads only or for seismic loads pre-1981 were Fig. 1. Fig. 2.