GNGTS 2018 - 37° Convegno Nazionale

GNGTS 2018 S essione 2.2 389 grouped in class C2, whereas buildings designed for seismic loads post-1981 were assigned to class D. Moreover, these classes were further specialized to three ranges of height, i.e. low-rise: 1-2 stories, mid-rise: 3-4 stories, and high-rise: >4 stories (Fig. 2). To this end, these 6 (=3×2) sets of fragility curves were derived as a weighted average of the abovementioned 15 (=5×3) sets of typological fragility curves, using as weights the probabilities of occurrence of each typology within the corresponding class, evaluated based on ISTAT census data at national scale, consistent with the aim of national-scale applications. Example of application to Campania (Southern Italy) region. This section presents an example of application with reference to the Campania region. The proposed fragility models were used to derive a damage scenario for the whole region. The scenario was derived with the PGA demand corresponding to a return period T R =475 years (Fig. 3a). For the sake of clarity, for each Municipality the results are illustrated in terms of mean damage (μ D ), i.e. the weighted average of the DS index (from 0 to 5) within a given Municipality (Fig. 3b). The territorial distribution of μ D roughly reflects the distribution of PGA intensity, as expected, except for some cases in the provinces of Avellino and Salerno, where a relatively lower μ D value is observed in some Municipalities where the reconstruction process following the Irpinia 1980 event leads to a prevalence of class D buildings (i.e., post-1981 RC buildings designed for seismic loads). Conclusions. In this study, data on observed post-earthquake damage provided by the by the Italian Department of Civil Protection through the online platform Da.D.O. were used to derive empirical fragility curves for classes of masonry and RC residential buildings. Damage States were assumed consistent with EMS-98 and damage data were processed accordingly. Fragility curves were derived for different building typologies and then for building classes, in accordance with the aim of a national-scale application based on census data. The availability of empirical data allowed the derivation of fragility curves that should reliably reflect the characteristics of the building stock they will be applied to. Acknowledgements. This study was developed under the financial support of the Italian Department of Civil Protection, within the ReLUIS-DPC 2014-2018 project. This support is gratefully acknowledged. Fig. 3.