GNGTS 2019 - Atti del 38° Convegno Nazionale

26 GNGTS 2019 S essione 1.1 clearly recognised by visiting the ruins of the abandoned settlements (especially Poggioreale and S. Margherita) or the deserted neighbourhoods still visible in the reconstructed towns (e.g. Salemi, Menfi, Partanna). Analysis of the sources. We analysed sources starting from local and national newspapers, which report information on the earthquake effects in both the epicentral and felt areas. The first three days of the sequence are well documented, whereas afterwards the newspapers mostly argue on the slowness of rescue and the hardship conditions of people in the camps. Newspapers usually give an overview of the effects, cumulating the damage due to more shocks in a single day, so that it is impossible to discriminate them individually. As a result, we obtained a daily damage picture referring to the shocks occurred on 14, 15, 16 and 25 January, and a final scenario at the end of the sequence. Then we used the technical and scientific literature providing a detailed description of damage, along with accurate notes on the building characteristics (Bosi et al. , 1968; Cannata et al. , 1968; De Panfilis and Marcelli, 1968; Haas and Ayre, 1969). The authors surveyed the damaged area soon after the sequence, before the bulldozers raised to the ground collapsing buildings and removed ruins; their observations are essential to integrate newspaper information. Notes on building vulnerability. In our a-posteriori survey throughout the epicentral area, we observed the following EMS-98 vulnerability classes associated to relevant building typologies: • class A: structures built with materials easily available on site, mostly soft calcarenites, made up of coarse masonry with irregular or sometime roughly squared stones, assembled with poor mortar deteriorating over the years (Fig. 2a). Sometimes, old buildings had been modified but without adequate strengthening (Fig. 2b). Fig. 2 - Building typologies in the 1968 epicentral area and vulnerability classes according to the EMS-98. a) Class A: Poggioreale, collapse of a structure built with squared blocks of soft calcarenites assembled with little mortar; b) Class A: S. Margherita, interventions of elevation with RC slab floors and heavy blocks of calcarenites above a weak masonry; c) Class B: S. Margherita, structure characterised by numerous interventions that significantly modified masonry over time; note the RC slab floors positioned at different levels; d) Class C: Gibellina, the first floor was added without any structural connection to the underlying RC frame.