Empirical damage and liquefaction fragility curves from 2012 Emilia earthquake data

The study focuses on the effects of liquefaction on structures taken from data on about 1,000 private residential masonry buildings located in several municipalities struck by the 2012 Emilia earthquake. Survey data were collected by teams of experts coordinated by the Italian Department of Civil Protection in the immediate post-earthquake emergency phase. They included information on
 building characteristics and the level and extent of the damage to structural and non-structural  components. Furthermore, according to data related to the reconstruction process, information on the  liquefaction-induced type and extent of the damage was also collected. Through a comparative  analysis of the empirical damage, it was found that liquefaction strongly affected the buildings,  confirming its relevance in the damage scenario under specific subsoil conditions. Based on this  evidence, the paper proposes a correlation between structural damage and liquefaction when it comes  to deriving proper preliminary empirical fragility curves. A suitable parameter to define liquefaction  effects at ground level is introduced and correlated to damage grades defined according to the  European Macroseismic Scale: EMS-98.