Stima di curve di fragilità sismica per strutture prefabbricate in c.a. sulla base di dati osservazionali sul danneggiamento prodotto dal terremoto dell’Emilia/Estimation of seismic fragility curves for precast RC industrial buildings from damage observational data from the 2012 Emilia earthquake

The paper presents empirical seismic fragility models for precast RC buildings, fitted using observational damage data gathered after the 2012 Emilia earthquake. Damage data in 1890 buildings was collected, analyzed and classified according to a six level scale derived from the European Macroseismic Scale. The completeness of the damage database and the spatial distribution of the buildings were analyzed using cadastral data as a reference. The intensity of the ground-motion was quantified by the maximum horizontal peak ground acceleration (PGA), which was obtained from shakemaps. Bayesian regression was then used in order to fit two different classes of models: i) models considering the different damage levels independently and ii) an ordinal logistic model which leads to non-overlapping fragility curves. The fragility curves obtained in the present work, when compared to literature fragilities for cast in place RC frame buildings, indicate that precast industrial buildings are significantly more vulnerable.