The Emilia Earthquake: Seismic Performance of Precast Reinforced Concrete Buildings

On 20 and 29 May 2012, two earthquakes of M_W5.9 and M_W5.8 occurred in the Emilia region of northern Italy, one of the most developed industrial centers in the country. A complete photographic report collected in the epicentral zone shows the seismic vulnerability of precast structures, the damage to which is mainly caused by connection systems. Indeed, the main recorded damage is either the loss of support of structural horizontal elements, due to the failure of friction beam-to-column and roof-to-beam connections, or the collapse of the cladding panels, due to the failure of the panel-to-structure connections. The damage can be explained by the intensity of the recorded seismic event and by the exclusion of the epicentral region from the seismic areas recognized by the Italian building code up to 2003. Simple considerations related to the recorded acceleration spectra allow motivating the extensive damage due to the loss of support.