I terremoti del Maggio 2012 in Emilia. Potenziale distruttivo del moto del terreno

The seismic sequence that struck the Emilia Region in 2012 has been recorded by a number of instruments of the Italian strong motion network, managed by the Department of Civil Protection. In this study, the accelerograms recorded by the stations located within 25 km from the epicentres are analysed from an engineering standpoint. Different intensity measures and acceleration, displacement and energy response spectra are calculated. A comparison with the accelerograms recorded during L'Aquila 2009 earthquake is also performed. The study shows that that the strong motion was rather severe in the near fault, especially in terms of horizontal displacements and vertical accelerations, and highlights the presence of a rather long pulse in the N-S components of the near-fault records. This is probably related to the N-S direction being approximately normal to the causative faults. The comparison with L’Aquila earthquake proves that, even though the acceleration-related measures were stronger in L'Aquila than in Emilia, the opposite occurs for the displacement demand.