Numerical Simulation of soil liquefaction during the 20 may 2012 M6.1 Emilia earthquake in Northern Italy: the case study of Pieve di Cento

On May 20, 2012, a seismic event of moment magnitude MW = 6.1 hit and caused severe damage on a large area in the river Po Valley, located in the northern Italy. This earthquake was characterized by extensive occurrence of soil liquefaction and basin effects lying over deep deposits. Within the scope of the European research project titled LIQUEFACT, a reference site located in the countryside near the hamlet of Pieve di Cento (at the boundary of the province of Bologna towards Ferrara) was selected as a trial field in order to assess the effectiveness of several mitigation measures against liquefaction. As a first step of the task, this paper presents the geotechnical model of the site based on in-situ investigations and pre-existing geological studies, which allowed to locate the bedrock depth. As a second step, representative input motions for the LIQUEFACT project were selected aiming at simulating the 20.V.2012 seismic event as well as three possible future scenarios with an increasing level of seismic intensity. Finally, preliminary dynamic analyses are presented, that reproduce the observed liquefaction triggering after the 2012 main event and predict the seismic soil response at the test site.