Influence of Strong Motion Records Characteristics on Numerical Simulations of Soil Liquefaction

The selection of the appropriate input motion plays a crucial role in advanced numerical simulations of cyclic liquefaction. In the present paper, a numerical model validated against the evidence of soil liquefaction phenomena observed during the Emilia 2012 earthquake in Italy is used to assess the influence of the ground motion selection process. The numerical model has been developed using the finite element code OpenSees and adopting the pressure dependent elasto-plastic multi-yield constitutive model for the liquefiable layers. The model has been first calibrated by using laboratory and in situ tests from the San Carlo site. Then a large set of strong motion records has been used and results have been classified based on liquefaction occurrence. The most influent parameters for design purposes have been identified through a cluster analysis. The results underline that the selection criterion should be based on the estimation of expected ground motion parameters rather than on a pure spectral matching criterion.