Evaluating seismic behavior of intermediate silty sands of low plasticity from Emilia Romagna, Italy.

The performance of silty soils in Emilia Romagna, Italy, during the 2012 earthquake offers an interesting opportunity for understanding their response under cyclic loading and susceptibility to liquefaction. A comprehensive investigation based on both in situ tests and laboratory tests (undrained cyclic simple shear tests) was performed for evaluating the cyclic strength of these low plasticity silty soils and thus analyzing data in light of the screening criteria for liquefaction triggering susceptibility. The laboratory results indicate that the soils are susceptible to liquefaction, whereas some types of interpretation approaches based on in situ tests appear to overestimate the liquefaction resistance of soils when applied to sands containing non plastic or low plasticity fines, thus suggesting a revision of the existing methods of analysis.