Assessment of liquefaction triggering by seismic dilatometer tests: comparison between semi-empirical approaches and non-linear dynamic analyses

The evaluation of soil liquefaction potential can be assessed using approaches with an increasing level of complexity. In engineering practice, the most common method is based on the use of empirical charts where the soil cyclic resistance is correlated to the soil resistance as measured in field tests, such as standard penetration test (SPT) and cone penetration test (CPT). Similarly, also seismic dilatometer tests (SDMT) can be used to assess the potential triggering of liquefaction in soil deposits as already shown in several case studies in Italy and around the world. In the present study, the results of seismic dilatometer tests carried out along a sketch of a river dyke highly damaged by the 2012 Emilia Earthquake have been used to assess the liquefaction potential of the embankment and the foundation deposits, using semi-empirical methods and dynamic analysis. Both methodologies highlighted high liquefaction risk for the investigated soils which is also compatible with the results obtained by more sophisticated non-linear dynamic analysis of the dyke carried out in effective stress condition. Finally, the advantages and limitations of the adopted approaches are discussed and practical guidelines are provided for SDMT-based methods.