The standard stress-based approach to evaluate the liquefaction triggering potential of a soil deposit is the most widely used in geotechnical engineering practice. However, this method requires several correction factors and cannot be confidently applied to soils other than clean sands or silty sands with moderate fine content. The energy-based method, although not yet used in geotechnical practice, allows to overcome these limitations and has been applied in this work. Specifically, the liquefaction assessment of the foundation soils of volcanic origin of a rockfill dam in Southern Italy is investigated using the Berrill and Davis model for pore water pressure generation implemented in a well-known effective stress code. This energy-based model uses an empirical relation linking the cumulative dissipated energy per unit volume and the excess pore water pressure generated during cyclic loading. The calibration is carried out based on cyclic undrained laboratory tests on undisturbed specimens. The results of preliminary 1D site response analyses are examined and discussed.