This paper presents numerical simulationsof the behavior of a sandy layer subjected to a cyclic horizontal acceleration in shaking table tests, with a particular attention focused on the settlements of a dry sand layer, and on the liquefaction of saturated sand. A compaction/liquefaction model (C/L) is applied to these simulations. The infl uence of specifi c parameters of the model on the compaction and liquefaction of a sandy layer is shown and discussed. The results of simulations are compared with selected experimental data.