Abstract The paper presents the results of laboratory tests carried out on undisturbed specimens of a gravelly soil sampled by in situ freezing. Because of the heterogeneity of the natural deposit, the grain size distribution of the specimens ranged from uniform sand with a very low percentage of gravel to well-graded sandy gravel, and could be divided into three different families (respectively, named A, B and C). The testing programme consisted of drained and undrained monotonic triaxial tests and undrained cyclic triaxial tests, carried out on both isotropically and anisotropically ( K 0 ) consolidated specimens. Because of the coarse gradations of the soils, a large triaxial cell was used. The monotonic and cyclic tests showed that the two finer materials (soil A and B) behave in a similar way, confirming that the fabric matrix dominates the overall mechanical behavior when coarser particles are few and floating. The results also confirmed that the coarsest material (soil C) has a lower tendency to liquefy. The tendency to undergo liquefaction or cyclic mobility during undrained cyclic tests was referred to initial soil conditions expressed through the state parameter ψ , which proved once more to be a parameter very useful to this aim.