The use of the Hollow Cylinder Apparatus in the study of liquefiable soils

The behaviour of liquefiable soils is often assessed through cyclic triaxial tests, even if it is well established that the loading conditions do not match the loading imposed by earthquakes events. In contrast, the Hollow Cylinder Apparatus (HCA) allows different and eventually more realistic consolidation and loading conditions to be applied to samples. The paper presents the characteristics of the HCA available at the University of Coimbra, Portugal, and discusses in detail its ability to assess the small-strain response of Hostun sand as well as its behaviour at very large-strains, in particular at or near the critical state, comparing the results obtained with triaxial tests equipped with Bender Elements. The results provide further insight into the importance of testing soils under realistic conditions, namely in liquefaction studies, suggesting that it is important to carry out laboratory experiments and develop soil models that simulate as close as possible real loading conditions.