On the volumetric response of a compacted clay subjected to wetting and drying cycles

Experimental evidence on the volumetric response of a compacted clay was collected in controlled suction oedometric tests, with the aim to assess the volumetric response of this soil when subjected to wetting and drying cycles. The overall soil behaviour seems mainly to depend on the double structural arrangement observed in the compacted specimens. Selected results are presented and discussed focusing on the influence of the stress history on the volumetric response. Test results are simulated by a double-structure suction-dependent elasto-plastic constitutive model, in which the mechanical response is related to micro and macrostructural deformations and their mutual interactions. The procedure used to derive elastic and plastic constitutive parameters is presented along with the adopted simplifying assumptions. The comparison between simulations and experimental results is quite good and it also results satisfactory for the test that was not included in the calibration procedure.