Effective stress in swelling soils during wetting drying cycles

• The cyclic evolution of the effective stress parameter χ can be related to the soil fabric.
• The soil fabrics were investigated by the Mercury Intrusion Porosimetry tests.
• The effective stress model could be used to accurately describe the cyclic behaviour of the swelling soils.

In this study, the cyclic evolution of an effective stress parameter χ is determined for different swelling soils. This parameter can be modelled using the macro-, meso- and microscales in interaction, stemming from mercury intrusion porosimetry (MIP) tests. The proposed model for χ was calibrated using the experimental results from successive suction cycles for different swelling soils without a vertical stress. Finally, an effective stress model was used to describe the cyclic behaviour of both the loose and dense samples for suction cycles between 8 and 40 MPa. Comparisons between the simulations and the experimental results showed that the effective stress model could be used to accurately describe the cyclic behaviour of the swelling soils over different suction ranges.