Effective stress concept on multi-scale swelling soils

Abstract It is important to predict the behavior of swelling soils during hydro-mechanical solicitations in order to investigate their long-term behavior. The complex hydromechanical behavior of swelling materials is generally connected to their fabric. For swelling soils, the determination of the effective stress parameter (χ) becomes more complicated because of their multiple scales: macro-, meso- and micro-scale. In this work, the χ parameter is related to the degree of saturation of each scale in interaction. Using the effective stress approach, the hydro-mechanical behavior was studied for loosely, intermediately and densely compacted samples. This approach helps us to define the yield surfaces for the compacted samples in the (effective stress–total applied stress) and (suction-effective stress) planes.