Abstract
In this paper, a new osmotic oedometer with double flux is developed. The results on loading–unloading stress path with constant suction, for a high plastic marl (wL = 54%, Ip = 28%), are presented. Two initials conditions were considered: consolidated samples at a vertical stress of 100 kPa and compacted samples at the standard optimum Proctor conditions. The results show that suction influence greatly the compressibility parameters and contribute to the stiffness of the soil. The interpretation of results with effective stress concept shows that curves are gathered satisfactorily around the normally consolidated line, justifying the validity of this concept for the unsaturated soil.