This article presents the results of experimental work carried out both in situ (coring; pressuremeter test) and in the laboratory (drying-wetting and oedometric tests) to describe the volumetric behavior on drying-wetting path of a swelling clayey soil of eastern Algeria. In order to perform drying-wetting tests the osmotic technique and saturated salts solutions were used. These suction-imposed methods have gained widespread acceptance as reliable methods for imposing suction on soil specimens. They allowed to sweep a wide range of suctions between 0 and 500 MPa. The ability to impose suction on soil specimens allows for drying and wetting stress paths to be applied to evaluate resulting changes in state parameters (void ratio, degree of saturation and water content). These paths were carried out on specimens with different initial states. Slurries of soil were used to characterize the reference behavior, while the undisturbed soil samples allow to describe the behavior of material under in situ conditions. In the last part of this article and to specify the behavior observed in the saturated domain, a comparison between the resulting deformations of the drying-wetting test and those resulting from the oedometric test was made.

This work presents an experimental study of the hydromechanical behavior of a natural swelling soil taken from Boumagueur region east of Algeria. Several pathological cases due to the soil shrinkage / swelling phenomenon were detected in this area. In a first part, the hydric behavior on drying-wetting paths was made, using the osmotic technics and saturated salts solutions to control suction. In The second part, using a new osmotic oedometer, the coupled behavior as a function of applied stresses and suction was investigated. It was shown that soil compressibility parameters was influenced by suction variations that an increase in suction is followed by a decrease in the virgin compression slope. On the other hand, the unloading slope of the oedometric curves was not obviously affected by the imposed suction. The decrease in suction strongly influences the apparent preconsolidation pressure, ie during swelling of the samples after wetting.