Experimental Characterization of the Hydromechanical Properties of the Gypsum Soil of Sebkha of Oran

This paper deals with hydro-mechanical investigation of salinegypsum soil properties from Sebkha of Oran in respect withtheir impact on the feasibility of the project of the second runwayof the Es-Sénia airport in Oran (Algeria). The geologicaland in-situ geotechnical studies prior to the construction phaseof the airport runway revealed underground cavities supposedto be created from salts and gypsum dissolution in the Sebkhasoil. Standard laboratory experiments are used to determinepermeability coefficient, isotherm curve, shear resistance andelastic parameters of two soils. These ones are affected by thevariation of water table level that varies according to the dryperiod (summer) or the rainy period (winter), creating cyclichydric conditions. The paper presents a comparison of parametersof these two soils in saturated and partially saturatedconditions. The results of tests performed in laboratory arecompared with those performed in situ in order to check theirrepresentativeness before a detailed comparison of the effect ofwater conditions. The two soils have similar behavior highlysensible to water with some particularities.