Shear Strength and Permeability of Granite Residual Soil—The Influence of BTEX Components

Currently the mix fuel from breakdown of underground storage tanks, and rain water are infiltrating into the ground with potentially large geo-environmental impacts. The contaminated soils are changed towards a new equilibrium level so we need knowing its physical and chemical properties and its mechanical behaviour. We used triaxial tests in evaluating the environmental effects of gasoline (BTEX elements) on the shear stress-strain behaviour and on the hydraulic conductivity or permeability coefficient; they are performed with clean and contaminated soil specimens of residual granitic soil. The influence of confining pressure and hydraulic head on hydraulic conductivity were also addressed. The physical and chemical properties and retention mechanisms in contact with contaminants cause spatial rearrangements, consequently, hydraulic conductivity with increasing stress levels is randomly decreasing. This effect manifests itself in smooth increasing shear strength of contaminated soil.