Abstract: Clay is often used to block the migration of pollutants on account of its low permeability. However, the organic solvents can significantly increase the permeability of clay which will result in the failure of barrier. In order to study the effects of dielectric constant and viscosity of organic solution on the permeability of clay, we carried out tests on the consistency limits and permeability of silty clay with different mass fractions of glycerol-water solutions. Results unveil that with the increase of mass fraction of glycerol-water solutions, the liquid limit and plastic limit of silty clay both increase while the hydraulic conductivity increases first and then decreases. Soil permeability is related to microstructure distribution and fluid properties. If the mass fraction is smaller than 40%, permeability is controlled by fabric; when mass fraction is over 40%, the increase of viscosity leads to the decrease of permeability. In addition, the intrinsic permeability increases in the beginning and then declines with the growth of mass fraction owing to the increment of viscosity. For water-soluble organic solvents, the impacts of viscosity on permeability should be considered.

Key words: silty clay, glycerol-water solution, limit moisture content, hydraulic conductivity, dielectric constant, viscosity