Hydraulic conductivity and pore fluid chemistry in artificially weathered plastic clay

Triaxial and oedometer tests have examined how freezing–thawing (FT) and drying–wetting (DW) affect the hydraulic conductivity of a natural plastic clay. Because the clay was expansive, FT and DW in the laboratory produced only one order of magnitude increase in hydraulic conductivity above the ‘undisturbed’ value when permeated with water. Permeation with sodium carbonate or dimethyl sulfoxide reduced the hydraulic conductivity towards the undisturbed value, though some increases still remained. Hydraulic conductivities measured by oedometer were lower than those in the triaxial tests and varied strongly with applied pressure.