Soil suction and soil-water potentials in swelling clays in engineered clay barriers

This paper is concerned with the interactions resulting from water uptake by partly saturated swelling soils in their role as liner material for engineered clay barriers. The energy status of the soil-water (i.e. pore-water) provides the focus for the mechanistic view of the microstructure and mesostructure interactions that govern the development of those ‘matric’ and ‘osmotic’ forces responsible for water uptake by the swelling soils. Central issues in the interactions developed are the governing roles played by the interlayer and interparticle forces in the presence of water, and the need to differentiate between unit layer separations, micropores and macropores in the articulation of void volumes or pore spaces. The matric and osmotic components of soil suction and soil-water potential need to be distinguished in respect to micro and meso–macro applications, particularly when interpretations of measured values are needed.