The ability of electrokinetic phenomena to transport water, charged particles and free ions through fine-grained soils has been well established since their discovery by Reuss in 1809. The water content of fine-grained soils is a fundamental physical characteristic of the material and has a large impact on the material’s strength. Controlling water in fine-grained soils, such as clay, is therefore of paramount importance but presents recurrent problems owing to the very low hydraulic permeability of the materials.
In 1939, Casagrande (1952) demonstrated that applying electrokinetics to fine-grained soils with high water contents resulted in an increase in the effective stress within the soil through the generation of negative pore water pressures. He used this to increase soil shear strength and thus stabilize steep railway cuttings. Since that time, however, the widespread application of electrokinetics has been prevented by a variety of technical problems.