Applications of Electrokinetics in Grouting

Electrokinetic phenomena are defined as phenomena associated with the application of an electrical field to soil. Commonly, direct current is utilized. The electric field causes water to flow through the pores of soils of low permeability and, for a variety of reasons, hardens the soil. It is suggested that while the electric field is being applied the permeability of the soil is increased by a factor of 2 or more, thereby reducing the time required to introduce a grout when pumping at a specified pressure. The electric field also acts to pump grout into the soil or causes the development of negative pore pressures near a grout pipe which effectively increase the grouting pressures without increasing the danger of surface heave. A summary is presented of some recently reported successful applications of electrokinetics in grouting in Rumania, Israel, the United States and Great Britain. Several possible limitations of the method are suggested and an indication of the cost of power is presented.