Electro-Osmotic Grouting for Liquefaction Mitigation in Silty Soils

An electro-kinetic permeation technique for injection of grouting materials into silty soils is introduced in this paper. Preliminary experimental data indicates that it is feasible to inject colloidal silica and silicate grouts into silty soils by means of a dc current. 1-D column experiments and 3-D model tests show that the soil grouted by silicate and colloidal silica by means of electro-osmosis showed significant improvement in strength. For 1-D condition, the grout penetration rate by electro-osmotic injection is about 10^–5 cm/s under an electric gradient of 1v/cm. Typical permeation grout penetration rate by hydraulic means in silty soils is about 10^–5 cm/s or less under a unit hydraulic gradient. Traditional permeation grouting in silty soils would require very high pumping capacity making it cost prohibitive, whereas preliminary bench-scale model tests indicate that electro-osmotic grouting is cost-effective.