Laboratory and Field Study of Electroosmosis Dewatering for Pavement Subgrade Soil

Electroosmosis (EO) is considered a promising technique for reducing water content in soft soils. In this study, a multiscale experiment was conducted to investigate the effectiveness of EO in controlling the water content of in-service pavement subgrade soil. First, the effect of EO dewatering was investigated through a laboratory-scale experiment considering three types of soils and two levels of electric voltages. Then a field-scale pavement subgrade was constructed to evaluate the engineering feasibility of EO. Conventional natural drainage was also investigated for the purpose of comparing the efficiency of EO dewatering. Results from the laboratory-scale experiments indicate that natural drainage is only useful for sand and silt, but EO dewatering works well for clay because the average reduction of the water content of the two clays is 3.47 and 3.78% with a voltage of 24 V/m, and the dewatering performance is improved with an increase in voltage. The validity of EO dewatering in reducing the water content of clay ground is confirmed through the field-scale experiment. (C) 2017 American Society of Civil Engineers.