Strengthening Of Soft Clays Research Articles

Effects of intervening media on dielectrophoretic strengthening of soft clays

The process of dielectrophoresis has been shown to be applicable for soil improvement. This paper presents the results of continuous investigation into factors affecting dielectrophoretic strengthening of soft clays. The discussion is focused on the configuration of nonuniform electric fields, which is one of the key factors for effectiveness of dielectrophoretic treatment. The distribution of an ideal cylindrical electric field is derived and analyzed in light of the influence of intervening media in the space between electrode and soil. A series of dielectrophoretic experiments are conducted on a soft, sensitive natural clay to investigate the effects of intervening media and to examine the theory. The results indicate that the increase in undrained shear strength and decrease in soil water content after a dielectrophoretic treatment are dominated by the type and water content of intervening media. By minimizing the space between soil and electrode and adapting a clay slurry of relatively low water contents as the medium, the process of dielectrophoretic strengthening can be enhanced. Key words : soil improvement, dielectrophoresis, electrokinetic techniques, sensitive clays, electric field.