Influence of initial water content and voltage gradient on electroosmotic dewatering of ultra-fine soils using novel electrokinetic geosynthetics

Abstract

Electroosmotic (EO) dewatering has gained substantial attention as an alternative method for improving weak soil deposits. One aspect that has not received sufficient attention in this approach is the influence of initial water content and voltage gradient on the EO treatment. This study aimed to provide a comprehensive understanding of the key operational parameters and post-dewatering performance metrics of EO treatment with varying initial water contents and voltage gradients. A number of electrical, hydraulic and soil water retention parameters were monitored during the treatment process, and the material response to the EO treatment was evaluated by assessing various geotechnical and physiochemical parameters. The results indicate that, regardless of the voltage gradients, overall, the EO dewatering led to a reduction of at least one-third of the original water content. The EO treatment resulted in a sevenfold, ninefold and twentyfold relative increase in undrained shear strength for the experiments with the lowest, intermediate and highest initial water contents, respectively, indicating an exponential increase as the initial water content of the slurry increases. The implications of the findings to improve the viability of EO treatment for large-scale applications using electrokinetic geosynthetics are also discussed.