Electroosmotic flow in soft clay and measures to promote movement under direct current electric field

Electroosmosis has been proposed as a technique to reduce moisture and thus increase the stability of soft clay. However, its high energy consumption and uneven reinforcement effect has limited its popularization and application in practical engineering. This paper presents the results of some electrokinetic tests performed on clayey specimens with different electrification time and anode boundary conditions. The results indicate that the timing of the formation of electroosmotic flow (EF) by the water originally contained in different soil cross sections, from the anode to the cathode, varies. The measuring soil cross section nearest the anode first reached the limiting water content of 22%±3% and electroosmosis had to be stopped. Water injection into the anode during electroosmosis enhanced further drainage of other four measuring soil cross sections until the second soil cross section from the anode reached the limiting water content of 30%±2%. Electroosmosis with water injection into the anode technique provides more uniform reinforcement, increasing EF, and environmental protection. The experimental results highlighted the relevant and expected contribution of water injection into the anode on the effectiveness of the electroosmotic treatment as a soft clay improvement technique.