Experimental study on soil improvement by electrochemical injection of calcium chloride solutions with time interval

Abstract Injection of chemical solutions during electroosmosis is effective in enhancing the effect of electroosmosis and increasing the strength of soil. However, the improvement is mostly limited to the anode or cathode region. An improved method is proposed in this paper to enhance the non-uniform effect and efficiency of electroosmosis. Such method is electroosmosis with injection of calcium chloride through the anode, followed by injection through the central tube with a suitable time interval between injections. Experimental results indicate that using this method can significantly improve the non-uniform reduction in water content throughout the soil, mitigate the formation of cracks in the anode section, and therefore considerably inhibit the increase in the electric resistance. After treatment, the drained water could be raised to 3.59 times more than that of pure electroosmosis, and 1.3 times that of simultaneous injection through both the anode and the central tube. Moreover, the area of cementation was also expanded, approximately twice larger than that of pure electroosmosis and one and a half that of simultaneous injection. The results demonstrate that electroosmosis with a suitable time interval between injections could improve the efficiency of electroosmosis and expand the treatment region in soils.