Improvement of clay soil by electro-osmosis technique

•pH and EC of anode and cathode reservoirs are dependent on the applied voltage.•Efficiency factor (β) is dependent on the applied voltage.•Electro-osmotic permeability (Ke) is dependent on the time and applied voltage.•Changes of the Atterberg limits leading to an increase in shear strength of the soil

The use of electro-osmosis for treatment of soft clay soils is a common ground improvement technique. A number of chemical, physical and mechanical interactions occur during the improvement of soil by this technique. This paper presents the results of an experimental study on the effects of treatment on the settlement and chemical and physical reactions of a clay soil. A series of experiments were conducted in a designed apparatus with electrical vertical drains (EVD) under different voltages. The experimental results showed that pH, electrical conductivity (EC) and Atterberg limits changed during the tests. In addition, electro-osmosis caused a significant increase in the settlement and undrained strength of the soil.