Soil improvement of electroosmosis with the chemical treatment using the suitable operation process

Previous studies show that improved soil strength is usually limited to regions near the anode or cathode in electroosmotic chemical treatments. Laboratory studies have shown that a suitable operation process strengthens soft clay for the entire specimen, from the anode to the cathode. The suitable operation process first injects a calcium chloride solution until the current decreases, and then injects a sodium silicate solution until there is no drain from the cathode during electroosmosis. A field test was carried out in this study to verify the suitable operation process and to assess the effectiveness of this treatment. The results indicate that the region of improvement was expanded from the anode to the cathode (except near the anode) by the suitable operation process and reveal homogeneous strength distributions over the region of improvement and an overall increase in strength. The largest cone resistance was near the cathode and measured 4,500 kPa, an increase in 300 %. A significant increase in cone resistance was also found near the middle, between the anode and cathode, and measured 3,700 kPa, which is an increase in 280 %. The average cone resistance and undrained shear strength from the anode to the cathode increased 125-130 %. The suitable operation process of electroosmosis chemical treatment is therefore proven to be effective in a field-scale test.