Influence of Voltage and Electrode Materials on the Performance of Electrokinetic Dewatering of Dredged Soil: A Laboratory Study
摘要
The geotechnical engineers are working on the enhancement of soft grounds to stabilize and utilize them for construction activities. Preloading, prefabricated vertical drains, mechanical stabilization, chemical stabilization, etc. are a few methods of soft soil improvement. Electrokinetic dewatering/stabilization is a method in which soil is supplied with D.C. voltage through electrodes, and due to the application of potential difference, water starts moving from the anode to the cathode. This study aims to find out the influence of voltages, and electrode materials on the performance of electrokinetic dewatering/stabilization of saturated soil. Further, the necessity of seating pressure for effective electrokinetic dewatering was also studied. Experiments were carried out using a laboratory scale Indian patented test setup having dimensions 25 cm × 25 cm × 20 cm. Soil collected from the Barejadi area of Gujarat, India was used for carrying out the experiments. A hexagonal pattern of electrodes was adopted with a 90 mm center-to-center distance between the cathode and anodes. Electrodes made up of stainless steel and brass were used for EKD tests while voltages varied were 9 and 12 V. Results show that the seating pressure of 6 kPa has a positive impact and showed a nearly 151.35% increase in the volume of dewatering as compared to the control test without seating pressure. Further, for EKD tests with identical voltage, the increase in volume of dewatering was 12.61%. For a higher voltage of 12 V, the total volume of dewatering collected at the cathode was measured on the higher side as compared to the voltage of 9 V for identical electrode material. Electrode material plays a major role in the total volume and cost of EK dewatering. Considering the volume of dewatering, brass electrodes were noted to be efficient as compared to stainless steel electrodes under an identical voltage and seating pressure. This study may help geotechnical engineers to study the effectiveness of electrode materials and necessity of seating pressure for EK dewatering technique.