Field Test on Consolidation of Hydraulically Filled Sludge via Vertical Gradient Electro-osmotic Dewatering

An E-tube system to provide vertical gradient electro-osmosis and better vacuum condition in deep soft ground is presented. Consolidation effect was improved in two ways: upward water flow generated by vertical gradient electro-osmosis and improvement of vacuum condition by gathering water in E-tube. Field test was carried out to verify the proposed method. Test result shows that after consolidation, water content decreased from 80 similar to 95% to 44 similar to 59% and dry density increased from 0.76 similar to 0.85 g/cm(3) to 0.95 similar to 1.23 g/cm(3); shear strength increased from 1 similar to 2 kPa to 16 kPa and bearing capacity increased from 10 similar to 20 kPa to about 70 kPa. Energy consumption in this field test was 30.5 kW.h/m(3). This indicates that SCR is not an energy efficient way to build electro-osmosis DC power source. High frequency switch-mode DC power source with PFC might be a better choice.

Automated summary

An E-tube system is proposed to provide vertical gradient electro-osmosis and improve vacuum condition in deep soft ground. The consolidation effect is enhanced by the upward water flow generated by vertical gradient electro-osmosis and the improved vacuum condition achieved by gathering water in the E-tube. Field test results demonstrate significant improvements in consolidation, including decreased water content, increased dry density, and improved shear strength and bearing capacity.