Laboratory testing principles for the electrokinetic consolidation method

As about 40% of the world’s population and over 87% of the Australian population live within 50 km of the coast, there is a high demand for ground improvement dealing with saline groundwater. Salinity can vary from a light brackish level to 38 ppt for offshore infrastructures, such as Brisbane Port. The application of traditional ground improvement methods may not be effective due to the extremely high water content of marine soils. The electrokinetic consolidation method (EK) is an innovative technique that dewaters soils with electromagnetic force. As water molecules are dipoles with two positive hydrogen atoms, they are drained towards cathodes. Meanwhile, soil particles with a negative surface charge move towards anodes and consolidate there. EK is enhanced with the presence of saline ions because they increase the polarization of water molecules. This chapter describes core principles in laboratory testing for EK including workplace safety, material selection, voltage application and electrode configurations. The influence of salinity on the efficacy of EK is also discussed thoroughly with evidence from testing with soils from the Brisbane Port Expansion project.