Measurement methodology and characteristics of interfacial resistance in electro-osmosis

Abstract

The electro-osmosis technique can be used for rapid dewatering and consolidation of deep soft foundations. Considering the abnormal volt-ampere characteristics of soil at the initial stage of electro-osmosis using electrokinetic geosynthetics (EKG) electrodes, the hypothesis that the interfacial resistance between electrode and soil is related to current was formulated. A new method was used to distinguish the soil resistance and interfacial resistance, and an experiment was designed to verify them. The results show that the soil resistance does not change with the changing current in the circuit, but the interfacial resistance is closely related to the current. The interfacial resistance decreases as the current increases and is approximately a power function of the current. This relationship applies to aluminium, copper, iron and EKG electrodes. In addition, a design for the field application of electro-osmosis was developed focusing on power supply and efficiency. The calculation results show that the proportion of soil effective potential is closely related to the potential gradient imposed by the power supply. The experimental results reveal the relationship between the potential gradient and the efficiency of electro-osmosis, which provides a theoretical basis for the determination and optimisation of electric power in electro-osmosis system design.