Engineering and physicochemical response of soft clay with electrokinetic consolidation process

In this study, the response of soft clay was assessed during electrokinetic consolidation. The laboratory-based experimental study was conducted in a custom-designed test set-up focusing on soft clay's engineering and physicochemical response during and at the end of the electrokinetic consolidation. Six electrokinetic consolidation tests were performed under self-weight for 24 h with different voltage gradients. The operational response was investigated by monitoring the electric current and the power consumed during the test. Further, the variation of ohmic heating, volumetric water content, and water potential was continuously measured. The efficacy in enhancing the engineering response is analysed by investigating cumulative discharge, surface settlement, water content, and undrained shear strength of the soft soil. At the end of the test, the effect of electrochemical reactions in altering the soft clay's pH, microfabric, and mineral phases was investigated. Finally, the quantification of the surface crack was investigated, and their dependence on the applied voltage gradient was established. The study results show substantial enhancement in the engineering characteristics of soft clay. It significantly accelerates the dewatering efficacy, increases the undrained shear strength and surface settlement, and reduces the water content of the soft clay irrespective of the applied voltage gradient. The electrokinetic consolidation increases the temperature of the soft clay. The measured surface cracks give the crack intensity factor of 1.95, 2.10, and 2.15% for the applied voltage gradient of 0.05, 0.10, and 0.15 V/mm, respectively.