One-dimensional large strain electro-osmotic consolidation model based on multi-field coupling

Abstract

Current electro-osmotic consolidation theories and numerical models usually ignore the variation of chemical fields and are applicable to soft clay soils with a single chemical composition. In this paper, a numerical model, called EC4, is presented for one-dimensional large strain electro-osmotic consolidation with coupled electrical-hydro-chemical fields. The algorithm accounts for non-linear variation of soil parameters, ion transport and a variety of chemical reactions, including ionization-neutralisation reactions, ion adsorption–desorption reactions and electrolytic water reactions at electrodes. The laboratory electro-osmotic consolidation tests on kaolin samples with different NaCl concentrations were conducted. The laboratory results were used to verify the accuracy of EC4. Then EC4 was implemented to example problems to investigate the effect of important chemical characteristics on the electro-osmotic consolidation. The effects of electrical voltage and initial pH on settlement, degree of consolidation, excess pore pressure and energy consumption of multi-field coupled electro-osmotic consolidation were further analyzed.