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Chemical electro-osmosis with an injected saline solution can be described as an efficient method for adjusting the soil microstructure and improving soil conductivity, and the effect of electro-osmotic consolidation on soft foundations can also be improved by this novel technology in regard to foundation treatment. To better study the electro-osmotic characteristics of soft clay from Taizhou with different grouting solutions, a series of chemical electro-osmotic experiments concerning the injection of CaCl2, MgCl2, NaCl, KCl, and deionized water were conducted in the laboratory based on custom test devices. The actual treatment effects of these experiments were compared by monitoring the drainage, current, voltage, elemental mass fractions in the soil, and soil structure. The chemical electro-osmotic method was further studied from a theoretical perspective based on the inherent link between the macro- and microlevel indexes. The results of the model test indicated that the crystal structure of the soil changed from an initial flocculated structure to a granular or laminated structure with the injection of CaCl2 and MgCl2 saline. Na+ was hereby replaced by multicharged ions, which served as the key factor that affected both the drainage efficiency and conductivity of the electro-osmotic process. Moreover, a novel one-dimensional electro-osmotic consolidation equation was introduced that considered variations in the electro-osmotic permeability coefficient, which better illustrated how the excess pore water pressure was deduced when compared with Esrig's consolidation equation. Furthermore, the results of this experiment may be adopted as a reference or as evidence for the subsequent promotion and application of the electro-osmosis method. [ABSTRACT FROM AUTHOR]

Soil voltage is generally assumed to show a linear relationship with distance from the cathode according to the established electroosmotic consolidation equation. However, this assumption is inconsistent with experimental results. To more reasonably reflect the soil consolidation process during electroosmosis treatment, it is necessary to consider the influence of the actual soil voltage distribution trend when establishing the electroosmotic consolidation equation. Electroosmosis results show that soil voltage exhibits nonlinear distribution characteristics against distance from the cathode. The change trend of soil voltage can be well reflected by cubic polynomial fitting. Then, the anodic electrode was taken as the research object, and a two-dimensional horizontal plane model of electroosmosis was established because it represents practical electroosmosis applications more closely than some other models. Based on this established model, the dissipation equation describing the excess pore water pressure and the soil consolidation equation were derived for the electroosmosis treatment process. The derivation process considered both linear and nonlinear soil voltage distributions, wherein the anode was closed and the cathode was open. Finally, the analytical solution was analyzed and validated with model test cases in terms of the excess pore water pressure and average moisture content of the soil. The trend observed in the measured excess pore water pressure was more consistent with that of the theoretical results calculated assuming a nonlinear soil voltage distribution than that obtained using a linear distribution. In addition, the measured values of the average moisture content in the soil were closer to the values calculated under a nonlinear distribution of soil voltage than to those calculated under a linear distribution. These results further show that the established consolidation equation is reasonable when a nonlinear distribution of soil voltage is considered. The proposed consolidation equation can thus improve the application of electroosmotic methods in the future. [ABSTRACT FROM AUTHOR]