Analytical solution for one-dimensional electroosmosis consolidation considering threshold potential gradient under time-dependent loading

The concept of the threshold potential gradient is introduced into the electroosmosis consolidation theory. The governing equation for one-dimensional electroosmosis consolidation considering the effective potential attenuation with time-dependent loading is established based on the corresponding assumptions. The general analytical solutions for electroosmosis consolidation are obtained by the algebraic transformation and variable separation methods. Meanwhile, the expressions for the analytical solutions of electroosmosis consolidation under common loading patterns are given. The correctness of the proposed solutions is verified by comparing the degenerative analytical solutions in this study with the existing analytical solutions, combined with the comparison between the calculated results of the proposed solutions and the finite difference solutions. Based on the proposed analytical solutions, the effects of the related parameters on the electroosmosis consolidation characteristics of soft soils are analyzed. The results show that the existence of the threshold potential gradient reduces the absolute value of the excess pore water pressure and the settlement of soft soils. The decrease in hydraulic permeability coefficient is conducive to electroosmosis consolidation. The settlement of soft soils increases with the increasing ratio of electroosmosis permeability coefficient to hydraulic permeability coefficient, which leads to a better drainage and consolidation effect. When the soft soils are strengthened by the combined electroosmosis and surcharge preloading, the electroosmosis reduces the maximum value of the positive excess pore water pressure caused by time-dependent loading, which is helpful in improving the stability of soft soils during the consolidation process.