Thermal consolidation modeling of unsaturated soil with semi-permeable boundary: Semi-analytical and numerical investigation

This paper focuses on investigating the one-dimensional thermal consolidation of unsaturated soil. Through the utilization of the Laplace transformation, decoupling method, and inverse Laplace transformation, the semianalytical solutions for excess pore pressures and ground settlement are deduced, particularly in the context of a single-sided semi-permeable boundary. To further investigate the thermal consolidation characteristics in unsaturated soils, numerical modeling is employed, encompassing both single-sided semi-permeable and symmetric semi-permeable boundaries. Consequently, the proposed solution is subjected to a rigorous comparison and analysis against existing published solutions and numerical results, thereby establishing a remarkable degree of consistency. A comprehensive parametric analysis is conducted to discuss the thermal consolidation behavior, revealing the temperature effect can lead to negative pore-water pressure at the end of dissipation and a rebound phenomenon of the ground settlement. Notably, the variation in temperature affects the final settlement of the soil. Furthermore, alterations in top permeability parameters influence the dissipation of excess pore pressures within specific depth ranges, wherein the influence depth increases as the boundary permeability strengthens. Of particular interest is the applicability of the current solution, which accommodates the one-dimensional thermal consolidation model for unsaturated soils characterized by varying permeability topsides and depth-dependent linear initial conditions.