Coupled thermo-hydro-mechanical mechanism in view of the soil particle rearrangement of granular thermodynamics

This paper established a coupled thermo-hydro-mechanical mechanism in view of the soil particle rearrangement for saturated/unsaturated soils under the framework of granular thermodynamics. This model avoids concepts such as the flow rule, yield function, dissipation potential function, and hardening criterion. The effects of the loading path and the soil structure are reflected by constructing a density function of elastic potential energy considering the structural strength of a solid skeleton with a degradation factor. That is, the changes in the stress states are closely related to soil particle rearrangement and the transitions between different matter phases. A generalized effective stress principle is derived and is suitable for the coupled thermo-hydro- mechanical process. The deduced generalized phase stresses differ from the classical effective principle based on linear elastic porous media and can automatically consider the impact of the stress path, temperature path and soil structure. The established model spans the complete process from unsaturated to saturated soils and is verified by the typical test results.

Automated summary

This paper established a coupled thermo-hydro-mechanical mechanism for saturated/unsaturated soils considering soil particle rearrangement, reflecting the effects of loading path and soil structure through an elastic potential energy density function. The derived generalized effective stress principle automatically considers the impact of stress path, temperature path, and soil structure, covering the complete process from unsaturated to saturated soils.