Terzaghi Consolidation as a Special Case of Static Energy / Enthalpy Equilibrium (SEE) An Energetic Interpretation of One-Dimensional Soil Consolidation

(i) This work introduces, for the first time, an energetic reinterpretation of classical one-dimensional soil consolidation within the framework of Static Energy / Enthalpy Equilibrium (SEE). (ii) Rather than proposing an alternative to classical soil mechanics, the study demonstrates that Terzaghi’s consolidation theory can be rigorously understood as a special case of an energy-driven relaxation process in saturated granular systems. The dissipation of pore-water pressure is interpreted as the kinematic expression of a directed evolution toward a static energetic minimum. (iii) The SEE framework makes explicit what remains implicit in the classical formulation: the existence of an energetic end state, the stability conditions of continuous consolidation, and the physical reason why consolidation must terminate. Within this interpretation, the classical consolidation equation emerges naturally as a linearized relaxation dynamic, valid only as long as the energetic state space remains convex. (iv) A central contribution of this work is the identification of an energetic stability criterion that defines the fundamental limit of classical consolidation theory. When this criterion is violated, continuous consolidation is no longer physically admissible and a structural state transition—such as spontaneous liquefaction—becomes possible. (v) Consolidation and liquefaction are thus shown to represent two regimes of the same energetic landscape, rather than separate or unrelated phenomena. (vi) The study is deliberately restricted to static conditions and does not address cyclic or dynamic loading. Its purpose is conceptual: to provide a physically consistent energetic foundation that unifies consolidation, post-consolidation densification, and structural collapse within a single state-based framework. (vii) This contribution is intended as a foundational reference for subsequent developments of SEE-based models and for future extensions toward multi-layer systems, instability fronts, and dynamic energy input.