ABSTRACT
The derivation of Eq. (1) relies on the soil particles and water phase combining and forming aggregates under equilibrium conditions. This may be shown to minimise the thermodynamic potential and is a requirement of equilibrium conditions. The equation has been shown to allow examination of the volumetric and anisotropic stress-strain behaviour both of the aggregates and between the aggregates in unsaturated fine-grained soils. The heterogeneous internal straining constitutes a level of straining between the macro-mechanical level and the micro-mechanical, particulate level.
