A compressibility framework to describe the volume change behaviour of unsaturated clayey soils

Natural soils are usually deposited under 1D conditions. 1D conditions correspond to a non-isotropic stress state, usually described through the coefficient of earth pressure at rest K0 and thus 1D consolidated soils tend to acquire preferred directions. This stress induced, inherent anisotropy significantly affects the mechanical behaviour of soils (Gens 1982). Belokas and Kavvadas (2011) proposed an ICF to describe the Intrinsic State Envelope where initially structured soil elements shouldlie after substantial structure degradation (Belokas and Kavvadas 2010).