Modeling Grain Crushing and Debonding of Soils

The effects of two structural factors — grain crushing and bonding — were investigated using model materials — granulated silica gel (for the compression) and cement-sand mixture (for the shear resistance). Grain crushing correlates well with kinking of the (oedometric) compression curves. It is suggested that this is the reason for a garlandlike shape of compression and creep curves. Ratio of compression indices C_α/C_c is a constant. Bonding finds place within a specific bonding surface where the behavior is brittle. Outside of this surface, debonded material (sand) behaves in a standard manner, e.g. as ductile (if loose). Both structural factors — grain crushing and debonding — deeply affect the constitutive behavior of geomaterials.