ABSTRACT
In this paper, an anisotropic elasto-plastic damage model in strain space has been established to describe the behaviour of geomaterials under compression dominated stress fields. The research work focuses on rate-independent and small-deformation behaviour during isothermal processes. The salient features of geomaterials is fully defined in the starting points: (1) an equivalent state based on which the formulation is symmetric with respect to the sign of the stress/strain and (2) a general free energy function including the mechanisms of damage, plasticity and damage residual effects. The constitutive relations are developed in the well-established continuum mechanics. The prime results include: (1) a one-parameter damage dependent elasticity tensor deduced based on tensorial algebra and thermodynamic requirements; (2) a fourth-order damage characteristic tensor which determines anisotropic damaging, deduced in the framework of Rice’s “normality structure”; (3) a procedure for the determination of the damage tensor according to the geological data is described here. Finally, some numerical results are presented.
