A constitutive model for crushed salt

Abstract

A constitutive model for crushed salt is presented in this paper. A creep constitutive model is developed¿rst and compared with test results. The constitutive model presented here concentrates on creepdeformation because saline media behave basically in a ductile and time-dependent way. An idealizedgeometry is used as a common framework to obtain stress–strain macroscopic laws based on twodeformation mechanisms: ¿uid-assisted diffusional transfer creep and dislocation creep. The model is ableto predict strain rates that compare well with results from laboratory tests under isotropic and oedometricconditions. Macroscopic laws are written using a non-linear viscous approach, which incorporates also aviscoplastic component, based on critical state theory. The viscoplastic term is intended for non-creepdeformation mechanisms such as grain reorganization and crushing