On The Effect of Insoluble Materials on Rock Salt Dilatancy

Abstract : In this paper we study the effect of the presence of insoluble materials on the volumetric behavior of rock salt during classic laboratory tests. We conduct numerical investigations in order to avoid the limitations of the experimental work. The modeling approach consists in considering a salt specimen as a pure halite matrix with inclusions representing the heterogeneities. The behavior of the inclusions is assumed to be linear elastic whereas the halite matrix is considered a viscoplastic material. The used viscoplastic model is comprised of a deviatoric creep law and a tension mechanism of Rankine type. The overall behavior of the structure shows similar patterns to what is typically observed in the laboratory for salt specimens. This result suggests that rock salt dilatancy can be a consequence of the material spatial heterogeneity. This approach is then used to investigate the effect of the shape, the distribution and the elastic constants of the inclusions on the volumetric behavior. Finally, a promising perspective using the random field theory is proposed to allow the extension of this work at the field scale.