Thermomechanically Consistent Constitutive Model for Rock Salt Creep
Ren Zhongjun(1), Peng Xianghe(1),Wan Ling(1),Yang Chunhe(2)
(1 Department of Engineering Mechanics, Chongqing University, 400044, Chongqing, China)
(2 Institute of Rock and Soil Mechanics, The Chinese Academy of Sciences, 430071, Wuhan, China)

Abstract: A thermomechanically consistent constitutive model is proposed for the elastic-viscoplastic behavior of rock salt，where the internal variables are adopted to describe the irreversible deformation history of rock salt and a proper generalized time scale. A damage tensor of rank four is introduced to demonstrate the anisotropic damage, the unilateral damage effect of damage and the anisotropic damage evolution, due to the geometrical anisotropy of micro-defects in rock materials, are taken into account. An experiment is conducted for the rock salt creep under triaxial complex loading histories，and the experimental results, as well as that by Yahya are simulated with the proposed model. The comparison between the computed and experimental results shows satisfactory agreement to verify the validity.
Keyword: rock salt, creep, damage, constitutive model.