(1. Chongqing Key Laboratory of Geomechanics and Geoenvironmental Protection，Army Logistics University of PLA，Chongqing 401311，China；2. School of Sciences，Qingdao Technological University，Qingdao，Shandong 266033，China)
Abstract：In order to describe the anisotropy and the stress direction dependence of geomaterials，a new stress tensor，named the equivalent stress tensor，was defined on the basis of the internal stress of granular materials，so that the stress magnitude，fabric level together with the directional relationship between the stress and fabric can be described. The isotropic constitutive models were used to describe the mechanical properties of particle interfaces and the equivalent stress was used to describe the contact stress between particles. The existing isotropic models can be modified into the anisotropic ones with the equivalent stress method. A new non-linear model was thus established which takes the anisotropy and the stress direction dependence of geomaterials into account. The new model has only three parameters which can be determined by the rigorous theoretical calculations and simple laboratory tests. The nonlinear model predicts accurately the anisotropic shear deformation and peak strength of specimens from the results of shear tests with the principal stress in fixed direction.
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2018, Vol. 37 
