Stress Transfer Mechanism of the Jointed Rock Media with Strong Anisotropy

Abstract

In this paper experimental as well as numerical results are reported for stress distribution in jointed rock media having various types of discontinuities, and these are compared with the corresponding results for a homogeneous elastic media.
When the angle θ between the joint surface and horizontal axis of cohesionless jointed rock media is varied in the range 0<θ<90°, it is found that there exists a certain traditional angle θ where the stress distribution is also found to changes suddenly. The stress distribution is also found to change suddenly when the tensile strength σ_t is reduced below a certain critical value. Further this stress distribution becomes equal to that of the homogeneous elastic media when the cohesion C and tensile strengthσ_t are larger than the corresponding critical values respectively, and the shear modulus G of joint surfaces is set at G=E/(2 (1+ν)) which is obtainable from the elastic theory (ν: Poisson's ratio). The Mohr-Coulomb's linear expression for shearing stress is used for the yield criterion.
The numerical method of analysis employed in this study is found to be applicable to the analyses of homogenous media as well as discretized jointed rock media, and it is believed that the present analysis can be effectively used for clarifying the mechanical characteristics of rock media of strong anisotropy.