Effect of finite size joints on the deformability of jointed rock in three dimensions

A numerical decomposition technique, which has emerged from a linking between joint geometry modelling and generation schemes and a distinct element code (3DEC), is used to evaluate the effects of joint geometry parameters of finite size joints on the deformability properties of jointed rock at the three-dimensional (3-D) level. Variation of deformability parameters of jointed rock with joint geometry parameters such as joint density, joint size/block size and joint orientation, are shown through 3-D plots. Relations are developed between deformability properties of jointed rock and fracture tensor parameters. An incrementally linear elastic, orthotropic constitutive model is suggested to represent the pre-failure mechanical behaviour of jointed rock. This constitutive model has captured the anisotropic, scale-dependent behaviour of jointed rock. In this model, the effect of the joint geometry network in the rock mass is incorporated in terms of fracture tensor components. Some insight is given related to estimation of Representative Elementary Volumes (REVs) and REV property values with respect to deformability properties of jointed rock.