Evaluation of scale and loading direction effects on strength and deformability of jointed rock mass: case study of Tazareh coal mine, Iran

Determining the strength and deformation of jointed rock masses is an inevitable part of geomechanical projects. The strength and deformability of a rock mass with stochastic joint sets are conceivably anisotropic and are mainly controlled by joints mechanical and geometrical properties. In this paper, the strength and deformation behavior of jointed rock masses against different scales and loading directions has been evaluated at the Tazareh coal mine, Iran. Field mappings through the scanline method have been used to collect joints spatial features on rock surfaces. A statistical evaluation has been carried out on field data using Dips software. Then, the geomechanical properties of intact blocks have been measured by conducting a uniaxial compressive strength test. Finally, the rock mass is modeled using 3DEC, and its behavior is analyzed in some cases with different loading directions and block sizes to obtain representative elementary volume (REV) based on strength and deformation, respectively.