EFFECT OF FRACTURE GEOMETRY ON STRENGTH AND DEFORMABILITY OF 3-D DISCRETE FRACTURE NETWORK SYSTEM

Estimation of strength and deformability of fractured rock masses are important tasks in geomechanics and geological engineering disciplines as well as structural geology. This study provides a conceptual insight to the relation between the fracture geometry parameters and the behaviors of rock mass strength and deformability. A procedure was implemented to link 3-D discrete fracture network (DFN) system to 3-D distinct element method (DEM) to estimate strength and deformability of rock masses having finite size fractures. Fracture entities were treated as finite size square planes in the DFN systems. Directional strength and deformability for 10 m cubes having various stochastic 3-D DFN system were estimated to examine the effect of orientation, density and size distribution of fractures on strength and deformability of fractured rock masses. Directional Poisson’s ratio, deformation modulus and strength reduction factor in 3-D were estimated for the DFN cubes under true triaxial in-situ stress condition. The results obtained from this study show that there exist significant effect of orientation, density and size of fractures on anisotropic strength and deformability of fractured rock masses.