Numerical Simulation of the Effect of Joint Angle and Joint Distance from Tbm’s Disc on the Rock Fragmentation

In this paper, the influences of joint angle and joint spacing on the rock fragmentation have been investigated using Particle Flow Code in two dimensions (PFC2D). Firstly calibration of PFC has been done using proper micro parameters. For this purpose, both of the Uniaxial test and Brazilian test have been done on the NX samples. These tests were simulated by numerical method and then the proper micro parameters have been chosen by try and error. After calibration, 21 models with dimension of 11cm ×10 cm consisting one joint have been prepared. The joint angels were 0°, 15°, 30°, 45°, 60°, 75°, and 90°. The joint distances from cutter were 1cm, 2.5 cm and 4cm. Shear properties of joints have been determined using simulation of direct shear test on the modeled joints. One u shape cutter with diameter of 2 cm was in contact to the model surface. Axial force was applied to the model trough cutter.  The results show that both of the joint angle and joint spacing have important effect on the failure pattern and final failure load.