The effect of confining stress directionality on the TBM disc penetration using PFC2D

In this paper, the effect of confining pressure directionality on the rock fragmentation has been investigated using PFC2D. For this purpose five different directionality was used, i.e. 0°, 30°, 45°,60° and 90°. Tensile strength of all models is 2.1 MPa. These models are under confining pressure of 5%, 10% and 15% of crack initiation stress. Totally 15 model were simulated. Disc cutters are U shape and its spacing was fixed (1a: a, is cutter width). The result shows that the optimum directionality for confining pressure is when its angularity is 0°.