Studies on Rock-Breaking of Positive Disc Cutter and Edge Disc Cutter

Based on TBM disc cutter layout, a rock-breaking model of positive disc cutter and edge disc cutter is built. Sequential rock-breaking of the two cutters under different parameters is simulated; rock fragmentation, three-axis force and energy consumption are studied; optimal rock-breaking condition with different parameters is determined; feasibility of the simulation model is finally verified by experiment. The results show that three-axis force of positive disc cutter and edge disc cutter both increase with the increase of rock strength. Also, the increase of installation angle leads to larger three-axis force of edge disc cutter. Compared with positive disc cutter, edge disc cutter suffers larger squeezing strength from rocks, which results in larger three-axis force in edge disc cutter. Specific energy consumption variation has an inflection point. To meet optimal rock-breaking condition, the optimal values of installation angle in breaking siltstone, granite and marble are respectively 6°, 7° and 7°.