Abstract: In order to study the effects of different cut depths and cut spacings on cutting force and specific cutting energy acting on a conical pick, the laboratory linear rock cutting tests were carried out on carbonaceous slate and rhyolite clastic rock based on the TRW-300 true triaxial electro-hydraulic servo system and self-designed innovative pick loading platform. Experimental results indicate that there were four types of failure modes on a conical pick in rock cutting, and there was a synergistic effect between two adjacent picks. The mean cutting force linearly increases with the increasing cut depth and cut spacing. The specific cutting energy decreases with the increasing cut depth in a power-function way. The specific cutting energy decreases first and then increases with the increasing ratio of cut spacing to cut depth, and there is a minimum value that is optimal, where it is far less than energy under an unrelieved cutting groove. The optimum value of the ratio of cut spacing to cut depth is 2 or 3. Based on the results of laboratory tests, the pick arrangement on the cutting head of the cantilever roadheader is optimized, and applied to the field industrial test of non-explosive tunneling of roadheader, which significantly increases tunneling efficiency and reduces tunneling costs.

Key words: conical pick, rock cutting, cut depth, cut spacing, specific cutting energy