Medium-length hole mixed wedge cut blasting method capable of realizing directed fracture using cutting cartridge bag for solid rock roadway
The invention discloses a medium-length hole mixed wedge cut blasting method capable of realizing directed fracture using a cutting cartridge bag for a solid rock roadway. According to the method disclosed by the invention, 3-4 pairs of vertical wedge cutting holes are arranged at lower half places of an excavating working face; the vertical wedge cutting holes comprise mirror-arranged primary cutting holes and secondary cutting holes that are arranged at the two sides of the primary cutting holes; the primary cutting holes comprise three blast holes that are arranged side by side; the secondary cutting holes comprise four blast holes that are arranged side by side; 1-2 straight holes are formed in the middle portion of each primary cutting hole; a distance between every two adjacent blast holes in the primary cutting holes is 800-1000mm. According to the method disclosed by the invention, the advantage of directed fracture blasting of the cutting cartridge bag is fully utilized, so that an orifice distance and a row distance of the primary cutting holes are increased, the number of blasting holes is reduced, explosive unit consumption is decreased, disturbance damage to the roadway surrounding rocks by cut blasting is effectively controlled, the original strength and stability of the roadway surrounding rocks are guaranteed, and favourable conditions are provided for repairing and maintenance works during later roadway support and operation progresses. 1. A hard rock tunnel deep-hole mixing wedge-shaped slit in the bag fixed to the fracture underholing blasting method, which is characterized in that arranged middle hyponastic drivage working face 3-4 pair of vertical wedge-shaped undercutting hole, vertical wedge-shaped undercutting hole comprising an Image-a levels of undercutting hole and arranged at the two sides of the two-stage undercutting hole, said level undercutting hole is composed of three are arranged side by side of a blast hole, said secondary undercutting hole is composed of four are arranged side by side of a blast hole, the level is in the middle of the undercutting hole 1-2 a straight hole, the breaking-in hole at the level of each of the two adjacent distance of which is between the blast hole 800-1000mm, the secondary undercutting hole in each of the two adjacent blast hole to hole pitch between 300-400mm, when the arrangement of the two straight hole, the straight hole to hole pitch between 300-500mm, the level for the distance between the slot out 800-1000mm, the secondary out to the distance between the slot 1200-1400mm, said secondary undercutting hole by a coupling continuous charge, said straight Kong Kong bottom charge, the blast hole in undercutting hole at the level of the dip angle is 65 °-80 °, the secondary undercutting hole in the blast hole angle of 70 °-80 °, the level of the vertical depth of undercutting hole 1300-1500mm, the secondary undercutting hole of the vertical depth is 2500-2700mm, the depth is the vertical states the straight hole 2600-2800mm. 2. A hard rock tunnel deep-hole mixing wedge-shaped slit in the bag fixed to the fracture underholing blasting method according to Claim 1, characterized in that said level undercutting hole from the inside to the outside are sequentially filled with the tube, strips and hwangto stemming, the loess stemming water stemming is filled in, the external circular surface of the tube is provided with a slit axially, the two ends of the cutting of the end portion close to the vicinity of the stop. 3. A hard rock tunnel deep-hole mixing wedge-shaped slit in the bag fixed to the fracture underholing blasting method according to Claim 1, characterized in that the pipe is composed of a PVC tube, or the double anti-tube process.