Smooth blasting method for hard rock tunneling roadway

Abstract

The invention discloses a hard rock tunneling roadway smooth blasting method. The hard rock tunneling roadway smooth blasting method comprises the following steps that S1, blast holes are arranged according to the determined actual position of a tunneling roadway; s2, the blast holes are formed, the blast holes comprise empty holes, underholing holes, auxiliary holes and peripheral holes, and the underholing holes are spiral underholing holes; s3, a blast hole reverse non-coupling charging structure is adopted, and stemming is adopted for non-coupling interval plugging; s4, stemming blocking is conducted on a blast hole opening, and the blocking length is not smaller than the minimum resistance line length; s5, detonating by adopting a detonating tube detonating method, and implementing segmented delayed detonating by adopting a network in a series-parallel combination mode; and S6, detonation is conducted, and a gun pile is cleaned. The method has the characteristics of improving the blast hole utilization rate, improving the initial blasting efficiency and reducing explosive misfire.

Description

Technical Field

[0001] The invention relates to the technical field of underground mine blasting engineering, and in particular to a hard rock tunnel smooth blasting method. Background Art

[0002] The surrounding rock in metal mines is mainly hard rock, and smooth blasting is mainly used to dig tunnels in hard rock. Smooth blasting refers to a controlled blasting technology that drills holes along the designed tunnel contour line by correctly selecting blasting parameters and reasonable construction methods, and then blasts after loading explosives to obtain a relatively flat tunnel contour surface. After smooth blasting, a clearly visible half-side hole wall mark can usually remain on the newly formed wall surface, and the over-excavation volume is greatly reduced, which reduces the burden on the excavation, loading and transportation system and further speeds up the excavation speed. After smooth blasting, the rock mass remains stable, no or very few blast cracks are generated after blasting, the bearing capacity of the surrounding rock itself is enhanced, the stress concentration phenomenon on the rock surface is reduced, and the hazards of rock bursts can be reduced on the deep rock wall surface, which is conducive to safe mining in the mine.

[0003] However, there are still the following problems in the current application of smooth blasting:

[0004] (1) In patent 201911212157.X, most of the smooth blasting holes are detonated simultaneously, and the blasting vibration is also relatively large, which is not conducive to the stability of the surrounding rock;

[0005] (2) In Patent 202011109929.X, the charging method is mainly continuous charging or uncoupled air charging, which results in serious over-excavation and under-excavation of the tunnel, poor blasting effect, poor tunnel formation, and the need for secondary treatment of the blasting surface after blasting is completed;

[0006] (3) At the same time, due to the unreasonable use of explosives, the energy-gathering effect between blastholes is poor, the slag throwing is chaotic, the consumption of explosives is too large, the unit consumption of explosives is large, the utilization efficiency is low, and the economic benefits need to be improved;

[0007] (4) In Patent 201910154202.4, the blast holes are charged manually. After the charge roll is placed at the hole mouth, it is poked into the bottom of the hole with a stick, and the detonator is placed in the charge roll at the bottom of the blast hole. This method causes some explosives to misfire, greatly endangering mine safety and making the end tunnel surface flat. Summary of the invention

[0008] In order to overcome the above technical problems, the purpose of the present invention is to provide a hard rock tunnel smooth blasting method, which has the characteristics of improving the utilization rate of blastholes, improving the initial blasting efficiency, and reducing the misfire of explosives.

[0009] In order to achieve the above object, the technical solution adopted by the present invention is:

[0010] A hard rock tunnel smooth blasting method comprises the following steps:

[0011] S1: Arrange blastholes according to the actual position of the determined tunnel;

[0012] S2: setting the blastholes, wherein the blastholes include empty holes, grooved holes, auxiliary holes and peripheral holes, and the grooved holes are spiral grooved holes;

[0013] S3: Carry out reverse uncoupled charging structure of blastholes and use blasthole mud for uncoupled interval plugging;

[0014] S4: The blasthole mouth is blocked with gun mud, and the blocking length is not less than the minimum resistance line length;

[0015] S5: Detonation is carried out by using the detonating cord detonation method, the network is a series-parallel combination, and segmented delayed detonation is implemented;

[0016] S6: Detonate and clear the gun pile.

[0017] In S1, the excavation tunnel profile is designed as a three-center arch tunnel, and the arch height is one-fourth of the span.

[0018] The blasthole arrangement is a polygonal design to form a relatively regular excavation contour. The blastholes are arranged on the excavation contour line according to the designed blasthole positions, and the peripheral blastholes are detonated after the main blasting area inside the tunnel using uncoupled charges to form a blasting operation with a flat contour surface. In the polygonal design, the blastholes are parallel to each other and the bottoms of the holes fall on the same plane.

[0019] The polygonal arrangement can ensure that the blast holes are parallel to each other and the bottom of the holes fall on the same plane, thereby ensuring that no "root" is left on the tunnel floor after blasting, and the bottom of the bottom hole exceeds the bottom plate contour line to avoid unevenness after blasting.

[0020] In S2, the slot holes are divided into a central slot hole (blast hole 1) and peripheral slot holes (blast holes 10-14), and an empty hole is arranged between the central slot hole and the peripheral slot holes. The central slot hole is a vertical hole perpendicular to the tunnel surface, and the empty holes (blast holes 2-9) and the peripheral slot holes are inclined holes, which are inclined toward the central slot hole, and finally form a "wedge-shaped" slot hole arrangement mode, wherein the blast hole depth is determined according to the hardness coefficient of the hard rock, and the empty holes and the peripheral slot holes are arranged around the central slot hole so as to have sufficient compensation space during blasting;

[0021] Among them, the arrangement of the groove holes is spiral, the arrangement of the empty holes and auxiliary holes (blast holes 15 to 19) is square outline, and the peripheral holes are arranged at equal intervals around the tunnel contour inside the tunnel contour line, and the peripheral eyes are located 100 mm away from the tunnel contour.

[0022] The peripheral holes are arranged at equal intervals around the tunnel contour, and the peripheral holes include waist holes, top holes, bottom holes and drainage holes, wherein the waist holes (blast holes 20-22, blast holes 28-31) are located at the left and right waist positions of the tunnel to form the tunnel sidewall contour;

[0023] The top holes (blastholes 23 to 27) are located at the top of the tunnel, forming the arch profile of the tunnel;

[0024] The bottom holes (blast holes 32-35) are located at the bottom of the tunnel, forming the tunnel floor contour;

[0025] The drainage hole (blasthole 36) is located at the lower right end of the tunnel, which can form the outline of the tunnel drainage ditch; the peripheral holes are all external inclined holes, spreading 5° around, and the bottom of the hole falls on the same plane;

[0026] The auxiliary holes are arranged at 450mm to 550mm inside the peripheral holes and are vertical holes arranged in a polygonal shape to ensure that the blast holes are parallel to each other and the bottoms of the holes fall on the same plane.

[0027] In the S3, reverse charging means that the primer is placed at the charging end of the eye bottom, and the energy-gathering spaces of all the primer rolls are directed to the eye mouth, and the explosion wave propagates toward the eye mouth; uncoupled charging means that the diameter of the explosive roll is smaller than the diameter of the blasthole, and a gap is left between the explosive and the blasthole wall; the blastholes all adopt a reverse uncoupled gun mud interval energy-gathering charging structure, and use a semi-cylindrical rod to transport the gun rolls and gun mud, and determine the weight of each roll of the gun roll and the unit consumption of explosives, wherein the first roll of explosives is close to the bottom of the blasthole, and the selected gun rolls are all modified ammonium oil explosives, which can make the blasting effect more significant and also improve the energy utilization rate.

[0028] The charge structure is divided into a full-hole charge structure and a half-hole charge structure;

[0029] The full-hole charging structure uses charge roll 1 and taphole mud 2 for alternate charging. Charge roll 1 is loaded from the bottom of the blasthole, filling the blasthole without reserving air intervals. The full-hole charging structure requires 9 rolls of explosives, and taphole mud 2 is used to seal the end. The blocking length is not less than the minimum resistance line length.

[0030] The half-hole charging structure also uses a charge roll 1 and a gun mud 2 for interval charging. The charge roll 1 is loaded from the bottom of the hole to the middle of the gun hole. There is an air interval 5 from the middle to the end of the gun hole. The half-hole charging structure uses 4 rolls of explosives, and the end is sealed with gun mud 2. The blocking length is not less than the minimum resistance line length.

[0031] The blasting is initiated by the detonation method of the detonating cord 4, and the electronic detonator 3 is inserted into the second roll of explosives at the end of the blasthole in reverse as a detonator; wherein, two electronic detonators are inserted into the second roll of explosives at the end of the blasthole in the center groove.

[0032] The detonation method adopts segmented delayed detonation and implements a ten-stage detonation method; by accurately controlling the time interval of each detonation stage, the superposition effect of stress waves can be achieved, and the working capacity of the explosion stress field can be enhanced; at the same time, the free surface effect is increased, the crushing effect between rock blocks is improved, and it is helpful to improve the blasting effect;

[0033] The middle part of the excavation tunnel is a slotted eye, the lower part of the slotted eye is an inclined slotted eye, the two sides of the middle slotted eye are two sides of the inclined slotted eye, the middle part is a slotted eye with inclined slotted eyes arranged above and below, the upper part of the upper inclined slotted eye is an auxiliary eye, the lower part of the lower inclined slotted eye is a lower auxiliary eye, the periphery of the excavation tunnel is a peripheral eye, the top center of the excavation tunnel, the periphery of the top center and the bottom are peripheral eyes, and the two bottom corners of the excavation tunnel are peripheral eyes;

[0034] The middle groove hole is designed as one-stage blasting, the lower inclined groove hole is designed as two-stage blasting, the two-side inclined groove holes are designed as three-stage blasting, the upper and lower inclined groove holes are designed as four-stage blasting, the upper auxiliary hole is designed as five-stage blasting, the lower auxiliary hole is designed as six-stage blasting, the end wall peripheral holes are designed as seven-stage blasting, the peripheral holes on the top except the center are designed as eight-stage blasting, the top center and the bottom peripheral holes are designed as nine-stage blasting, and the two bottom corner peripheral holes are designed as ten-stage blasting. Among them, the detonation time interval of adjacent detonation sections differs by 50 to 100 ms, and finally a one-time smooth surface blasting is achieved.

[0035] Beneficial effects of the present invention:

[0036] (1) The present invention utilizes the fact that the decay rate of explosives in solids is much lower than that in air, and adopts a full-hole charging structure and a half-hole charging structure, so that the taphole mud is filled between the cartridges at intervals, thereby making the shock wave generated by the explosives act more effectively on the rock, thereby improving the utilization rate of the blasthole;

[0037] (2) The design of the peripheral holes of the present invention follows the principle of "more drilling and less charging", so that the excavation tunnel presents a complete contour section, effectively suppressing the phenomenon of over-excavation and under-excavation; at the same time, the empty holes and the peripheral groove holes are arranged around the central groove hole to provide enough compensation free surface during blasting, and double detonating cords are used to realize the detonation of the central groove hole, thereby improving the initial blasting efficiency and increasing the blasting safety;

[0038] (3) The present invention inserts the electronic detonator into the second roll of explosives at the end, and utilizes the shock wave generated by the explosion of the roll of explosives to detonate the first roll of explosives and subsequent explosives. The superposition effect of the end shock wave can effectively improve the flatness of the tunnel section. The invention can greatly reduce the misfire phenomenon of the explosive roll.

[0039] (4) The present invention adopts a ten-stage detonation method, which can effectively reduce the interaction of rocks in each blasting process, not only improving the blasting efficiency, but also reducing the impact of blasting on the surrounding environment and structure, adding sufficient compensation space for subsequent blasting, and can form a smooth surface blasting in one time, reducing the secondary repair of the tunnel and improving labor productivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 The figure is a schematic diagram of the arrangement of blastholes in the hard rock tunnel smooth blasting method of the present invention.

[0041] Figure 2 It is a schematic diagram of the AA section arrangement of blastholes in the hard rock tunnel smooth blasting method of the present invention.

[0042] Figure 3 It is a schematic diagram of the blast hole detonation sequence of the hard rock tunnel smooth blasting method of the present invention.

[0043] Figure 4 The present invention is a schematic diagram of the blasthole charging structure of the hard rock tunnel smooth blasting method.

[0044] Figure 5 It is a schematic diagram of the charging structure of peripheral holes 21, 24, 26 and 29 of the hard rock tunnel smooth blasting method of the present invention.

[0045] Figure 6 This is a schematic diagram of the charging structure of the No. 1 blast hole of the center slot hole of the hard rock tunnel smooth blasting method of the present invention.

[0046] Reference numerals:

[0047] 1- modified ammonium nitrate oil explosive volume; 2- gun mud; 3- electronic detonator; 4- detonating cord; 5- air spacer. DETAILED DESCRIPTION

[0048] The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0049] like Figures 1 to 6 As shown, according to the specific implementation method provided in the embodiment of the present invention, the cross-section of the hard rock excavation tunnel of the present invention is a three-center arch, the arch height is one-fourth of the span, the cross-sectional area is 2.5m×2.5m, the surrounding rock strength coefficient f=6~9, and the advance of each cycle is 2.5m; an air-leg rock drill is used for drilling, the blasthole diameter is 40mm, the blasthole utilization rate is 90%, and the blasthole depth is 2.5m.

[0050] The tunnel has a span of 2.5m and a height of 2.5m, with a waist height of 1.875m and an arch height of 0.625m.

[0051] Optionally, blastholes are arranged according to the actual position of the determined excavation tunnel, wherein the arrangement of the slot holes is spiral, the arrangement of the empty holes and auxiliary holes is square, and the peripheral holes are arranged at equal intervals around the tunnel contour, and the peripheral eyes are located 100 mm away from the tunnel contour.

[0052] like Figures 1-2 As shown, there are 6 slot holes and 8 empty holes, mainly blast holes 1 to blast holes 14. The central slot hole 1 is a vertical hole; empty holes 2 to 9 are all inclined holes, with a blast hole spacing of 150mm and a row spacing of 150mm. The blast holes are all inclined toward the central slot hole, with an angle of 1° with the axis, and the bottom of the hole is 20mm away from the bottom of the central slot hole; the peripheral slot holes 10 to 14 are all inclined holes, inclined toward the central slot hole, with a blast hole spacing of 150mm, and the blast holes are all inclined toward the central slot hole, among which the angle between slot holes 10 to 13 and the axis is 3°, and the angle between slot hole 14 and the axis is 5°, finally forming a "wedge-shaped" slot hole arrangement.

[0053] like Figures 1-2 As shown in the figure, the peripheral holes are arranged at equal intervals around the tunnel contour, following the principle of "more drilling and less charging", and a total of 17 peripheral holes are arranged: a total of 17 peripheral holes are arranged, including 7 waist holes, 5 top holes, 4 bottom holes and 1 drainage hole, mainly blast holes 20 to blast holes 36. The blast holes are all inclined to the outside of the tunnel contour, with an angle of 5° with the axis. The openings of the waist holes and top holes are 100mm away from the inside of the tunnel contour, and the bottom of the hole exceeds the tunnel contour line by 100mm; the opening of the bottom hole is 100mm higher than the bottom plate level, and the bottom of the hole exceeds the bottom contour line by 100mm. Among them, the spacing between the left waist holes 20-22 blast holes is 560mm, the spacing between the right waist holes 28-31 blast holes is 500mm, the spacing between the top holes 23-27 blast holes is 450mm, and the spacing between the bottom holes 32-35 blast holes is 600mm.

[0054] like Figures 1-2 As shown, a total of 5 auxiliary holes are arranged, mainly blast holes 15 to blast holes 19, which are evenly distributed between the groove holes and the peripheral holes. Among them, the auxiliary hole 16 is 450mm away from the top peripheral hole, and the remaining auxiliary holes are 550mm away from the peripheral holes.

[0055] like Figure 4As shown, a reverse uncoupled charging structure is adopted. The full-hole charging structure adopts charge roll 1 and taphole mud 2 for interval charging. Charge roll 1 is loaded from the bottom of the blasthole, fills the blasthole and does not reserve air interval. The full-hole charging structure needs to use 9 rolls of explosives, and taphole mud 2 is used to seal the end. The blocking length is not less than the minimum resistance line length. This charging structure can improve the continuity and uniformity of the blasting effect. The half-hole charging structure also adopts charge roll 1 and taphole mud 2 for interval charging. Charge roll 1 is loaded from the bottom of the hole to the middle of the blasthole, and there is an air interval of 5 from the middle of the blasthole to the end. The half-hole charging structure uses 4 rolls of explosives, and the end is sealed with gun mud 2, and the blocking length is not less than the minimum resistance line length. The charging structure can have good flexibility and pertinence; the blasting is initiated by the detonating cord 4 detonation method, and the electronic detonator 3 is reversely inserted into the second roll of explosives at the end of the blasthole as a detonator, which can improve the utilization rate of the blasthole and enhance the crushing of rocks, and reduce the rate of large blocks; among them, two electronic detonators are inserted into the second roll of explosives at the end of the blasthole in the center groove hole, which can improve the blasting effect and safety and avoid misfires.

[0056] like Figure 4 As shown, the selected modified ammonium oil-fired explosive rolls, each roll of which weighs 0.15 kg, has a roll diameter of 32 mm, and a roll length of 200 mm; the distance between adjacent rolls is 60 mm, which is the length of the taphole mud, and the taphole mud diameter is 38 mm.

[0057] like Figure 5 As shown, the peripheral holes 21, 24, 26, and 29 all adopt a half-hole charging structure, using a total of 4 rolls of powder, which are loaded from the bottom of the blasthole, and the middle empty hole position is an air gap 5.

[0058] like Figures 4 to 6 As shown, the detonation is initiated by the detonating cord method, and the electronic detonator 3 is inserted into the second roll of explosives at the end of the blast hole as a detonator in reverse, and the first roll of explosives and subsequent explosives are detonated by relying on the blasting shock wave; wherein, the central slot hole 1 adopts double detonating cord detonation to improve the initial blasting efficiency, and two electronic detonators are inserted into the second roll of explosives at the end of the blast hole. Figure 6 .

[0059] like Figure 3As shown, the tunneling tunnel profile is designed as a three-center arch tunnel with a tunnel span of 2.5m and a height of 2.5m, of which the waist height is 1.875m and the arch height is 0.625m. The segmented delayed detonation and the ten-stage detonation method are adopted. By accurately controlling the time interval of each detonation, the superposition of stress waves can be achieved, and the working capacity of the explosive stress field can be enhanced. At the same time, the free surface effect is increased, the crushing effect between rock blocks is improved, which helps to improve the blasting effect. The middle groove hole is used as one-stage blasting, the lower inclined groove hole is used as two-stage blasting, the two side inclined groove holes are used as three-stage blasting, the upper and lower inclined groove holes are used as four-stage blasting, the upper auxiliary hole is used as five-stage blasting, the lower auxiliary hole is used as six-stage blasting, the end wall peripheral hole is used as seven-stage blasting, the top peripheral hole except the center is used as eight-stage blasting, the top center and the bottom peripheral hole are used as nine-stage blasting, and the two bottom corner peripheral holes are used as ten-stage blasting. Among them, the detonation time interval between adjacent detonation sections differs by 50 to 100 ms, achieving one-time smooth blasting.

[0060] Optionally, the charge capacity of a single hole in the full-hole interval charging structure is 1.35 kg, and the charge capacity of a single hole in the half-hole charging structure is 0.6 kg; the present invention arranges 36 holes per cycle, with a total engineering volume of 14.54 m 3 , 34.80kg of explosives were consumed, and the unit consumption was 2.39kg / m 3 .

[0061] In the above scheme, gun mud is used to fill the space between adjacent rolls of explosives, so that the shock wave generated by the explosives can act on the rock more effectively, thereby improving the utilization rate of the blastholes; following the principle of "more drilling and less charging", the excavation tunnel presents a complete contour section, effectively suppressing the phenomenon of over-excavation and under-excavation; at the same time, empty holes are evenly arranged around the periphery of the central groove eye to provide enough compensating free surfaces, and double detonating cords are used to realize the detonation of the central groove eye, thereby improving the initial blasting efficiency; the electronic detonator is inserted into the second roll of explosives at the end, and the superposition effect of the shock wave at the end can effectively improve the flatness of the tunnel section, and the use of this invention can greatly reduce the misfire phenomenon of the explosive roll; and the use of a ten-stage detonation method can effectively reduce the interaction of rocks in each blasting process, thereby increasing sufficient compensation space for subsequent blasting, and can form a smooth surface blasting in one time, thereby reducing the secondary repair of the tunnel and improving labor productivity.

[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for smooth blasting of hard rock tunnels, characterized in that: The following steps are involved: S1: Arrange blastholes according to the actual position of the determined tunnel; S2: setting the blastholes, wherein the blastholes include empty holes, grooved holes, auxiliary holes and peripheral holes, and the grooved holes are spiral grooved holes; S3: Carry out reverse uncoupled charging structure of blastholes and use blasthole mud for uncoupled interval plugging; S4: The blasthole mouth is blocked with gun mud, and the blocking length is not less than the minimum resistance line length; S5: Detonation is carried out by using the detonating cord detonation method, the network is a series-parallel combination, and segmented delayed detonation is implemented; S6: Detonate and clean up the gun pile.

2. A hard rock tunnel smooth blasting method according to claim 1, characterized in that: In S1, the tunneling tunnel profile is designed as a three-center arch tunnel, and the arch height is one-fourth of the span; The blasthole arrangement is a polygonal design to form a relatively regular excavation contour. The blastholes are arranged on the excavation contour line according to the designed blasthole positions, and the peripheral blastholes are detonated after the main blasting area inside the tunnel using uncoupled charges to form a blasting operation with a flat contour surface. In the polygonal design, the blastholes are parallel to each other and the bottoms of the holes fall on the same plane.

3. A hard rock tunnel smooth blasting method according to claim 1, characterized in that: In S2, the slot holes are divided into central slot holes and peripheral slot holes, and an empty hole is arranged between the central slot holes and the peripheral slot holes. The central slot hole is a vertical hole perpendicular to the tunnel surface, and the empty hole and the peripheral slot holes are inclined holes, which are inclined toward the central slot hole, and finally form a "wedge-shaped" slot hole arrangement mode, wherein the blasthole depth is determined according to the hardness coefficient of the hard rock, and the empty hole and the peripheral slot holes are arranged around the central slot hole so as to have sufficient compensation space during blasting; Among them, the arrangement of the groove eyes is spiral arrangement, the arrangement of the empty eyes and auxiliary eyes is square outline arrangement, the peripheral eyes are arranged inside the tunnel contour line at equal intervals around the tunnel contour, and the position of the peripheral eyes is 100mm away from the tunnel contour.

4. A method for smooth blasting of hard rock tunneling according to claim 3, characterized in that: The peripheral eyes are arranged at equal intervals around the roadway contour, and the peripheral eyes include waist eyes, top eyes, bottom eyes and drainage eyes, wherein the waist eyes are located at the left and right waist positions of the roadway to form the roadway sidewall contour; The top eye is located at the top of the tunnel, forming the arch profile of the tunnel; The bottom eye is located at the bottom of the tunnel, forming the bottom contour of the tunnel; The drainage holes are located at the lower right end of the tunnel, which can form the outline of the tunnel drainage ditch; the peripheral holes are all external inclined holes, spreading 5° around, and the bottom of the holes fall on the same plane; The auxiliary holes are arranged at 450mm to 550mm inside the peripheral holes and are vertical holes arranged in a polygonal shape to ensure that the blast holes are parallel to each other and the bottoms of the holes fall on the same plane.

5. A hard rock tunnel smooth blasting method according to claim 1, characterized in that: In the S3, reverse charging means that the primer is placed at the charging end of the eye bottom, and the energy-gathering spaces of all the primer rolls are directed to the eye mouth, and the explosion wave propagates toward the eye mouth; uncoupled charging means that the diameter of the explosive roll is smaller than the diameter of the blasthole, and a gap is left between the explosive and the blasthole wall; the blastholes all adopt a reverse uncoupled gun mud interval energy-gathering charging structure, and use a semi-cylindrical rod to transport the gun rolls and gun mud, and determine the weight of each roll of the gun roll and the unit consumption of explosives, wherein the first roll of explosives is close to the bottom of the blasthole, and the selected gun rolls are all modified ammonium oil explosives, which can make the blasting effect more significant and also improve the energy utilization rate.

6. A hard rock tunnel smooth blasting method according to claim 5, characterized in that: The charge structure is divided into a full-hole charge structure and a half-hole charge structure; The full-hole charging structure adopts charge rolls (1) and taphole mud (2) to load charges at intervals. The charge rolls (1) are loaded from the bottom of the blasthole, filling the blasthole without reserving air intervals. The full-hole charging structure requires 9 rolls of explosives, and the end is sealed with taphole mud (2). The blocking length is not less than the minimum resistance line length. The half-hole charging structure also uses charge rolls (1) and gun mud (2) to load charge at intervals. The charge roll (1) is loaded from the bottom of the hole to the middle of the gun hole. The middle to the end of the gun hole is an air interval (5). The half-hole charging structure uses 4 rolls of explosives. The end is sealed with gun mud (2). The blocking length is not less than the minimum resistance line length.

7. A hard rock tunnel smooth blasting method according to claim 1, characterized in that: In S5, the blasting is initiated by a detonating cord (4), and the electronic detonator (3) is inserted into the second roll of explosives at the end of the blasthole as an initiator in reverse; wherein two electronic detonators are inserted into the second roll of explosives at the end of the blasthole in the center groove.

8. A hard rock tunnel smooth blasting method according to claim 1, characterized in that: In S5, the detonation method adopts segmented delayed detonation, and implements a ten-stage detonation method; The middle part of the excavation tunnel is a slotted eye, the lower part of the slotted eye is an inclined slotted eye, the two sides of the middle slotted eye are two sides of the inclined slotted eye, the middle part is a slotted eye with inclined slotted eyes arranged above and below, the upper part of the upper inclined slotted eye is an auxiliary eye, the lower part of the lower inclined slotted eye is a lower auxiliary eye, the periphery of the excavation tunnel is a peripheral eye, the top center of the excavation tunnel, the periphery of the top center and the bottom are peripheral eyes, and the two bottom corners of the excavation tunnel are peripheral eyes; The middle groove hole is designed as one-stage blasting, the lower inclined groove hole is designed as two-stage blasting, the two-side inclined groove holes are designed as three-stage blasting, the upper and lower inclined groove holes are designed as four-stage blasting, the upper auxiliary hole is designed as five-stage blasting, the lower auxiliary hole is designed as six-stage blasting, the end wall peripheral holes are designed as seven-stage blasting, the peripheral holes on the top except the center are designed as eight-stage blasting, the top center and the bottom peripheral holes are designed as nine-stage blasting, and the two bottom corner peripheral holes are designed as ten-stage blasting. Among them, the detonation time interval of adjacent detonation sections differs by 50 to 100 ms, and finally a one-time smooth surface blasting is achieved.

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