Deep hole blasting method for overhard rock of underground coal mine driving working face

Abstract

The invention discloses a deep hole blasting method for overhard rock of an underground coal mine driving working face, and relates to the technical field of underground coal mine deep hole blasting, and the method comprises the following steps: S1, according to geological data of the driving working face, the size of a roadway section and information of a water exploring hole, determining the length, the diameter and the row spacing of a charging hole and an empty hole, and marking the charging hole and the empty hole; s2, explosive charging holes and empty holes are drilled in the driving working face according to the marks, punching and drainage are completed, and the directions of the explosive charging holes and the empty holes are parallel to the direction of the driving working face; s3, a detonating cord is laid in the charging hole, and one end of the detonating cord is required to be exposed out of the charging hole; s4, all the charging holes are filled with explosives; s5, the charging holes filled with the explosives are sealed; and S6, a detonating cord outside the charging hole is connected and merged into the blasting network, a detonating electronic detonator is installed, the detonating electronic detonator is connected with an exploder, and then detonating is conducted. The rock roadway tunneling speed is increased, the problem of tension of excavation connection is solved, and high-yield and high-efficiency production of a mine is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of deep hole blasting in coal mines, in particular to a deep hole blasting method for hard rock in an underground coal mine excavation working face. Background Art

[0002] Tunnel excavation is one of the most important links in the coal production process. Tunnel excavation efficiency directly affects the progress of tunnel development and the production continuity of coal mining. With the continuous exploitation of coal resources, the amount of simple and easy-to-mine coal in the shallow part is becoming less and less, and it is constantly transferred to the deep part. The hard rock that is more widely distributed in the deep part compared to the shallow part brings many negative impacts to the excavation work: ① It is difficult for the comprehensive excavator to cut hard rock, and the cutting speed is slow, which affects the advance of the tunnel excavation; ② The cutting head of the comprehensive excavator is easy to damage, the maintenance cost is high, and the maintenance takes up the time of cutting rock, resulting in a decrease in the efficiency of rock tunnel excavation; ③ A large amount of respirable dust is generated at the head of the tunnel excavation, resulting in low visibility inside the excavation tunnel, which greatly reduces the speed of tunnel excavation and causes serious harm to the health of workers at the head of the excavation.

[0003] How to safely increase the excavation speed of hard rock tunnels has become a key technical problem that the current Chinese coal mining industry urgently needs to study and solve. Based on this, the present invention proposes a deep hole blasting method for hard rock in the underground coal mine excavation working face to solve the above problem. Summary of the invention

[0004] The purpose of the present invention is to provide a deep hole blasting method for hard rock in an underground coal mine excavation working face, so as to solve the problems existing in the above-mentioned prior art, improve the rock tunnel excavation speed, solve the problem of tight mining and excavation connection, and ensure high-yield and efficient production of the mine.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides a deep hole blasting method for hard rock in an underground coal mine excavation working face, comprising the following steps:

[0007] S1: According to the geological data of the excavation working face, the cross-sectional dimensions of the tunnel and the information of the water exploration holes, the length, diameter and spacing of the charging holes and empty holes are determined, and corresponding marks are made on the working face;

[0008] S2: Drill charging holes and empty holes on the excavation working face according to the markings. The directions of the charging holes and empty holes are parallel to the direction of the excavation working face. Clean the residual rock cuttings in the charging holes and drain the water in the charging holes.

[0009] S3: The detonating cord is laid throughout the charging hole, and one end of the detonating cord is required to be exposed outside the charging hole;

[0010] S4: Fill all charging holes with explosives;

[0011] S5: sealing each charging hole filled with explosives;

[0012] S6: Connect the detonating cord outside the charge hole to the blasting network, install the blasting electronic detonator, connect the blasting electronic detonator to the detonator, and then detonate.

[0013] In one embodiment, in step S3, the detonating cord is exposed 1.5 m out of the charging hole.

[0014] In one embodiment, in step S3, when laying the detonating cord, one end of the detonating cord is inserted into the drug delivery tube of the charge loader, the detonating cord is inserted to a length of 1.5 m, the detonating cord is delivered to the bottom of the hole by the drug delivery tube, and then the drug delivery tube is pulled out 1 m.

[0015] In one embodiment, in step S4, the explosive is loaded into the charging hole by a charge loader, including: maintaining the position of the charge delivery tube in the charging hole, connecting the other end of the charge delivery tube to the charge loader; pouring the sieved explosive into the charge loader, turning on the charge loader switch, spraying the detonating cord and the explosive plugged in the charge delivery tube at the same time, fixing the detonating cord at the bottom of the hole, and then turning off the charge loader switch; pulling the charge delivery tube out 2m toward the hole mouth, and then turning on the charge loader switch, when the 2m charging hole is full of explosives, turning off the charge loader switch, and repeating the above operations until the charging hole is completely charged.

[0016] In one embodiment, in step S5, the charging hole is sealed by a charging device, including: sieving loess and loading it into the charging device, plugging the drug delivery tube into the charging hole; pulling the drug delivery tube 2m toward the hole mouth, turning on the charging device switch to start sealing the hole, and when the 2m charging hole is filled with loess, turning off the charging device switch, and repeating the above operation until the loess is filled to the hole mouth.

[0017] In one embodiment, in step S6, the detonating cord outside the charging hole is connected in an overlapping manner and incorporated into the blasting network. Two detonating electronic detonators are provided, and the two detonating electronic detonators are connected in parallel to the blasting wire, and the blasting wire is connected to the detonator.

[0018] In one embodiment, the detonating cord and the detonating electronic detonator are wrapped in a flame retardant tube.

[0019] In one embodiment, the energy focusing hole of the detonating electronic detonator points toward the charge hole.

[0020] In one embodiment, in step S1, the geological data of the excavation working face includes the distribution of the top plate, bottom plate and hard rock of the excavation working face; the distribution direction and lithology of the hard rock of the excavation working face are further determined through the water exploration holes.

[0021] In one embodiment, in step S4, the explosive is a third-level powdered emulsion explosive permitted for use in coal mines.

[0022] Compared with the prior art, the present invention has achieved the following technical effects:

[0023] The present invention determines the deep hole blasting method according to the hard rock lithology and distribution state of the underground coal mine excavation working face, improves the rock tunnel excavation speed, solves the problem of tight mining and excavation connection, saves the cutting head and maintenance time of the comprehensive excavator, and ensures high-yield and efficient production of the coal mine. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 This is a flow chart of a method for deep hole blasting of hard rock in an underground coal mine excavation working face in an embodiment of the present invention;

[0026] Figure 2 It is a schematic diagram of deep hole blasting in hard rock at an underground excavation working face of a coal mine in an embodiment of the present invention;

[0027] Figure 3 It is a schematic diagram of the arrangement of blastholes in the excavation working face in an embodiment of the present invention.

[0028] In the figure: 1-top plate; 2-bottom plate; 3-hard rock; 4-charging hole; 5-empty hole; 6-detonating cord; 7-charger; 8-charge delivery tube; 9-charger switch; 10-explosive; 11-loess; 12-detonating electronic detonator; 13-detonator; 14-first charging hole; 15-second charging hole; 16-third charging hole; 17-fourth charging hole; 18-fifth charging hole; 19-sixth charging hole; 20-seventh charging hole; 21-eighth charging hole; 22-ninth charging hole; 23-tenth charging hole; 24-first empty hole; 25-second empty hole; 26-third empty hole; 27-fourth empty hole. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] The purpose of the present invention is to provide a deep hole blasting method for hard rock in an underground coal mine excavation working face, so as to solve the problems existing in the prior art, improve the rock tunnel excavation speed, solve the problem of tight mining and excavation connection, and ensure high-yield and efficient production of the mine.

[0031] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] like Figure 1-Figure 2 As shown, this embodiment provides a deep hole blasting method for hard rock in an underground coal mine excavation working face, comprising the following steps:

[0033] S1: According to the geological data of the excavation working face, the cross-sectional dimensions of the tunnel and the information of the water exploration holes, the length, diameter and spacing of the charging holes 4 and the empty holes 5 are determined, and corresponding marks are made on the working face;

[0034] The geological data of the excavation working face include the distribution of the top plate 1, bottom plate 2 and hard rock 3 of the excavation working face. The cross-sectional dimensions of the tunnel are 5.0m long and 3.0m high. The distribution direction and lithology of the hard rock 3 of the excavation working face are further determined through the water exploration holes, and the charging holes 4 are determined to be parallel to the excavation direction of the working face. The charging holes 4 are 24 meters long and 65mm in diameter, and the spacing and row spacing are both 500mm. In addition, the hard rock 3 weakened by underground blasting in the coal mine is in a three-way compression state, with no original crushing space and only one free surface. In order to achieve an ideal pre-cracking loosening effect, a certain number of empty holes 5 need to be drilled, and the diameter of the empty holes 5 is 95mm.

[0035] S2: Drill charging holes 4 and empty holes 5 on the excavation working face according to the markings. The directions of the charging holes 4 and empty holes 5 are parallel to the direction of the excavation working face. Record the depth of each charging hole 4. Clean the residual rock cuttings in the charging hole 4 and drain the water in the charging hole 4.

[0036] S3: Determine the permissible length of the detonating cord 6 in the coal mine according to the length of each charging hole 4. The detonating cord 6 is laid throughout the charging hole 4, and the length of one end of the detonating cord 6 exposed outward from the charging hole 4 is required to be 1.5 m;

[0037] When laying the detonating cord 6, insert one end of the detonating cord 6 into the drug delivery tube 8 of the charge loader 7, the detonating cord 6 is inserted for a length of 1.5m, and slowly send the detonating cord 6 to the bottom of the hole using the drug delivery tube 8, then pull out the drug delivery tube 8 for 1m; the length of the detonating cord 6 is 26m.

[0038] S4: Loading explosives 10 in all charging holes 4; Specifically, loading explosives 10 in charging holes 4 through charging device 7, including: keeping the position of drug delivery tube 8 in charging hole 4, connecting the other end of drug delivery tube 8 to charging device 7; disassembling and sieving the powdered emulsion explosive rolls permitted for third-level coal mines, pouring the sifted explosives into charging device 7, ensuring that there is no agglomeration of explosives in charging device 7, and avoiding the blocking of drug delivery tube 8 during the drug delivery process of charging device 7; turning on charging device switch 9, ejecting detonating cord 6 and explosives plugged in drug delivery tube 8 at the same time, fixing detonating cord 6 at the bottom of the hole, and then turning off charging device switch 9; pulling drug delivery tube 8 out 2m toward the hole mouth, and then turning on charging device switch 9, when 2m charging hole 4 is filled with explosives 10, turning off charging device switch 9, and repeating the above operation until charging hole 4 is completely charged. Charging length is 16m. The density of the powdered emulsion explosive in the blast hole must be ensured each time the explosive is loaded.

[0039] S5: Seal the charge holes 4 filled with explosives; specifically, seal the charge holes 4 through the charge device 7, including: sieve loess 11 and load it into the charge device 7, plug the drug delivery pipe 8 into the charge hole 4; pull the drug delivery pipe 8 out 2m toward the hole mouth, turn on the charge device switch 9 to start sealing the hole, and when the 2m charge hole 4 is filled with loess 11, turn off the charge device switch 9, and repeat the above operation until the loess is filled to the hole mouth. The sealing length is 8m.

[0040] S6: connect the detonating cord 6 outside the charging hole 4 in an overlapping manner and incorporate it into the blasting network, and install the detonating electronic detonator 12. There are two detonating electronic detonators 12. The energy-gathering hole of the detonating electronic detonator 12 points to the charging hole 4. The two detonating electronic detonators 12 are connected in parallel to the blasting line. The blasting line is connected to the detonator 13. The detonating cord 6 and the detonating electronic detonator 12 are wrapped with a flame-retardant tube, and then detonated and accepted.

[0041] At the rock tunnel excavation working face of a coal mine in Shanxi, the excavation rock mass is sandstone with a strength coefficient greater than 8, and the length of the area to be blasted is 24m. The original construction plan adopted the drilling and blasting method and the direct cutting method of the tunnel boring machine. Among them, the drilling and blasting method is to drill 2.4m charging holes perpendicular to the working face. The number of charging holes is 2 rows, and the row spacing and spacing are both 1.5m. After blasting, the length of the residual hole reaches more than 1.2m. The phenomenon of throwing waste rock at a long distance often occurs, damaging the equipment behind the working face, and cannot meet the normal connection requirements. When the tunnel boring machine is used for direct cutting, the cutting speed is slow, with a daily footage of about 1.0m. The cutting head of the tunnel boring machine is easily damaged, the maintenance cost is high, and the maintenance takes up the time of rock cutting, resulting in a decrease in the efficiency of rock tunnel excavation. The deep hole blasting method for hard rock in the underground excavation working face of a coal mine of the present invention is adopted, and the drilling and blasting parameters and construction process are designed based on this, and three rows of blast holes are arranged along the excavation direction of the working face. Figure 3As shown, there are two rows of charging holes 4 and one row of empty holes 5. There are 10 charging holes 4 in total, and 5 holes in each row, namely the first charging hole 14, the second charging hole 15, the third charging hole 16, the fourth charging hole 17, the fifth charging hole 18, the sixth charging hole 19, the seventh charging hole 20, the eighth charging hole 21, the ninth charging hole 22 and the tenth charging hole 23. The diameter of the charging hole 4 is 65mm, the spacing and row spacing are both 500mm, the depth is 24.0m, the charging length is 16m, and the sealing length is 8m. There are 4 empty holes 5, namely the first empty hole 24, the second empty hole 25, the third empty hole 26 and the fourth empty hole 27. The empty hole 5 is arranged between the two rows of charging holes 4 and is staggered with the charging holes 4. The diameter of the empty hole 5 is 95mm, the spacing is 500mm, and the depth is 24.0m. The powder emulsion explosive charging and loess plugging are completed by the charging device 7. The test results show that the method of the present invention improves the speed of rock tunnel excavation, solves the problem of tight mining and excavation connection, saves the time of the cutting head and maintenance of the comprehensive excavator, and ensures high-yield and efficient production of the coal mine.

[0042] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A deep hole blasting method for hard rock in an underground coal mine excavation working face, characterized in that: The following steps are involved: S1: According to the geological data of the excavation working face, the cross-sectional dimensions of the tunnel and the information of the water exploration holes, the length, diameter and spacing of the charging holes and empty holes are determined, and corresponding marks are made on the working face; S2: Drill charging holes and empty holes on the excavation working face according to the markings. The directions of the charging holes and empty holes are parallel to the direction of the excavation working face. Clean the residual rock cuttings in the charging holes and drain the water in the charging holes. S3: The detonating cord is laid throughout the charging hole, and one end of the detonating cord is required to be exposed outside the charging hole; S4: Fill all charging holes with explosives; S5: sealing each charging hole filled with explosives; S6: Connect the detonating cord outside the charge hole to the blasting network, install the electronic detonator, connect the electronic detonator to the detonator, and then detonate.

2. The deep hole blasting method for hard rock in underground coal mine excavation working face according to claim 1 is characterized by: In step S3, the detonating cord is exposed 1.5m out of the charging hole.

3. The deep hole blasting method for hard rock in underground coal mine excavation working face according to claim 1 is characterized by: In step S3, when laying the detonating cord, one end of the detonating cord is inserted into the drug delivery tube of the charge loader, the detonating cord is inserted to a length of 1.5 m, the detonating cord is delivered to the bottom of the hole by the drug delivery tube, and then the drug delivery tube is pulled out 1 m.

4. The deep hole blasting method for hard rock in underground coal mine excavation working face according to claim 3 is characterized by: In step S4, the explosive is loaded into the charging hole through the charge loader, including: keeping the position of the charge tube in the charging hole and connecting the other end of the charge tube to the charge loader; pouring the sieved explosive into the charge loader, turning on the charge loader switch, spraying the detonating cord and the explosive plugged in the charge tube at the same time, fixing the detonating cord at the bottom of the hole, and then turning off the charge loader switch; pulling the charge tube out 2m toward the hole mouth, and then turning on the charge loader switch, when the 2m charging hole is full of explosives, turning off the charge loader switch, and repeating the above operations until the charging hole is completely charged.

5. The deep hole blasting method for hard rock in underground coal mine excavation working face according to claim 1 is characterized by: In step S5, the charging hole is sealed by a charging device, including: loading the loess into the charging device after screening, and plugging the drug delivery tube into the charging hole; pulling the drug delivery tube 2m toward the hole mouth, turning on the charging device switch to start sealing the hole, and when the 2m charging hole is filled with loess, turning off the charging device switch, and repeating the above operation until the loess is filled to the hole mouth.

6. The deep hole blasting method for hard rock in underground coal mine excavation working face according to claim 1, characterized in that: In step S6, the detonating cord outside the charge hole is connected in an overlapping manner and incorporated into the blasting network. Two detonating electronic detonators are provided, and the two detonating electronic detonators are connected in parallel to the blasting wire, and the blasting wire is connected to the detonator.

7. The deep hole blasting method for hard rock in underground coal mine excavation working face according to claim 6 is characterized by: Detonating cord and electronic detonator are wrapped in flame retardant tubes.

8. The deep hole blasting method for hard rock in underground coal mine excavation working face according to claim 6 is characterized by: The energy-focusing hole of the detonating electronic detonator points to the charging hole.

9. The deep hole blasting method for hard rock in underground coal mine excavation working face according to claim 1, characterized in that: In step S1, the geological data of the excavation working face includes the distribution of the top plate, bottom plate and hard rock of the excavation working face; the distribution direction and lithology of the hard rock of the excavation working face are further determined through the water exploration holes.

10. The deep hole blasting method for hard rock in underground coal mine excavation working face according to claim 1, characterized in that: In step S4, the explosive is powdered emulsion explosive permitted for use in third-class coal mines.

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