Detonator-free spaced charge structure and construction method for smooth tunnel blasting

Abstract

This invention discloses a detonator-free spaced-charge structure and construction method for smooth blasting in tunnels. The total charge inside the blast hole is the same as that used in normal smooth blasting. The detonating charge is placed at the bottom of the blast hole, and the electronic detonator uses reverse detonation. Adjacent charges are spaced using specially made air bags containing a mixture of aluminum powder and carbon powder. The blast hole opening is filled with a combination of water bags and stemming material. This invention, used in smooth blasting operations in tunnels, solves the problem of needing to use detonating cords in conventional smooth blasting, and has advantages such as low production cost, simple process, and high production efficiency.

Description

Technical Field

[0001] This invention relates to the field of tunnel smooth blasting operations, specifically to a detonator-free interval charging structure and construction method for tunnel smooth blasting. Background Technology

[0002] For smooth blasting, explosive charges are typically delivered using air-layered, uncoupled charges. However, due to channel effects or excessively long gaps between charges, the charges may self-extinguish or fail to detonate within the borehole. In large-section tunnel excavation, perimeter holes often employ in-hole detonating cord initiation and propagation. Because of the large number and length of perimeter holes, detonating cord consumption is substantial. Compared to other blasting materials such as explosive charges and detonators, detonating cord is expensive. Therefore, detonating cord consumption accounts for a significant proportion of the cost of smooth blasting in tunnel excavation. Furthermore, laying detonating cord wastes considerable time and increases the labor intensity of the project. Therefore, eliminating detonating cord is crucial for accelerating construction progress and reducing costs. Additionally, during tunnel blasting, construction units often neglect plugging or improperly plug blast holes to expedite the process. This not only results in significant energy loss from the explosive charge but also poor blasting performance. Therefore, transforming the traditional production strategy into a safe, clean, and efficient production system is essential.

[0003] Chinese Publication No. CN110057257A discloses a three-section charging structure and charging method for smooth blasting holes in hard rock tunnels, without detonating cord or bamboo strips.

[0004] The specific charging structure and method involve a reinforced charging section at the bottom of the borehole, a normal charging section in the middle, and a reduced charging section at the top. Air is used as the medium between adjacent charging sections. The detonation point is located in the middle of the normal charging section, and detonation occurs in the reverse direction. This invention has advantages such as simple construction, safety and reliability, low labor intensity, low cost, and high efficiency. However, this invention is only applicable to smooth blasting excavation of hard rock tunnels with a cycle advance not exceeding 4.5m, and it only involves a three-stage charging system in the borehole. Therefore, with a fixed charging length, it cannot be reasonably adjusted to match the borehole length, limiting its widespread application. Summary of the Invention

[0005] Therefore, to address the aforementioned shortcomings, this invention discloses a detonator-free spaced-charge structure and construction method for smooth blasting in tunnels. The total charge inside the blast hole is the normal smooth blasting charge. The detonating charge is placed at the bottom of the blast hole, and the electronic detonator uses reverse detonation. Adjacent charges are spaced using specially made air bags containing a mixture of aluminum powder and carbon powder. The blast hole opening is filled with a combination of water bags and stemming material. This invention, used in smooth blasting operations in tunnels, solves the problem of needing to use detonating cords in conventional smooth blasting, and has advantages such as low production cost, simple process, and high production efficiency.

[0006] According to the present invention, a detonator-free interval charge structure for smooth blasting in tunnels is characterized in that: the total charge inside the blast hole is the normal smooth blasting charge; the detonating charge is arranged at the bottom of the blast hole; the electronic detonator uses reverse detonation; and adjacent charges are spaced by specially made air bags containing a mixture of aluminum powder and carbon powder; the blast hole opening is filled with a combination of water bags and stemming material.

[0007] According to the present invention, a detonator-free interval charging structure for smooth blasting in tunnels is characterized in that: the detonating charge is placed at the bottom of the blast hole, the detonator shaped charge cavity points towards the hole opening, and the hole opening of the smooth blasting hole is sealed by filling with water bags and blasting mud.

[0008] According to the present invention, a detonator-free interval charging structure for smooth tunnel blasting is characterized in that: the charging section inside the hole uses half of a #32 emulsion explosive charge, and the charging length of a single section is 16cm.

[0009] According to the present invention, a detonator-free spaced-charge structure for smooth tunnel blasting is characterized in that: a specially designed air bag with a length of 40cm is used between the charge sections inside the borehole. The contents of the specially designed air bag include: a mixture of aluminum powder and carbon powder, and air.

[0010] According to the present invention, a detonator-free interval charging structure for smooth tunnel blasting is characterized in that the orifice is sealed by filling with water bags and stemming material, wherein the length of the water bags is 50cm and the length of the stemming material is 30cm.

[0011] A method for constructing detonator-free interval charging for smooth blasting in tunnels, characterized in that the specific construction process is as follows:

[0012] 1) Clean the drilled blast holes and use measuring tools to remeasure the blast holes to ensure that their length reaches the design requirements for the depth of the blast hole.

[0013] 2) Prepare the detonating charge. Send the prepared detonating charge to the bottom of the hole to ensure reverse detonation. Extend the detonator lead out of the blast hole to complete the loading of the detonating charge.

[0014] 3) Install a special air bag interval on the bottom detonating charge, and insert the special air bag into the blast hole through the blast rod to ensure that the special air bag is in full contact with the already filled detonating charge.

[0015] 4) Continue filling the dispensed explosive packs and special air bags to achieve the designed explosive charge and length, thus completing the explosive charge filling process.

[0016] 5) Use a 50cm long water-filled bag to fill the hole, and finally fill it with 30cm of clay to seal the blast hole.

[0017] According to the present invention, a method for detonatorless interval charging in tunnel smooth blasting is characterized in that: after the detonating charge is detonated, due to the presence of a small amount of aluminum powder and carbon powder mixture in the specially designed air bag, the sympathetic detonation distance between the detonating charge and the charged charge increases. The explosion after blasting causes the aluminum powder in the air bag to react, resulting in a linear increase in energy such as high temperature and high pressure compared to conventional conditions. Furthermore, the energy is not easily dispersed in the narrow space of the smooth blast hole, and the blasting jet has a longer range than the jet under conventional conditions, which to a certain extent increases the sympathetic detonation distance between the charged charges.

[0018] The advantages of this invention compared to the prior art are as follows: (1) This invention can be applied to various variations in borehole depth and various types of surrounding rock, provided that the normal sympathetic detonation of each charge section is guaranteed; (2) The specially designed length of the air bag can serve as an air gap in the charge structure and can also increase the sympathetic detonation distance of the explosive cartridge; (3) Smooth blasting can be carried out with reduced detonating cord, without the need for binding with bamboo strips, and a multi-segment charge structure is used in the blasting charge structure, so that the distribution of the cartridge in the smooth blast hole is more uniform, which is conducive to the formation of a smooth surface; (4) This charge structure process can be widely applied to blasting operations in coal mines and gas tunnels, where only the length of the air bag is different from the length of the air bag in other environments, and the rest of the structure can remain unchanged. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the tunnel smooth blasting smooth blasting hole charging structure of the present invention;

[0020] Figure 2 This is a schematic diagram of the detonation charge installed at the bottom of the hole.

[0021] Figure 3 This is a diagram showing the product after being filled with a special air bag.

[0022] Figure 4 This is a diagram showing the dispensing kit and the air bag after they have been filled.

[0023] Figure 5 This is a schematic diagram of the water bag after it has been filled.

[0024] Figure 6 This is a schematic diagram of the filling of the blasting mud.

[0025] Among them: 1. Tunnel surrounding rock, 2. Blasting hole, 3. Detonating charge, 4. Electronic detonator, 5. Electronic detonator lead wire, 6. Special air bag, 7. Activated charge, 8. Water bag, 9. Boiling mud. Detailed Implementation

[0026] The following will be combined with the appendix Figures 1-6This invention will be described in detail, and the technical solutions in the embodiments of this invention will be clearly and completely described. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0027] This invention provides an improved detonator-free spaced charge structure and construction method for smooth tunnel blasting, such as... Figure 1 As shown, the total charge inside the borehole is the normal smooth blasting charge. The detonating charge 3 is located at the bottom of the borehole, and the electronic detonator 4 uses reverse detonation. Adjacent charges are separated by specially made air bags 6 containing a mixture of aluminum powder and carbon powder. The borehole opening is filled with a combination of water bags 8 and stemming clay 9.

[0028] like Figure 2 As shown, prepare the detonating charge, send the prepared detonating charge to the bottom of the hole to ensure reverse detonation, extend the detonator lead 5 out of the blast hole, and complete the loading of the detonating charge.

[0029] like Figure 3-4 As shown, a special air bag 6 is installed at intervals on the bottom detonating charge 3. The special air bag 6 is then inserted into the detonation hole 2 through the blasting rod, so that the special air bag 6 is in full contact with the already filled detonating charge 3. The detonating charge 7 and the special air bag 6 are then filled to achieve the designed charge amount and charge length, thus completing the charging part.

[0030] like Figure 5-6 As shown, a 50cm long water-filled bag 8 was used to fill the hole, and finally 30cm of clay 9 was used to seal the blast hole 2.

[0031] When the detonating charge 3 is detonated, the sympathetic detonation distance between the detonating charge 3 and the charged charge 7 increases because the special air bag 6 contains a small amount of aluminum powder and carbon powder mixture. The explosion after the explosion causes the aluminum powder in the air bag 6 to react, and the energy such as high temperature and high pressure generated increases linearly compared with the normal situation. It is not easy to disperse in the narrow space of the light detonation hole 2, and the blast jet has a longer range than the jet under normal conditions, which increases the sympathetic detonation distance between the charged charges 7 to a certain extent.

[0032] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for detonator-free interval charging in tunnel smooth blasting, comprising a detonator-free interval charging structure, wherein the total charge inside the borehole of the charging structure is the normal smooth blasting charge, the detonating charge (3) is arranged at the bottom of the borehole, the electronic detonator (4) is detonated in reverse, and adjacent charges are spaced by specially made air bags (6) containing a mixture of aluminum powder and carbon powder; the borehole opening is filled with a combination of water bags (8) and stemming mud (9); the charging sections inside the borehole are separated by specially made air bags (6) with a length of 30-50cm; the contents of the specially made air bags (6) include: a mixture of aluminum powder and carbon powder, and air, characterized in that: The specific construction process is as follows; (1) Clean the drilled blast holes and use measuring tools to re-measure the blast holes to ensure that their length meets the design requirements for the blast hole depth (2). (2) Make the detonating charge, put the processed detonating charge into the bottom of the hole to ensure reverse detonation, extend the detonator lead wire (5) out of the blast hole, and complete the loading of the detonating charge; (3) Add an air bag (6) to the bottom detonating charge (3) and insert the air bag (6) into the blast hole (2) through the blasting rod so that the air bag (6) is in full contact with the charge portion of the detonating charge that has been filled. (4) Continue to fill the dispensed medicine package (7) and air bag (6) to achieve the required amount and length of medicine, and complete the medicine filling part; (5) Use a 50cm long water-filling bag (8) to fill the hole, and finally fill 30cm of clay (9) to seal the blast hole (2). When the detonating charge (3) is detonated, the sympathetic detonation distance between the detonating charge (3) and the charged charge (7) increases because the air bag (6) contains a small amount of aluminum powder and carbon powder mixture. The explosion after the explosion can cause the aluminum powder in the air bag (6) to react, and the high temperature and high pressure energy generated is linearly increased compared with the normal situation. It is not easy to disperse in the narrow space of the light blast hole (2), and the blasting jet has a longer range than the jet under normal conditions, which increases the sympathetic detonation distance between the charged charges (7) to a certain extent.

2. The method for detonator-free interval charging in tunnel smooth blasting according to claim 1, characterized in that; The detonating charge is placed at the bottom of the blast hole, the detonator's shaped charge is pointed towards the hole opening, and the opening of the blast hole (2) is sealed by filling with a water bag (8) and blasting mud.

3. The method for detonator-free interval charging in tunnel smooth blasting according to claim 1, characterized in that... The in-hole charging section uses half of the #32 emulsion charge, and the charging length of a single section is 16cm.

4. The method for detonator-free interval charging in tunnel smooth blasting according to claim 1, characterized in that; The orifice is sealed by filling with water bag (8) and filling with clay. The length of water bag (8) is 50cm and the length of clay filling is 30cm.

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