Automatic explosive loading method using anchor bag

Abstract

To provide an automatic explosive loading method using an anchor sleeve covering inside of a blast hole allowing a blast hole to be sealed through pressured charging only with ANHO explosive and allowing sealing operation to be eliminated.SOLUTION: An automatic explosive loading method using an anchor sleeve covering inside of a blast hole comprises the steps of: loading a primer dynamite as an initiator in a bottom of the blast hole after it is attached on a tip of a loading pipe and inserted in the anchor sleeve; and feeding ANFO (Ammonium Nitrate Fuel Oil explosive) explosive with pressure in its rear to make a filling rate of ANFO explosive in the blast hole close to 100% as much as possible, to allow loading in the blast hole to be carried out without sealing operation.SELECTED DRAWING: Figure 2A

Description

[Technical field]

[0001] The present invention relates to an automatic explosives loading method for a blast hole, and more particularly to an explosives loading method that uses an anchor bag and allows blast hole sealing to be performed only by automatic loading of ANFO explosives. [Background technology]

[0002] Many of the accidents in mountain tunnel construction occur near the tunnel face. In particular, the explosives loading work in the blasting method requires the workers to work close to the tunnel face, and there are many cases where the collapse of the tunnel face, such as mirror-like surface collapse, leads to serious accidents. In addition, the explosives loading work is a repetitive simple task of inserting explosives and clay into all holes and poking them with a loading rod, and the work is done in a difficult working environment and posture, so it can be said to be a very painful job. Furthermore, the geology of the tunnels may have a developed surface structure that is prone to peeling, so measures to prevent skin-fall accidents at the tunnel face are considered as a safety priority from the beginning of the construction plan. Therefore, in order to safely and efficiently proceed with tunnel construction aimed at early completion, a remote explosives loading device has been proposed that can automate a series of explosives loading operations with the aim of avoiding dangers at the tunnel face and reducing painful work by improving working posture (Non-Patent Document 1). Compared to conventional manual work, this system not only improves the safety of workers during the loading work and relieves them from the painful work, but also shortens the time required for loading work and reduces the time workers spend at the face. As a result, it is possible to ensure stable excavation progress.

[0003] However, as shown in Figure 3, the explosive loading process requires loading a cartridge explosive, which is an explosive packaged in paper or plastic film, as the parent die at the bottom of the blasthole, and then loading fluid explosives (additive die) such as ammonium nitrate oil explosive (ANFO), bulk emulsion explosive, and slurry explosive from a chute using compressed air and water. Then, bean paste is supplied from a bean paste supply feeder behind the fluid explosives, which is then molded in a bean paste molding device and then supplied to the blasthole from the loading pipe of the loading hose. After filling the hole with bean paste (clay), the parent die is detonated to explode the fluid explosives. This requires the use of a complex explosive loading device. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Efforts to fully automate explosives loading using a remote explosives loading system (Kumagai Gumi) Summary of the Invention [Problem to be solved by the invention]

[0005] Thus, it is difficult to simplify the explosives loading process even if an automated loading device is used, as long as packaged dies and packing blocks are used. In addition, if the inner wall of the blast hole is rough, the pipe will hit the protrusions on the inner wall of the blast hole, preventing the filling density from improving and preventing the desired blasting efficiency from being achieved. In view of these problems, the present invention aims to provide an explosives loading method that can significantly improve the workability of explosives loading. [Means for solving the problem]

[0006] Therefore, as a result of intensive research, the inventor has found that if an anchor bag is used to cover the inside of a blast hole for explosive loading work, a parent die as an explosive is attached to the tip of a loading pipe and inserted into the anchor bag to load it at the bottom of the blast hole at the back, and ANFO (Ammonium Nitrate Fuel Oil explosive) explosive is pumped behind it, the anchor bag is made of a soft synthetic resin material and is a flexible hose with a closed tip and an open rear end that is larger in diameter than the blast hole, and due to the nature of the ANFO explosive, the anchor bag is a flexible hose with a larger diameter than the blast hole, and this, combined with the fact that the anchor bag is a flexible hose with a larger diameter than the blast hole, makes it possible to fill the blast hole with ANFO explosive as close to 100% as possible, and the blast hole can be sufficiently sealed, and a specified blasting efficiency can be obtained, and has been completed. The method is characterized by comprising the steps of: attaching a parent die, which serves as an explosive, to the tip of an ANFO loading pipe and inserting it into a flexible anchor bag that is larger in diameter and longer in overall length than the blast hole; inserting the loading pipe with the parent die attached to its tip inserted into the anchor bag into the blast hole together with the anchor bag; positioning the parent die at the back of the blast hole via the anchor bag; and separating the parent die from the loading pipe and, while pulling the loading pipe out of the anchor bag, pressure-feeding and filling the ANFO explosive into the anchor bag from the tip of the loading pipe.

[0007] The feature of the present invention is that a parent die or explosive serving as an initiator is loaded using a soft synthetic resin anchor bag with a diameter larger than the blast hole, and ANFO explosive is pressure-fed and filled into the blast hole behind the parent die to seal it. Normally, in a blast hole with a diameter of 45 cm, even if a packaged ANFO explosive (30 cmΦ) is stopped behind the parent die, the loading rate of the fluid explosive in the blast hole is not sufficient, and it is necessary to seal the blast hole using an anchor. In the present invention, a parent die or explosive serving as an initiator is attached to the tip of a loading pipe, the loading pipe is inserted into the blast hole together with an anchor bag, and after the parent die is set, the loading pipe is pulled out from the anchor bag while the ANFO explosive is pressure-fed from the loading pipe to the rear of the parent die, thereby improving the filling rate of the blast hole to nearly 100%, and sufficient blasting efficiency equivalent to sealing with an anchor can be obtained. Therefore, the use of the present invention is revolutionary because it allows safe and efficient automatic explosive loading. Of course, after loading the ANFO explosive, the blast hole may be sealed with an ampoule.

[0008] According to the present invention, the parent die is covered by an anchor bag and is loaded into the blast hole. In addition, the soft anchor bag protects the 0.4 to 0.42 mmΦ lead wire from the detonator of the parent die from damage. In addition, since the flexible bag is made to an arbitrary outer diameter slightly larger than the blast hole diameter, even if the inner wall of the blast hole is rough, it is covered with the anchor bag, so that the filling rate can be made close to 100% by pumping ANFO explosives behind the explosives of the parent die. Normally, without using ANFO, the explosives may not reach the back of the blast hole due to resistance from small protrusions in the blast hole when automatically loading explosives, but in the present invention, even if there are such protrusions, the explosives are made flat by the anchor bag, and since a slip agent is added, loading to the back is possible. Therefore, not only is it not necessary to seal the entrance of the blast hole with an anchor, but the filling rate can be improved, and automatic loading of explosives into the blast hole can be realized safely and easily.

[0009] In addition, the lower half of the tunnel has many water holes, and the bulk ANFO is not waterproof, but according to the present invention, by using anchor bags for automatic loading, it has the same effect as using bulk ANFO to create the largest diameter piece ANFO on-site, so that the loading of ANFO explosives can be obtained with the largest hole diameter, resulting in a high filling rate and high blasting efficiency.

[0010] The anchor bag used in the present invention is preferably made flexible using a soft synthetic resin material. The material is not particularly limited, and polyethylene, polypropylene, polyvinyl chloride, etc. can be used. It is preferable to perform antistatic treatment. For example, antistatic treatment can be performed by mixing, dispersing, or incorporating conductive fibers, conductive powder, metal fibers, metal powder particles, or metal wires into the synthetic resin material of the bag. It is also preferable to add a slip agent to the bag and apply it to the surface of the bag as necessary.

[0011] The outer diameter of the bag is preferably 10 to 15% larger than the diameter of the blast hole, which is usually 45φmm, and it has been found that nearly 100% packing density can be obtained by pressure-feeding ANFO using an anchor bag. The tip is beveled to make it easier to insert into the blast hole, while the loading opening is folded back to provide strength, making it easier to insert the loading pipe. If the bag is too thin, it is prone to tearing, and if it is too thick, it will not fit inside the blast hole, reducing the packing rate of the ANFO explosive being pumped. A film with a thickness of about 0.02 mm to 0.2 mm is appropriate for the anchor bag, and a preferred shape that can obtain high packing efficiency by pressure-feeding is selected taking into consideration the condition of the blast hole and the fluidity of the ANFO explosive.

[0012] The ANFO explosive used in the present invention is an explosive that is composed of ammonium nitrate and fuel oil (flash point 50°C or higher), does not contain other gunpowder, explosives, metal powder, etc., and does not detonate with an industrial detonator or electric detonator, and is widely available on the market. An example of the composition is one that is composed of 94% ammonium nitrate and 6% fuel oil. Usually, it is supplied as a detonator that detonates and propagates other explosives (dynamite, etc.). Around the parent die or cartridge explosive, a bulk emulsion explosive, a slurry explosive, or other fluid explosive may be mixed with an ammonium nitrate oil explosive (ANFO) in place of a part of the ANFO explosive, and the fluidity may be adjusted and the explosive may be loaded. In the present invention, the physical properties of the fluid explosive represented by such an ANFO explosive can be used to increase the filling rate and eliminate the sealing of the blast hole with anko, but anko sealing may be performed as in the conventional manner. The filling density of the ANFO explosive may be uniform, or the filling density may be increased from the back to the entrance. This is to obtain the effect of sealing the blast hole with ANFO by filling it. [Brief description of the drawings]

[0013] [Figure 1] 1 is an overall view showing an outline of an automatic explosive loading system used in the present invention. [Figure 2A] This is a process diagram showing steps (1) to (4) of the automatic explosives loading method of the present invention. (1) A parent die 20 is attached to the tip of a loading pipe 10. (2) A plastic anchor bag 20 is prepared. (3) The loading pipe 10 with a parent die 21 attached is inserted into the anchor bag 20. (4) The loading pipe 10 with the parent die attached and the anchor bag 20 inserted therein are loaded into a blast hole 30. [Figure 2B] In this process diagram showing steps (5) to (7) of the automatic explosive loading method of the present invention, (5) the parent die 20 is removed from the tip of the loading pipe 10, (6) the loading pipe is pulled out of the blast hole while the bulk ANFO explosive is pumped into the anchor bag 20, and the ANFO explosive is loaded behind the parent die 21. Then (7) a sufficient amount of ANFO explosive is loaded, and it may be detonated as is or as if it were packed with bean paste. [Diagram 3] FIG. 1 is a diagram showing the configuration of a conventional automatic explosive loading device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The automatic explosive loading method according to the present invention is comprised of steps (1) to (7) and is shown in Figures 2A and 2B. The steps shown in Figure 2A are (1) a step of attaching a parent die 21 to the tip of a loading pipe 10, (2) a step of preparing an anchor bag 20 into which the loading pipe 10 is to be inserted, (3) a step of inserting the loading pipe 10 with the parent die 21 attached to its tip into the anchor bag 20, and (4) a step of inserting the anchor bag 20 containing the loading pipe 10 into a blast hole 30. As shown in Fig. 2B, the loading pipe 10 enclosed in the anchor bag 20 is inserted into the blast hole 30, a parent die 21 is placed at the back of the loading pipe 10, the parent die 21 is separated from the loading pipe 10, and the loading pipe 10 is pulled out of the blast hole 30, while gradually pumping and filling the granular ANFO explosive behind the parent die 21 placed at the back of the blast hole 30 through the anchor bag 20, (6) while pulling out the loading pipe 10, pumping and filling the ANFO explosive 22 at almost 100% filling density behind the parent die 21, and (7) completing the ANFO filling 22, and packing the end 20a of the anchor bag 20 into the blast hole 30 to seal it. Hereinafter, the present invention will be described in detail based on the specific example shown in the drawings. FIG. 1 is a schematic diagram of the device used in the automatic explosive loading method according to the present invention. As shown in the figure, a trolley 40 is equipped with a rock drill 41 and a loader 42, and the loading hose 11 and loading pipe 10 are operated from a remote loading device 51 mounted on a rear vehicle 50. The remote explosive loading device 51 is composed of the explosive supply, anco supply, and loading devices and a computer that controls them. The current loading procedure for this device is as follows: first, a parent die (explosive + detonator) is attached to the tip of the loading pipe, and air pressure is used to feed it to the end of the blast hole. Next, a specified number of additional dies (explosive only) is set using a control button on hand, and when the additional die firing command button is pressed, the set number of additional dies are continuously pressure-fed and loaded into the hole. Once the loading of all the additional dies has been confirmed, a command to load the anchor is issued and a specified number of continuously shaped anchors are pumped through the same loading device. In the present invention, an anchor bag 20 is attached to the tip of the loading pipe 10, and steps (1) to (4) shown in Figure 2A and steps (5) to (7) shown in Figure 2B are repeated to automatically load explosives into each blast hole 30 by remote control. As described above, after the parent die 21 is set at the tip of the pipe 10 and set in the anchor bag 20 and inserted into the blast hole 30, the parent die 21 can be detached from the loading pipe 10 by simply operating a button at hand, and the ANFO explosive can be automatically pumped and loaded from the rear cart via a hose. In the conventional manual loading work, the worker had to insert the parent die, additional die, and filling die while pushing with a wooden filling rod in a state of being in close contact with the face for a long time, but the loading work by the automatic loading method by remote control of the explosives allows the worker to load the explosives in a relatively comfortable position from a position about 1.5 m away from the face, which not only improves the safety of the face work but also reduces physical fatigue by being able to load the explosives in a comfortable position. Moreover, since the sealing of the blast hole with filling die is no longer necessary due to the filling of the ANFO explosives, the automatic loading work is also reduced, making it easy to carry out.

[0015] In the present invention, an anchor bag 100 is used for automatic explosive loading. The bag 100 is made of a soft synthetic resin material, such as soft polyethylene, to which an antistatic agent and a slip agent are added, and is manufactured into a hose shape having a larger diameter than the diameter of the blast hole 30 by extrusion molding or the like, with the front end closed and the rear end open. For example, when the diameter of the blast hole 40 is 45φmm, the bag is manufactured into a hose shape with an outer diameter D of 48φmm to 52φmm and a thickness of 0.02mm to 0.2mm. The loading hole 20a is also manufactured to have a larger diameter than the diameter of the blast hole 30. For example, when the diameter of the blast hole 30 is 45φmm, the outer diameter of the loading hole 20a is slightly larger than the cutting diameter.

[0016] In the above embodiment, the parent die was attached to the tip of the loading pipe and the explosive loading operation was performed, but the parent die may be inserted with a loading rod and then the loading pipe may be inserted. Also, although only ANFO explosive was loaded behind the parent die, the explosive loading operation may be performed by replacing part of the ANFO explosive with other fluid explosives. It goes without saying that a person skilled in the art may make some modifications without departing from the spirit of the present invention. [Explanation of symbols]

[0017] 10 Loading Pipe 20 Anchor Bag 21 Parent Die 22 ANFO explosives 30 Blast Holes

Claims

1. 2) inserting the loading pipe with the parent die attached to its tip, which has been inserted into the anchor bag, into the blast hole together with the anchor bag; 3) placing the parent die at the back of the blast hole via the anchor bag; 4) separating the parent die from the loading pipe, and while pulling the loading pipe out of the anchor bag, pumping and filling the ANFO explosive from the tip of the loading pipe through the anchor bag from the back of the blast hole to the blast hole mouth; and 5) packing the end of the anchor bag into the blast hole mouth and sealing it, a method for automatically loading ANFO explosive into a blast hole, characterized in that it is not necessary to seal the blast hole with an anchor bag.

2. A method for automatically loading ANFO explosive as described in claim 1, in which in the process of pressure-filling the ANFO explosive (4), a filling density of nearly 100% is obtained, eliminating the need to seal the blast hole with an adhesive.

3. A method for automatically loading ANFO explosives as described in claim 1, wherein in step 2), a loading rod is used instead of the loading pipe, a parent die is attached to the tip of the rod, the rod is inserted into the anchor bag and positioned deep inside the blast hole, and then the loading pipe is inserted all the way to the back.

4. An automatic loading method of the ANFO explosive according to claim 1, in which a part of the ANFO explosive is replaced with other fluid explosives. method.

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