Explosive loading method

Abstract

To provide an explosive loading method capable of loading explosive smoothly while removing rocks and other debris from a blast hole causing the hole rough without requiring much time and effort.SOLUTION: The explosive loading method includes: a blast hole formation step of drilling to a blast hole 31 in the ground 30 at a face 30a with a drilling rod 24 having a drilling bit 23 attached to a drifter forming a drilling body 22 of a face drilling machine 21; a hole clearing step of finishing the blast hole 31, after the drifter 22 is fitted with an insertion tube 11 provided with a hole finishing bit 13 in place of the drilling rod 24, by inserting the insertion tube 11 into the blast hole 31 until the hole finishing bit 13 reaches the vicinity of a hole end 31a while supplying air or water to the hollow inside; and an explosive loading step of loading an explosive 32 to the hole end 31a by pushing the explosive 32 into the drilled blast hole 31.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to an explosive loading method, and more particularly to an explosive loading method for loading explosives into blast holes formed in a tunnel face in mountain tunnel construction. [Background technology]

[0002] In mountain tunnel construction, a method is sometimes employed in which excavation is performed while collapsing the ground at the face, such as bedrock, by blasting with explosives. To collapse the ground at the face, such as bedrock, by blasting with explosives, blast holes are drilled and formed at multiple predetermined positions on the face, explosives are loaded into the formed blast holes, and the loaded explosives are then detonated by a detonator. As the heavy machinery for drilling and forming the blast holes for this purpose, a well-known heavy machinery for drilling, such as a drill jumbo equipped with a face drilling machine, is used (see, for example, Patent Document 1).

[0003] In drilling heavy equipment, the mounted face drilling machine has a drifter as the drilling machine body, which has the function of moving the connected equipment back and forth at a high speed of, for example, about 3,600 times per minute, as well as the function of rotating it.A drilling rod with a drilling bit at its tip is connected to this drifter, and by striking the drilling bit and pushing the drilling rod into the ground at the face of the rock, etc., blast holes are drilled. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 3461600 [Patent Document 2] Patent No. 4621149 Summary of the Invention [Problem to be solved by the invention]

[0005] On the other hand, in the work of loading explosives into a drilled blasthole, for example, in Patent Document 1, a loading device mounted separately from the face drilling machine is used to insert a loading hose into the drilled blasthole, supply explosives from a supply port at the base end of the inserted loading hose, and then use a push rod to push the supplied explosives through the hollow interior of the loading hose, thereby loading the explosives into the end of the blasthole. Also, in Patent Document 2, for example, a work platform equipped on a drilling heavy machine that can rise and fall and move back and forth and left and right relative to the face is used as a scaffold, and a worker approaches the face and pressure-feeds the explosives through the loading hose and loading pipe, thereby loading the explosives into the end of the blasthole.

[0006] However, if the hole wall surface is stable, it is possible to smoothly insert the loading hose or loading pipe all the way to the end of the blast hole. However, if the hole wall has collapsed and become rough, for example due to the effects of drilling an adjacent blast hole, collapsed rocks and the like will become obstacles, making it difficult to smoothly insert the loading hose or loading pipe all the way to the end of the hole.

[0007] In particular, since a predetermined number of blast holes are usually formed in a series along a predetermined design line, and then the work of loading explosives is switched to, if the ground at the face is brittle, when new blast holes are drilled around previously drilled blast holes, the wall surfaces of the previously drilled blast holes are likely to become rough due to surface wear, etc.

[0008] When a blast hole becomes rough, it is necessary to remove any obstructing debris, such as collapsed rock, from the blast hole before loading it with explosives. Conventionally, workers have had to enter the vicinity of the working face directly to remove the debris, but this type of removal requires a lot of work, and it is desirable for workers not to enter the vicinity of the working face directly. On the other hand, by making it possible to carry out the work from drilling the blast hole to loading the explosives as a series of operations using heavy drilling machinery, it is believed that it will be possible to load the explosives into the created blast hole efficiently without much work.

[0009] The present invention aims to provide an explosive loading method that enables the operations from drilling blast holes in rock formations prone to hole roughness to loading explosives to be carried out as a series of operations using heavy drilling machinery, and that enables explosives to be loaded safely and efficiently into the formed blast holes without requiring workers to work near the face or remove residue from the blast holes. [Means for solving the problem]

[0010] The present invention provides an explosive loading method for loading explosives into blast holes in a mountain tunnel construction method using heavy drilling machinery equipped with a face drilling machine for drilling blast holes in a face of a tunnel, the method comprising: a blast hole forming step in which a drilling rod having a drilling bit at its tip is attached to a drifter that forms the drilling machine body of the face drilling machine, and blast holes are drilled in the ground at the face of the tunnel; a hole finishing step in which an insertion cylinder having a hole finishing bit at its tip is attached to the drifter in place of the drilling rod, and the insertion cylinder is then inserted into the blast hole until the hole finishing bit reaches the vicinity of the end of the hole while supplying air or water to the hollow interior, thereby finishing the blast hole; and an explosive loading step in which an explosive is forced into the drilled blast hole and the forced explosive is loaded into the end of the hole.

[0011] In the explosive loading method of the present invention, it is preferable that the hole finishing bit is a hollow bit having a hollow through-hole portion with a cross-sectional shape similar to that of the hollow interior of the insertion tube.

[0012] In addition, in the explosive loading method of the present invention, it is preferable that in the explosive loading step, the explosive is pressurized through a pressure pipe connected to the rear end portion of the insertion cylinder left in the blast hole after the hole clearing step, and is forced by compressed air through the hollow interior of the insertion cylinder toward the end of the hole, and loaded into the end of the hole from the hollow through-hole portion of the hollow bit.

[0013] Furthermore, in the explosive loading method of the present invention, it is preferable that the parent die of the explosive to be loaded uses a wireless detonator.

[0014] Furthermore, in the explosive loading method of the present invention, it is preferable that the explosive loading step is carried out after the insertion tube inserted in the hole boring step is pulled out from the blast hole.

[0015] In addition, in the explosive loading method of the present invention, it is preferable that in the hole clearing process, the air or water supplied into the hollow interior of the insertion cylinder is discharged to the outside of the blast hole together with any residue in the hole through the gap between the hole wall surface of the blast hole and the outer peripheral surface of the insertion cylinder.

[0016] Furthermore, it is preferable that the explosive loading method of the present invention includes an additional discharge step in which, after the hole-drilling step, any residue remaining in the gap between the outer surface of the insertion tube and the inner wall surface of the blast hole is carried into the interior of the insertion tube by injecting air or water into these gaps, and then passes through the hollow interior of the insertion tube and is discharged from a discharge branch pipe provided at the rear end portion of the insertion tube. [Effects of the Invention]

[0017] According to the explosive loading method of the present invention, the work of drilling a blast hole in rock formation prone to hole roughness, to loading the explosive, can be carried out as a series of operations using heavy drilling machinery, and explosives can be loaded into the formed blast hole safely and efficiently without requiring workers to spend a lot of time working near the face or removing residue from the blast hole. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a schematic side view illustrating a drilling heavy machine equipped with a face drilling machine for carrying out an explosive loading method according to a preferred embodiment of the present invention. [Figure 2] 1 is a schematic side view illustrating an explosives loading device for carrying out an explosives loading method according to a preferred embodiment of the present invention. [Figure 3] FIG. 10 is a schematic side view illustrating the blast hole forming process. [Figure 4] FIG. 1 is a schematic side view illustrating the installation of an explosive loading device on a face drilling machine in place of a drilling rod and a drill bit. [Figure 5] FIG. 10 is a schematic side view illustrating a hole drilling step. [Figure 6] FIG. 10 is a schematic side view illustrating the explosive loading process. [Figure 7] (a) is a front view of the hollow bit, and (b) is a cross-sectional view taken along the line AA in (a). [Figure 8] FIG. 4 is an explanatory diagram of a rotation prevention mechanism. [Figure 9] FIG. 10 is a schematic side view illustrating another apparatus for carrying out an explosive loading method. [Figure 10] FIG. 10 is a schematic side view illustrating a main part of another type of explosive loading device. [Figure 11] FIG. 10 is a schematic, partially cutaway side view illustrating the removal of residue using another form of explosive loading device. DETAILED DESCRIPTION OF THE INVENTION

[0019] A preferred embodiment of the explosive loading method of the present invention is carried out using a drilling machine 20 equipped with a face drilling machine 21 that drills a blast hole 31 in the ground 30 at the face of the rock face, as shown in Fig. 1. In this embodiment, an explosive loading device 10 (see Fig. 2) is attached (see Fig. 4) instead of a drilling rod 24 having a drill bit 23 at its tip, which is preferably attached to a drilling machine body 22 of the face drilling machine 21. The explosive loading device 10 is used to drill the drilled blast hole 31 (drilling step, see Fig. 5), and a main die 32a and an auxiliary die 32b are loaded as explosives 32 into the bottom 31a of the drilled blast hole 31, which is the deepest part of the drilled blast hole 31, together with a filling material 32c (explosive loading step, see Fig. 6). In the explosive loading method of this embodiment, even if the wall of a blast hole 31 drilled into the ground 30 at the working face 30a has collapsed, causing hole roughness and leaving obstructing residue such as collapsed rocks in the hole, the drilling heavy equipment 20 can be used as is to crush and remove the residue, thereby removing the obstructing residue from the roughened blast hole 31 without much effort, and allowing explosives 32 to be loaded efficiently and smoothly into the formed blast hole 31.

[0020] The explosive loading method of this embodiment is a loading method for loading explosives 32 into blast holes 31 using a heavy drilling machine 20 equipped with a face drilling machine 21 for drilling and forming blast holes 31 in a face 30a in a mountain tunnel construction method (see FIG. 1). As shown in FIGS. 3 to 6, the method includes a blast hole forming step (see FIG. 3) in which a drilling rod 24 having a drill bit 23 at its tip is attached to a drifter forming a drilling machine body 22 of the face drilling machine 21, and the blast hole 31 is drilled and formed in the ground 30 of the face 30a. 2, replacing the drilling rod 24 with an insertion cylinder 11 having a hole finishing bit 13 attached to its tip 11a (see Figure 4), and then inserting this insertion cylinder 11 into the blast hole 31 while supplying air or water into the hollow interior until the hole finishing bit 13 reaches the vicinity of the hole end 31a, thereby finishing the blast hole 31 (see Figure 5), and the process includes an explosive loading process (see Figure 6) in which explosives 32 are forced into the drilled blast hole 31 and the forced explosives 32 are loaded into the hole end 31a.

[0021] In addition, in the explosive loading method of this embodiment, the hole finishing bit 13 is preferably a hollow bit having a hollow penetration portion 13a with a cross-sectional shape similar to the hollow interior of the insertion tube 11 (see Figures 7(a) and (b)), and in the explosive loading process, the explosive 32 is pressurized through the pressure supply pipe 18 connected to the rear end portion 11b of the insertion tube 11 left in the blast hole 31 after the hole clearing process, and is forced by compressed air through the hollow interior of the insertion tube 11 toward the hole end 31a, and is loaded from the hollow penetration portion 13a of the hollow bit 13 into the hole end 31a (see Figure 6).

[0022] In this embodiment, the drilling heavy equipment 20 equipped with a face drilling machine 21 used in carrying out the explosive loading method has a configuration substantially similar to that of a well-known drilling heavy equipment known as, for example, a drill jumbo. As shown in FIG. 1 , in addition to a heavy equipment main body 25 equipped with a traveling section and the above-mentioned face drilling machine 21 mounted on the heavy equipment main body 25, it is configured to include a compressor, a water tank, a water supply device, a control panel, etc., as well as a man gauge 26 serving as a work platform. The drilling heavy equipment 20 moves the face drilling machine 21 by the traveling section to a position facing the tunnel face 30a, and then is fixed to the ground in a stable state by outriggers 25a, so that the blast hole forming process of drilling and forming a blast hole 31, the hole plowing process of finishing the blast hole 31, and the explosive loading process of loading explosives 32 into the blast hole 31 can be smoothly carried out.

[0023] The face drilling machine 21 also has a configuration similar to that mounted on known heavy drilling equipment, and includes a drilling machine body (drilling machine) 22, a drilling rod 24 connected to the drifter 22 and having a drilling bit 23, a drilling boom 21a supported on a heavy machine body 25 so as to be able to be raised and lowered and rotated, a guide shell 21b that guides the advance and retreat of the drifter 22 along the advance and retreat axis direction X, a rotary actuator 21c, a slide cylinder 21d, and an advance and retreat mechanism (not shown) for advancing and retreating the drifter 22. The face drilling machine 21 discharges water or the like supplied from a supply pipe (not shown) from the tip of the drilling bit 23, and performs a blast hole formation process in which the drifter 22, to which the drilling rod 24 is connected, advances and retreats toward the ground 30 of the face 30a while reciprocating and rotating at high speed, thereby drilling and forming a blast hole 31 to a predetermined depth (see FIG. 3). In addition, by connecting an explosive loading device 10 having an insertion tube 11 with a hole finishing bit 13 attached to the tip 11a instead of the drilling rod 24 having a drilling bit 23 to the drifter 22 of the face drilling machine 21 (see Figure 4), it becomes possible to carry out the hole clearing process (see Figure 5) and the explosive loading process (see Figure 6).

[0024] In addition, in this embodiment, preferably, a supply pipe connection valve section 15 that can be opened and closed is provided at the rear end portion 11b of the insertion cylinder 11 in the explosive loading device 10, to which a supply pipe 19 that supplies air or water during the hole drilling process is connected, and a discharge valve section 16 that can be opened and closed is provided to discharge water remaining inside the hollow interior of the insertion cylinder 11.

[0025] Furthermore, in this embodiment, the explosive loading device 10 preferably has a connection arm 17 that is joined integrally to the rear end portion 11b of the insertion cylinder 11 via a connection base 17a and extends parallel to the insertion cylinder 11 on the rear side of the insertion cylinder 11. A connection joint 14 for connecting to the drifter 22 is attached to the rear end of this connection arm 17, and a pressure feed pipe connection valve 12 to which a flexible pipe 18 is connected is provided at the rear end of the insertion cylinder 11.

[0026] In this embodiment, the insertion cylinder 11 constituting the explosive loading device 10 is made of a hollow steel or aluminum pipe member having a circular cross section, for example, with an inner diameter of about 34 mm and an outer diameter of about 42 mm, and has a length of, for example, 3,000 to 3,500 mm so that the tip 11a can be inserted until it reaches the vicinity of the end 31a of the blast hole 31 during the hole drilling process and the explosive loading process. A hollow bit 13 serving as a hole finishing bit is integrally attached to the tip 11a of the insertion cylinder 11.

[0027] 7(a) and 7(b), the hollow bit 13, which is a hole finishing bit, is preferably a molded metal (steel) product with a carbide tip 13b embedded in the outer peripheral surface of the tip portion, and has a cylindrical connection base end portion 13c and a leading cone-shaped tip portion 13d, with a hollow through-portion 13a that passes through these in the axial direction and preferably has an inner diameter similar to that of the insertion cylinder 11. The outer peripheral surface of the leading cone-shaped tip portion 13d is a tapered portion 13e whose outer diameter decreases toward the tip. In this way, the outer surface of the hollow bit 13 (the outer diameter at the connection point with the insertion cylinder is, for example, 42 mm) has a tapered portion 13e with the outer diameter narrowing toward the tip (the outer diameter at the tip is, for example, 40 to 41 mm), which makes it easier to insert the insertion cylinder 11 into the blast hole 31 during the hole drilling process, and when the blast hole 31 is drilled while crushing obstructing residues such as rocks, the crushed rocks, etc. are sent backward through the gap between the hole wall surface of the blast hole 31 and the outer surface of the hollow bit 13, and are crushed into smaller pieces.This makes it easier to pass the crushed rocks, etc. out of the blast hole 31 through the gap between the blast hole 31 and the insertion cylinder 11 and discharge them outside the blast hole 31.

[0028] In this embodiment, the connection joint 14 connecting the insertion cylinder 11 to the drifter 22 is preferably attached to the rear end of the connection arm 17. The connection arm 17 is provided to deviate the central axis of the insertion cylinder 11 from the axial direction X of the drifter 22, allowing the flexible piping 18, through which the explosive 32 is pumped, to be connected in a straight line to the rear end of the insertion cylinder 11. The connection arm 17 is integrally joined to the rear end portion 11b of the insertion cylinder 11 via a connection base 17a and is provided to extend parallel to the insertion cylinder 11 on the rear side of the insertion cylinder 11. A known connection joint 14 for connecting to the drifter 22 is attached to the rear end via, for example, a connection sleeve 17b. This allows the insertion cylinder 11 to reciprocate back and forth at high speed along the central axis parallel to the axial direction X of the drifter 22 during the hole-drilling process, while also moving back and forth together with the drifter 22 along the guide shell 21b.

[0029] In this embodiment, when the drilling process and the explosive loading process are performed using the explosive loading device 10, the function of rotating the insertion cylinder 11 by the drifter 22 is stopped. Furthermore, it is preferable to provide a rotation prevention means 27 to prevent the insertion cylinder 11 from shifting circumferentially relative to the drifter 22 during these processes. The rotation prevention means 27 can be, for example, a pair of locking rods 27a fixed to the connection arm 17 by welding or the like and extending in a V-shape toward the lower guide shell 21b, as shown in FIGS. 2 and 8 . The rotation prevention means 27 includes a pair of locking rods 27a arranged on both sides of the guide shell 21b. When one of the locking rods 27a abuts against the side of the guide shell 21b, excessive circumferential shift of the insertion cylinder 11 relative to the drifter 22 during the process can be prevented.

[0030] The pressure-feeding pipe connection valve unit 12 is a connection valve unit having a known configuration for openably connecting a flexible pipe 18, similar to the loading hose used in the explosive loading method and loading device of Patent Document 2 (Japanese Patent No. 4621149), to the rear end of the insertion tube 11. During the explosive loading process, as described below, the pressure-feeding pipe connection valve unit 12, when opened, allows the explosive 32 to pass through the flexible pipe 18, preferably via the insertion tube 11 and through the hollow penetration portion 13a of the hollow bit 13 to load the explosive 32 into the end 31a of the blast hole 31. The flexible pipe 18 is preferably a transparent or semi-transparent pipe (hose) whose interior can be seen so that the position of the explosive 32 being pumped can be seen (see FIG. 6).

[0031] The supply pipe connection valve unit 15 is a connection valve unit for openably connecting a supply pipe 19 that supplies air or water to the hollow bit 13 to reduce friction during cutting, for example, when drilling the blast hole 31 formed by the insertion cylinder 11 of the explosive loading device 10 during the drilling process. In this embodiment, the supply pipe connection valve unit 15 is attached to a supply branch pipe 15a that protrudes outward at the rear end portion 11b of the insertion cylinder 11, and can supply air or water from the supply pipe 19 to the hollow interior of the insertion cylinder 11 by, for example, closing the pressure pipe connection valve unit 12 and / or the discharge valve unit 16 (described later) and opening the valve unit. In addition, the air and water supplied into the hollow interior of the insertion cylinder 11 during the hole drilling process are discharged outside the blast hole 31 through the gap between the hollow bit 13 or insertion cylinder 11 (e.g., φ42 mm) and the inner wall surface of the blast hole 31 (e.g., φ45 mm), along with any obstructing residues such as rocks removed by the hole drilling.

[0032] The discharge valve section 16 is a valve section for draining water, in particular, remaining in the insertion cylinder 11 after the drilled blast hole 31 has been drilled in the drilling process, preferably before the explosive 32 is pressure-fed from the flexible piping 18 to the insertion cylinder 11. In this embodiment, the discharge valve section 16 is attached to a discharge branch pipe 16a that protrudes diagonally downward at the rear end portion 11b of the insertion cylinder 11, and by opening the discharge valve section 16 with the pressure-fed pipe connection valve section 12 and the supply pipe connection valve section 15 closed, for example, the water remaining in the hollow interior of the insertion cylinder 11 can be drained out of the insertion cylinder 11 together with slime, preferably by gravity flow. If the slime, etc. remaining inside the hollow interior of the insertion cylinder 11 cannot be sufficiently discharged, for example, after the insertion cylinder 11 is first pulled out of the blast hole 31, the discharge valve section 16 is closed and the supply pipe connection valve section 15 is opened to supply air or water, which pushes out the remaining slime, etc. from the tip of the hollow bit 13, making it possible to discharge the slime, etc.

[0033] In this embodiment, explosives 32 can be loaded into the end 31a of the drilled and locked blast hole 31 using the face drilling machine 21 and explosive loading device 10. That is, a drilling rod 24 having a drilling bit 23 at its tip is attached to the drifter 22 of the face drilling machine 21 to drill and form a blast hole 31 in the ground 30 of the face 30a (blast hole forming process, see Figure 3), and then, as shown in Figure 4, an explosive loading device 10 having an insertion tube 11 is attached to the drifter 22 in place of the drilling rod 24, and a flexible pipe 18 is connected to the pressure pipe connection valve unit 12 and a supply pipe 19 is connected to the supply pipe connection valve unit 15. Thereafter, with the pressure pipe connection valve section 12 and the discharge valve section 16 closed, as shown in Figure 5, the insertion cylinder 11 is inserted into the drilled blast hole 31 while supplying air or water into its hollow interior from the supply pipe 19, and the hollow bit 13 at the tip 11a is moved back and forth at high speed using the drifter 22 to apply impacts while being inserted into the blast hole 31 until it reaches the vicinity of the end of the hole, thereby crushing and removing any obstructing residues such as rocks inside the blast hole 31, thereby performing hole drilling (hole drilling process). After the blast hole 31 has been dug, the supply pipe connection valve section 15 is closed and the pressure pipe connection valve section 12 is opened. As shown in Figure 6, explosives 32 are pressurized into the insertion tube 11, preferably via flexible piping 18, and the pressurized explosives 32 are pushed into the blast hole 31 through the hollow penetration section 13a of the hollow bit 13, and the pushed-in explosives are loaded into the hole end 31a (blast hole formation process).

[0034] As a result, according to the explosive loading method of this embodiment, the work from drilling and forming the blast hole 31 to loading the explosive 32 is carried out as a series of operations using the drilling heavy equipment 20, and even if the blast hole 31 becomes rough, the explosive 32 can be loaded into the formed blast hole 31 safely and efficiently without much effort.

[0035] In this embodiment, the parent die 32a of the explosives 32 to be loaded preferably uses a wireless ignition circuit (wireless detonator) that does not require wiring near the working face 30a, and is preferably covered with a cardboard or other paper tube for protection during pressure feeding. The parent die 32a, along with the supplementary die 32b and the bulkhead 32c, are attached to the flexible piping 18 in a connected state using a loading machine similar to that used in the explosive loading method and loading device of the aforementioned Patent Document 2 (Japanese Patent No. 4621149), and are preferably pressure fed as a unit, so that they are sequentially loaded into the butt 31a of the blast hole 31 via the insertion tube 11 and hollow bit 13.

[0036] In this embodiment, the parent die 32a of the explosive 32 may be a wire-type detonator with a leg wire. In this case, after the hole has been drilled, the insertion tube 11 is temporarily withdrawn from the blast hole 31, and the parent die 32a, from which the leg wire extends, is attached to the hollow penetration portion 13a of the hollow bit 13 at the tip end 11a. In this state, the leg wire is withdrawn to the outside of the blast hole 31 through the gap between the hollow bit 13 or the insertion tube 11 and the inner wall surface of the blast hole 31, and the insertion tube 11 is reinserted into the blast hole 31 until the tip end 11a reaches the vicinity of the hole end 31a. Air is then pumped in to load the parent die 32a into the hole end 31a. Thereafter, the add-on die 32b and the core material 32c are pressurized through the flexible piping 18 and the insertion cylinder 11 in the same manner as described above and pushed into the blast hole 31 through the hollow penetration portion 13a of the hollow bit 13, thereby loading the explosive 32, which is connected to the main die 32a, add-on die 32b and core material 32c, into the hole end 31a of the blast hole 31.

[0037] Furthermore, in this embodiment, in the explosive loading step, explosive 32 is loaded into the end 31a of blasthole 31 by pressure-feeding it through insertion tube 11 left in the blasthole after the drilling step, but the explosive loading step can also be carried out without using insertion tube 11 left in blasthole 31. For example, after the insertion tube 11 inserted in the drilling step is pulled out of blasthole 31, the explosive loading step can be carried out using a heavy drilling machine equipped with a face drilling machine in the same manner as the explosive loading methods described in Patent Document 1 (Japanese Patent No. 3461600) and Patent Document 2 (Japanese Patent No. 4621149) mentioned above.

[0038] The present invention is not limited to the above embodiment and various modifications are possible. For example, the hole-finishing bit does not necessarily have to be a hollow bit having a hollow through-hole with a cross-sectional shape similar to the hollow interior of the insertion tube. Various other hole-finishing bits capable of finishing the wall surface of a drilled blast hole can be used. The blast hole forming process, hole-drilling process, and explosive loading process of the explosive loading method of the present invention can also be performed using a drilling and loading device 40 as shown in FIG. 9. That is, in the drilling and loading device 40 shown in FIG. 9, an insertion tube 42 connected to a drifter 41 has, at its connection base end, an openable explosive insertion opening 43, an openable water supply pipe connection valve 44 for drilling and drilling, and an openable air supply pipe connection valve 45 for pressurizing explosives. The blast hole forming process can be performed by attaching a drilling bit 46 to the tip of the insertion tube 42 and opening the water supply pipe connection valve 44. The hole shaping process can be carried out by temporarily withdrawing the insertion cylinder 42, attaching a hollow bit 47 instead of the boring bit 46, and opening the water supply pipe connection valve 44. Furthermore, the explosive loading process can be carried out by attaching an explosive to the connecting base end portion of the insertion cylinder 42 through the explosive insertion opening 43, closing the water supply pipe connection valve 44, and opening the air supply pipe connection valve 45.

[0039] It is preferable that the explosives be moved through the hollow interior of the flexible piping or insertion tube at a speed that will not cause an explosion due to friction during pumping or the impact of hitting the bottom of the hole. An emulsion type die can be used for the additional die. Furthermore, it is preferable that the supply pipe connection valve, discharge valve, and pressure pipe connection valve be remotely controlled electromagnetic valves, etc., so that workers do not need to approach the face to perform their work.

[0040] In the explosive loading method of the present invention, as shown in FIG. 10, another form of explosive loading device 10' can be used, for example, the explosive loading device 10 shown in FIG. 2, in which air packer members 35 are attached to predetermined positions of the insertion cylinder 11. That is, the explosive loading device 10' shown in FIG. 10 has the same configuration as the explosive loading device 10 shown in FIG. 2, and in addition, is provided with air packer members 35. The air packer members 35 are formed so as to be deformable, preferably into a three-dimensional doughnut shape, when expanded (see FIG. 11), preferably by supplying air or water under pressure, so as to fit closely to the outer circumferential surface of the insertion cylinder 11 and to fit closely to the working face 30a while closing the gap between the opening edge of the blast hole 31 in the working face 30a and the outer circumferential surface of the insertion cylinder 11. The air packer members 35 are attached so as to be slidable in the axial direction along the insertion cylinder 11 before expansion.

[0041] 10, an auxiliary supply valve 36 is attached to the supply pipe 19 connected to the supply pipe connection valve part 15 provided at the rear end part 11b of the insertion cylinder 11, at a position branching off from the connection part with the supply pipe connection valve part 15. The other end of a pressure resistant hose 37, one end of which penetrates the air packer member 35 and opens on the hollow bit 13 side of the air packer member 35 (see FIG. 10), is connected to this auxiliary supply valve 36.

[0042] In the explosive loading device 10' shown in Figure 10, a plurality of pressure-resistant hoses 37 are preferably provided, branching off from the other end connected to the auxiliary supply valve 36. One end of each pressure-resistant hose 37 is disposed so as to extend along the insertion cylinder 11, as shown in Figure 11, and penetrates the air packer member 35. The open end face of one end of each pressure-resistant hose 37 opens outward on the side of the air packer member 35 on the hollow bit 13 side, and a control valve 37a is attached to this open end face. Furthermore, an opening hole 37b that opens into the inside of the air packer member 35 is formed at the part of one end of each pressure-resistant hose 37 that penetrates the air packer member 35. Air or water is supplied under pressure from the supply pipe 19 via the auxiliary supply valve 36 and flows into the air packer member 35 through the opening hole 37b, causing the air packer member 35 to expand preferably into a three-dimensional doughnut shape, so that the expanded air packer member 35 can be tightly attached to the outer peripheral surface of the insertion cylinder 11 and the opening periphery of the blast hole 31 on the working face 30a.

[0043] In addition, the control valve 37a attached to the open end face portion of one end of the pressure-resistant hose 37 is set so that air or water supplied under pressure from the supply pipe 19 flows into the inside of the air packer member 35 through the opening hole 37b and inflates the air packer member 35, and when the inside of the inflated air packer member 35 reaches a predetermined internal pressure, the control valve 37a is released and the air or water supplied under pressure can be sent from the side of the air packer member 35 on the hollow bit 13 side into, for example, the gap between the hole wall surface of the blast hole 31 and the outer peripheral surface of the insertion cylinder 11.

[0044] According to the explosive loading device 10' shown in Figure 10, in the hole-drilling process, if, for example, the hollow bit 13 is unable to crush the obstructing residues, such as rocks remaining in the blast hole 31, into small enough pieces to be sent rearward through the gap between the wall surface of the blast hole 31 and the outer surface of the hollow bit 13 and therefore unable to discharge them completely, after the hole-drilling process, an additional discharge process can be carried out in which the residues remaining in the gap between the outer surface of the insertion cylinder 11 and the wall surface of the blast hole 31 are carried into the insertion cylinder 11 by injecting air or water into these gaps, and then passed through the hollow interior of the insertion cylinder 11 and discharged from the discharge branch pipe 16a provided at the rear end portion 11b of the insertion cylinder 11.

[0045] That is, in the additional discharge step, after the hole-drilling step, the discharge valve 16 of the discharge branch pipe 16a of the explosive loading device 10' is opened and the supply pipe connection valve 15 is closed. Then, the auxiliary supply valve 36 is opened and air or water is supplied by pressure-feeding the pressure-resistant hose 37. This causes the packer element 35, which has been moved to the vicinity of the opening periphery of the blasthole 31, to expand and be brought into close contact with the face 30a and the outer circumferential surface of the insertion cylinder 11, thereby blocking the gap between the outer circumferential surface of the insertion cylinder 11 at the face 30a and the opening periphery of the blasthole 31. When the pressure inside the expanded packer reaches a predetermined internal pressure, the control valve 37a is preferably automatically released, allowing air or water to flow into the gap between the wall surface of the blasthole 31 and the outer circumferential surface of the insertion cylinder 11. As a result, for example, any residue that has not been sufficiently crushed and remains between the outer surface of the insertion cylinder 11 and the wall surface of the blast hole 31 is swept away by the inflowing air or water and carried into the interior of the insertion cylinder 11 through the hollow through-hole 13a of the hollow bit 13 together with the air or water, and after being pushed backward so as to pass through the hollow interior of the insertion cylinder 11, it can be discharged from the opened discharge valve portion 16 of the discharge branch pipe 16a.

[0046] If the insertion cylinder 11 becomes clogged with residue carried inside, the auxiliary supply valve 36 is closed to stop the supply of air or water through the pressure-resistant hose 37, the discharge valve 16 is then closed, the insertion cylinder 11 is temporarily pulled out of the blast hole 31, and the supply pipe connection valve 15 is opened to supply air or water into the insertion cylinder 11, thereby discharging the clogged residue from the tip of the hollow bit 13. Once the residue has been discharged from inside the insertion cylinder 11, the supply pipe connection valve 15 and the discharge valve 16 are closed, and the pressure pipe connection valve 12 is opened, allowing the loading of explosives to begin. [Explanation of symbols]

[0047] 10,10' explosive loading device 11 Insertion cylinder 11a Tip 11b Rear end part 12 Pressure pipe connection valve 13 Hollow Bit 13a Hollow penetration 13b carbide tip 13c Connection base end part 13d Tip side part 13e Tapered part 14 Connection joint 14a Connecting sleeve 15 Supply pipe connection valve section 16 Exhaust valve section 16a Discharge branch pipe 17 Connecting arm 17a Connection base 18 Flexible piping 19 Supply piping 20 Heavy equipment for drilling 21 Face drilling machine 21b Guide Shell 22 Drifter (drilling machine body) 23 Drill Bit 24 Perforated Rod 25 Heavy machinery body 25a Outrigger 26 Mangauge (Working Floor) 27 Anti-rotation means 27a Locking rod 30 Ground at the face 30a Face 31 Blasthole 31a Hole end 32 Explosives 32a Parent die 32b Increase die 32c Anko wood 35 Packer member 36 Auxiliary supply valve 37 Pressure-resistant hose 37a Control valve 37b Opening hole 40 Perforation loading device X forward / backward axis direction

Claims

1. In a mountain tunnel construction method, an explosive loading method is provided in which explosives are loaded into a blast hole using a drilling machine equipped with a face drilling machine for drilling a blast hole in a face, A blast hole forming process in which a drilling rod having a drilling bit at its tip is attached to a drifter that forms the drilling machine body of the face drilling machine to drill a blast hole in the ground of the face; After the blast hole forming process, a drilling process is performed in which an insertion cylinder having a hole finishing bit at its tip is attached to the drifter in place of the drilling rod, and the insertion cylinder is inserted into the blast hole until the hole finishing bit reaches the vicinity of the end of the hole while supplying air or water to the hollow interior, thereby removing any residue that may be an obstacle due to roughness in the drilled blast hole and finishing the blast hole. The explosive loading method includes, after the drilling step, an explosive loading step of forcing explosives into the drilled blast hole and loading the forced explosives into the hole bottom.

2. 2. The explosive loading method according to claim 1, wherein the hole finishing bit is a hollow bit having a hollow through-hole portion with a cross-sectional shape similar to that of the hollow interior of the insertion tube.

3. 3. The explosive loading method according to claim 2, wherein in the explosive loading step, the explosive is pressurized through a pressure pipe connected to the rear end portion of the insertion tube left in the blast hole after the hole clearing step, and is forced by compressed air through the hollow interior of the insertion tube toward the end of the hole, thereby loading the explosive into the end of the hole from the hollow penetration portion of the hollow bit.

4. 3. The explosive loading method according to claim 1, wherein the parent explosive of the explosives to be loaded uses a wireless detonator.

5. 3. The explosive loading method according to claim 1, wherein the explosive loading step is carried out after the insertion tube inserted in the hole boring step is withdrawn from the blast hole.

6. 3. The explosive loading method according to claim 1, wherein in the hole clearing step, the air or water supplied into the hollow interior of the insertion tube is discharged to the outside of the blast hole together with any residue in the hole through a gap between the hole wall surface of the blast hole and the outer peripheral surface of the insertion tube.

7. 7. The explosive loading method according to claim 6, further comprising an additional discharge step of carrying residue remaining in a gap between the outer peripheral surface of the insertion tube and the wall surface of the blast hole into the interior of the insertion tube by injecting air or water into the gap after the hole clearing step, passing the residue through the hollow interior of the insertion tube, and discharging the residue from a discharge branch pipe provided at the rear end portion of the insertion tube.

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