JP2022034953A - Rock bolt installation method using anhydrous drilling, anhydrous drilling system used therefor, and drilling opening treatment device - Google Patents

Abstract

To provide a rock bolt installation method using anhydrous drilling applicable within a ground tunnel pit vulnerable in bulging of the bed rock.SOLUTION: A rock bolt installation method using anhydrous drilling comprises steps of: installing a drilling opening treatment device at an attachment position of a rock bolt; drilling with a double tube of an inner rod and an outer rod each of which is provided with a bit at a tip thereof; recovering the inner rod, filling mortar and inserting the rock bolt therein; recovering the outer rod and the drilling opening treatment device and filling additional mortar; and attaching a bearing plate and a nut on the rock bolt. The drilling opening treatment device is provided with: an insertion hole into which the double tube is inserted; leak preventing means of compressed air supplied through the inner rod; an outlet discharging with slim the compressed air diverted between an inner outer rod and the ground; and a supply inlet of fresh compressed air opened in a common space with the outlet.SELECTED DRAWING: Figure 1

Description

The present invention relates to a lock bolt driving method using anhydrous drilling, an anhydrous drilling system used therein, and a mouth treatment device, and the dust generated by drilling is collected in a dust collector by compressed air without using cutting water. Anhydrous and dust-free double-tube drilling method for discharging rock bolts by anhydrous drilling that can be applied to tunnel pits in the ground where swelling is likely to occur, and the anhydrous drilling system used for it. Regarding mouth treatment equipment.

In the construction of mountain tunnels, it is common to place rock bolts to reinforce the ground around the tunnel. When placing the lock bolt, a hole is drilled to insert the lock bolt. Drilling of the lock bolt insertion hole proceeds by attaching a rod having a bit at the tip to a rock drill, pushing the rod into the ground while rotating it, and scraping the ground with the bit at the tip. At this time, cutting water is injected from the tip of the bit and circulated in order to discharge the chestnut powder crushed by the bit. Since the cutting water also functions as a cooling machine and a bit, it plays an important role in drilling the lock bolt insertion hole.

However, in the case of a stratum where the ground is prone to swelling, it has been found that the displacement is increased by the supply of groundwater, and if cutting water is injected when drilling the lock bolt insertion hole, the ground will be damaged and the ground will expand. May promote. Therefore, for drilling such a ground, a "anhydrous" drilling method that does not use cutting water is required.

When drilling holes by anhydrous, compressed air is used instead of cutting water. Compressed air is ejected from the tip of the bit through the hollow rod, cools the bit, entrains the crushed powder by the bit, and returns between the rod and the ground toward the base of the rod. Since the compressed air that reaches the end of the drilled hole is ejected from between the rod and the ground, large dust is deposited around the rod, but fine dust is released into the air as dust.
For this reason, it is necessary to take measures against dust in the drilling holes in the tunnel pit, which is a closed space. In particular, in the case of a board swelling countermeasure work for an existing tunnel, work may be required while general vehicles are coming and going, and in such a case, dust countermeasures are indispensable.

Patent Document 1 aims at measures against dust in such drilling using compressed air, and Patent Document 1 includes a dust collector lid covering the drilling port and a dust collector mounted on the punching machine main body. A dust transport pipe for a dust collector for a punch, which is provided with a coarse grain separator having a cross-sectional area larger than the passage cross-sectional area of the dust transport pipe in the middle of the dust transport pipe for transporting the drilled dust. Is disclosed.
The technique of Patent Document 1 is effective for drilling holes in general ground, but in the case of a ground where the ground is prone to swelling, the wall surface drilled is deformed in the direction of reducing the inner diameter. It cannot be applied as it is to drilling holes. That is, a drilling technique using a double pipe including an outer pipe (outer rod) for preventing deformation of the drilled inner wall is required.

Patent Document 2 is a drilling device using a double pipe, in which a gas flow outward path is formed in an inner pipe (inner rod) and a gas flow return path is formed between the inner pipe and the outer pipe. The bit member is provided with a sediment discharge section that introduces the earth and sand generated by excavating the ground with the bit member into the gas flow outbound route, and guides the gas that has flowed through the gas flow outbound route from the gas flow outbound route to the distribution inbound route. A drilling device is disclosed in which a plurality of guide paths are formed, and the gas flows through the guide paths to suck the earth and sand toward the outbound gas flow path through the earth and sand discharge portion.

However, in the case of a ground where the ground is prone to swelling, it is necessary to reinforce a wide range of ground, and the lock bolt used for reinforcement must be a long one exceeding 10 m. Therefore, it is necessary to drill holes accordingly. However, if deep drilling is performed, the friction between the outer pipe and the ground becomes large, and the outer pipe may not rotate, which may cause problems in drilling. Therefore, the outer bit at the tip of the outer pipe is formed so that the diameter is slightly larger than the outer diameter of the outer pipe, and the drilling is advanced so that a gap is created between the outer pipe and the ground during drilling. Is valid.

When a gap is created between the outer pipe and the ground, the compressed air supplied through the inner pipe is diverted not only between the inner pipe and the outer pipe but also between the outer pipe and the ground, so that when drilling a hole. The chestnut powder will be discharged by these two flows. However, it has been found that the route between the outer pipe and the ground tends to become unstable due to the deformation of the ground, and that the chestnut powder is also easily clogged. If the path between the outer pipe and the ground is clogged with chestnut powder, the rotation of the outer pipe will be hindered, so it is important to discharge the powder stably. Therefore, it is desirable to provide a drilling system that enables double-tube drilling of anhydrous and dust-free dust that can be applied to reinforcement in tunnels in the ground where the board is prone to swelling, and a lock bolt driving technology using the drilling system. Is done.

Jitsuzensho 58-172589 Gazette Japanese Unexamined Patent Publication No. 2006-328756

The present invention has been made in view of the problems in the above-mentioned conventional drilling method and drilling system, and an object of the present invention is to compress the dust generated by drilling without using cutting water. Anhydrous and dust-free double-tube drilling that discharges to the dust collector by air, a lock bolt driving method with anhydrous drilling that can be applied to the tunnel pit of the ground where the board is prone to swelling, and anhydrous drilling used for it. To provide a hole system as well as a mouth treatment device.

The lock bolt driving method by anhydrous hole drilling according to the present invention, which is performed to achieve the above object, is a method of anhydrously drilling a hole in a tunnel and driving a lock bolt, and the mouth is treated at the lock bolt mounting position. At the stage of installing the device, at the stage of drilling a hole with a double pipe of an inner rod having an inner bit at the tip and an outer rod having an outer bit at the tip, and at the stage of collecting the inner rod and filling it with mortar. The mouth treatment device has a stage of inserting a lock bolt, a stage of collecting the outer rod and the mouth treatment device and additionally injecting mortar, and a stage of attaching a bearing plate and a nut to the lock bolt. An insertion hole for inserting the double pipe, a means for preventing leakage of compressed air supplied through the inner rod at the stage of drilling, and the outer rod and the ground in the supplied compressed air. It is characterized by having an discharge port for discharging the compressed air separated between the air to the dust collector together with the dust, and a new compressed air supply port opening in a space common to the discharge port.

At the stage of drilling with the double pipe, the compressed air generated by drilling is divided between the inner rod and the outer rod in the compressed air supplied via the inner rod. The discharge port of the mouth treatment device together with the first path for discharging air together with the outer rod via the outer rod, the compressed air shunted between the outer rod and the ground, and the new compressed air supplied from the supply port. It is preferable to include a step of discharging by two routes, that is, a second path of discharging from the air, and a step of separating the discharged chestnut powder from compressed air by a dust collector and collecting it.

The stage of installing the mouth treatment device at the lock bolt mounting position is the stage of directly anchoring to the concrete pavement surface so as to cover the hole with the core removed in advance, and the outer installed at the center of the hole with the core removed in advance. Either the stage where the outer circumference of a hollow circular tubular drill rod having a larger outer diameter than the rod is filled with mortar to close the gap with the ground and then the mouth treatment device is attached to the head of the drill rod. It is preferable to include one step.
The suction amount of the dust collector is preferably larger than the amount of compressed air supplied at the time of drilling.

The mouth treatment device according to the present invention made to achieve the above object is a mouth treatment device used for drilling with a double pipe in a lock bolt driving method using anhydrous drilling, and is used for drilling. An insertion hole for inserting a heavy pipe, a means for preventing leakage of compressed air supplied through the inner rod of the double pipe at the stage of drilling, and a precipitator of the supplied compressed air together with dust. It is characterized by including a discharge port for discharging to a dust collector and a new compressed air supply port which opens in a space common to the discharge port.

The anhydrous drilling system according to the present invention made to achieve the above object is an anhydrous drilling system used for drilling for driving a lock bolt in a tunnel, and is a drilling machine and the drilling machine. A double pipe equipped with an inner rod and an outer rod having a bit at the tip, respectively, an air compressor that supplies compressed air at the time of drilling, an insertion hole for inserting the double pipe, and drilling. A dust collector together with dust collecting the compressed air leak prevention means supplied through the inner rod at the stage of making a hole and the compressed air separated between the outer rod and the ground among the supplied compressed air. A mouth treatment device having a discharge port for discharging to the air, a new compressed air supply port opened in a space common to the discharge port, an intermediate dust collector and a dust collector, and an inner rod and an outer rod. It is characterized by having a dust collecting means for separating and collecting the compressed air discharged between the compressed air and the compressed air discharged between the outer rod and the ground.

According to the lock bolt driving method by anhydrous drilling according to the present invention, the cutting water is used to advance the drilling while discharging the chestnut powder by using compressed air instead of the cutting water. The injection makes it possible to proceed with drilling without damaging the ground.

Further, according to the lock bolt driving method by anhydrous drilling according to the present invention, new compressed air is supplied to promote the discharge of the chestnut powder from the path between the outer pipe and the ground. Since it is possible to discharge the powder stably without clogging, it prevents the rotation from being hindered by the contact between the outer pipe and the ground or the outer pipe and the packed powder at the time of drilling, and exceeds 10 m. It enables deep drilling corresponding to the placement of long lock bolts.

Further, according to the lock bolt driving method by anhydrous drilling according to the present invention, the compressed air is discharged by the compressed air divided into two paths, the inner pipe and the outer pipe, and the outer pipe and the ground. In order to guide the dust collecting means without leaking the dust, even in the closed existing tunnel space, the cutting that maintains a clean work environment that does not generate dust without blocking the passage of general vehicles in the adjacent lane. It is possible to place holes and lock bolts.

According to the anhydrous drilling system and the mouth treatment device according to the present invention, the mouth treatment device opens in a space common to the discharge port for discharging the chestnut powder from the path between the outer pipe and the ground. Since it is equipped with a new compressed air supply port, it is possible to stably discharge the chestnut powder without clogging the discharge pipe.

It is a figure which shows schematically the anhydrous drilling system by 1st Embodiment used in the lock bolt driving method by the anhydrous drilling of this invention. It is a figure which shows schematic structure of the mouth processing apparatus by 1st Embodiment of this invention. It is a figure which shows schematically the anhydrous drilling system by the 2nd Embodiment used in the lock bolt driving method by the anhydrous drilling of this invention. It is a figure which shows schematic structure of the mouth processing apparatus by the 2nd Embodiment of this invention. It is a flowchart for demonstrating the lock bolt driving method by the anhydrous hole drilling according to embodiment of this invention.

Next, a specific example of a mode for carrying out the lock bolt driving method by anhydrous drilling according to the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram schematically showing an anhydrous drilling system according to the first embodiment used in the lock bolt driving method by anhydrous drilling of the present invention.
Referring to FIG. 1, the anhydrous drilling system 1 according to the first embodiment of the present invention includes a drilling machine 10, an air compressor 20, a double pipe 30 attached to the drilling machine 10, a mouth processing device 40, and a mouth processing device 40. A dust collecting means 50 is provided.

The lock bolt driving method by anhydrous drilling according to the present invention is a rock bolt driving method applicable to reinforcement of a tunnel provided in a stratum where board swelling is likely to occur, and is a method of drilling a lock bolt insertion hole. At this time, drilling is performed using a double pipe 30 for surely performing a deep drilling having a predetermined inner diameter even in a ground that is easily deformed without using cutting water that may damage the ground 60. Use the drilling method. Compressed air is used instead of cutting water to discharge the chestnut powder generated during drilling, but when drilling in a layer where swelling is likely to occur, deformation of the ground 60 occurs due to drilling. In some cases, if the dust is clogged between the double pipe 30 and the ground 60, the frictional force increases and the drilling is hindered.

Therefore, in the anhydrous drilling system 1 according to the embodiment of the present invention, new compressed air different from that for drilling is supplied in the middle of the discharge path of the chestnut powder passing between the double pipe 30 and the ground 60. Then, by encouraging the discharge of the chestnut powder from this discharge path, clogging of the chestnut powder is prevented.
Further, since the anhydrous drilling system 1 is applied to the reinforcement work in the tunnel, it includes not only the dust discharged from the above discharge path but also the dust discharged via the inside of the double pipe 30. Compressed air containing all the dust is guided to the dust collecting means 50, and the dust collecting means 50 separates and collects the dust and discharges the purified air.

As described above, in the lock bolt driving method by anhydrous drilling according to the present invention, the ground 60 is not damaged by drilling anhydrously, and new compressed air is supplied when drilling with the double pipe 30. Prevents clogging of the chestnut powder discharged from between the double pipe 30 and the ground 60, which are easily clogged with the chestnut powder, and enables stable and deep drilling even in the formation where board swelling is likely to occur. Achieves clean drilling that collects the drilled powder generated by drilling and prevents the scattering of dust. By using the double pipe 30 in this way, a driving method is provided that makes the best use of its characteristics and maintains the shape of the insertion hole for the rock bolt that has been drilled to facilitate the insertion of the lock bolt.

As the drilling machine 10 included in the anhydrous drilling system 1, the drilling machine 10 having a rotary percussion function is used in the embodiment. Although not shown, the drilling machine 10 independently clamps the inner rod 31 and the outer rod 35 to the portion of the drill head 11 so that the double pipe 30 including the inner rod 31 and the outer rod 35 can be attached. Equipped with clamping means.

The drill head 11 can apply a rotational force and a striking force to the inner rod 31 and the outer rod 35 through the clamping means. Both the inner rod 31 and the outer rod 35 are hollow circular tubes, and an inner bit 32 is provided at the tip of the inner rod 31, and the outer rods are separated and surrounded so as to have a certain space on the outer peripheral side of the inner rod 31. An outer bit 36 arranged in a ring shape is provided at the tip of the 35. Both the inner rod 31 and the outer bit 36 advance the drilling by the rotational force and the striking force applied from the drill head 11.

Since the outer bit 36 forms a gap between the outer rod 35 and the ground 60 at the time of drilling, the outer bit 36 is installed so that the outermost diameter of the outer bit 36 is larger than the outer diameter of the outer rod 35. By forming such a gap, it is possible to prevent the generation of rotational resistance due to the frictional force between the outer rod 35 and the ground 60 during drilling.

The crown of the inner rod 31 is provided with a supply pipe connecting means for supplying compressed air into the inner rod 31, including a joint such as a swivel joint, and a supply pipe 21 from the air compressor 20 is provided at the time of drilling. Connect and drill holes while flowing compressed air. The inner bit 32 is provided with an outlet for ejecting compressed air to the drilled portion, and the compressed air supplied from the air compressor 20 passes through the inside of the inner rod 31 from the outlet to the drilled portion. It is ejected. This compressed air is used to cool the inner bit 32 and the outer bit 36 that generate heat during drilling, and to discharge the chestnut powder generated during drilling.

The compressed air ejected from the ejection port of the inner bit 32 entrains the dust and returns to the drill head 11 side in the space between the inner rod 31 and the outer rod 35, and the outer rod 35 and the ground. It is divided into two routes, the second route 37, which returns to the opening side between the mountain 60 and the mountain 60, and is used for discharging the chestnut powder.

Although the inner rod 31 is rotatably inserted through the crown of the outer rod 35,
It is provided with a swivel joint (not shown) that guides compressed air mixed with powder that has returned to the drill head 11 side through the first path 33 to the discharge port without leaking. The compressed air mixed with the dust that has returned to the drill head 11 side through the first path 33 is sent to the dust collecting means 50 through the discharge pipe 12 connected to the discharge port of the swivel joint.

The mouth processing device 40 is a device that guides the compressed air mixed with the powder flowing through the second path 37 passing through the gap between the outer rod 35 and the ground 60 to the discharge port without leaking.
The mouth treatment device 40 is installed at the starting point where holes are drilled by the double pipe 30, but if it is simply fixed, compressed air mixed with dust will flow out from the gap between the mouth treatment device 40 and the ground plane. This will cause dust to be generated. Therefore, in the first embodiment, the mouth processing device 40 is installed according to the following procedure.

The tunnel to be reinforced by placing rock bolts is premised on a state in which a roadbed 61 having a predetermined thickness is formed on the ground 60 and a roadbed concrete 62 is formed on the roadbed 61. Starting from this state, the core of the roadbed concrete 62 is first removed. The core removal is to hollow out the roadbed concrete 62 in a columnar shape, and the core removal is for the purpose of treating the bottom of the core removal to prevent the leakage of compressed air later, and also to lock the lock after placing the lock bolt. The purpose is to make it easier to drive the reinforcing bars to reinforce the bolt head to the side surface. In the first embodiment, since the bottom portion from which the core has been removed is subjected to a treatment for preventing the leakage of compressed air later, the bottom portion is removed with a margin wider than the portion for attaching the mouth treatment device 40.

Next, a short drill rod 70 for attaching the mouth processing device 40 is driven so that the core removed portion and the central axis are coaxial with each other. The drill rod 70 has a circular tubular shape and has an inner diameter larger than the outermost outer diameter of the outer bit 36 so that the double pipe 30 can pass through the drill rod 70. A mortar 71 is applied to the bottom of the core removed from the periphery of the driven drill rod 70 so that compressed air does not leak from the gap between the ground 60 and the drill rod 70.

After preventing leakage around the drill rod 70 in this way, the mouth processing device 40 is attached to the crown of the drill rod 70. A flange or a screw or the like is provided in advance on the crown of the drill rod 70, and a flange or a screw or the like is provided on the mouth processing device 40 in advance so that compressed air does not leak. And attach it to the drill rod 70. When mounting with a flange, prevent leakage by inserting packing in between.
Since the details of the mouth processing device 40 are shown in FIG. 2, they will be described with reference to FIG. 2 below.

FIG. 2 is a diagram schematically showing the structure of a mouth treatment device according to the first embodiment of the present invention. FIG. 2A is a perspective view of the mouth processing device 40 attached to the drill rod 70, and FIG. 2B shows a partial cross section obtained by cutting a main part along the line AA of FIG. 2A. It is a figure.
Referring to FIG. 2, the mouth treatment device 40 according to the first embodiment of the present invention is supplied via an insertion hole 41 for inserting the double pipe 30 and an inner rod 31 at the stage of drilling. The leakage prevention means 42 of the compressed air, the discharge port 43 for discharging the compressed air separated between the outer rod 35 and the ground 60 from the supplied compressed air to the dust collecting means 50 together with the dust, and the discharge port 43. It is provided with a new compressed air supply port 44 that opens in a common space 46 with the outlet 43.

The leak preventing means 42 leaks compressed air around the double pipe 30, which rotates or moves in the axial direction at the time of drilling, that is, around the outer rod 35 so as not to hinder the operation of the double pipe 30. It closes so that it does not exist. The leak prevention means 42 is realized by a prepender having an elastic body at a portion in contact with the double pipe 30 and having a tube inflated by air pressure in the embodiment. The prepender is attached to the insertion hole 41, and with the outer rod 35 inserted, air is injected into the tube to inflate it, and the prepender is brought into close contact with the outer circumference of the outer rod 35 to close the gap between the insertion hole 41 and the outer circumference of the outer rod 35. .. In another embodiment, instead of the prepender, O-rings and rubber packings may be provided single or multiple times, and the elasticity of the O-rings and rubber packings may be used to close the outer periphery of the outer rod 35.

In this way, the leakage prevention means 42 prevents leakage from the insertion hole 41, so that the compressed air supplied through the inner rod 31 is separated between the outer rod 35 and the ground 60, and is the first. The compressed air flowing through the two paths 37 is discharged from the discharge port 43 without leaking to the outside. A discharge pipe 53 connected to the dust collecting means 50 is connected to the discharge port 43, and the chestnut powder flowing through the second path 37 is sent to the dust collecting means 50 without flowing out to the outside.

The function of the mouth processing device 40 described above, that is, the insertion hole (insertion hole 41) attached to the crown of the circular tube (drill rod 70) and through which the rotating body (outer rod 35) rotating in the circular tube is inserted. The function of preventing the leakage of compressed air from the surroundings and guiding it to the discharge port (discharge port 43) without hindering the rotation of the rotating body is attached to the crown of the outer rod 35, and the inner rod 31 is provided. It is the same as the above-mentioned swivel joint that guides the compressed air flowing in the outer rod 35 to the discharge port without leaking while being rotatably inserted.

The first path 33, which returns the space between the inner rod 31 and the outer rod 35 to the drill head 11 side, stably circulates compressed air mixed with groundwater without changing the flow path, but the outer rod 35. In the second path 37, which returns to the opening side between the ground 60 and the ground 60, the perforated wall surface of the ground 60 is easily deformed, and if groundwater is generated, it is easily affected by it, and the compression of the ground water is mixed. The air flow tends to be unstable. Therefore, the chestnut powder from the second path 37 may be stagnant and clogged.

Therefore, the mouth processing device 40 is provided with a new compressed air supply port 44 for promoting the discharge of the chestnut powder from the second path 37. The supply port 44 opens in a space 46 common to the discharge port 43, and a supply pipe 22 for guiding compressed air supplied from the air compressor 20 is connected to the supply port 44. The new compressed air supplied from the supply port 44 is discharged from the discharge port 43 together with the compressed air mixed with the dust flowing through the second path 37. By supplying the new compressed air, the compressed air mixed with the crimp powder flowing through the second path 37 is accelerated, and the crimp powder can be easily discharged.

In FIG. 2, the supply port 44 is shown at a position orthogonal to the discharge port 43, but may be provided at a position facing the discharge port 43, or may have a positional relationship other than that at an arbitrary angle with each other. Further, the supply port 44 may have a simple opening shape that opens in the space 46 common to the discharge port 43, but the supply port 44 may have a nozzle shape so as to further eject new compressed air toward the discharge port 43 in the space 46. It may have an opening shape of. The compressed air ejected toward the discharge port 43 entrains the compressed air mixed with the surrounding dust and contributes to reducing the pressure in the space 46, so that the compression between the outer rod 35 and the ground 60 is performed. The effect of sucking up air is added, and the clogging of the chestnut powder is less likely to occur.

With reference to FIG. 1 again, the compressed air mixed with the dust flowing through the second path 37 passes through the discharge pipe 53, and the compressed air mixed with the dust powder flowing through the first path 33 passes through the discharge pipe 12. And is sent to the dust collecting means 50. The dust collecting means 50 includes an intermediate dust collecting machine 51 and a dust collecting machine 52.

The intermediate dust collector 51 installs a shielding plate inside and guides the compressed air mixed with the chestnut powder sent from the discharge pipes (12, 53) so as to be folded up and down, and relatively of the chestnut powder during this period. This is for reducing the load of dust collection by the dust collector 52 in the subsequent stage by sinking and collecting the large-sized chestnut powder 54.

The dust collector 52 is provided with a fan for suction and a bag filter, and finer dust is removed from the exhaust from which the relatively large dust 54 is removed by the intermediate dust collector 51, and the cleaned air is removed. To discharge. By providing the intermediate dust collector 51, the life of the bag filter can be extended and the frequency of filter replacement can be reduced.

The fan provided in the dust collector 52 is for sucking the compressed air mixed with the dust and discharging the air normalized by the bag filter, but if the suction amount is insufficient, the flow of the compressed air is reduced. The chestnut powder sinks and becomes easily clogged. Therefore, it is necessary to have a sufficient margin in the suction capacity of the dust collector 52.

Assuming that the amount of compressed air supplied from the air compressor 20 into the inner rod 31 at the time of drilling is A (m ³ / min), this compressed air flows through the first path 33 and is A ₁ (m ³ ). / Min) and A ₂ (m ³ / min) flowing through the second path 37. At this time, the amount of compressed air flowing in each path is determined by the cross-sectional area ratio of each path. For example, in the case of a double pipe 30 in which the outer diameter of the standard outer bit 36 is 101 mm, the outer diameter and inner diameter of the outer rod 35 are 96 mm and 69 mm, respectively, and the outer diameter of the inner rod 31 is 57 mm.
A ₁ : A ₂ = π × (69 2-57 ² ) / ^{4: π × (101 2-96 2 )} / ⁴
= 1: 0.65
Will be.

When the double pipe 30 having standard dimensions is used in this way, the flow path of the second path 37 is originally narrow, and the flow path is further narrowed due to the deformation of the ground 60, or the hole wall surface of the ground 60 is formed. The roughness may increase and the flow rate A2 of the _second path 37 tends to decrease. In such a situation, the compressed air supplied from the same source loses the balance of the diversion, the flow rate A2 of the _second path 37 drops sharply, and only between the outer rod 35 and the ground 60. However, the dust is easily clogged even in the mouth processing device 40, the discharge pipe 53, and the like. The new compressed air supplied from the supply port 44 of the mouth treatment device 40 prevents such clogging. Assuming that the supply amount of this new compressed air is A ₀ (m ³ / min), the above-mentioned compressed air amount is A (m ³ / min) plus this supply amount A ₀ (m ³ / min). , The total amount of compressed air supplied with drilling. Assuming that the suction capacity of the dust collector 52 is B (m ³ / min), this suction capacity needs to be larger than the total amount of compressed air supplied by drilling. That is,
B> A + A ₀
A dust collector 52 is used.

Since the balance between the flow rate A1 of the _first path 33 and the flow rate A2 of the _second path 37 is important, a flow meter is provided on the second path 37 side where the flow rate is likely to fluctuate, and the flow rate on the second path 37 side. May be able to detect whether or not the flow rate falls below a predetermined flow rate. Specifically, for example, when a flow meter is attached in the middle of the discharge pipe 53 or at the supply port 44 of the mouth treatment device 40 and the flow rate of the compressed air mixed with the dust flowing through the discharge pipe 53 is lower than the predetermined flow rate, for example, once a hole is drilled. Prevents clogging of dust by stopping the operation and moving the outer rod 35 up and down, reducing the flow rate of the discharge pipe 12 on the first path 33 side, or increasing the supply amount of new compressed air from the supply port 44. You may try to take measures for this. If the flow rate of the compressed air mixed with the dust flowing through the discharge pipe 53 is lower than the predetermined flow rate, an alarm device may be further provided to issue an alarm.

FIG. 3 is a diagram schematically showing an anhydrous drilling system according to a second embodiment used in the lock bolt driving method by anhydrous drilling of the present invention.
Referring to FIG. 3, the anhydrous drilling system 2 according to the second embodiment of the present invention includes a drilling machine 10, an air compressor 20, a double pipe 30 attached to the drilling machine 10, a mouth processing device 48, and a mouth processing device 48. A dust collecting means 50 is provided.

The anhydrous drilling system 2 includes a mouth processing device 48 instead of the mouth processing device 40 of the anhydrous drilling system 1 shown in FIG. 1, and the other configurations are the same as those of the anhydrous drilling system 1. Therefore, anhydrous drilling is performed. Descriptions that overlap with those described in the hole system 1 will be omitted.
The mouth processing device 48 differs from the mouth processing device 40 in the mounting method. The mouth treatment device 40 is formed so as to be attached to the crown of the drill rod 70 after being treated in advance to prevent leakage from around the drill rod 70 by using the drill rod 70. The 48 is directly attached to the roadbed concrete 62 by using the anchor 72 without using the drill rod 70. The details of the mouth processing device 48 will be described with reference to FIG.

FIG. 4 is a diagram schematically showing the structure of the mouth treatment apparatus according to the second embodiment of the present invention.
4 (a) is a perspective view of the mouth processing device 48 attached by the anchor 72, and FIG. 4 (b) is a view showing a partial cross section of a main part cut along the line BB of FIG. 4 (a). Is.
Referring to FIG. 4, the mouth treatment device 48 according to the second embodiment of the present invention has an insertion hole 41 for inserting the double pipe 30, and the outer rod 35 and the ground 60 in the supplied compressed air. It is provided with an discharge port 43 for discharging the compressed air separated between the air and the dust collecting means 50 together with the dust, and a new compressed air supply port 44 opening in a space 46 common to the discharge port 43. Further, providing the leakage preventing means 42 in the insertion hole 41 is the same as that of the mouth processing device 40.

A flange having a hole for inserting the anchor 72 is formed in the attachment portion of the mouth treatment device 48, and after installing the mouth treatment device 48 in accordance with the anchor 72 previously driven into the roadbed concrete 62, the hole of the flange is inserted. By fastening the nut to the protruding anchor 72, the mouth processing device 48 is fixed. By sandwiching the packing 45 on the lower surface of the flange, the gap with the roadbed concrete 62 is closed and the leakage of compressed air is prevented. Also in this embodiment, the core is removed for the purpose of making it easier to drive the reinforcing bar for reinforcing the lock bolt head after the lock bolt is placed on the side surface, but the packing 45 is on the outer peripheral side of the opening of the core removed portion. Since the mouth treatment device 48 is attached so as to cover the surface, it is possible to save the trouble of allocating the mortar 71 as in the case of the mouth treatment device 40 of the first embodiment, and it can be used more easily.

FIG. 5 is a flowchart for explaining a method of placing a lock bolt by anhydrous drilling according to an embodiment of the present invention.
Referring to FIG. 5, in step S500, the mouth processing device (40, 48) is installed at the place where the lock bolt is placed. As described above, the mouth treatment device (40, 48) has a different mounting method depending on the embodiment, and therefore, the mounting method according to the mouth treatment device (40, 48) is adopted. In the case of the mouth treatment device 40 attached to the crown of the drill rod 70, the core of the roadbed concrete 62 is first removed, and then the circular tubular drill rod 70 is driven into the center of the hole where the core is removed to drill. A mortar 71 is applied to the bottom of the hole from which the core has been removed around the rod 70 to take measures against leakage of compressed air, and then the mortar 71 is attached to the top of the drill rod 70.

In the case of the mouth treatment device 48 directly attached to the roadbed concrete 62, since the mouth treatment device 48 is attached so as to cover the hole from which the core has been removed in advance, it corresponds to the position of the anchor hole of the lower end flange of the mouth treatment device 48. After driving the anchor 72 into the roadbed concrete 62, a flange is installed so that the anchor 72 inserts the hole for the anchor, and the anchor 72 is fastened with a nut. At this time, the packing 45 is sandwiched so that the packing 45 covers the outer peripheral side of the opening of the core punching portion, and is attached so that compressed air does not leak from the gap between the roadbed concrete 62 and the lower end flange of the mouth treatment device 48.

Next, an anhydrous drilling of the lock bolt insertion hole is performed by a drilling machine 10 equipped with a double pipe 30 including an inner rod 31 having an inner bit 32 at the tip and an outer rod 35 having an outer bit 36 at the tip. The chestnut powder is discharged together with compressed air from the first path 33 between the inner rod 31 and the outer rod 35 and the second path 37 between the outer rod 35 and the ground 60 (step S510).

Compressed air for discharging the chestnut powder is supplied from the air compressor 20 to the inside of the inner rod 31 via a joint such as a swivel joint, and is ejected from the ejection port at the tip of the inner rod 31, and then the first path 33. And, it is divided into the second path 37.
The compressed air flowing through the first path 33 entrains a part of the dough scraped by the inner bit 32 or the outer bit 36, and from the outlet of the swivel joint provided on the top of the outer rod 35 to the discharge pipe 12 together with the dough. It is discharged. The compressed air flowing through the second path 37 entrains the rest of the crispy powder carved by the inner bit 32 or the outer bit 36, flows into the mouth processing apparatus (40, 48), and then supplies new compressed air from the supply port 44. It is mixed with and accelerated, and is discharged to the discharge pipe 53 from the discharge port 43 together with new compressed air and dust.

The compressed air mixed with the dust discharged to the discharge pipes (12, 53) is introduced into the dust collecting means 50, and the dust is separated and recovered by the dust collecting means 50 (step S520). The dust collecting means 50 sinks and collects the relatively large-sized dust 54 by the intermediate dust collector 51 in the front stage, and removes the finer dust by the bag filter of the dust collector 52 in the rear stage to make the air normalized. And discharge. As a result, even when working in a closed tunnel, dust does not fill up, and the worker can perform reinforcement work in a good working environment.

In order to perform deep drilling, the double pipe 30 for drilling is increased in depth by adding a relay pipe as the drilling progresses. Therefore, the drilling machine 10 includes a clamp portion (not shown) that operates between the drill head 11 and the mouth processing device (40, 48). The clamp portion is provided with an inner rod clamp portion and an outer rod clamp portion that operate independently of each other, whereby the relay pipe or the outer rod 35 or the inner rod 31 already connected for drilling is clamped. By rotating the clamping means on the drill head 11 side, the relay pipe can be connected or disconnected.

When the drilling to the required depth is completed, the inner rod 31 is collected in step S530, the mortar for fixing the lock bolt is filled in the lock bolt insertion hole, and then the lock bolt is inserted. When filling the mortar, insert the tip of the injection hose to the bottom of the lock bolt insertion hole before injecting. As a result, even if there is spring water in the hole, it can be replaced with mortar. If the spring water replaced by mortar injection rises to the mouth, it can be removed by suction with a small vacuum.

During the process of step S530, even if the ground 60 tries to be deformed, the outer rod 35 supports the outer wall of the drilled hole, so that the workability is not affected. By attaching a spacer to the lock bolt, it can be inserted so as to maintain an appropriate position in the insertion hole. If a long lock bolt is required, it is possible to connect and use a lock bolt of an appropriate length that is easy to handle with a coupler. An electric winch mounted on the rotary percussion drill type drilling machine 10 may be used for inserting the lock bolt.

After the insertion of the lock bolt is completed and it is confirmed by measuring the top end of the lock bolt that the lock bolt has been inserted to a predetermined depth, in step S540, the outer rod 35 and the mouth treatment device (40, 48) are used. To collect. At this point, the mortar has not yet solidified, and when the outer rod 35 is collected, the mortar may permeate into the gaps and cracks on the outside of the outer rod 35, and the upper surface of the mortar may be lowered. In that case, after the sedimentation of the mortar has subsided after a while, additional mortar is injected to a predetermined height.

With the mortar hardened to an appropriate height, the bearing plate is fastened to the head of the lock bolt with a nut in step S550 to complete the rock bolt placement. At this point, the reinforcing effect of the lock bolt will be exhibited.
After that, in order to flatten the road surface as a road, the top of the rock bolt will be filled with roadbed mortar and pavement with ultra-fast concrete. At this time, after driving the reinforcing bar diagonally downward from above the top of the lock bolt toward the side wall of the core pulling part, bend the head of the reinforcing bar so that it fits inside the core pulling part, and then lock including this reinforcing bar. Fill the top of the bolt with roadbed mortar and pavement with ultra-fast concrete. By reinforcing with reinforcing bars in this way, it is possible to prevent the subduction of the roadbed mortar and the ultra-premature strong concrete in which the top of the lock bolt is embedded even after the traffic is opened.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the present invention is not limited to the above-described embodiments and is variously modified within the range not departing from the technical scope of the present invention. It is possible to do.

1, 2 Anhydrous drilling system 10 Drilling machine 11 Drill head 12, 53 Discharge pipe 20 Air compressor 21, 22 Supply pipe 30 Double pipe 31 Inner rod 32 Inner bit 33 1st path 35 Outer rod 36 Outer bit 37th 2 paths 40, 48 Mouth treatment device 41 Insertion hole 42 Leakage prevention means 43 Discharge port 44 Supply port 45 Packing 46 Space 50 Dust collector 51 Intermediate dust collector 52 Dust collector 54 Crush powder 60 Ground 61 Roadbed 62 Roadbed concrete 70 Drill rod 71 mortar 72 anchor

Claims (6)

It is a method of drilling an anhydrous hole in a tunnel and driving a lock bolt.
At the stage of installing the mouth treatment device at the lock bolt mounting position,
At the stage of drilling a hole with a double pipe of an inner rod equipped with an inner bit at the tip and an outer rod having an outer bit at the tip.
At the stage of collecting the inner rod, filling it with mortar, and inserting the lock bolt,
At the stage of collecting the outer rod and the mouth treatment device and additionally injecting mortar,
It has a stage of attaching a bearing plate and a nut to the lock bolt.
The mouth processing device includes an insertion hole for inserting the double pipe, a leakage prevention means for compressed air supplied via the inner rod at the stage of drilling, and the supplied compressed air. It is characterized by having an outlet for discharging the compressed air separated between the outer rod and the ground to the dust collector together with the dust, and a new compressed air supply port opening in a space common to the outlet. Lock bolt placement method using anhydrous drilling. The stage of drilling with the double pipe is
Of the compressed air supplied via the inner rod, the compressed air generated by drilling is discharged via the outer rod together with the compressed air shunted between the inner rod and the outer rod. By two paths, one path and the second path that discharges the compressed air split between the outer rod and the ground and the new compressed air supplied from the supply port from the discharge port of the mouth treatment device. The stage of discharging and
The method for placing a lock bolt by anhydrous drilling according to claim 1, wherein the discharged chestnut powder is separated from compressed air by a dust collector and collected. At the stage of installing the mouth treatment device at the lock bolt mounting position,
At the stage of fixing directly to the concrete pavement surface with an anchor so as to cover the hole from which the core was removed in advance,
The head of the drill rod is filled with mortar to close the gap between the drill rod and the ground, and the outer circumference of the hollow circular tubular drill rod, which has a larger outer diameter than the outer rod installed in the center of the hole from which the core has been removed in advance, is filled with mortar. At the stage of attaching the mouth treatment device to
The method for placing a lock bolt by anhydrous drilling according to claim 1 or 2, wherein the method includes any one of the steps. The method for placing a lock bolt by anhydrous drilling according to any one of claims 1 to 3, wherein the suction amount of the dust collector is larger than the amount of compressed air supplied at the time of drilling. It is a mouth treatment device used for drilling with a double pipe in the lock bolt driving method by anhydrous drilling.
An insertion hole for inserting the double pipe used for drilling, and
A means for preventing leakage of compressed air supplied via the inner rod of the double pipe at the stage of drilling, and
An outlet that discharges the divided flow of the supplied compressed air together with the dust collector to the dust collector,
A mouth treatment device including a new compressed air supply port that opens in a common space with the discharge port. An anhydrous drilling system used for drilling holes for rock bolt placement in tunnels.
With a drilling machine,
A double pipe attached to the drilling machine and having an inner rod and an outer rod, each having a bit at the tip,
An air compressor that supplies compressed air during drilling,
An insertion hole for inserting the double pipe, a means for preventing leakage of compressed air supplied through the inner rod at the stage of drilling, and the outer rod and the ground among the supplied compressed air. A mouth treatment device having a discharge port for discharging the compressed air separated between the air and the dust collector together with the dust, and a new compressed air supply port opening in a space common to the discharge port.
It is equipped with an intermediate dust collector and a dust collector, and separates the compressed air discharged between the inner rod and the outer rod and the compressed air discharged between the outer rod and the ground. An anhydrous drilling system characterized by having a dust collecting means for collecting.

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