JP2004190270A - Pipe connection structure of all ground fasten (agf) construction method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pipe connection structure for reducing cost while minimizing industrial waste in excavating a tunnel. <P>SOLUTION: Pipes driven into the natural ground comprise four pipes which are a tip pipe 1, a first intermediate pipe 10, a second intermediate pipe 20, and an end pipe 30, and the adjacent pipes are connectable to each other by screws. The tip pipe 1, first intermediate pipe 10 and second intermediate pipe 20 are cylindrical steel pipes, and the end pipe 30 is a cylindrical resin pipe. The screws 22, 31 formed at the rear end part of the second intermediate pipe 20 and the front end part of the end pipe 30 (a joint 40) are left-hand screws, and the end pipe 30 is turned left relative to the second intermediate pipe 20 for connection. The screw 31 at the front end part of the end pipe 30 is a reverse screw to the screws 11, 21 at the front end parts of the other pipes 10, 20. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connection structure between pipes used for pouring a hardening agent for reinforcing a ground when excavating a tunnel.
[0002]
[Prior art]
To perform tunnel excavation work safely, it is necessary to reinforce the ground to prevent the mountain from collapsing. For this purpose, a hardener is poured into the ground to solidify the ground.
In order to pour the hardener into the ground, a plurality of steel pipes are sequentially driven from the tunnel face slightly outward from the axial direction of the tunnel. At that time, we expect to have a first-aid effect by driving in while connecting multiple steel pipes.
Then, a hardener is poured into the tube. Since a plurality of holes are formed in the peripheral side wall of each steel pipe, the hardening agent flows into the ground from the holes, and the ground can be hardened and reinforced. This makes it possible to excavate the tunnel with the excavator safely.
[0003]
Conventionally, a widening AGF method is known as a method of driving the steel pipe into the ground. FIG. 13 is a schematic diagram showing the widening AGF method.
In this method, a steel pipe driving portion is provided slightly wider than the required height of the tunnel, and a steel pipe 91 is driven from the widened portion 90 slightly outward from the axial direction of the tunnel. According to this method, the steel pipe 91 can be installed at a nearly horizontal angle (α = 3 to 5 °), and it was possible to drive the steel pipe 91 into the ground up to the end portion.
However, widening and excavating takes time, and furthermore, the cost of material such as concrete for filling the widened portion 90 is not economical.
[0004]
Therefore, in recent years, a non-widening AGF (All Ground Fasten) method has been proposed. FIG. 14 is a schematic view showing a conventional non-widening AGF method.
This method is a method in which a steel pipe 92 is driven directly from the tunnel face slightly outward from the axial direction of the tunnel without providing a widened portion unlike the widened AGF method. Therefore, in this method, the steel pipe 92 is driven into the ground at an angle (β = 8 to 10 °) as compared with the widening AGF method.
[0005]
According to the non-widened AGF method, it is not necessary to provide a widened portion, and therefore, compared to the widened AGF method, no time is required, and no material cost is required because the widened portion is not filled. As described above, since the excavated cross section is small and the excavated amount is small, the cycle time can be shortened, the construction period is shortened, and the material such as concrete is reduced, so that the cost is reduced.
[0006]
However, in the non-widening AGF method, there is a disadvantage that the base end portion 92a of the steel pipe 92 is not driven into the ground to the end and is left on the cross-section inside the tunnel. Therefore, there is a possibility that the blade of the excavator may be damaged when the blade of the excavator hits the remaining protrusion. The excavated steel pipe was treated as industrial waste.
[0007]
Therefore, for example, as disclosed in Patent Document 1 below, a method has been proposed in which, of the steel pipes 92 to be connected, a terminal pipe on the base end side is a resin pipe. In this method, drilling is performed from the inside of the excavated section, and a PVC pipe (resin pipe) is used on the near side, so that the steel pipe at the end can be driven to the upper end of the steel support, and the special section in the section can be driven. Excavate while breaking the buried pipe. That is, by making the terminal pipe on the near side a resin pipe, it is possible to excavate while also shaving the resin pipe without damaging the blade of the excavator.
[0008]
[Patent Document 1]
JP-A-11-182174
[Problems to be solved by the invention]
However, unlike the earth and sand, the shavings of the resin pipe shaved together with the ground have to be treated as industrial waste. However, the handling of industrial waste is strictly specified, the cost of disposal is high, and the environment is adversely affected. Moreover, in any of the construction methods, the pipes could not be reused at all, which not only increased the cost but also was not good for the environment.
Thus, collecting and reusing the terminal tube has not been considered in the past.
[0010]
The present invention has been made in view of the above circumstances, and a main object of the present invention is to provide a pipe connection structure that can reduce industrial costs as much as possible when excavating a tunnel and reduce costs.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, the present invention relates to a connection structure for pipes used when digging a tunnel by reinforcing the ground by the AGF method, wherein a plurality of pipes connected to each other are used. The terminal tube on the proximal end connected to the foremost side is characterized in that, after being buried once, the connection of the front end is released, removed, recovered, and reused.
[0012]
In addition, preferably, in addition to the above-mentioned configuration, the terminal tube and the intermediate tube connected to the front end are detachably connected by a screw type, and the terminal tube once buried has a screw at the front end. The pipe connection structure is characterized in that the pipe connection structure is rotated in a direction of loosening, removed, collected, and reused.
[0013]
In addition, preferably, in addition to the above configuration, the plurality of pipes are each connected by a screw type, and among the connection parts, a connection part between the terminal pipe and an intermediate pipe connected to the front end is another part. A pipe connection structure characterized in that it is detached with a screw structure that rotates less than the connection portion or with a screw structure that is easy to loosen compared to other connection portions.
[0014]
In order to achieve the above object, the present invention relates to a connection structure for pipes used when digging a tunnel by reinforcing the ground by the AGF method, wherein a plurality of pipes are each screw-type. It is characterized in that one of the connection portions is connected to the other connection portion and the screw is rotated in the opposite direction.
[0015]
In addition, preferably, in addition to the above-described configuration, a screw at a front end of a proximal end tube connected to the foreground is a reverse screw with a screw at a front end of another tube. Structure.
[0016]
In addition, preferably, in addition to the above configuration, the connecting portion between the terminal tube and the intermediate tube connected to the front end portion has a screw structure that is easier to loosen than the other connecting portions with less rotation than other connecting portions. It is a pipe connection structure characterized by being attached and detached.
[0017]
Preferably, in addition to the above configuration, the terminal tube is a resin tube, and a rear end portion (commonly called a prolong portion) of a metal cylindrical joint is fixed to a front end portion of the terminal tube. The pipe connection structure is characterized in that a screw connected to the intermediate pipe is formed at a front end of the joint.
[0018]
Further, in order to achieve the above object, the present invention provides a non-widening AGF method constructed by using a plurality of pipes to which the above-described pipe connection structure is applied, and the terminal pipe once buried. Is a non-widening AGF method characterized in that it is rotated in a direction of loosening a screw at a connection portion at a front end thereof, removed, collected, and reusable.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
The present invention relates to a tunnel auxiliary construction method for tunnel construction in the civil engineering and construction industry, specifically, an injection-type long precedent receiving method (AGF method). The present invention relates to a long steel pipe forpiling and the like. Hereinafter, the connection structure between pipes of the present invention used at the time of excavation of a tunnel and the non-widening AGF method using a pipe having the connection structure will be described in more detail based on examples. In addition, although the connection structure between pipes of the present invention can be applied to the widening AGF method, an example applied to the non-widening AGF method will be described below.
FIG. 1 is an exploded view of a pipe to which the connection structure of the present invention is applied.
[0020]
In this embodiment, the pipes driven into the ground are composed of, for example, four pipes, namely, a tip pipe 1, a first intermediate pipe 10, a second intermediate pipe 20, and a terminal pipe 30, and adjacent pipes can be connected to each other by screws. It is. Each of the tubes 1, 10, 20, 30 is, for example, about 3 m15 cm to 3 m20 cm, and when connected, the total length of about four pipes is about 12.5 m.
[0021]
The end pipe 1, the first intermediate pipe 10, and the second intermediate pipe 20 are cylindrical metal pipes, for example, steel pipes, and the terminal pipe 30 is a cylindrical resin pipe, for example, a Hi-Vp pipe (hard PVC pipe) or the like. It is said. In addition, four rows of holes 1a, 10a, and 20a that communicate the inside and outside at regular intervals in the axial direction are formed in the peripheral side walls of the distal end pipe 1, the first intermediate pipe 10, and the second intermediate pipe 20 at equal intervals in the circumferential direction. Have been.
[0022]
The connection of each pipe, that is, the tip pipe 1 and the first intermediate pipe 10, the first intermediate pipe 10 and the second intermediate pipe 20, and the second intermediate pipe 20 and the terminal pipe 30 are each of a screw type.
In this embodiment, a male screw 2 is formed on the outer peripheral surface of the rear end portion of the distal end tube 1. The first intermediate pipe 10 has a female screw 11 formed on the inner peripheral surface of the front end, and a male screw 12 formed on the outer peripheral surface of the rear end. Further, the second intermediate pipe 20 has a female screw 21 formed on an inner peripheral surface of a front end portion, and a female screw 22 is also formed on an inner peripheral surface of a rear end portion. An external thread 31 is formed on the outer peripheral surface of the front end of the terminal tube 30 via a tubular joint (40), which will be described later. The male screw and the female screw of the adjacent pipes can be screwed together when connecting the pipes.
[0023]
In this embodiment, the screws 2, 11, 12, 21 formed on the rear end of the distal end tube 1, the front end and the rear end of the first intermediate tube 10, and the front end of the second intermediate tube 20, respectively, are The tubes are connected by turning the proximal tube to the right with respect to the distal tube.
[0024]
On the other hand, the screws 22 and 31 formed on the rear end of the second intermediate pipe 20 and the front end of the terminal pipe 30 (joint 40) are left-handed screws. Turn left to connect.
Thus, the screw 31 at the front end of the terminal tube 30 is a reverse screw to the screws 11 and 21 at the front end of the other tubes 10 and 20.
[0025]
The connection between the terminal pipe 30 and the second intermediate pipe 20 is detachable with less rotation than the other connection parts. That is, the screwing amount (screw length) 31a when connecting the terminal tube 30 to the second intermediate tube 20 is smaller than the screwing amounts 12a and 2a of the other connecting portions. Specifically, the number of threads of the screw 31 (22) formed at the front end of the terminal pipe 30 and the rear end of the second intermediate pipe 20 is the same as that of the other screws 2 (11) and 12 (21). Less than the number of mountains. For example, when connecting the distal end tube 1 and the first intermediate tube 10 and connecting the first intermediate tube 10 and the second intermediate tube 20, the proximal end tube is connected to the distal end tube by rotating it 5 times. When connecting the second intermediate pipe 20 and the terminal pipe 30, the connection can be made only by rotating the terminal pipe 30 three times with respect to the second intermediate pipe 20.
Further, the screws 31 and 22 of the terminal tube 30 and the second intermediate tube 20 may be trapezoidal screws having an easily loosened screw structure, and the other screws 2 (11) and 12 (21) may be thread screws. The use of a reverse screw, the reduction of the number of screw threads, and the change of the screw structure can be appropriately combined.
[0026]
By the way, a mark for identifying the direction of the tube and the direction of the tube is attached to the tip of each tube 1, 10, 20, 30. For example, as shown in FIG. 1, the front end of the distal end tube 1 is marked with a mark 1c on the peripheral side in blue, and the front end of the first intermediate tube 10 is marked with a mark 10c on the peripheral side in yellow. ing. The front end of the second intermediate tube 20 is double-marked 20 c on the peripheral side in yellow, and the front end of the terminal tube 30 is marked in red on the peripheral side 30 c.
In addition, a hole 30d for inserting a tool when attaching and detaching the terminal tube 30 is formed in a rear end portion of the terminal tube 30.
[0027]
FIG. 2 is a partially omitted cross-sectional view showing a connecting portion between the first intermediate tube 10 and the second intermediate tube 20 and a connecting portion between the second intermediate tube 20 and the terminal tube 30.
A joint 40 (prolong) made of metal (steel in the present embodiment) is fixed to the front end of the PVC end tube 30. The joint 40 has a stepped cylindrical shape, and has a male screw which can be screwed to a female screw 22 formed on the inner peripheral surface of the rear end of the second intermediate pipe 20 on the outer peripheral surface of the small diameter portion on the front end side. A screw 31 (left screw) is formed.
[0028]
The large-diameter portion 41 on the rear end side of the joint 40 is externally fitted to a small-diameter portion 30a formed on the front end side of the terminal tube 30 and is fixed by bonding or welding. The second intermediate pipe 20 and the terminal pipe 30 are connected via the joint 40. When the second intermediate pipe 20 and the terminal pipe 30 are connected, it is preferable that the rear end face 20 b of the second intermediate pipe 20 abuts on the front end face 41 b of the large diameter portion 41 of the joint 40.
[0029]
FIG. 3 is an exploded perspective view showing a connection structure between the front end of the distal end tube 1 and the ring bit 50.
A ring bit 50 is attached to the front end of the distal tube 1. The ring bit 50 has a stepped cylindrical shape, and a small diameter portion 51 on the rear end side can be inserted into the front end portion of the distal end tube 1. Further, a carbide tip 53 serving as a cutting edge in the circumferential direction is provided on the front end face of the large diameter portion 52 on the front end side.
[0030]
The connection between the tip tube 1 and the ring bit 50 is free and falls into the groove 51a formed on the outer peripheral surface of the small diameter portion 51 of the ring bit 50 and the groove 1b formed on the inner peripheral surface of the tip tube 1. This is performed by attaching the prevention clip 60. The falling-off prevention clip 60 is a plate spring formed in a substantially short cylindrical shape with a part cut away, and is firmly attached to the groove 1b of the distal end tube 1 by trying to spread outward. It does not come off. When the tip tube 1 is provided with the ring bit 50, the ring bit 50 is freely rotated with respect to the tip tube 1.
[0031]
FIG. 4 is a front view showing a state where the pipe and the drill rod are connected.
When the pipes 1, 10, 20, 30 are driven into the ground, a drilling rod (inner rod) 77 is inserted into the pipes 1, 10, 20, 30. This drilled rod 77 is formed by connecting a plurality of rod-shaped rods, similarly to the pipe. In the present embodiment, four rods of a tip rod 70, a first intermediate rod 72, a second intermediate rod 74, and a terminal rod 76 are provided. Rods are connected.
[0032]
FIG. 5 is a view showing a state in which the distal end rod 70 is inserted to the end of the distal end tube 1, and shows a state viewed from the distal end side.
An inner bit 80 is provided at the front end of the tip rod 70. The inner bit 80 has a substantially cylindrical shape having a diameter larger than the diameter of the rod 70, and a plurality of carbide tips 81 are provided on a front end surface thereof.
[0033]
As shown in FIG. 5, when the tip rod 70 is inserted into the tip tube 1, the inner bit 80 is shaped to removably engage with the ring bit 50. Further, the ring bit 50 rotates in accordance with the rotation of the inner bit 80.
[0034]
Next, a method of using the AGF method pipe of the present embodiment in the non-widening AGF method will be described.
FIG. 6 is a front view showing a state where the pipe and the drilling rod 77 are driven into the ground by the drill jumbo 100.
[0035]
First, the tip rod 70 is inserted into the tip tube 1.
Then, the rear end of the tip rod 70 is hit and rotated by the drifter air (compressed air) of the drill jumbo (drilling machine) 100, and is driven at an angle of, for example, about 8 to 10 ° with respect to the axial direction of the tunnel. Go out.
[0036]
FIG. 7 is a partial cross-sectional view showing a state where the tip rod 70 is inserted into the tip tube 1.
When driving the drilling rod 77 with the drill jumbo 100, the inner bit 80 of the tip rod 70 rotates and excavates the ground. Then, the inner bit 80 rotates the ring bit 50 integrally while pushing the tip tube 1. As described above, the ring bit 50 also rotates following the rotation of the inner bit 80, and the tip tube 1 enters the ground so as to be drawn into the inner bit 80.
[0037]
FIG. 8 is a partial sectional view showing a flushing state.
When excavating the ground with the inner bit 80 and the ring bit 50, pressurized water is caused to flow inside the pipe. This water is released to the ground, and as shown in FIG. 8, when the drilling rod is pulled out of the pipe, the excavated earth and sand flows along with the water inside the pipe and around the pipe toward the hand. Come.
[0038]
After driving the tip tube 1 and the tip rod 70 to some extent, the first intermediate tube 10 is connected to the tip tube 1 and the first intermediate rod 72 is added. At this time, since the screw 2 at the rear end of the distal tube 1 and the screw 11 at the front end of the first intermediate tube 10 are right-handed screws, the first intermediate tube 10 is moved rightward with respect to the distal tube 1. It is possible to connect by rotating to. Then, similarly to the case of the distal end pipe 1, the first intermediate pipe 10 is driven into the ground.
[0039]
Thereafter, similarly, the second intermediate pipe 20 and the terminal pipe 30 are connected, and the second intermediate rod 74 and the terminal rod 76 are also added and driven. Note that the screw 22 at the rear end of the second intermediate pipe 20 and the screw 31 at the front end of the terminal pipe 30 are left-handed screws. Rotate and connect.
[0040]
FIG. 9 is a front view showing a state where four pipes are driven into the ground.
As shown in FIG. 9, after the end tube 30 is driven into the rear end portion, the drilling rod 77 is pulled out.
FIG. 10 is a front view showing a state where the injection insert tube 85 is inserted into the tube.
As shown in FIG. 10, after the drilling rod 77 is pulled out from the tube, the injection insert tube 85 is inserted into the inside of the terminal tube 30 from the rear end of the terminal tube 30.
[0041]
FIG. 11 is a front view showing a state where the terminal tube 30 is being collected.
After inserting the injection insert tube 85, the terminal tube 30 is recovered from the base end side of the injection insert tube 85.
When the terminal tube 30 is collected, the screw 31 formed at the front end of the terminal tube 30 is a left-handed screw, so that the screw (tip tube 1, the first intermediate tube 10, the second intermediate tube 20) on the distal side is used. On the other hand, the terminal tube 30 may be turned in a loosening direction, that is, clockwise in the present embodiment. When the terminal tube 30 is collected, the terminal tube 30 is turned to the right, and even if the distal end tube is rotated to the right, the connection between the other tubes is a right-handed screw. Only the force is applied and the other connecting portions do not come off, and only the connecting portion between the second intermediate tube 20 and the terminal tube 30 comes off.
[0042]
In addition, since only the connecting portion between the terminal 30 and the second intermediate tube 20 is formed with a small number of threads, it is easy to remove, and only the terminal tube 30 can be securely removed. In addition, the screws 31 and 22 of the terminal tube 30 and the second intermediate tube 20 are trapezoidal screws, and the other screws 2 (11) and 12 (21) are threaded screws, so that the terminal tube 30 is more reliably collected. be able to. Then, the collected terminal tube 30 becomes a collection tube, and can be used repeatedly from the next time.
[0043]
FIG. 12 is a front view showing a state where the curing agent 87 is being poured from the injection insert tube 85.
After collecting the terminal tube 30, the other end of the injection insert tube 85 is connected to the injection device 88, and the hardener 87 is poured into the tube. The hardening agent 87 flows out from the holes 1a, 10a, 20a formed in the tip tube 1, the first intermediate tube 10, and the second intermediate tube 20 to the ground, and solidifies the mountain. By solidifying the ground, the risk of collapse during excavation is reduced, and construction can be performed safely.
[0044]
Note that a bag-like packer is attached in the middle of the injection insert tube 85. The packer is inserted into the tube in a deflated state, expands by a predetermined operation from the proximal end side, and closes the proximal end of the tube. Thereby, the curing agent 87 does not flow backward.
[0045]
In this embodiment, since the screw portion 31 of the terminal tube (collection tube) 30, that is, the joint 40 is made of metal, the screw portion 31 is hardly damaged, has excellent durability, and can withstand reuse. Further, since the terminal tube 30 is a special resin tube (hard PVC tube), the terminal tube 30 is light and excellent in durability, can be handled by human power, and can withstand reuse.
[0046]
Since the terminal pipe 30 can be collected, there is no pipe broken during excavation as in the related art, and no industrial waste is generated.
Also, even if the terminal tube cannot be collected and remains, it can be broken by an excavator because the terminal tube 30 itself is a resin tube.
Further, by collecting and reusing the terminal tube 30, it is possible to reduce material costs and disposal costs, thereby achieving cost reduction.
[0047]
In the non-widening AGF method, it is not suitable to make all the pipes steel pipes because the base end of the steel pipe hits the blade of the excavator during excavation. Therefore, by replacing the terminal pipe with a resin pipe, it becomes possible to excavate a tunnel while breaking it with an excavator. However, it becomes necessary to dispose of the terminal pipe as industrial waste by destroying it. Furthermore, disposing of all tubes is a waste of resources and costs.
[0048]
This would be expensive and time-consuming. Therefore, by making the terminal tube detachable, the terminal tube is not destroyed, and no industrial waste is produced. However, when the screw portion is formed on the resin tube and reused, the screw portion is also made of resin, so that it is weak and easily broken. Therefore, the terminal tube having such a configuration is not suitable for reuse.
Thus, in the present invention, the screw portion is made of metal, so that the terminal tube can be collected and can be used again. Moreover, even if the terminal tube cannot be collected without being removed, there is no inconvenience because the terminal tube is made of a resin tube.
[0049]
As described above, according to the present invention, it is possible to collect the terminal pipe 30 hammered into the ground and reuse it.
By the way, in the above embodiment, the screw 31 at the front end of the terminal pipe (collection pipe) 30 is reversely screwed to the other screws 2 (11) and 12 (21), but the other screw 2 ( It is good also as a screw of the same direction as 11) and 12 (21). That is, the screw 31 of the joint 40 and the screw 22 at the rear end of the second intermediate pipe may be right-handed screws in the above embodiment.
By rotating the terminal tube 30 with respect to the tip tube 1, the first intermediate tube 10 and the second intermediate tube 20 in a direction to loosen the screw, the terminal tube 30 can be removed from the second intermediate tube 20 and collected. It is. For example, the number of threads of the screw 31 at the front end of the terminal tube 30 may be formed smaller than the number of threads of the other connecting portions. Furthermore, the screw of the screw 31 at the front end of the terminal tube can be a trapezoidal screw, and the other screws 2 (11) and 12 (21) can be a thread, which can be combined with reducing the number of threads. Good.
[0050]
In addition, the pipe connection structure of the AGF method of the present invention is not limited to the configuration of the above embodiment, and can be appropriately changed.
In the above-described embodiment, the pipe is divided into four parts: the distal end pipe, the first intermediate pipe, the second intermediate pipe, and the end pipe.
Further, in the above embodiment, the screws formed at the rear end of the distal end pipe, the front end and the rear end of the first intermediate pipe, and the front end of the second intermediate pipe are respectively right-handed threads, and The screws formed at the rear end and the front end of the terminal tube are left-handed screws, but may be reversed.
Further, the connection between the distal end pipe and the first intermediate pipe and / or the connection between the first intermediate pipe and the second intermediate pipe may not be of a screw type but may be fitting.
[0051]
【The invention's effect】
As described in detail above, according to the pipe connection structure of the present invention, at least the terminal pipe can be collected and reused, so that it is not necessary to generate industrial waste, and it is possible to reduce costs such as material costs. It becomes possible.
[Brief description of the drawings]
FIG. 1 is an exploded view showing a pipe to which a connection structure of the present invention is applied.
FIG. 2 is a partially omitted cross-sectional view showing respective connecting portions of a first intermediate tube and a second intermediate tube, and a second intermediate tube and a terminal tube.
FIG. 3 is an exploded perspective view showing a connection structure between a front end portion of a distal end tube and a ring bit.
FIG. 4 is a front view showing a state where a pipe and a drilling rod are connected.
FIG. 5 is a view showing a state in which an inner bit is engaged with a ring bit.
FIG. 6 is a front view showing a state where a pipe and a drilling rod are driven into the ground by a drill jumbo;
FIG. 7 is a partial cross-sectional view showing a state where a tip rod is inserted into a tip tube.
FIG. 8 is a partial sectional view showing a flushing state.
FIG. 9 is a front view showing a state where four pipes are driven into the ground.
FIG. 10 is a front view showing a state where an injection insert tube is inserted into the tube.
FIG. 11 is a front view showing a state where the terminal tube is being collected.
FIG. 12 is a front view showing a state where a curing agent is poured from an injection insert tube.
FIG. 13 is a schematic view showing a conventional widening AGF method.
FIG. 14 is a schematic view showing a conventional non-widening AGF method.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Tip tube 1a Hole 1b Groove 2 Male screw 10 First intermediate tube 10a Hole 11 Female screw 12 Male screw 20 Second intermediate tube 20a Hole 21 Female screw 22 Female screw 30 Terminal tube 31 Male screw 40 Joint 50 Ring bit 51 Small diameter portion 52 Large diameter portion 53 Carbide tip 60 Drop-off prevention clip 70 Tip rod 72 First intermediate rod 74 Second intermediate rod 76 Terminal rod 77 Drilling rod 80 Inner bit 81 Carbide tip 85 Injection insert tube 87 Hardener 88 Injection equipment 90 Widened portion 91 Steel pipe 92 Steel pipe 92a Base end

Claims (8)

It is a connection structure between pipes used when digging a tunnel by reinforcing the ground with the AGF method,
Of the plurality of tubes connected to each other, the terminal tube on the proximal end connected to the foreground is once buried, then disconnected at the front end, removed, recovered, and reused. A pipe connection structure characterized by being made possible. The terminal tube and the intermediate tube connected to the front end are detachably connected with a screw type,
2. The pipe connection structure according to claim 1, wherein the buried terminal pipe is rotated in a direction of loosening a screw at a front end thereof, removed, collected, and reused. The plurality of pipes are respectively connected by a screw type,
Of the connecting parts, the connecting part between the terminal pipe and the intermediate pipe connected to the front end part is detachable with less rotation than other connecting parts or with a screw structure that is easier to loosen than other connecting parts. The pipe connection structure according to claim 2, characterized in that: It is a connection structure between pipes used when digging a tunnel by reinforcing the ground with the AGF method,
A plurality of pipes are connected with screw type respectively,
A pipe connection structure characterized in that one of the connection portions has a screw rotating direction opposite to that of another connection portion. The pipe connection structure according to claim 4, wherein the screw at the front end of the proximal end pipe connected to the foremost side is a reverse screw to the screw at the front end of another pipe. A connection portion between the terminal tube and an intermediate tube connected to the front end portion is detachably attached or detached with less rotation than other connection portions or with a screw structure that is easier to loosen than other connection portions. Item 6. The pipe connection structure according to Item 5. The terminal tube is a resin tube,
At the front end of this terminal tube, the rear end of a metal tubular joint is fixed,
The pipe connection structure according to any one of claims 2, 3, 5, and 6, wherein a screw connected to the intermediate pipe is formed at a front end of the joint. . A non-widening AGF method constructed using a plurality of pipes to which the pipe connection structure according to any one of claims 2 to 7 is applied,
The non-expandable AGF method, wherein the buried terminal pipe is once removed and recovered by being rotated in a direction of loosening a screw at a connection portion at a front end thereof, and is made reusable.

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