JP3249952B2 - Multi-stage steel pipe injection system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-expandable steel pipe preloading method for reinforcing a ground in front of a cutting face of a tunnel prior to excavating a tunnel (including an underground cavity for oil storage, etc.). Belongs to the technical field of tunnel excavation.

[0002]

2. Description of the Related Art In excavation of a tunnel, prior to excavation, in order to prevent loosening of earth and sand, rocks, rocks and the like forming the excavated tunnel wall surface and to ensure the safety of construction.
In order to reinforce the ground in front of the excavation face of the tunnel, and to excavate the tunnel, a widened steel pipe tip receiving type excavation method is used.

[0003] However, this excavation method has a problem that when excavating a tunnel in the ground, extra material excavation is required to excavate more than the area required for the tunnel, so that the material cost and the construction cost increase.

[0004] In order to solve the above-mentioned problems, the applicant of the present invention has proposed a method of excavating a steel pipe without widening (Japanese Patent Application No. 9-1990).
365460).

[0005] This method, as shown in FIG. 10, the steel pipe A
A resin pipe B is connected to the rear end of the
The steel pipe A is driven until its rear end is located outside the excavation area G in the ground F from the periphery of the excavation face E of the tunnel D, and then the resin pipe B exposed on the near side of the face E is driven. After inserting a hardening agent injection pipe from the rear end, and injecting the hardening agent into the ground F through the steel pipe A, excavate the front face E of the tunnel D together with the resin pipe B remaining in the excavation area G. Things.

[0006] Even in the case of one geological land F, the geology is various, and the type of hardening agent to be injected is selectively used depending on the type of geology where the groundwater vein passes and the type where the groundwater vein does not.

That is, in the above-mentioned excavation method without widening steel pipe, one kind of hardener is supplied to one steel pipe A by using a hardener injection pipe. Is used, a urethane-based or silica-resin-based curing agent that has the effect of preventing groundwater from leaking to the face E through the steel pipe A is used. Agent was used.

[0008] The urethane-based curing agents and the like are quick-curing, but have the disadvantage of low strength after curing. On the other hand, a cement-based curing agent, it is a drawback that a long curing time is in the high hardness degree.

Therefore, the face E of the steel pipe A is so set that the advantages of the respective hardeners can be extracted from the steel pipe A.
It is conceivable to supply a fast-curing urethane-based curing agent or the like to the side and a high-strength cement-based curing agent to the back side from the face E side.

[0010]

However, in the non-widening steel pipe precedent drilling method, as described above, one kind of hardener is supplied to one steel pipe A using a hardener injection pipe. For example, if a urethane-based hardening agent or the like is supplied to the face E side of the steel pipe A first, it hardens in a short time. Next, supply a cement-based hardening agent from the same hardening agent injection pipe. In this case, the hardening agent injection pipe is closed, and the cement hardening agent cannot be supplied.

Conversely, if a cement-based hardening agent is first supplied to the inner side of the steel pipe A from the face E side , the hardening agent flows through the steel pipe A to the face E before hardening. Even if a urethane-based curing agent is supplied from a tube, the curing agent injection tube may be closed, and a problem that the urethane-based curing agent cannot be supplied may occur.

Accordingly, the present invention is directed to a predeter- mined steel pipe through which a certain type of hardening agent can be reliably injected through a single steel pipe into a predetermined range of the ground on the face side and deeper than the predetermined range. It is an object to provide a multi-stage injection device. In the multi-stage injection pipe for steel pipe according to the present invention, the tunnel includes an underground cavity for oil storage and the like.

[0013]

In order to solve the above problems, the present invention uses the following means.

First, the invention according to claim 1 of the present application (hereinafter referred to as the invention)
According to a first aspect of the present invention, a steel pipe having a resin pipe connected to a rear end thereof is disposed from the periphery of the excavation face of the tunnel in the ground in the axial direction of the tunnel or slightly obliquely outward. In a multi-stage steel pipe receiving apparatus used for injecting a hardening agent into the ground in the non-widened steel pipe pre-receiving method to be removed, an injection main pipe inserted into the steel pipe, and the main pipe attached to an outer peripheral surface thereof. Multiple pipes inserted into steel pipe with pipe
Installed near the front end of the injection tube and the injection main
And a plurality of infusion tubes having
Of one of the tubes is after the front end of the injection main
On the other side, located in the packer and one other tube
The tip of the probe is located further behind the packer.
In addition, the back end of these injection tubes has a quick-setting hardener
Feeder is connected and at the rear end of the injection main
Is high hardness supplied to the space in front of the front end of the main pipe.
The hardening agent supply device is connected to the
The front end of the main pipe has an opening in the space in front of the front end of the main pipe.
The air bleeding tube is attached .

The invention according to claim 2 (hereinafter referred to as the second invention) is characterized in that, in the multi-stage steel pipe receiving apparatus of the first invention, the injection main pipe is located at the center of a cross section orthogonal to the axial direction. An inner tube portion, and an outer tube portion located concentrically with the inner tube portion, a concave portion extending in the axial direction is provided on the outer peripheral surface of the outer tube portion, and the wall of the inner tube portion and the concave portion are formed. The wall is connected to form an axially extending cavity surrounded by the wall of the inner tube, the wall of the outer tube, and the wall of the recess, and the inner tube has a cross section on the cross section. The thickness of the wall, the wall of the outer tube portion, and the thickness of the wall of the concave portion are substantially equal.

With the above arrangement, the following effects can be obtained according to the present invention.

Firstly, according to the first invention, after toward the steel tube was connected to the resin tube in the axial direction oblique outward of the tunnel to the ground Yamauchi from the periphery of the excavation working face of a tunnel is disposed in the rear end portion When injecting the hardening agent into the ground, a multi-stage steel pipe receiving tube inserted into the steel pipe, the injection main pipe and a plurality of injection tubes attached to the outer peripheral surface thereof ,
With a packer mounted near the front end
In one of the plurality of injection tubes,
The tip is located above the packer on the rear side of the front end of the injection pipe.
And the tip of one other tube is
Since located Risarani rearward, substantially package in the steel tube
The hardening agent is supplied to the rear end side from the car mounting position through the injection tube, and the hardening agent is supplied to the front end side in the steel pipe through the injection main pipe. Moreover, the above injection
At the rear end of the tube is a quick-setting hardener supply device.
In addition, a supply device for a hardening agent of high hardness is provided at the rear end of the injection main pipe.
Since location is adapted to be connected, one curing agent fast curing on the natural ground of the natural ground, i.e. working face side of the rear end of the steel pipe through the steel pipe, the distal end side of the steel pipe natural ground that will be a high hardness degree of the curing agent to the back side of the natural ground from the working face side is reliably injected, thereby, the leakage of ground water to be Nagaredeyo the working face side is suppressed, cured strength against the natural ground Can be increased. Furthermore, on the outer peripheral surface of the injection main pipe,
Is an open end of the main pipe in the space in front of the front end.
Since the tube for removing the holes is attached,
Air can be discharged from the space.

[0018] According to the second invention, the injection mains has a inner tube portion located in the center of the cross section perpendicular to the axial direction, an outer tube portion located on the inner tube portion concentric with its However, since the wall of the concave portion provided on the outer peripheral surface of the outer tube portion and extending in the axial direction is connected to the wall of the inner tube portion, the outer tube portion and the inner tube portion are integrated and have high rigidity. Become. Moreover, the portion formed by being surrounded by the wall of the inner tube, the wall of the outer tube, and the wall of the recess is a cavity extending in the axial direction, so that the weight of the injection main tube is reduced. Accordingly, the material cost of the injection main pipe can be reduced due to the reduction of the material used.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a steel pipe multistage injection apparatus according to an embodiment of the present invention will be described.

As shown in FIGS. 1 to 3, a multi-stage steel pipe receiving apparatus 1 comprises an injection main pipe 2, a first silica resin-based hardener injection tube 3, a second silica resin-based hardener injection tube 4, and a third silica resin. It has a system hardening agent injection tube 5, an air vent tube 6, and a cement system hardening agent injection pipe 7.

[0021] The injection main pipe 2 is molded by extrusion in synthetic resin, as shown in FIG. 2, which is shaped like a lotus root in a cross section perpendicular to the axial direction. The injection main pipe 2 is provided with four tube holding grooves 2a extending in the axial direction at intervals of 90 degrees in the circumferential direction.
2a, a through hole 2b located at the center in a cross section orthogonal to the axial direction and extending in the axial direction, and four through holes 2c... 2c extending in the axial direction so that the thickness on the cross section becomes uniform.
Are provided.

[0022] The shape of the tube holding groove 2a ... 2a is,
The main pipe 2 is formed in an Ω-shape in a cross section orthogonal to the axial direction of the injection main pipe 2, and the opening width to the outer peripheral surface of the main pipe 2 is smaller than the inside of the tube holding grooves 2a. Are smaller than the outer diameters of the first to third silica resin-based curing agent injection tubes 3 to 5 and the air release tube 6. Oh, these four tubes 3-6
Is made of an elastic synthetic resin, and can be mounted in the tube holding grooves 2a... 2a by being deformed. These four tubes 3 to 6 do not fall back from the tube holding grooves 2a.

Further, the through hole 2b is shaped to fit holding the cement-based curing agent injection pipe 7.

Furthermore, the outer peripheral surface near both ends of the injection main pipe 2, in general first cylindrical is called covering member and packer, second packer 8a, in a state where 8b at both ends portion thereof is narrowed Each is attached by a belt 9. Both packers 8a and 8b are made of a material through which a silica resin-based curing agent can pass.

At the center of the first packer 8a located at the rear end side (the right side in the side view of FIG. 1) of the injection main pipe 2, the tip 3a of the first silica resin-based hardener injection tube 3 is provided.
However, in the center of the second packer 8b located on the distal end side (left side in FIG. 1 side view) of the injection main pipe 2, the distal end portion 4a of the second silica resin-based hardener injection tube 4 is provided with the first and second packers. At the center between 8a and 8b, a distal end portion 5a of a third silica resin-based hardening agent injection tube 5 is disposed, and a distal end portion 6a of the air release tube 6 (see FIG. 8) is used to inject a cement-based hardening agent. The pipe 7 is provided so as to protrude from a tip 7 a of the pipe 7.

Further , the cement-based hardening agent injection pipe 7
Is protruded at a position away from the tip of the injection main pipe 2 by a predetermined amount. The cement hardening agent injection pipe 7 is made of a synthetic resin.

[0027] The end portion of the distal end side of the four thinned-out part 2c ... 2c is closed by padding member 10 ... 10. Further, groove filling members 11 are attached to predetermined portions of the tube holding grooves 2a 2a so that the insides of the first and second packers 8a 8b are closed spaces.

The rear ends of the first to third silica resin-based hardening agent injection tubes 3 to 5 of the multi-stage steel pipe receiving device 1 are connected to a silica resin-based hardening agent supply device 13 for supplying a silica resin-based hardening agent 12. And the rear end of the cement-based hardener injection pipe 7 of the multi-stage steel pipe receiving device 1 is connected to a cement-based hardener injection device 15 that supplies a cement-based hardener 14. Has become.

[0029] Here, in the non-widened steel destination受工method using the destination受鋼tube multistage injection device 1, for example, as shown in FIG. 4, the steel pipe 20 is used. The steel pipe 20 has a groove 20b in the circumferential direction of the outer peripheral surface of the front end portion 20a, a plurality of injection holes 20c... 20c at predetermined intervals in the longitudinal direction from the front end portion 20a, and an inner peripheral surface of the rear end portion 20d. Screw part 2
It has a shape and a 0e.

[0030] Then, the steel tube 20, injection plurality of the threaded portion 21b and the tip portion 21a on the outer peripheral surface of the distal end portion 21a in a cylindrical shape at a predetermined distance in the longitudinal bore 21c ... 2
1c, the two screw portions 20e, 21b
Of being connected by screwing.

The drill 22 is rotatably mounted by engaging mounting members 22a... 22a provided on the drill 22 with the grooves 20b of the steel pipe 20, and from the rear end 21d of the resin pipe 21. The rod 23 inserted into the steel pipe 20 is connected to the rear end 22 of the drill 22.
b. The rod 23 is detachable from the drill 22.

Next, a description will be given of a tunnel excavation with the continuously widening steel tube destination受工method.

First, as shown in FIGS. 5-7, with the drill 22 is attached to the steel tube 20, by which the drill 22 is connected to the steel pipe hammering device 24 via the rod 23, The steel pipe 20 is set in the steel pipe driving device 24. The drill 22 receives a rotational force from a steel pipe driving device 24 via a rod 23 to drill a ground 25.

[0034] That is, excavating the working face 27 of the tunnel 26 the drill 22 attached to the distal end portion 20a of the steel tube 20
And the drill 22 penetrates into the ground 25 in front while drilling the ground 25 by the rotational force given by the steel pipe driving device 24. At this time, the steel pipe 20 is drawn into the ground 25 by the driving force of the drill 22.

When the rear end 20d of the steel pipe 20 is retracted until the rear end 20d is positioned outside the excavation area 28 in front of the excavation face 27, the rotation of the drill 22 is stopped, and the rod 23 attached to the drill 22 is stopped. Is removed. In addition, the drill 22 is attached to the steel pipe 20 and
25 .

[0036] In this way, after the steel pipe 20 is arranged inside the natural ground 25, but will be the curing agent is injected, in the present embodiment, the above受鋼tube multistage injection device 1 described above Injection of the curing agent is performed as follows.

[0037] That is, as shown in FIG. 8, a curing agent injection device 1 from the rear end 21c of the resin tube 21 is inserted at the head tip portion 6a side of the air vent tube 6, the natural ground 25
Is set at a predetermined position in the steel pipe 20 so that the first packer 8a is positioned on the face 26 side of the steel pipe 20. In addition, the rear ends of the first to third silica resin-based hardener injection tubes 3 to 5 of the above-described steel pipe multi-stage injection device 1 are connected to a silica resin-based hardener supply device 13 (FIG. 1) for supplying a silica resin-based hardener 12. ), And the rear end of the cement-based hardener injection pipe 7 of the hardener-injection device 1 is connected to a cement-based hardener supply device 15 (see FIG. 1 ) that supplies a cement-based hardener 14. Connected.

[0038] Then, first, the resin pipe 21 from the distal end 3a~5a of Shirikarejin curing agent 12 supplied from Shirikarejin curing agent feeder 13 first to third Shirikarejin curing agent injection tube 3-5 After being injected into the ground 25 through the plurality of injection holes 21c... 21c provided, and after the silica resin-based curing agent 12 has been cured, the cement-based curing agent 14 supplied from the cement-based curing agent injecting device 15 is used as a cement-based curing agent. Tip 7a of hardener injection pipe 7
.. 20c provided in the steel pipe 20
Through the ground 25 .

Next, after being injected the cement curing agent 14 has cured, Shirikarejin curing agent injection device 13
To first to third silica resin-based curing agent injection tubes 3 to
5 is removed, and the cement-based hardener injection device 1 is removed.
The cement hardening agent injection pipe 7 is removed from 5.
Then, as shown in FIG. 9, the excavation face 27 of the tunnel 26 is excavated by an excavator (not shown) together with the resin pipe 21 and the multi-stage injection pipe 1 for the steel pipe remaining in the excavation area 28 in front of the excavation face 27. You.

As described above, according to this non-widened steel pipe front receiving method, the resin pipe 21 is connected to the rear end 20d of the steel pipe 20, and the drill 22 is rotatably attached to the front end 20a of the steel pipe 20. by thrust of the drill 22, the steel tube 20 and the resin tube 21 while drilling the natural ground 25, excavating the rear end portion 20d of the front excavation working face 27 of the steel pipe 20 region 2
8 until it is outside. And the face 2
From the rear end portion 21c of the resin tube 21 to expose the 7 previously受鋼pipe multi
The step injection device 1 is inserted, and the curing agent is injected into the ground 25.

In this case, the pre-received steel pipe multistage injection device 1 has an injection main pipe 2, first to third silica resin-based hardening agent injection tubes 3 to 5, and a cement-based hardening agent injection pipe 7, and three injections. Since the distal ends 3a to 5a of the tubes 3 to 5 are arranged on the rear end side from the distal end of the injection main pipe 2, the silica resin which is fast-hardened through the three injection tubes 3 to 5 at the rear end side in the steel pipe 20. The hardening agent 12 is supplied, and the tip 7a of the cement hardening agent injection pipe 7 is provided so as to protrude at a position away from the tip of the injection main pipe 2 by a predetermined amount. high hardness of the cement-based curing agent, through a cement-based curing agent injection pipe 7 14
Will be supplied. That is, the hardening silica resin-based hardening agent 12 in the predetermined range a of the ground 25 on the side of the face 27 through the inside of one steel pipe 20 is higher than the predetermined range b of the ground 25 deeper than the predetermined range a. the hardness of the cement-based curing agent 14
Is surely injected, and as a result, the face 27
The leakage of the groundwater that tends to flow to the side is suppressed, and the hardening strength for the ground 25 can be increased.

[0042] Then, the first Shirikarejin curing agent injection tube 3 in the outer peripheral surface of the injection main second tip portion 3a
The portion where the tip 4a of the second silica resin-based curing agent injection tube 4 is located is covered with the first and second packers 8a and 8b through which the silica resin-based curing agent 12 can pass. The silica resin-based curing agent 12 supplied through the tubes 3 and 4 is supplied to the first and second packers 8.
a, 8b, and then through both packers 8a, 8b
To be injected into the ground 25. Therefore, the hardener 12 does not diffuse more than necessary in the steel pipe 20, whereby the hardener 12 can be effectively injected in a small amount into the predetermined range a of the ground 25.

[0043] In addition, the distal end portion 6a of the air vent tube 6
Is provided so as to protrude from the tip 7a of the cement-based hardening agent injection pipe 7, so that even if the silica resin-based hardening agent 12 is hardened first and the rear end side of the steel pipe 20 is closed, The air remaining in the pipe 20 is discharged out of the steel pipe 20 through the air release tube 6. Thereby, the cement-based hardener 14 can be smoothly supplied from the cement-based hardener injection pipe 7 into the steel pipe 20 without the air remaining in the steel pipe 20 becoming a resistance. Moreover, the steel pipe 2 is passed through the air release tube 6.
When the hardener 14 flows out of zero, it can also be confirmed that the steel pipe 20 and the ground 25 around the steel pipe 20 are filled with the hardener 14.

[0044] Further, the tip portion 7a of the cement-based hardening agent injection pipe 7, so is disposed in a predetermined amount away of the distal side of the second packer 8b, the tip portion 7a by Shirikarejin hardener 12 The cement hardener 14 can be reliably supplied into the steel pipe 20 without being blocked.

In addition, the injection main pipe 2 is located at the center of a cross-section orthogonal to the axial direction of the injection main pipe 2 with the walls of the tube holding grooves 2a. Since it is connected to the wall of the through hole 2b, it has high rigidity, and even if the cement hardening agent 14 is supplied at a high pressure to the cement hardening agent injection pipe 7 inserted into the through hole 2b, The pressure does not damage the injection main pipe 2. Moreover, four wall-thickened portions 2c extending in the axial direction so that the thickness of each wall on the cross section becomes uniform.
Since the injection pipe 2c is provided, the weight of the injection main pipe 2 can be reduced, and accordingly, the material cost of the injection main pipe 2 can be reduced by reducing the materials used.

The injection main pipe 2 is made of synthetic resin and formed by extrusion. When the injection main pipe in a high temperature state is cooled to room temperature, a cross section orthogonal to the axial direction of the injection main pipe 2 is formed. Since the thickness of each of the upper walls is substantially equal, the cooling is uniformly performed. As a result, the injection main pipe 2 is formed in a required shape without deformation due to thermal strain caused by uneven cooling, and a large number of inexpensive and high-quality ones are formed.

The multi-stage injection pipe for steel pipe 1 of the present embodiment has a cement hardening agent injection pipe 7 inserted into the through hole 2b of the injection main pipe 2, and the cement 25 is inserted into the ground 25 through the steel pipe 20. Although the hardening agent 14 is injected, the hardening agent 14 may be supplied directly through the through hole 2b without using the hardening agent injection pipe 7.

Further , the injection main pipe 2 may be used as a joint for extending the cement hardening agent injection pipe 7.

[0049]

As described above, according to the first aspect of the present invention, a steel pipe having a resin pipe connected to the rear end portion is inserted into the ground from the periphery of the excavation face of the tunnel in the axial direction of the tunnel or slightly obliquely outward. After arranging for the hardening agent into the ground, the prior steel pipe multi-stage injection device inserted into the steel pipe,
Injection mains and multiple injection tubes attached to the outer circumference
And a packer mounted near the front end of the injection mains
And having one of the plurality of injection tubes.
The tip of one tube is behind the front end of the injection main .
And is located in the packer above the other tube.
Since the end is located further rearward than the packer , a hardening agent is supplied to the rear end side from the substantially packer mounting position in the steel pipe through the injection tube, and hardened through the injection main pipe to the front end side in the steel pipe. The agent will be supplied.
In addition, a quick-setting hardener is located at the rear end of the injection tube.
Supply device, and the rear end of the injection main pipe has high hardness
Is connected to the hardener supply device
Then, a hardening agent having a rapid hardening property is applied to the ground on the rear end side of the steel pipe, that is, the ground on the face side, through the inside of one steel pipe, to the ground on the front end side of the steel pipe, that is, the ground on the back side of the face side. high hardness of the curing agent is to be reliably injected. Thereby, the leakage of the groundwater that tends to flow to the face side can be suppressed, and the hardening strength against the ground can be increased. In addition,
On the outer peripheral surface of the main pipe, a space is provided in front of the front end of the main pipe.
The air vent tube with the open end is attached
Air can be discharged from the front space.
I will be able to.

[0050] According to the second invention, the injection mains has a inner tube portion located in the center of the cross section perpendicular to the axial direction, an outer tube portion located on the inner tube portion concentric with its However, since the wall of the concave portion provided on the outer peripheral surface of the outer tube portion and extending in the axial direction is connected to the wall of the inner tube portion, the outer tube portion and the inner tube portion are integrated and have high rigidity. Become. Moreover, the portion formed by being surrounded by the wall of the inner tube, the wall of the outer tube, and the wall of the recess is a cavity extending in the axial direction, so that the weight of the injection main tube is reduced. Accordingly, the material cost of the injection main pipe can be reduced due to the reduction of the material used.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view showing a multi-stage steel pipe receiving apparatus according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view taken along the line AA of FIG.

FIG. 3 is a cross-sectional view of a portion a of FIG. 1 as viewed from the same direction as a woo line of FIG. 2;

FIG. 4 is a cross-sectional view showing an example of a steel pipe or the like used in the non-widening steel pipe tip receiving method.

FIG. 5 is a schematic sectional view illustrating excavation of a tunnel by a non-widening steel pipe pre-receiving method using a pre-received steel pipe multistage injection device.

FIG. 6 is an enlarged sectional view of a main part of FIG. 5;

FIG. 7 is an enlarged cross-sectional view of another main part for explaining excavation of a tunnel by a non-widening steel pipe precedent method using a precedent steel pipe multistage injection device.

FIG. 8 is an enlarged cross-sectional view of another principal part for explaining the excavation of the tunnel.

FIG. 9 is another enlarged cross-sectional view of a main part, similarly illustrating excavation of a tunnel.

FIG. 10 is a cross-sectional view illustrating excavation of a tunnel by a non-widening steel pipe tip receiving excavation method.

[Explanation of symbols]

DESCRIPTION OF REFERENCE NUMERALS 1 Multi-stage injection pipe for steel pipe 2 Injection main pipe 2a ... 2a Tube holding groove (recessed part) 2b Through hole (inner pipe part) 2c ... 2c Thinned part (hollow part) 3 First silica resin-based curing agent injection tube (injection tube) 4) Second silica resin-based hardener injection tube (injection tube) 5 Third silica resin-based hardener injection tube (injection tube) 6 Air release tube 8a, 8b Packer (coating member) 12 Silica resin-based hardener (hardener) 13 Silica resin System-based hardener supply device (hardener supply device) 14 Cement-based hardener (hardener) 15 Cement-based hardener supply device (hardener supply device) 20 Steel pipe 21 Resin tube 25 Chiyama 26 Tunnel 27 Drilling face

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) E21D 9/04

Claims (2)

(57) [Claims] 1. A steel pipe having a resin pipe connected to a rear end thereof is disposed from a peripheral portion of an excavation face of a tunnel to a ground in an axial direction of the tunnel or slightly obliquely outward, and then the resin pipe is removed. What is claimed is: 1. A multi-stage steel pipe pre-injection apparatus for use in injecting a hardening agent into the ground in a non-widening steel pipe pre-receiving method, comprising: an injection main pipe inserted into the steel pipe; Several injection tubes inserted into the steel tube with the tube
And a packer mounted near the front end of the injection mains
And having one of the plurality of injection tubes.
The tip of one tube is behind the front end of the injection main.
And is located in the packer above the other tube.
The edge is located further behind the packer and
At the rear end of these injection tubes, a quick-setting hardener
And the rear end of the injection main is connected to the main
Of hardener supplied to the space in front of the front end of
A supply device is connected, and the outer peripheral surface of the injection main pipe is
Air vent opening at the front end into the space ahead of the front end of the main pipe
A multi-stage injection pipe for receiving steel pipes, which is provided with a tubing . 2. The injection main pipe has an inner pipe located at the center of a cross section orthogonal to the axial direction, and an outer pipe located concentrically with the inner pipe. A concave portion extending in the axial direction is provided on the outer peripheral surface, and a wall of the inner tube portion and a wall of the concave portion are connected to each other to form an axial direction surrounded by a wall of the inner tube portion, a wall of the outer tube portion, and a wall of the concave portion. The hollow portion extending to the inner tube portion is formed, and the thickness of the wall of the inner tube portion, the wall of the outer tube portion, and the wall of the concave portion on the cross section are made substantially equal. Multi-stage steel pipe injection equipment.