JPH10220165A - Reinforcing method of unsolidified natural ground and reinforcing member formation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a reinforcing member with high efficiency by the application of low cost and general purpose equipment. SOLUTION: Prior to the formation of an arch shell-shaped reinforcing member in front of an excavated surface, at first, a first bore hole 14A is excavated with an excavation hole pit 34. Then, the excavation hole pit 34 is pulled out and a guide rod 40 is inserted into a second bore hole 14A where a second bore hole 14B is excavated with the excavation hole pit 34. Then, the excavation hole pit 34 and the guide rod 40 are pulled out, thereby inserting the guide rod 40 into the second bore hole 14B. At that time, while an injection material 62 is being discharged from the tip of the guide rod 40 into the first bore hole 14A, the guide rod 40 is inserted thereinto so that the injection material may be filled up in the first bore hole 14A. When the guide rod 40 is inserted into the second bore hole 14B, a third bore hole 14C is excavated with the excavation hole pit 34.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for reinforcing unconsolidated ground and a device for forming a reinforcing member for preventing and stabilizing the collapse of the ground in tunnel construction or the like at the unconsolidated ground.

[0002]

2. Description of the Related Art In tunnel construction at an unconsolidated ground,
The following methods are known as a reinforcing method for stabilizing the ground in front of a tunnel excavation surface (face). (1) Pre-bolt bolt system A narrow ring-shaped excavation surface is provided on the face, and rock bolts and steel pipes are placed at regular intervals on the outer periphery of the tunnel diagonally in front of the face to reduce the overload when the face is excavated. These bolts and steel pipes are used as beams to reduce the earth pressure acting on the excavated surface. (2) Injection pile method A borehole is drilled on the outer periphery of the tunnel diagonally forward of the face, and high-pressure jet grout is performed from the tip of the drill when the bit is pulled out after the completion of the drilling. Form a pile. This operation is repeated one by one to form a continuous arch-shaped consolidated body so that the pile diameters formed in the piles overlap each other. (3) Chain cutter method While moving a chainsaw having a length of several meters circumferentially around the tunnel, cutting grooves and filling concrete from behind the chainsaw to form an arched solid body. .

[0003]

However, in the above-mentioned bolt receiving method of (1), since the earth and sand fall off between bolts and pipes which are laid at regular intervals during excavation, the effect of bearing the overload is not expected. . There is also a method of solidifying the surrounding earth and sand by grouting from a hollow bolt or a pipe to prevent the falling off, but the filling material is expensive. Further, in the method of providing a ring-shaped narrow excavation surface, work efficiency is extremely poor because of the narrowness. Next, in the injection pile method of the above (2), since the pump and the drilling device for supplying the high pressure jet are special machines, they are more expensive than the method of the above (1). In addition, since the hole is drilled by a high-pressure jet, the injected material is mixed with the discharged earth and sand, and the sludge is discharged. For this reason, the treatment cost of this sludge is also required separately. Next, the above (3)
In the chain cutter method, a special device for driving the chainsaw is required. Therefore, the object of the present invention is to
It is an object of the present invention to provide a method for reinforcing an unconsolidated ground mountain and a device for forming a reinforcing body, which can efficiently form a reinforcing body with inexpensive general-purpose equipment.

[0004]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention is to form a large number of holes forming a substantially slit-like groove in front of an excavation surface, and to fill and solidify the groove with an injection material. Thus, a method for reinforcing an unconsolidated ground mountain in which a substantially arch-shaped reinforcing body is formed in front of an excavation surface, wherein, when drilling the hole, a guide rod is inserted into the already drilled first hole. Insert
A second hole, a part of which is connected to the first hole, is drilled by a drill bit which advances while approaching the guide rod, and then the guide rod is pulled out of the first hole and the drill bit is removed. Is pulled out of the second hole, and then a guide rod is inserted into the second hole, and a third part of which is partially connected to the second hole by a drill bit which advances while approaching the guide rod. And filling the first hole with an injection material from the guide rod, drilling with such a drill bit, inserting the guide rod into the hole, and filling the hole with the guide rod. Is characterized by forming a substantially arch-shaped reinforcing body by repeating the filling of. Further, the present invention is characterized in that the filling of the injection material is performed by the injection material being injected into the hole from the tip of the guide rod while the guide rod is inserted into the hole. Also,
The present invention is characterized in that the opening of the hole filled with the filling material is closed when the filling material is filled.

Further, the present invention provides a method of forming a substantially arch-shaped groove in front of a digging surface by drilling a plurality of holes forming a substantially slit-like groove in front of the digging surface, filling the groove with an injection material and solidifying the hole. An apparatus for forming a reinforcing body, comprising: a guide rod inserted into an already drilled hole; and a drilling bit disposed at a tip thereof and disposed in parallel with the guide rod. A rod and a bracket for supporting the base of the guide rod so that the outer peripheral portion of the drill bit advances forward while approaching the outer peripheral portion of the guide rod, and for supporting the drill rod in a rotatable and axially movable manner. And an injection path that extends inside the guide rod from the base to the tip of the guide rod and that is opened as an injection hole in the outer peripheral surface of the guide rod. Further, the present invention is characterized in that the injection hole of the guide rod is opened at the end of the guide rod on the side opposite to the side where the drill bit is arranged. Further, according to the present invention, a plurality of protrusions projecting radially and continuously extending in the longitudinal direction of the guide rod are provided on the outer periphery of the distal end of the guide rod at intervals in the circumferential direction of the guide rod. A plurality of protrusions are formed, and the protrusions are formed in such a size as to press or bite into the inner wall of the hole drilled by the drill bit. Also, the present invention
At the bracket portion on the side of the guide rod, a closing member is provided at the same pitch as the pitch between the guide rod and the drilling rod, and the closing member is formed in a shape to close the hole drilled by the drill bit. And being biased forward by a biasing member.

In the method and apparatus for reinforcing an unconsolidated ground of the present invention, first, a first hole for forming a substantially slit-shaped groove in front of an excavation surface is drilled with a drill bit. I do. Next, a guide rod is inserted into the first hole, and a second hole adjacent to the first hole is drilled with a drill bit. Thereafter, the drill bit and the guide rod are pulled out from each hole, and then the guide rod is inserted into the second hole. On this occasion,
The injection material is discharged from the guide rod into the first hole, and is filled in the first hole. Then, after inserting the guide rod into the second hole, the third hole adjacent to the second hole is drilled by a drill. Next, the drilling bit and the guide rod are pulled out from each hole, and the guide rod is inserted into the third hole. At this time, the injection material is discharged from the guide rod into the second hole and is filled in the second hole. Then, after inserting the guide rod into the third hole, the fourth hole adjacent to the third hole is drilled with a drill bit. Then, a fourth hole adjacent to the third hole is drilled by a drill bit. The above operation is sequentially repeated on the excavated surface to form a substantially arch-shaped slit groove, and the injection material filled in the groove is solidified to form an arch-shell-shaped reinforcement. The injection material filled in each hole starts to harden within a few minutes and reaches a predetermined strength within a few hours, so that the injection material in each hole solidifies firmly to form an integral reinforcing body. it can.

In general, in order to form a reinforcing body in front of a face, it is necessary to make the position of a drilling hole and the posture of a rock drilling machine accurate, such as the drilling angle and the interval for providing an overlapping portion. For this reason, the conventional method requires a special positioning jig such as moving the drilling device along an arcuate rail or the like. However, in the reinforcing body forming apparatus of the present invention, drilling can be performed based on the hole formed immediately before by using the guide rod, and the moving stroke of the guide rod and the drill bit is small. Accurate drilling can be performed. Then, when the guide rod is inserted, the filling material can be filled at the same time, and an efficient operation can be performed. In addition, it is possible to use a general-purpose rock drilling machine to configure a device in which the guide rod and the drill bit are mounted, and it is not necessary to use a special machine, and the reinforcing member can be formed with an inexpensive device.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a method for reinforcing an unconsolidated ground and a device for forming a reinforcing body according to the present invention will be described. FIG. 1 is a perspective view showing an example of a reinforcing body formed in front of a tunnel face according to the present invention. As shown in the figure, a large number of continuous bore holes 14 are formed in front of the excavation surface (face) 12 along the outer periphery of the tunnel, and each of the bore holes 14 is filled with an injection material, so that an arch shell-shaped reinforcing body 10 is formed. Is formed. In addition, 1 in the figure
Reference numeral 6 denotes a tunnel bottom, on which the excavation surface 1 is formed on the bottom 16 using the reinforcing body forming apparatus according to the present invention.
The reinforcement body 10 is formed for 2.

FIG. 2 is a cross-sectional side view showing the structure of the reinforcing member forming apparatus in this embodiment. 3 to 8 show steps of forming the reinforcing body 10 by the reinforcing body forming apparatus shown in FIG. As shown in FIG. 2, the apparatus for forming a reinforcing body of the present embodiment is provided with a bracket 22 at the tip of a gantry 20 mounted on, for example, a general-purpose drill jumbo (not shown). And the guide rod 40 and the water stop mechanism 50 are supported. Stand 2
Numeral 0 is provided so as to be movable in the front-rear direction with respect to the excavation surface 12, so that the foot pad 24 moves forward to a position where the foot pad 24 contacts the excavation surface 12. The bracket 22 is
It supports the base of the guide rod 40 and supports the drilling rod 32 of the drilling drill 30 so as to be rotatable and movable in the axial direction. The bracket 22 is provided with a support member 54 that supports the water stop board 52 of the water stop mechanism 50.

The drill 30 has a drill bit 34 fixed to the tip of a drill rod 32 by screwing or the like. The drilling rod 32 is rotatably supported by a rod support (not shown) disposed behind the bracket 22, and is supported by a drifter (not shown) disposed further behind the rod support. And is rotationally driven. The drilling bit 34 is a bit suitable for an unconsolidated ground, specifically, an auger-shaped one, so that excavated earth and sand can be discharged.

In order to smoothly discharge earth and sand during drilling, a through hole (not shown) is formed at the center of the drill bit 34 and the drill rod 32, and the through hole 1 is formed from the through hole.
Air may be sent to the inside of the nozzle 4. Further, when the drilling hole 30 is pulled out from the bore hole 14, in a ground where the drilled hole wall collapses, when the drilling hole 30 is pulled out, the coating agent mixed with air from the through hole is sprayed onto the hole wall. The hole wall may be prevented from collapsing within a few minutes after completion of drilling.

Next, the guide rod 40 is provided with the drilling drill 30.
By inserting into the bore hole 14 drilled by the drill hole 30, the positioning and guiding of the drill hole 30 when drilling the next bore hole 14 by the drill hole 30 are performed. The function is described in
-291686, JP-A-8-291687, JP-A-8-291688 and the like. Guide rod 4
The base of “0” is fixed to the bracket 22 by the connecting member 46, and is inserted into the borehole 14 by moving the bracket 22, that is, the gantry 20 in the front-rear direction.

9 to 11 are a sectional side view, a sectional front view, and a side view showing the structure of the distal end portion of the guide rod 40. FIG. The guide rod 40 is provided with a tip cone 44 at the tip of a main body rod 42 having a double pipe structure including an inner pipe 422 and an outer pipe 424. The outer pipe 424 is rotatably provided with respect to the inner pipe 422. ing. Tip cone 44
Is screwed into a screw portion 422A formed at the tip of the inner tube 422 of the main body rod 42. And the body rod 4
2 inner tube 422, tip cone 44 and connecting member 46
Has an injection path 40 for supplying the injection material 62 in the axial direction.
2 are formed extending. As shown in FIG. 2, an injection hose 60 led from a supply device (not shown) for the injection material 62 is connected to a rear end of the connecting member 46 via a connector (not shown). The injection material 62 is supplied into the passage 402. The inside diameter of the injection path 402 and the injection hose 60 is about several tens mm.

The injection material 62 used in the present apparatus can be, for example, cement mortar or sprayed concrete as a general-purpose material for tunnel construction, and the injection material supply device is also used in ordinary tunnels. It can be constituted by a concrete plant, a mixer, a pump and the like, and there is no need to use a special device. And
With such an injection material 62, curing starts within a few minutes,
It reaches a predetermined intensity within a few hours.

The injection path 402 is opened at the outer peripheral surface of the tip cone 44, and the injection hole 402A is formed by the opening. The injection hole 402A faces the side opposite to the side where the drilling drill 30 is arranged. In. A projection 48 projecting radially and continuing in the axial direction of the guide rod 40 is formed on the outer peripheral surface of the tip cone 44 in the circumferential direction of the guide rod 40.
Four are formed at 0 ° intervals. These projections 48
As shown in FIG. 8 (2), as shown in FIG. 8 (2), the injection material 62 discharged from the injection hole 402A is filled in the second bore hole 14B (the second hole to be drilled and the guide rod 40 is inserted), and the third bore hole 14C (The guide rod 4 is inserted into the second borehole 14B.
The first bore hole 14A (the first hole drilled) is prevented from flowing into the third hole (the hole drilled third) in a state where 0 is inserted, so that the hole is reliably filled. . More specifically, in a state in which the guide rod 40 is inserted into the bore hole 14B, the protrusion 48 presses against the inner wall surface of the bore hole 14B, thereby dividing the inside of the bore hole 14B in the circumferential direction, and the injection material 62 is separated from the bore hole 14A. Is filled securely. In the case where the ground is soft, a more effective inflow prevention effect can be obtained by making the protrusion 48 bite into the hole wall. In the vicinity of the top of the tunnel, the boreholes 14 are arranged horizontally. However, the provision of the projections 48 ensures that the injection material 62 is discharged and filled in the lateral direction.

Next, as shown in FIG. 2, when the injection material having a high fluidity is used, the injection material 62 filled in the bore hole 14A as described above is used for the water stopping mechanism 50 as shown in FIG. A water stop board 52 (corresponding to a closing member in the claims) formed to have a shape to close the entrance of the bore hole 14A, and a water excavation surface 12 supporting the water stop board 52. And a support member 54 provided with a coil spring 54A (corresponding to a biasing member in the claims) pressed against the side.

Next, a description will be given of a working process in the case of forming the reinforcing body 10 using the reinforcing body forming apparatus having the above-described configuration. First, as shown in FIGS. 3 (1) and (2),
A first borehole 14A is drilled at a location closest to the bottom 16 of the tunnel with a drilling drill 30. Then, the hole drill 30 is pulled out from the first bore hole 14A. In addition,
When the solidification degree of the ground is low and the hole wall of the borehole does not stand by itself and partially collapses, the volatile coating agent mixed into the air is sprayed from the tip of the drilling drill 30 and sprayed onto the hole wall. ,
A membrane is formed to cover the hole walls, so as to serve the collapse of the hole walls.

Next, as shown in FIGS. 4A and 4B,
The guide rod 40 is inserted into the first bore hole 14A. At this time, in the ground where the degree of consolidation is low, the projection 48 of the guide rod 40 is inserted into the bore wall of the bore hole. Next, as shown in FIGS. 5A and 5B, a second borehole 14B adjacent to the first borehole 14A is drilled by a drilling drill 30 along the guide rod 40. At this time, the drilling rod 32 bends toward the guide rod 40 due to resistance during drilling received by the drilling bit 34,
Excavation is performed while the drill bit 34 contacts the guide rod 40. Then, the second bore hole 14B is drilled so as to partially overlap the first bore hole 14A in the radial direction. Depending on the degree of solidification of the ground, the drill bit 34 may be hit.

Thereafter, the drilling rod 32 and the guide rod 40
From each of the bore holes 14A, 14B, and then as shown in FIGS. 6 (1), (2), 7 (1), (2),
The guide rod 40 is inserted into the second bore hole 14B.
At this time, the guide rod 40 is inserted while discharging the injection material 62 from the injection hole 402A to the first bore hole 14A side, and the distal end cone 44 reaches the inner part of the first bore hole 14A so that the first bore hole is inserted. 14A is filled with the injection material 62. In addition, if necessary, the first bore hole 14A
Is closed by a water stop panel 52 to prevent the injection material 62 from leaking.
In addition, when there is no leakage of the injection material 62 and there is no need for the water stop board 52, the drilling can be performed by the drilling drill 32 in parallel with the insertion of the guide rod 40, thereby shortening the working time. Can be. Then, as shown in FIG. 8, when the injection material 62 is filled in the first bore hole 14A and the guide rod 40 is inserted to the depth of the second bore hole 14B, the third hole adjacent to the second bore hole 14B is formed. Of the borehole 14C is drilled by the drilling drill 30.

By repeating the above operation along the outer periphery of the excavation surface, a substantially arch-shaped slit groove is formed, and at the same time, the injection material filled in the groove is solidified, so that the arch shell-shaped reinforcing member 10 is formed. Is formed. The injection material 62 filled in each of the bore holes 14 starts to harden within several minutes, and reaches a predetermined strength within several hours.
0 can be configured.

After the formation of the reinforcing member 10 is completed, the inside of the tunnel face surrounded by the reinforcing member 10 is excavated. At this time, the load from the upper part of the tunnel is reduced by the arch shell structure of the reinforcing body 10, the earth pressure acting on the excavation surface is reduced, and the excavation can be performed safely even in an unconsolidated ground. . In the case where boulders or gravel are mixed in the ground, the drilling drill is replaced with a drill for rock, and the reinforcing member 10 is formed in the same operation procedure as described above.
Can be formed, and the range of applicable ground is widened. In addition, the machinery used is a general-purpose machine used in normal tunnel construction, does not require special machinery such as the conventional construction method,
Even if the ground suddenly changes from bedrock to unconsolidated ground, it can be dealt with promptly and tunnel construction can proceed smoothly.

As described above, in the method of reinforcing the unconsolidated ground and the apparatus for forming the reinforcing body in this embodiment, even the unconsolidated ground is partially overlapped by using the drilling drill 30 and the guide rod 40. The slit-shaped groove can be formed from the plurality of holes to be formed, and at the same time, the arch shell-shaped consolidated reinforcing body 10 can be formed in front of the face. Due to the solidification reinforcement 10, a part of the overload acting upon excavation of the ground inside is received by the ground itself by arch hardening, and the load acting on the solidification reinforcement 10 is also reduced. The earth pressure acting on the face is reduced, and the face can be stabilized. Further, in the method for reinforcing an unconsolidated ground and the apparatus for forming a reinforcing body in this example, the filling of the injection material 62 into the hole is performed when the guide rod 40 serving as the guide of the drilling drill 30 is inserted. Lumber 62
The filling of the injection material 62 can be performed very efficiently without increasing the number of special steps for filling. Further, the injection material 6
2 is performed by the guide rod 40 that guides the drilling drill 30, no special member is required for filling the injection material 62, and the arch is formed by a minimum number of members and a compact structure. The shell-shaped consolidated reinforcing body 10 can be formed in front of the face.

The guide rod 40, which serves as a guide for the drilling drill 30 and fills the injection material 62, can be easily attached to the tip of a gantry of a general-purpose drill jumbo rock drill used in ordinary tunnel construction. . For this reason, even if the ground suddenly changes during construction and becomes unconsolidated ground, drilling of continuous holes can be handled with a general-purpose drill jumbo without using special machinery, and equipment cost is low. become. The guide rod 40 has a double-pipe structure. The inner core is a hollow inner pipe 422, and the injection rod 60 is connected to the end of the guide rod 40 on the bracket 22 side. Can be easily filled. Also, the inner diameter of the inner pipe 422 is
Since it can secure 0 mm, it can be used as a transport pipe for cement mortar or sprayed concrete as a general-purpose material for tunnel construction, for example, and it is not an effective injection material used in the conventional construction method, but also uses these inexpensive materials as an injection material it can. In this case, a special pump for injection is not required, and the injection can be performed by a concrete plant, a mixer, or a pump used in a normal tunnel, and the construction is more inexpensive.

When the boreholes are drilled in order, the amount of movement of the rock drill from the previous borehole to the next borehole is small, and the positioning and insertion of the guide rod 40 is easy. Also, if the first borehole is accurately positioned for drilling, the position of the subsequent drilling is easily determined by the guide rod 40, and the operation can be performed very efficiently without using a special positioning jig. In addition, since a general-purpose drill jumbo is used, even if a boulder or the like appears on the ground, drilling is possible only by replacing the drill with a bit for rock, and the range of applicable geology is wide.

[0025]

As described above, in the method and apparatus for reinforcing an unconsolidated ground of the present invention, a number of holes are continuously formed in the ground to form slit grooves. When an injection material is injected and solidified to form an arch-shaped reinforcing body, a guide rod is inserted into a hole that has been previously drilled,
Drilling is performed by the drilling rod guided by the guide rod, and the injection material is injected into the hole drilled two immediately before by the guide rod inserted into the hole drilled immediately before. I did it. For this reason, drilling of continuous holes and injection of the injection material into each hole can be smoothly performed by a series of continuous operations, and work efficiency can be improved. In addition, construction can be performed with a general-purpose device, and cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a reinforcing body formed in front of a tunnel face according to the present invention.

FIG. 2 is a cross-sectional side view showing a configuration of a reinforcing body forming apparatus for forming the reinforcing body shown in FIG.

3A is a cross-sectional view showing a step of forming the reinforcing member shown in FIG. 1, and FIG. 3B is a cross-sectional view taken along line AA of FIG.

4A is a cross-sectional view showing a step of forming the reinforcing body shown in FIG. 1, and FIG. 4B is a cross-sectional view taken along line BB of FIG.

5A is a cross-sectional view showing a step of forming the reinforcing member shown in FIG. 1, and FIG. 5B is a cross-sectional view taken along line CC of FIG.

6A is a cross-sectional view showing a step of forming the reinforcing member shown in FIG. 1, and FIG. 6B is a cross-sectional view taken along line DD of FIG.

7A is a cross-sectional view showing a step of forming the reinforcing member shown in FIG. 1, and FIG. 7B is a cross-sectional view taken along line EE of FIG.

8A is a cross-sectional view showing a step of forming the reinforcing member shown in FIG. 1, and FIG. 8B is a cross-sectional view taken along line FF of FIG.

9 is a cross-sectional side view showing a configuration of a distal end portion of a guide rod in the reinforcing member forming device shown in FIG.

FIG. 10 is a sectional view taken along line GG of FIG. 9;

FIG. 11 is a side view of the distal end portion of the guide rod shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Reinforcement body 12 Excavation surface (face) 14, 14A, 14B, 14C Bore hole 20 Mounting stand 22 Bracket 30 Drilling drill 32 Drilling rod 34 Drilling bit 40 Guide rod 50 Water stop mechanism 52 Water stop board 54 Supporting member, 60 Injection hose 62 injection material 402 injection hole

 ──────────────────────────────────────────────────の Continued on front page (72) Inventor Takafumi Hara 4-6-115 Sendagaya, Shibuya-ku, Tokyo Inside Fujita Co., Ltd.

Claims (7)

[Claims] 1. A substantially arch-shaped reinforcement body is provided in front of an excavation surface by drilling a large number of holes forming a substantially slit-shaped groove in front of the excavation surface, filling the groove with an injection agent and solidifying the hole. A method for reinforcing an unconsolidated ground pile, the method comprising: when drilling a hole, inserting a guide rod into a first hole already drilled, and drilling forward while approaching the guide rod. Drilling a second hole, part of which is connected to said first hole by a bit, then withdrawing the guide rod from the first hole and withdrawing the drilling bit from the second hole; A rod is inserted into the second hole, and a third hole partially connected to the second hole is drilled by a drill bit that advances while approaching the guide rod. The hole is filled with the injection material from the guide rod, and the drilling bit is used to fill the hole. A substantially arch-shaped reinforcing body is formed by repeating drilling, inserting the guide rod into the hole, and filling the hole with the injection material by the guide rod, thereby reinforcing the unconsolidated ground. Method. 2. The unfilled ground reinforcement according to claim 1, wherein the filling of the injection material is performed by injecting the injection material into the hole from the tip of the guide rod while the guide rod is inserted into the hole. Method. 3. The method of reinforcing an unconsolidated ground according to claim 1, wherein an opening of the hole filled with the filling material is closed when the filling material is filled. 4. A substantially arch-shaped reinforcement body is provided in front of the excavation surface by drilling a large number of holes forming a substantially slit-shaped groove in front of the excavation surface, filling the groove with an injection material and solidifying the hole. A guide rod inserted into a hole already drilled, a drilling rod arranged in parallel with the guide rod and provided with a drill bit at the tip, A bracket for supporting the base of the guide rod so that the outer peripheral portion of the drill bit advances forward while approaching the outer peripheral portion of the guide rod, and for supporting the drill rod in a rotatable and axially movable manner; An apparatus for forming a reinforcing body, comprising: an injection path extending inside a guide rod from a base of the rod toward a front end thereof and opened as an injection hole in an outer peripheral surface of the guide rod. 5. The injection hole is formed at a tip of a guide rod,
The apparatus for forming a reinforcing body according to claim 4, wherein the apparatus is open on a side opposite to a side on which the drill bit is arranged. 6. A plurality of projections projecting radially and continuously extending in the longitudinal direction of the guide rod are provided on the outer periphery of the distal end of the guide rod at intervals in the circumferential direction of the guide rod. 6. The reinforcing member forming apparatus according to claim 5, wherein a plurality of the protrusions are formed, and the protrusions are formed so as to press or bite into the inner wall of the hole drilled by the drill bit. 7. A closing member is provided at a bracket portion on a side of the guide rod at the same pitch as the pitch between the guide rod and the drilling rod, and the closing member forms a hole drilled by a drill bit. 7. The reinforcing member forming apparatus according to claim 4, which is formed in a closing shape and is urged forward by an urging member.