JPH09195666A - Tunnel excavating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make driving of pipe type lock bolt possible even if the ground is unfavorable by limiting the transmission of pressing force from the driving machine side to the end or the and outer periphery of the end near at hand of the pipe type lock bolt and making the pipe type lock bolt oscillatory within a specific angle range using the connecting part as a fulcrum. SOLUTION: An inserting hole 15A formed in a tapered shaped is provided on the end of a driving adpater 11A a little less than a half way to the inside. The hole diameter at the mouth 30 of the inserting hole 15A is made larger than the major part of the outside diameter on the at-hand side end of the pipe type lock bolt 7, or in other words, a sleeve 3 and the inner part of the hole 15A is made smaller than the outside diameter on the at-hand side end of the pipe type lock bolt 7. Because impact force from the driving machine 13 side is uniformly applied as pressure force all around the pipe type lock bolt 7 from the at-hand side end or the end periphery of the pipe type lock bolt 7, the at-hand side sleeve 3 never deforms in an irregular shape such as crooking. Thus the pipe type lock bolt 7 can be steadily driven and excavation can be carried out by impact even if the geological condition is inferior.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention does not support by a steel arch member even if the hole is rough and there are many cracks such as shale and the hole wall is not self-supporting. The present invention relates to a tunnel excavation method capable of excavating while forming a rock support by a pipe type rock bolt.

[0002]

2. Description of the Related Art In tunnel construction for mountains, etc., a steel arch support and wood sheet piles are used instead of the conventional construction method for supporting the ground.
The TM method (New Austrian Tunneling Method) has been widely adopted. This NATO method is used to reinforce the ground in a radial direction from the wall to the inside of the bedrock in order to prevent the ground from collapsing by spraying quick-setting shotcrete on the wall after excavating the ground. A lock bolt is driven, the tip of the bolt is fixed to the ground, or cement or resin is injected to fix it to the ground.

In recent years, various improvements have also been added to the lock bolts, and new types have been actively developed. Among them, what is drawing attention is that after the rock is inserted, it is expanded and expanded by injecting a pressure liquid into the rock to secure the rock near the inner wall of the tunnel and prevent the rock from collapsing. There is a pipe-type lock bolt that does this.

As shown in FIG. 12, the pipe type lock bolt (hereinafter, also simply referred to as a lock bolt) has the following structure.
While crushing the steel pipe body 1 in the radial direction to make it double,
After rolling both sides into a substantially double tubular pipe 2, FIG.
As shown in (4) to (5), the cylindrical sleeve 3 for reinforcement is fitted to the left end which is the proximal end, the end surface is welded, and then the side surface of the sleeve 3 is directed toward the center from the predetermined position. Pressurized liquid (pressurized water, etc.) by drilling a small hole that penetrates into the pipe 2
The injection hole 4 is formed, and as shown in FIG. 13, the reinforcing sleeve 5 is fitted to the tip of the pipe 2 and the cone 6 is welded to the tip. FIG.
4 shows a cross sectional view thereof. The pipe type lock bolt is described in detail in Japanese Patent Publication No. 2-520.

In inserting and installing the pipe type lock bolt 7, as shown in FIG. 16, first, a rock bolt insertion hole (bore hole) 41 is formed in the ground by the drilling rod 40, and then the pipe type lock bolt is formed. The pipe-type lock bolt 7 is inserted into the insertion hole 41 in a state where the pressure liquid injection adapter 42 is fitted to the proximal end portion (sleeve portion) of the bolt 7.
Insert After that, high-pressure water is injected from the high-pressure water pump 43 connected to the pressure-liquid injection adapter 42 to expand and expand the diameter of the pipe-type lock bolt 7 and fix it on the ground. These operations are performed exclusively by the pressure fluid injection adapter 4
It is carried out manually by an operator holding the hand arm 44 connected to 2 in his hand.

On the other hand, the insertion work of the pipe type lock bolt 7 is performed by a driving machine (drifter) in order to improve the work efficiency.
There is also a case where it is performed mechanically using such as. In this case,
As shown in FIG. 17, the driving adapter 51 is attached to the tip of the shank rod of the drifter 50, and the sleeve 5 of the lock bolt 7 is inserted into the lock bolt insertion hole 51 a formed in the driving adapter 51. Insert in the mated state.

[0007]

However, even if the mechanical insertion using the drifter or the like has been performed in the past as described above, the insertion installation in such a case is aimed at a high quality ground. , It is to insert by inserting gently into the lock bolt insertion hole that has not been roughened in advance, and the hole wall does not stand on its own, and hits badly rough ground with rough holes. However, applying a considerable pressing force and forcibly inserting it has not been performed in the past because the problems described below occur.

A slight gap is provided between the insertion hole 50a of the lock bolt driving adapter 50 and the sleeve 3 in order to facilitate the removal after the insertion is completed.

Therefore, when the bore hole is bent or collapsed, the pipe type lock bolt 7
Since the tip of will hit the bedrock or collapsed stones, it will shift to the side,
The end on the proximal side is struck while swinging in the insertion hole 51a of the lock bolt driving adapter 51. In this case, as shown in FIG. 19, the inlet A ₁ , side A ₃ , and bottom A ₂ of the insertion hole 51a of the casting adapter 51 are hit against the side surface and the end surface of the sleeve 3 while locally hitting. A large local stress is generated in this portion, and the side surface of the sleeve 3 is distorted in an irregular shape. After the driving, the lock bolt driving adapter 51 is removed, and instead the pressure liquid injection adapter is fitted, the pressure liquid injection adapter 18 does not enter due to the irregular deformation of the side surface of the sleeve 3, or the outer peripheral surface of the sleeve 3. The sealing property between the insertion hole 17 and the insertion hole 17 is weakened, the work environment is deteriorated by leaking into the tunnel when the pressure liquid is injected, and the expansion of the pipe type lock bolt 7 is insufficient due to the pressure loss of the pressure liquid. However, there is a problem in that the desired fixing power cannot be exerted and the reliability of support work is reduced.

Further, in the case of forcibly inserting while striking with a drifter, as shown in FIG. 18, the axis L _R of the pipe type lock bolt 7 and the axis L _{D of the} shank rod are aligned. If not done, as in the case described above, the entrance, side face, and bottom face of the insertion hole 51a of the casting adapter 51 will be hit while hitting locally, and the same problem will occur. Since this problem occurs due to the joint state between the drifter 50 and the pipe lock bolt 7, it does not matter whether the ground is good or bad. To address this issue,
It is sufficient to properly align the two, but this work is more difficult than expected, and the mechanical operation on the drifter side becomes very complicated, which causes a deterioration in construction efficiency.

On the other hand, if the surrounding geological conditions are bad and the hole wall is not self-sustaining after drilling, or if the hole is rough, specifically, C _II or D according to the rock classification (classification by the Road Authority) However, since the support function cannot be fully expected until the infusate around the lock bolt hardens, it is basically necessary to perform pre-support of steel arch members to prevent ground deformation and collapse during that period. I am trying. That is, when the geological condition is bad, both the front support and the rock bolt support by the steel arch are required, and there is a problem that it takes a lot of time and labor to construct the support.

Further, when the geology of the expansive ground is poor, there is a possibility that so-called swelling of the bottom plate will occur, so tunnel excavation is carried out while pouring invert concrete at appropriate times. Therefore, during the period until the placed concrete hardens, no passing vehicles or heavy equipment can pass through, and there is a cycle of temporarily stopping the excavation of the face, which in turn causes a reduction in construction efficiency. It was Of course, in the past, the method of driving a lock bolt on the bottom side was also adopted, but if the hole is rough, it is difficult to insert it, and the hole cannot be sufficiently filled with the curing agent. In some cases, the ground itself is bad, so that it is not firmly fixed to the ground and the desired reinforcing effect cannot be expected, which causes various problems.

Therefore, the main object of the present invention is to drive a pipe-type rock bolt by hitting, even in the case of shale or the like where there are many cracks and the hole is rough and the geological condition is such that the wall of the hole is not self-supporting. By making it possible, it is possible to perform excavation while forming rock support by pipe type rock bolts without supporting by steel arch members, and to provide a tunnel excavation method and the like with improved construction efficiency. Especially.

[0014]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention aims to excavate the ground where the geological conditions are not good, from the inner wall surface of the tunnel to the ground without reinforcing the ground by steel supports. After inserting and installing, pressure liquid is supplied to the inside to expand and expand the diameter to fix it to the ground.The pipe type rock bolt is used for tunnel excavation while supporting the ground, and the pipe type rock bolt is drilled. After forming the insertion hole of the pipe type lock bolt by making a hole toward the planned installation position of the pipe type lock bolt by a machine, at the joint between the proximal end of the pipe type lock bolt and the driving machine side, The contact portion for transmitting the pushing force from the driving machine side is substantially limited to the end surface or the outer edge of the proximal end of the pipe type lock bolt, and While holding the pipe type lock bolt in a swingable state within a predetermined angle range with the fulcrum as a fulcrum, the pipe type lock bolt is inserted from the driving machine, and then the liquid pressure is applied to the inside of the pipe type lock bolt. Is supplied to expand and expand the diameter of the pipe type lock bolt.

The present invention relates to the insertion and installation of the pipe type rock bolt, and improves the state of the joint between the proximal end of the pipe type rock bolt and the driving machine side. However, it is possible to drive pipe type lock bolts. Further, since the pipe type lock bolt immediately exhibits the supporting function by the injection of the pressure liquid after the driving, it is possible to omit the pre-supporting work by the steel arch member.

That is, in the case of the present invention, when the pipe type lock bolt is inserted into the insertion hole while being hit,
Even if the bore hole is bent or there is a hole collapse and the tip of the pipe type lock bolt is laterally displaced and hit, the pipe type lock bolt can swing at the joint with the driving machine, Since the corner is bent without any external force constraint, a large local stress concentration does not occur on the side surface of the proximal end portion other than the proximal end surface of the lock bolt, for example. Further, even when the pipe type lock bolt is deviated from the planned insertion axis and in the inclined posture, the striking force from the driving machine side is substantially the end face or the end of the proximal end of the pipe type lock bolt. Since a uniform pressing force is applied from the outer edge over the entire circumference, the sleeve on the proximal side is not deformed into an irregular shape such as bending. Further, even if there is a deviation in the axial center between the pipe type lock bolt and the drifter-side rod, this can be easily absorbed by the function described above, so that the posture adjustment on the drifter side can be simplified.

For this reason, when the injection adapter for the next step is fitted to the proximal end of the lock bolt after the driving is completed,
It can be fitted smoothly. Further, since there is no unevenness on the outer surface of the proximal end, the sealing property between the lock bolt and the pressure liquid injection adapter is not impaired.

To give a concrete example of the shape of the joint on the side of the driving machine, firstly, on the side of the driving machine, the fitting hole for connecting the proximal end of the pipe type lock bolt is narrowed toward the bottom side. There can be mentioned an aspect in which the taper surface is a complete conical shape. In such a case, since distributed stress is applied over the entire circumference of the outer peripheral edge of the proximal end of the lock bolt, it does not locally deform into unevenness, and the end of the proximal end surface is narrowed over the entire circumference. It will be deformed while being rounded almost evenly.

Secondly, on the side of the driving machine, a fitting hole for connecting the end portion of the pipe type lock bolt on the proximal side is formed at least on the inner side of the portion where the end portion of the proximal side of the pipe type rock bolt contacts. A conical tapered surface that narrows toward the bottom side is provided, and a flexible material is provided around the peripheral wall of the fitting hole while leaving a cylindrical hole that substantially matches the shape of the pipe-shaped lock bolt. Can be mentioned. In this case, since the pipe-type lock bolt can be reliably held without deforming the sleeve 3 into a distorted shape, workability is improved especially when the pipe-type lock bolt is driven downward.

Thirdly, the connecting part structure on the side of the driving machine has a connecting part main body having a spherical recess partly opened,
It is also possible to adopt a mode in which the pipe-type lock bolt that is held by the spherical lock body that is fitted in the spherical recess and that has a fitting hole for the pipe-shaped lock bolt is swingable. In this case, after inserting the pipe-type lock bolt, the peripheral wall of the fitting hole may be a tapered surface that gradually expands toward the opening side in order to facilitate withdrawal on the driving machine side.

Therefore, by developing the method for installing the pipe type rock bolt, the pipe type rock bolt can be inserted into the ground while hitting even if the hole wall is not self-supporting or the hole is severely rough. Becomes Therefore, since the lock bolt expands and immediately exerts its supporting function by the injection of the pressure liquid after the insertion and installation, the pipe type rock bolt and the shotcrete have sufficient proof stress without using the steel arch member together. You will be able to build a support.

Further, in tunnel excavation, pipe face rock bolts may be inserted and installed on the bottom plate side of the present excavation space by the above-mentioned method to reinforce the bottom plate so that facet construction is prioritized over invert construction. become able to.

[0023]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a perspective view of a mounting adapter 1 for a rock bolt used in a method for installing a pipe type rock bolt according to the present invention.
FIG. 1A is a vertical cross-sectional view of 1A (hereinafter, simply referred to as a casting adapter). The driving adapter 11A has a rope screw portion 12 formed in about half of the inner side thereof, and the shank rod 14 held by the driving machine 13 is attached to the rope screw portion 1A.
It can be detachably connected to 2. The insertion hole 15A provided inside about a little less than half of the tip end side of the driving adapter 11A is formed in a tapered shape, and the inlet 30 of the insertion hole 15A has a hole diameter at the proximal end of the pipe lock bolt 7 ( It is made larger than the outer diameter of most of the sleeve 3) and the inner part is smaller than the outer diameter of the proximal end of the pipe lock bolt 7. The entrance 30 is rounded.

When the pipe type lock bolt 7 is driven into the bore hole (see reference numeral 10 in FIGS. 9 and 10) by using the lock bolt driving adapter 11A having the above-mentioned structure, it is gripped by the driving tool 13. The shank rod 14 is connected to the rope screw portion 12, the proximal end portion of the pipe type lock bolt 7 (most of the sleeve 3) is inserted into the insertion hole 15A, and the hammer 13 is struck by the hammer 13.

Since the insertion hole 15A has a tapered surface shape that widens toward the entrance and narrows toward the back, the axes of the pipe lock bolt 7 and the driving adapter 11A are linearly aligned. 2 (1), even if the two axes are slightly inclined, only the end of the pipe-side lock bolt 7 on the proximal side (the end surface of the sleeve 3) is struck at the time of driving. It abuts against the hole wall of the insertion hole 15A, and does not abut against other portions, that is, the side surface of the proximal end (the side surface of the sleeve 3) and the proximal end surface.

Therefore, even if the pipe-type lock bolt 7 is hit with the tip of the pipe-type lock bolt 7 displaced laterally due to a bent borehole or collapse of the hole, the proximal side surface of the pipe-type lock bolt 7 A large local stress concentration does not occur, for example, on the side surface (side surface of the sleeve 3) of the end portion on the proximal side other than the outer edge of the end.

Also, the adapter 11A for setting the lock bolt
On the other hand, when the pipe-type rock bolt 7 is hit with the shaft inclined, the insertion hole 15A abuts only a part of the peripheral edge during the first very short time, so that a local stress is generated. However, as soon as the corner of the abutting portion is slightly deformed and becomes rounded, the insertion hole 15A is formed over the entire circumference of the end of the pipe-side lock bolt 7 on the proximal side. It comes into contact with each other (see the mark x in FIG. 2C), and the dispersed stress is applied over the entire circumference, so that it is not locally deformed into unevenness.

Even if the axis of the pipe-type lock bolt 7 is inclined in the other direction with respect to the lock bolt driving adapter 11A, the insertion hole 15A is only in contact with a part of the peripheral edge during the first very short time. Because of contact, local stress is generated,
As soon as the corners of the abutting portions are slightly deformed and rounded, the insertion holes 15A come into abutment over the entire circumference of the end of the proximal end face of the pipe type lock bolt 7, and the insertion holes 15A are dispersed over the entire circumference. Since stress is applied, it is not locally deformed into unevenness.

As a result, as the driving work progresses, the end of the proximal end face of the pipe type lock bolt 7 is deformed while being rounded substantially evenly so as to be narrowed over the entire circumference. .

As shown in FIG. 4, even if the axes of the pipe type lock bolt 7 and the lock bolt driving adapter 11A are greatly deviated from each other, the inlet 30 of the insertion hole 15A is rounded. From the inlet 3 of the insertion hole 15A
0 does not hit the side surface of the sleeve 3 at the proximal end of the pipe-type lock bolt 7, and the side surface of the sleeve 3 is not locally deformed into a warp.

When the driving is completed, the diameter of the insertion hole 15A of the lock bolt driving adapter 11A is gradually increased toward the inlet 30, so that the lock bolt driving adapter 11A can be kept at hand regardless of the deformation of the sleeve 3. It can be easily removed from the pipe lock bolt 7 by pulling it in the direction.

As shown in FIG. 11, instead of the lock bolt driving adapter 11A, a pipe type lock bolt 7 is used.
When inserting the pressure liquid injection adapter 18 for the next process into the proximal end of the, the smooth operation is possible because the proximal end of the pipe type lock bolt 7 (most part of the sleeve 3) does not have irregular deformation. It is possible to perform a fitting operation at a predetermined position, and since the sealing member 21 such as an O-ring provided on the pressure liquid injection adapter 11A is in close contact with the outer surface of the sleeve 3 over the entire circumference, a good sealing is achieved. You can keep your sex.

Therefore, since the pipe-type lock bolt 7 is expanded and expanded in diameter, no liquid leakage occurs when pressurized water or the like is injected, so that the working environment can be kept good and there is no pressure loss of the pressurized liquid. The pipe-type lock bolt 7 can be sufficiently expanded and expanded in diameter to exert the desired fixing force, and the reliability of the supporting work is improved.

As shown in FIG. 5, if a plastic resin inner member 31 is detachably attached to the inner surface of the insertion hole 15B of the lock bolt driving adapter 11B,
The inner member 31 can be mainly deformed by the impact when the pipe type lock bolt 7 is struck, and only the pressing force can be transmitted to the proximal end face of the pipe type lock bolt 7 (the end face of the sleeve 3). It is possible to further reduce the deformation of the peripheral end of the proximal end surface of the pipe lock bolt 7.
The inner member 31 may be replaced at appropriate times according to the degree of wear.

Further, as shown in FIG. 6, the connecting portion of the driving adapter 11A has a tapered shape, and at least the peripheral wall of the tapered fitting hole 15A has the pipe-shaped lock bolt 7 attached thereto. It is also possible to wrap the flexible material 31 while leaving a cylindrical hole that substantially matches the shape. The pipe-type lock bolt 7 can be held while having a function of swingably supporting the pipe-type lock bolt 7, so that the pipe-type lock bolt 7 is stably supported and faces downward. It will be easy to install.

Next, a second example of the casting adapter is shown in FIG. The illustrated casting adapter 11C is a spherical fitting body having a connecting portion main body 16 having a spherical concave portion 16a which is partially opened, and a fitting hole 17a of the pipe-shaped lock bolt 7 which is fitted in the spherical concave portion 16a. With the construction of the pipe lock bolt 17, the pipe lock bolt 7 can be swingably supported. Even with such a structure, even if the bore hole is bent or the hole is collapsed and the pipe type lock bolt is displaced from the planned insertion axis into an inclined posture, the striking force from the driving machine 13 side is somewhat. Even if there is a deviation, the pressure is transmitted as a substantially uniform pressing force to the end surface of the proximal end of the pipe type lock bolt, so that the proximal sleeve will not be distorted.

In this structure, in order to facilitate the removal of the pipe type lock bolt 7 after the driving, the fitting spherical body 1 is used like the driving adapter 11D shown in FIG.
Fitting hole 17a of the pipe type lock bolt 7 formed in
It is also possible to make the peripheral wall of the taper surface to gradually expand toward the opening side.

As described above, the pipe type lock bolt is driven by using the driving adapter 11 described above in the following procedure. As shown in FIG. 9 (1), a borehole 10 is previously drilled vertically from the inner wall 9 of the tunnel toward the inside of the natural ground 8. On the other hand, as shown in FIG. 10, the shank rod 14 held by the driving machine (drifter) 13 is coupled to the rope screw portion 12 of the driving adapter 11. Then, after inserting the pipe-type lock bolt 7 from the cone 6 into the bore hole 10 a little, into the insertion hole 15 provided inside the tip end side of the lock bolt driving adapter 11 about a little less than half. Inserting the proximal end of the pipe type lock bolt 7 (most part of the sleeve 3) into the driving machine 13
Is operated, and is driven from the cone 6 into the borehole 10 (see (2) of FIG. 9 and FIG. 10).

When the driving is completed, the lock bolt driving adapter 11 is removed, and the pressure liquid injection adapter 18 is fitted to the sleeve 3 up to a predetermined position (see (3) in FIG. 9).

As shown in FIG. 11, the pressurizing liquid injection adapter 18 has an insertion hole 17 provided at the inner side of about a little less than half on the front end side. It has the same inner diameter as the outer diameter. At the center of the pressure fluid injection adapter 18, the insertion hole 17 is inserted from the right end of FIG.
The injection hole 24 is formed up to the position of the bottom wall of the insert hole 17, and one groove 19 for communicating the injection hole 24 and the injection hole 4 is formed from the right end of the insertion hole 17 to the inner wall. Groove 19
The tip portion 20 of the pipe is bored in the cylindrical spacer 22 located on the outer circumference of the sleeve 3 when the pressure liquid injection adapter 18 is fitted to a predetermined position on the proximal end portion of the pipe type lock bolt 7 after the driving. It is in a state of communicating with the injection hole 4 just through the formed small hole. A seal member 21 such as an O-ring is fitted on the inner wall of the insertion hole 17 at both sides of the spacer 22 when viewed in the axial direction.
When the pressure liquid is injected from the outside through the injection hole 24,
By the cylinder 23 and the spacer 22, the cylinder 23 and the spacer 22 are crushed in the direction of the entrance of the insertion hole 17 and closely adhere to the sleeve 3. As a result, the injected pressure liquid is discharged from between the sleeve 3 and the pressure liquid injection adapter 18 to the outside. It is designed not to leak out.

The pressure liquid injecting adapter 18 is fitted to the proximal end of the pipe type lock bolt 7, and the tip portion 20 of the groove 19 is fitted.
Is in communication with the injection hole 4, the injection hole 24
A pressurized liquid such as compressed water is injected from the inlet of. The pressure liquid is the injection hole 2
Pipe lock bolt 7 through 4, groove 19 and injection hole 4
And the high pressure causes the double pipe 2 of the pipe type lock bolt 7 to expand and expand in diameter. As a result, the pipe-type rock bolt 7 is fixed to the ground around the borehole 10 and immediately solidifies the ground near the inner wall of the tunnel and supports the ground inside the rock to prevent collapse around the inner wall. . When fixing is completed by injecting the pressure liquid, the pressure liquid injection adapter 18 is removed, and the liquid is drained into the pipe type lock bolt 7. Then, if necessary, after injecting an appropriate injection material into the inside of the pipe type lock bolt 7, FIG.
As shown in FIG. 3, the bearing plate 25 is fitted to the sleeve 3, and the cap 26 is covered to prevent the injection material from leaking and deterioration due to the ingress of air, water and the like.

According to the present invention, since the pipe type lock bolt 7 can be driven by driving as described above, the geological condition is bad and the hole wall is not self-supporting or the hole collapse is severe. Even in such a case, the tunnel excavation can be advanced by the support by the pipe-type rock bolt and preferably by spraying concrete without providing the front support by the steel arch member.

Generally, according to the specification by the Japan Highway Public Corporation, in the case of C ₂ and D grades according to the rock classification, in addition to the support of shotcrete and rock bolts, the support by steel arch members is required. It is based. That is, in the case of the conventional lock bolt construction, the time until the hardening of the mortar and resin for fixing the lock bolt, the support mechanism cannot be expected, and if there is a hole collapse, the mortar etc. may not be sufficiently filled. In addition, if there is a lot of spring water, the injected mortar may flow, and the desired rock bolt reliability cannot be obtained.Therefore, the steel arch member should be used to prevent the rock from collapsing. I'm teaching.

However, since the present invention enables the construction of the pipe type rock bolt, it is sufficient to omit the pre-support of the steel arch member or the like and only construct the shotcrete and the pipe type rock bolt 7. You will be able to provide safe support. Also, although the pipe type lock bolt itself is more expensive than the conventional lock bolt, the steel arch member is eliminated and the mortar injection work for fixing is eliminated, so the pipe type lock bolt is compared in terms of total construction cost. At the same time, the economical advantages such as the cheaper support by spraying concrete and sprayed concrete are brought about.

Further, when the ground is bad and so-called swelling is likely to occur, tunnel excavation is performed while pouring invert concrete at appropriate times, but as shown in FIG. By inserting and installing pipe type rock bolts 7, 7 ... on the bottom plate side of the base plate to reinforce the bottom plate, it is possible to prioritize facet construction over invert construction without placing invert concrete. .

[0047]

As described above in detail, according to the present invention, the sleeve portion is distorted even if the shale or the like has many cracks and the hole is rough and the hole wall is not self-supporting. Since it is possible to install the pipe type rock bolt while striking the pipe type rock bolt without deforming it, it is possible to form a natural rock support by the pipe type rock bolt without providing the pre-support of the steel arch member. You will be able to proceed with excavation.

When so-called swelling may occur, pipe type rock bolts are inserted and installed on the bottom plate side of the current excavation space to reinforce the bottom plate, so that face construction is prioritized over invert construction. It is also possible to do.

[Brief description of the drawings]

FIG. 1 is a vertical cross-sectional view of a driving adapter according to the present invention.

FIG. 2 is an operation explanatory view of a placing adapter.

FIG. 3 is an operation explanatory view of a placing adapter.

FIG. 4 is a diagram for explaining the operation of the placing adapter.

FIG. 5 is a vertical cross-sectional view of another driving adapter according to the present invention.

FIG. 6 is a vertical cross-sectional view of another driving adapter according to the present invention.

FIG. 7 is a vertical cross-sectional view of another driving adapter according to the present invention.

FIG. 8 is a vertical cross-sectional view of another driving adapter according to the present invention.

FIG. 9 is a diagram showing a procedure for inserting and installing a pipe type lock bolt.

FIG. 10 is a perspective view showing an inserted state of a pipe type lock bolt.

FIG. 11 is a sectional view of a state in which a pressure liquid injection adapter is mounted.

FIG. 12 is a manufacturing stage diagram of a pipe type lock bolt.

FIG. 13 is a perspective view of a pipe type lock bolt.

FIG. 14 is a view taken along line XIV-XIV of FIG.

FIG. 15 is a bottom plate reinforcement state diagram in tunnel excavation.

FIG. 16 is a view showing a conventional procedure for installing a pipe type lock bolt by manual operation.

FIG. 17 is a schematic diagram of a mechanical insertion method using a conventional drifter.

FIG. 18 is a diagram illustrating a problem in the case of a conventional mechanical insertion method using a drifter.

FIG. 19 is an enlarged view of a joint portion in the case of a conventional mechanical insertion method using a drifter.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Steel pipe main body, 3 ... Sleeve, 4 ... Injection hole, 7 ... Pipe type lock bolt, 11A-11C ... Placing adapter, 1
2 ... Rope screw part, 13 ... Driving machine, 14 ... Shank rod, 15A ... Insertion hole, 16 ... Connection part main body, 17 ... Spherical fitting body, 18 ... Pressure fluid injection adapter, 31 ... Flexible material

Claims (7)

[Claims] 1. Excavation and expansion of a soil with poor geological conditions by supplying pressurized fluid into the soil after inserting and installing it from the inner wall surface of the tunnel into the soil without reinforcing the ground by steel supports. By doing so, it is decided to excavate the tunnel while supporting the ground with pipe type rock bolts, and the pipe type rock bolts are cut by a boring machine toward the planned installation position of the pipe type rock bolts. After forming the insertion hole of the pipe type lock bolt by making a hole, a contact portion for transmitting a pushing force from the driving machine side at a joint between the proximal end of the pipe type lock bolt and the driving machine side Is substantially limited to the end surface or the outer edge of the proximal end of the pipe-type rock bolt, and the pipe-type rock bolt has a predetermined angle with the joint as a fulcrum. While maintaining the swingable state within,
A tunnel excavating method, characterized in that a pipe type lock bolt is inserted from the driving machine, and then a pressure liquid is supplied into the pipe type lock bolt to expand and expand the diameter of the pipe type lock bolt. 2. The tunnel excavation method according to claim 1, wherein a fitting hole for connecting the proximal end of the pipe type lock bolt is a conical taper surface narrowed toward the bottom side on the driving machine side. 3. On the side of the driving machine, a fitting hole for connecting the end of the pipe type lock bolt on the proximal side is provided with at least the back side of the pipe type lock bolt on the bottom side of the region where the proximal end of the pipe type rock bolt contacts. 2. A flexible material is provided around a conical tapered surface that narrows toward the periphery, and a cylindrical material that substantially matches the shape of the pipe-shaped lock bolt is left around the peripheral wall of the fitting hole. Tunnel excavation method. 4. A connection part structure on the side of the driving machine, a connection part main body having a spherical recess partly opened, and a spherical fit having a fitting hole for a pipe-shaped lock bolt fitted in the spherical recess part. The tunnel excavation method according to claim 1, wherein the pipe type lock bolt is composed of a united body and is held, wherein the pipe type lock bolt is swingable. 5. The tunnel excavating method according to claim 4, wherein the peripheral wall of the fitting hole is a tapered surface that gradually expands toward the opening side. 6. The method of excavating a tunnel according to claim 1, wherein, in addition to the ground support by the pipe type rock bolt, the ground support by spraying concrete on the inner wall surface of the tunnel is performed. 7. The face face construction is prioritized over the invert construction by inserting and installing the pipe type rock bolts on the bottom side of the present excavation space to reinforce the bottom plate. 6. The tunnel excavation method described in 6.