JP2000008796A - Pipe type lock bolt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve pull-out resistance of a pipe type lock bolt. SOLUTION: In a pipe type lock bolt 1 having an expansive diameter- enlargeable double pipe 2 expanded being filled with pressure liquid and provided with reinforcing sleeves 3, 5 at both ends, restraining pipes 7 are arranged between the reinforcing sleeves 3, 5 and insert-fitted to the outer periphery of the double pipe 2. The parts other than the restraining pipes 7 are expanded by filling the pressure liquid, but the parts of the restraining pipes 7 are not expanded. The pipe type lock bolt 1 is therefore formed in uneven shape to improve pull-out resistance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe-type lock bolt used for preventing collapse of ground in tunnel construction and the like, and more particularly to a pipe-type lock bolt capable of improving pull-out resistance.

[0002]

2. Description of the Related Art In the NATM method generally used for tunnel construction in mountains or the like, after excavating the ground (after hardening the wall with cement if necessary), a large number of the rocks are vertically inserted from the wall into the rock mass. And fix it with a predetermined fixing material such as cement or resin, or inject pressure liquid into the pipe type lock bolt to expand and expand the diameter.
The ground near the inner wall of the tunnel is strengthened and supported by the ground inside the rock to prevent collapse around the inner wall (support).

FIG. 11 illustrates a method of manufacturing a pipe-type lock bolt which expands and expands the diameter by injecting the above-mentioned pressure liquid. The steel pipe body 61 is crushed in the radial direction to be doubled, and both sides are rounded to form a double pipe 62 ((1) to (1) in FIG. 11).
(3)). Then, a cylindrical sleeve 63 for reinforcement is fitted to the left end, which is the proximal end, and the end surface is welded ((4), (5) in FIG. 11). A small hole that penetrates between the two pipe walls of the heavy pipe 62 is formed as an injection hole 64 for pressurized liquid (pressured water or the like) (FIG. 11).
(5)). A reinforcing sleeve 65 is also fitted to the distal end of the double pipe 62, and a cone 66 is welded to the distal end.
The pipe type lock bolt 67 as shown in FIG. FIG. 13 shows a cross section of the sleeve 63 of the pipe-type lock bolt 67.

FIG. 14 is an explanatory view showing how to use the pipe-type lock bolt 67. A borehole 70 is drilled in advance from the inner wall 68 of the tunnel to the inside of the ground 69 vertically (see (1) in FIG. 14). When the pipe-type lock bolt 67 is driven into the borehole 70, a lock bolt driving adapter 81 is used. That is, the lock bolt driving adapter 81 is connected to a shack rod of a driving machine (not shown), the driving machine is operated, and the sleeve 6 is driven.
The pipe-type lock bolt 67 fitted in the bearing plate 83 at the three positions is driven from the cone 66 into the borehole 70 (see (2) in FIG. 14). When the driving is completed, the lock bolt driving adapter 81 is removed, and the pressure liquid injection adapter 82 is fitted to the sleeve 63 to a predetermined position (see (3) in FIG. 14). That is, the pressure liquid injection adapter 82 is fitted to the proximal end of the pipe-type lock bolt 67, and the injection hole 64 formed in the sleeve 63 communicates with the injection hole 82 a of the pressure liquid injection adapter 82. And pressurized liquid such as pressurized water. As a result, the pressurized liquid passes through the injection hole 82a and the injection hole 64,
7 and the pipe type lock bolt 67
Is expanded and expanded. As a result, the pipe-type lock bolt 67 is fixed to the ground around the borehole 70,
Immediately strengthening the ground near the inner wall of the tunnel and supporting the ground inside the bedrock can prevent the collapse around the inner wall. When the fixing is completed by injecting the pressurized liquid, the adapter 82 for injecting the pressurized liquid is removed, and the liquid inside the pipe-type lock bolt 67 is drained. Then, if necessary, an appropriate injection material is injected into the pipe-type lock bolt 67.
(See FIG. 14 (4)). According to such a pipe-type lock bolt, the double pipe or the bolt 67 expands and expands radially in a quick and simple mounting operation, and the rock around the surrounding ground is
Instantly tighten the ground and soil. For example, FIG.
When the pipe-type rock bolt 67 is attached to a finely cracked rock as shown in FIG. 7A, the radial pressure increases the contact force between the rocks around the rock bolt, increasing the rock strength. . Also, as shown in FIG. 15 (b), when the pipe type lock bolt 67 is attached to the soil,
Immediately solidifies the soil around the rock bolt, increases the strength of the soil and increases the fixing capacity of the rock bolt. As shown in FIG. 16A, the length L of the pipe-type lock bolt 67 is reduced to L 'in the axial direction at the final stage of expansion of the double pipe. As a result, as shown in FIG.
The rock and ground in the 9 compaction areas 69a can be compacted in the axial direction.

[0005]

As described above, the pipe-type lock bolt is constructed such that the main pipe, which is a folded double pipe, is cast into the ground, and then the main pipe is expanded and expanded with a pressurized liquid or the like. In this way, the ground is fixed to the surrounding ground, and the surrounding ground is tightened by the pressing force due to the expansion and expansion.
However, in the conventional pipe-type lock bolt, the main pipe expanded by the expansion and the surrounding area where the main pipe comes into contact with the pull-out direction force (that is, the force that the ground pushes out toward the space in the tunnel). It only resisted the frictional force generated between the rock and the ground. For this reason, the conventional pipe-type rock bolt was disadvantageous (easy to pull out) in terms of pull-out strength in soft ground such as sandy rock. However, even with such soft ground, there is a demand for adopting a pipe-type lock bolt in terms of workability, ground improvement effect, and the like. Accordingly, an object of the present invention is to provide a pipe-type lock bolt having a large pull-out resistance.

[0006]

SUMMARY OF THE INVENTION According to the present invention, there is provided a main body tube which is inflated and expandable by injecting a pressurized liquid. In a pipe-type lock bolt provided with a casting rear end member having an injection hole for injecting a pressurized liquid, an expansion restraining cylindrical shape is provided on an outer periphery of a main body pipe between the casting front end member and the casting rear end member. This is achieved by disposing members. In this way, when the pipe-type lock bolt is driven into the ground and the inside of the main body pipe is pressurized, the main body pipe expands and expands at a portion where the expansion restricting tubular member is not provided, and the expansion restriction is performed. The expansion and diameter expansion is restricted at the portion where the tubular member is provided, and almost no expansion and diameter expansion occurs. As a result, irregularities are formed on the outer periphery of the main body tube in a form continuous with the axial center direction by a portion that has expanded and expanded and a portion that has hardly expanded and expanded. For this reason, even if a force in the axial direction, that is, in the pulling direction, acts on the pipe-type lock bolt of the present invention, the unevenness on the outer periphery of the main body tube is caught on the ground, and a large pulling resistance is exhibited. In addition, a plurality of expansion restricting tubular members are disposed on the outer circumference of the main body tube at predetermined intervals. By doing so, the pull-out resistance of the pipe-type lock bolt to the ground can be further improved. Also,
Both ends of the cylindrical sleeve are cut obliquely to form an expansion-constrained tubular member. According to this configuration, a part of the expansion-restraining tubular member is broken by the expansion and expansion and becomes an arrowhead shape and bites into the ground, so that the pull-out resistance of the pipe-type lock bolt against the ground can be further improved. . Further, a slit is provided in the axial direction of the cylindrical sleeve to form an expansion-constrained tubular member. With this configuration, a part of the expansion-constrained cylindrical member, that is, the vicinity of the slit is deformed so as to bite outward into the ground due to the expansion and expansion, and the deformed portion cuts into the ground and the ground of the pipe-type lock bolt. Can be further improved.

[0007]

FIG. 1 is a perspective view of a pipe-type lock bolt according to a first embodiment of the present invention, and FIG. 2 is a sectional view taken along line X1-Y1 of FIG.
FIG. 3 is a sectional view taken along line X2-Y2 of FIG. As shown in FIG. 1, the pipe-type lock bolt 1 of the first embodiment has a double pipe 2 substantially similar to a conventional pipe-type lock bolt. That is, as shown in FIGS. 2 and 3, the cross section of the double pipe 2 is obtained by crushing a cylindrical steel pipe flat from the side to form a double pipe, and then rounding both sides to form a cylindrical pipe. It is molded. A reinforcing sleeve 3 is inserted around the outer periphery of the end (arrow A side) in the axial direction (the direction of arrows A and B in FIG. 1) of the double pipe 2. The end 3 a is welded to the proximal end face of the double pipe 2. As shown in FIG. 2, an injection hole 4 is formed in the reinforcing sleeve 3 and the double pipe 2 so as to form an opening at a predetermined position on a side surface of the reinforcing sleeve 3. It penetrates and further penetrates between the two pipe walls of the double pipe 2. On the other hand, another reinforcing sleeve 5 is fitted on the outer peripheral side of the end of the double pipe 2 on the tip side (arrow B side),
A cone 6 is welded or mounted on the tip of the reinforcing sleeve 5.

Further, the pipe type lock bolt 1 is shown in FIG.
As shown in FIG. 3, four cylindrical constraining pipes 7 are provided so as to be fitted on the outer peripheral side of the double pipe 2 (the number of the constraining pipes 7 is not limited to four and may be one or more. Any number of the restriction pipes may be used.
Are arranged at positions that substantially divide the length between them (in FIG. 1, equally divide by 5). In addition, between the constraining pipes 7,
The distance between the reinforcing pipe 3 and the restraining pipe 7 and the distance between the restraining pipe 7 and the reinforcing sleeve 5 may not be equal to each other and may be uneven.

FIG. 4 is an explanatory view of a method of installing a pipe-type lock bolt of the present invention. FIG. 4 (a) shows a state in which the pipe-type lock bolt is mounted on the ground, and FIG. 4 (b) shows a pipe-type lock bolt. It is a figure showing the state where attachment of a lock bolt to the ground was completed. In order to attach the pipe-type lock bolt 1 to a soft ground 50 such as sandy rock on the inner wall side of the tunnel, the following is performed. First, the pipe-type lock bolt 1 is placed and installed from the inner wall of the tunnel (not shown) to the ground 50 by driving the cone 6 at the tip into the ground 50 and striking it from the reinforcing sleeve 3 side at hand. (Alternatively, as an alternative, if the ground has enough hardness that the hole wall can stand on its own,
First, after drilling a borehole, the pipe-type lock bolt 1 may be installed in the borehole. The installation of the pipe-type lock bolt 1 is performed in such a manner that a bearing plate (omitted in FIG. 4) is fitted in advance from the cone 6 at the tip to the reinforcing sleeve 3 at the hand side.
The bearing plate and the sleeve 3 are left outside the ground 50, and all other parts on the tip side from the reinforcing sleeve 3 are completely inserted into the ground 50. After the installation is completed and the state shown in FIG. 4A is obtained, a well-known pressure liquid injection adapter (not shown) is installed on the reinforcing sleeve 3 on the hand side, and compressed water or the like is supplied through the injection hole 4. Inject pressure fluid. As shown in FIG. 4B, the injection of the pressurized liquid causes the double pipe 2 to expand and expand in a radial direction (the direction of arrow C in FIG. 4B) at a predetermined portion 2a (described later). After that, when the pressure fluid injection adapter is removed, the pressure fluid comes out.
An appropriate injection material is injected into the inside of the device.

As described above, due to the expansion and diameter expansion of the double pipe 2 in the radial direction (the direction of arrow C), the double pipe 2 is pressed against the surrounding ground 50, and the pipe-type lock bolt 1 is
It is fixed to 0 and exerts the effect as a shoring work. The ground 50 around the pipe-type lock bolt 1 is pressed and tightened in the radial direction (the direction of arrow C) by the double pipe 2, and the shaft of the double pipe 2 is expanded to the extent that the double pipe 2 expands and expands. As the total length in the center direction (arrows A and B directions) shrinks, the ground 50 is compacted in the axial center direction (arrows A and B directions) and is improved into a firm ground. As described above, the pipe-type lock bolt 1 of the present embodiment does not impair the effects exhibited by the conventional pipe-type lock bolt.

The portion 2b of the double pipe 2 where the restraining pipe 7 is inserted (and the portion where the reinforcing sleeves 3 and 5 are inserted) is the same as the restraining pipe 7 (or the reinforcing sleeves 3 and 5). As shown in FIG. 4 (b), the expansion and expansion of the double pipe 2 is performed by inserting the restraining pipe 7 (or the reinforcing sleeves 3 and 5). This is performed only at the portion 2a that does not exist. That is, irregularities are formed on the outer periphery of the double pipe 2 in such a manner as to extend in the axial direction (the directions of arrows A and B) by the expanded and expanded portions 2a and the non-expanded and expanded portions 2b. . Therefore, when a force is applied to the pipe-type lock bolt 1 in the pull-out direction (the direction of the arrow A in FIG. 4B), the irregularities due to the portions 2a and 2b are hooked on the ground 50 and exhibit a large pull-out resistance. . In particular, as shown in FIG.
Axis direction (arrow A, B direction) with respect to each part 2a
Is an area that has not been drilled (that is, an area that has not been roughened when the pipe-type lock bolt 1 is driven into the ground 50), and therefore has a large shear strength as it is. Because of the holding, shearing this portion α by the portion 2a of the double pipe 2 requires an extremely large pulling force. That is, the movement of the pipe-type lock bolt 1 in the axial direction (the directions of arrows A and B) is generally hardly allowed. As described above, the pipe-type lock bolt 1 of the present embodiment can exhibit a greater pull-out resistance than the conventional pipe-type lock bolt in which the restraining pipe 7 and the like are not provided. It is a lock bolt.

FIG. 5 is a perspective view of a pipe-type lock bolt according to a second embodiment of the present invention, and FIG. 6 is a side view of a restraining pipe according to the second embodiment. The pipe-type lock bolt 11 is different from the pipe-type lock bolt of the first embodiment only in the structure of the restraining pipe, and the other structures are the same. That is, the pipe-type lock bolt 11 of the second embodiment has two restriction pipes 17 at a predetermined interval L2 (two in FIG. 5, but may be any number as long as it is one or more). . Each restraint pipe 17
As shown in the side view of FIG. 6, the both sides of the cylindrical sleeve are cut obliquely to the center axis. The constraining pipe 7 of the first embodiment is formed by cutting both sides of a cylindrical pipe material in a direction perpendicular to the central axis. Therefore, each restraining pipe 17 is a double pipe 2
The body 17a (length D2 in FIG. 6) continuously covers the outer circumference of the double pipe 2 over the entire circumference in a plane perpendicular to the axial direction of the double pipe 2 (the directions of arrows A and B). Site equivalent to)
And, in the form of partially covering in the circumferential direction, the main body portion 17a
Projecting portions 17b, 17b (lengths D1, D3 in FIG. 6) which are formed in the axial direction (arrows A, B directions) of the double pipe 2 from
). Further, when a portion formed by rolling a flatly crushed steel pipe into a tubular shape and having both sides meeting each other is formed as a folded portion 2t (FIG. 5), one of the constraining pipes 17 protrudes. Part 17b
Are arranged along the folded portion 2t.

FIG. 7 is an explanatory view of the operation of the restraint pipe of the second embodiment. When the pipe-type lock bolt 11 is driven into the ground 50 and the pressurized liquid is injected into the double pipe 2, the constraining pipe 17 of the double pipe 2 is inserted as shown in FIG. The unexposed portion 2a expands and expands in the radial direction, which is the direction of arrow C. In each of the constraining pipes 17, the protruding portions 17b, 17b, which are structurally less rigid than the main body portion 17a,
Is deformed by being pushed in the direction of arrow C by the expanding force of the double pipe 2. The deformed protrusions 17b, 17b
0 to improve the pull-out resistance of the pipe-type lock bolt 11. When the double pipe 2 expands, the double pipe 2
In particular, since the portion of the folded portion 2t tends to expand significantly in the upward direction in the drawing of FIG. 7B, the projecting portion 17b of each restraining pipe 17 located along the folded portion 2t is greatly deformed. Can be Further, since the protrusion 17b does not restrain the entire circumference of the double pipe, as the expansion of the double pipe progresses, the double pipe is broken as a result of deformation as shown in FIG. 7 (c).
The protruding portion 17b of each broken restriction pipe 17 has an arrowhead shape and bites into the ground 50, so that the pipe-type lock bolt 1
No. 1 can exhibit even greater pull-out resistance. In addition, since the portion 17a that has not been broken restrains the double pipe to prevent its expansion, as a result, an uneven portion is formed on the lock bolt as shown in FIG. 7A. As a result, when a force in the pull-out direction acts on the completed lock bolt, the unevenness formed on the lock bolt and the broken portion of the restrained pipe cut obliquely are hooked on the ground, thereby increasing the pull-out resistance. . Therefore, a greater pull-out resistance can be exhibited as compared with a conventional product without a constraining pipe.

FIG. 8 is a perspective view of a pipe-type lock bolt according to a third embodiment, and FIG. 9 is a side view of a restraining pipe according to the third embodiment. The pipe-type lock bolt 21 of the third embodiment differs from the pipe-type lock bolt of the first embodiment only in the structure of the restraining pipe, and the other structures are the same. That is, the pipe-type lock bolt 21 of the third embodiment has a restraining pipe 27 in which a slit is formed. Although only one restraining pipe 27 is shown in FIG. 8, a plurality of restraining pipes may be provided. As shown in the perspective view of FIG. 8 and the side view of FIG.
c, 27c. That is, the constraining pipe 27 continuously covers the outer periphery of the double pipe 2 over the entire circumference in the plane perpendicular to the axial direction of the double pipe 2 (the directions of arrows A and B). The main body 27a (the portion corresponding to the length D12 in FIG. 9) and a projection formed so as to partially cover in the circumferential direction and protrude from the main body 27a in the axial direction of the double pipe 2 (the direction of arrow A). Portion 27b (length D1 in FIG. 9)
1). That is, the protruding portion 27b is formed in a cylindrical shape divided by a slit 27c formed in the axial direction of the double pipe 2 (the direction of arrows A and B). In this embodiment, only two slits 27c are provided, but three or more slits may be formed.

FIG. 10 is a diagram for explaining the operation of the restraint pipe according to the third embodiment. When the pipe-type lock bolt 21 is set in the ground 50 (FIG. 10 (a)) and the pressurized liquid is injected into the double pipe 2, the portion of the restraining pipe 27 having the slit 27c is easily deformed and has no slit. Since the portion is hardly deformed, as shown in FIG.
Only 7b allows the expansion of the double pipe, and the body 27a continues to restrain the double pipe. As a result, unevenness is formed on the bolt, and the portion largely deformed by the slit 27c of the constraining pipe 27 is cut into the ground. That is, the portion 2a of the double pipe 2 where the constraining pipe 27 is not inserted is expanded and expanded by the pressurized liquid injection. Further, at the portion of the constraining pipe 27, the protruding portion 27b, which is structurally less rigid than the main body portion 27a, is turned outward by the force of the double pipe 2 expanding, particularly in the vicinity of the slit 27c, which has less rigidity. And is deformed. The deformed protruding portion 27b cuts into the ground 50 and improves the pull-out resistance of the pipe-type lock bolt 11. In this case, if the slit 27c is arranged along the folded portion 2t of the double pipe 2, the deformation of the protruding portion 27b can be increased in the same manner as in the second embodiment, and the pull-out resistance can be further improved. In addition, restraint pipe 2
7 is located on the hand side of the main body 27a (arrow A).
Side), and due to the expansion and expansion of the double pipe 2, the overall length of the double pipe 2 in the axial direction becomes shorter than before the expansion, and as a result, when the expansion and expansion proceeds Then, the entire double pipe 2 is pulled in the hand direction (the direction of arrow A) toward the washer (not shown) on the reinforcing sleeve 3 side. By this pulling, the protruding portion 27b of the constraining pipe 27 bites further into the ground, and the fixing of the pipe-type lock bolt 21 to the ground is further ensured. As described above, when the force in the pull-out direction is applied to the already-installed lock bolt, the unevenness generated by the lock bolt and the portion of the restrained pipe that caught on the ground exert a large pull-out resistance and can be easily pulled out. There is no.

[0016]

As described above, according to the present invention, when the pipe-type lock bolt is driven into the ground and the inside of the main body pipe is pressurized, the main body pipe is not fitted with the expansion-restraining tubular member. The diameter expands and expands at the portion, and hardly expands and expands at the portion where the expansion restricting tubular member is inserted. As a result, a portion where the diameter is expanded and a portion where the diameter is not expanded are generated on the outer periphery of the main body pipe, and irregularities are formed in a form connected in the axial direction. Even if a force is applied in the direction, that is, in the pulling direction, the irregularities on the outer circumference of the main body tube will be caught on the ground, and a large pulling resistance can be exhibited.

Further, according to the present invention, since a plurality of expansion-constrained tubular members are arranged at a predetermined interval on the outer periphery of the main body tube,
The pull-out resistance of the pipe-type lock bolt against the ground can be further improved.

Further, according to the present invention, since both ends of the cylindrical sleeve are cut obliquely to form the expansion-constrained cylindrical member,
A part of the expansion-restraining cylindrical member is broken by the expansion and expansion, and becomes in the shape of an arrowhead and bites into the ground, so that the pull-out resistance of the pipe-type lock bolt against the ground can be further improved.

Further, according to the present invention, the slit is provided in the axial direction of the cylindrical sleeve to form the expansion-constrained cylindrical member. Therefore, a part of the expansion-constrained cylindrical member, that is, the vicinity of the slit is outwardly expanded by expanding the diameter. Thus, the deformed portion cuts into the ground, and the deformed portion cuts into the ground to further improve the pull-out resistance of the pipe-type lock bolt with respect to the ground.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a pipe-type lock bolt according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line X1-Y1 of FIG.

FIG. 3 is a sectional view taken along line X2-Y2 of FIG.

FIG. 4 is an explanatory view of a method of installing a pipe-type lock bolt of the present invention.

FIG. 5 is a perspective view of a pipe-type lock bolt according to a second embodiment of the present invention.

FIG. 6 is a side view of a restraining pipe according to a second embodiment.

FIG. 7 is an explanatory view of an operation of the restraint pipe of the second embodiment.

FIG. 8 is a perspective view of a pipe-type lock bolt according to a third embodiment of the present invention.

FIG. 9 is a side view of a restraining pipe.

FIG. 10 is a diagram illustrating the operation of the restraint pipe according to the third embodiment.

FIG. 11 is an explanatory diagram showing a method of manufacturing a pipe-type lock bolt.

FIG. 12 is a perspective view of a conventional pipe-type lock bolt.

FIG. 13 is a sectional view of a conventional pipe-type lock bolt.

FIG. 14 is an explanatory view of how to use a conventional pipe-type lock bolt.

FIG. 15 is an explanatory diagram of an effect of a conventional pipe-type lock bolt.

FIG. 16 is a view for explaining another effect of the conventional pipe type lock bolt.

[Description of Signs] 1. Pipe type lock bolt 2. Main body pipe (double pipe) 3. Rear end member for installation (reinforcement sleeve) 5. End member for installation (reinforcement sleeve) 7. Expansion restraint tubular member (restraint pipe)

Claims (4)

[Claims] 1. A main body tube which is inflated and expandable by injecting a pressurized liquid, and has a front end member mounted at one end of the main body tube and a pouring hole at the other end for injecting the pressurized liquid. A pipe-type lock bolt provided with a rear end member, wherein an expansion-constrained tubular member is disposed on an outer periphery of a main body tube between the casting front end member and the casting rear end member. Type lock bolt. 2. The pipe-type lock bolt according to claim 1, wherein a plurality of said expansion-constrained tubular members are arranged at predetermined intervals on the outer periphery of said main body tube. 3. The pipe-type lock bolt according to claim 1, wherein the expansion restricting tubular member has a shape in which both ends of a cylindrical sleeve are obliquely cut. 4. The pipe-type lock bolt according to claim 1, wherein the expansion restricting tubular member has a shape having a slit in an axial direction of the cylindrical sleeve.