JP4244215B2 - Pipe type lock bolt and pipe type lock bolt construction method - Google Patents

Description

  The present invention relates to a pipe-type rock bolt and a pipe-type rock bolt construction method, and in particular, has a main body having a concave cross-sectional shape, and is placed in a bore hole drilled in a natural ground and pressurized inside the main body to expand and expand the diameter. The present invention relates to a pipe-type rock bolt that supports a natural ground and a pipe-type rock bolt construction method.

  In the NATUM method (NATM method), which is commonly used for tunnel construction in mountains, etc., after excavating the ground (after hardening the wall with cement if necessary), a number of rock bolts are driven vertically from the wall into the bedrock. , Support for natural ground is made. The type called a pipe-type rock bolt has a main body that crushed the pipe material in the lateral direction and rounded both sides to form a concave cross section, and it was placed in a bore hole drilled in the wall or a bit at the end of the lock bolt main body Is installed while drilling by itself, then injecting pressurized fluid into the main body and pressurizing and expanding, pressurizing the expanded outer periphery of the body to the bore hole, as a friction fixing type lock bolt The rock around the inner wall of the tunnel is fastened, and the earth pressure is further increased to prevent the collapse of the inner wall of the tunnel (Patent Document 1). Some pipe-type rock bolts can be further firmly supported by injecting a fixing material after placement and expansion (Patent Document 2).

  With this type of pipe-type rock bolt, it is possible to demonstrate the effect of supporting the natural ground by expanding and expanding the main body without injecting the fixing material. In some cases, the water in the mountains collects in the borehole, and the water flows out from the mouth of the borehole. When spring water comes out, the mine environment deteriorates, and it becomes an obstacle to rock bolt expansion and diameter expansion work, or causes natural ground to loosen. Furthermore, in the type in which the fixing material is injected after expansion and diameter expansion, the fixing material does not flow to the predetermined fixing target area by flowing into the spring water, the fixing failure occurs, or the mouth part of the bore hole is caulked before injection, There is a problem that it is necessary to prevent the spring water and the fixing material from flowing out.

Japanese Patent Publication No. 2-520 JP 2004-12449 A

  An object of the present invention is to provide a pipe-type rock bolt capable of stopping spring water when the main body is expanded in view of the above-described problems of the prior art.

  The present invention has a main body having a concave portion formed in a cross-sectional shape, and is placed in a bore hole drilled in a natural ground at the time of construction, and the inside of the main body is pressurized to expand and expand the diameter laterally. In the pipe-type lock bolt and the pipe-type lock bolt construction method for supporting the main body, the main body is expanded and expanded in the borehole at substantially the entire length in the axial direction of the main body or at least one recessed portion of the predetermined one or a plurality of locations. And a water stop means for closing the gap between the main body and the borehole hole wall to stop the water. For the water-stopping means, a viscoelastic material or a water-swellable material is used, or a resin capsule that is crushed as the main body expands and expands and contains a cured material that reacts with the crushed resin capsule piece and hardens. Can be used.

According to the present invention, even in a spring ground, when the inside of the body placed in the borehole is pressurized to expand and expand, the water stop means closes the gap between the borehole and the body and immediately Stop water. As a result, the underground water gathers in the borehole and the natural mountain is prevented from being loosened by the spring water, and an appropriate natural mountain supporting effect of the rock bolt can be exhibited, and the underground working environment is not deteriorated.
In addition, when the fixing material is injected after expansion of the main body, caulking work (installing a packer or packing waste) at the mouth of the borehole is not required to stop water, improving workability and fixing material. Rotate to a predetermined anchorage area without being swept away by spring water.

  A pipe-type lock bolt has a main body in which a steel pipe material is crushed in the lateral direction and is further rounded to form a concave portion in the cross section, and a front end sleeve and a rear end sleeve fitted on the front end portion and the rear end portion of the main body. The front end sleeve and the rear end sleeve are welded so as to close the inside of the main body at the end face of the main body, and a small hole for supplying pressurized fluid to the inside of the main body is formed in the rear end sleeve. The water stop means is provided so as to be accommodated in the recessed portion of the concave portion of the main body, or is provided so as to go around the outer periphery of the main body, and a part thereof is fitted into the concave portion of the concave portion. By storing the water stop means in the recessed portion of the concave portion, it is possible to avoid an obstacle that the water stop means hits the hole wall when the lock bolt is driven into the bore hole. The water stop means may be disposed over substantially the entire length in the axial direction of the main body, but may be disposed at a predetermined one or a plurality of locations such as near the rear end of the main body or near the center and the rear end. . After placing in the borehole, pressurizing the inside of the main body to expand and expand the diameter, the water stop means of the concave part is pushed out, the gap between the borehole hole wall and the main body is closed, and the flow of spring water in the borehole is immediately stop. Sponge-like material such as neoprene sponge rubber, viscoelastic material such as silicon rubber, water-swellable fiber or polymer material, hardened material that is crushed when external force is applied, and fragments are stored inside Resin capsules that are cured by reacting with natural rubber, natural rubber or synthetic rubber, and a mixture of these and cementitious materials can be used. If you want to inject the fixer after expansion of the main body, or if you want to inject the fixing material to the outside of the main body, use a drill or other appropriate means to form a discharge hole at the front end of the main body. May be broken). In addition, the fixing material is not limited to the purpose of fixing the lock bolt, but includes a material that penetrates into the ground and improves the natural ground.

  1 is an external plan view of a pipe-type rock bolt according to one embodiment of the present invention, FIG. 2 is a horizontal sectional view of the pipe-type rock bolt of FIG. 1, and FIG. 3 is taken along the line III-III ′ of FIG. It is sectional drawing. Reference numeral 1 denotes a pipe-type lock bolt, and 2 denotes a lock bolt main body (hereinafter referred to as “main body”) having a predetermined length, and a concave portion 3 is formed in a cross-sectional shape over the entire length in the axial direction. Reference numeral 4 denotes a distal end sleeve which is fitted on the distal end of the main body 2 to restrain and reinforce the distal end portion, and is fixed so as to close the internal space of the main body 1 by a welded portion 5 welded to the distal end surface of the main body 2. Reference numeral 6 denotes a rear end sleeve which is fitted on the rear end of the main body 2 to restrain and reinforce the rear end portion, and is fixed so as to close the internal space of the main body 2 by a welded portion 7 welded to the rear end surface of the main body 2. ing. However, the rear end sleeve 6 and the main body 2 have small holes 8 and 9 communicating with the outside and the internal space of the main body 2, and pressurized fluid is introduced into the main body 2 from the outside through the small holes 8 and 9. Supply. Water stop means 11 and 12 are attached to the recessed portion 10 of the recessed portion 3 near the center and rear end in the axial direction of the main body 2 (a little closer to the front end than the rear end sleeve 6).

  The water stop means 11 and 12 include a sponge-like material such as neoprene sponge rubber, a viscoelastic material such as silicon rubber, a fiber or polymer material having a water expansion property, and when crushed, the debris reacts with the curing agent contained therein. Resin capsules, natural rubber or synthetic rubber, and a mixture of them with cementitious materials can be used. As an example, a sponge-like material is used.

FIG. 4 is an explanatory diagram of a method for manufacturing a pipe-type rock bolt.
First, a steel pipe material 20 having a diameter D1 is prepared (FIG. 4 (1)), and the steel pipe material having a diameter D1 is laterally crushed by a crushing process to form a flat work material 21 once, near the center and the rear end. The water stop means 11 and 12 are mounted on (Fig. 4 (2)). Next, by rounding, both sides of the workpiece 21 are rounded to form the main body 2 having a concave cross section (FIG. 4 (3)). The concave portion 3 formed in the cross section of the main body 2 is continuous in the axial direction, and is fixed so that the water stop means 11 and 12 are accommodated in the concave portion 10 inside. In order to restrain and reinforce both ends of the main body 2, the front end sleeve 4 and the rear end sleeve 6 are fitted to the front end portion and the rear end portion, and are welded and fixed to the end surface of the main body 2. 7 to complete the pipe-type lock bolt 1 (FIG. 4 (4)). Small holes 8 and 9 for supplying pressure fluid to the inside of the main body are formed in the rear end sleeve 6 and the main body 2, and the rear end sleeve 6 is formed in the main body 2 so that the positions of the small holes 8 and 9 coincide with each other. It is fitted.

  An example of tunnel construction is shown in FIGS. A tunnel is excavated in the natural ground 30 with an excavator, a support 33 and sprayed concrete are applied to the inner wall 32 of the tunnel space 31, and the mirror surface 34 is formed by blowing concrete on the face face in front of the tunnel space. A large number of pipe-type rock bolts 1 are installed on the inner wall 32 of the tunnel space 31 to support the natural ground 30 near the tunnel inner wall of the natural ground 30, and a large number of pipe-type rock bolts 1 are also applied to the mirror surface 34. A mirror bolt that supports the mirror surface 34 is used (the pipe-type lock bolt 1 can be easily cut with a bit of an excavator).

FIG. 7 is an explanatory view of a construction method of the pipe-type rock bolt 1, and FIG. 8 is an explanatory view of the operation of the water stop means 11, 12. The operation of the pipe-type lock bolt 1 described above with reference to these drawings will be described below. explain.
In the construction method of each pipe-type rock bolt 1 on the inner wall of the tunnel, first, a bore hole 40 having a diameter D2 and a depth L is drilled from the tunnel space 31 toward the natural ground 30 (FIG. 7 (1)). The diameter D2 is 3% smaller than the diameter D1 of the steel pipe material 20 (that is, the circumference of the bore hole is 3% shorter than the circumference of the main body 2), and the depth L is the portion of the pipe-type lock bolt 1 except for the rear end sleeve 6. Length. When there is spring water in the natural ground 30, the spring water flows into the hole 40 and flows from the hole 41 to the tunnel space 31. If the spring water is left untreated, the inside of the mine will be flooded, the working environment will deteriorate and the natural ground will loosen, or the spring water will drain sand etc. in the natural ground 30 to the tunnel space 31 through the bore hole 40. It also becomes. In this embodiment, after the pipe-type rock bolt 1 is driven into the bore hole 40 (FIG. 7 (2), FIG. 8 (1)), an attachment 42 is attached to the rear end sleeve 6 and the pressure fluid (pressure water) is made into a small hole. The inside of the main body is supplied through 5 and 6 (arrows B and C in FIG. 7 (2)), and the main body 2 is expanded and expanded (FIG. 7 (2)). The main body 2 expands almost to the original diameter D1, but since the diameter D2 of the bore hole 40 is perforated by 3% smaller, the outer periphery of the main body closely contacts the hole wall 43 of the bore hole before returning to the original diameter D1. Further, a pressing force P is applied to the outer side in the radial direction to restore the shape of the steel pipe material (FIG. 7 (3), FIG. 8 (2)). At this time, the concave portion 3 does not completely expand after the expansion of the main body 2 and remains as a shallow concave portion 3a, but is stored in the concave portion 3 near the center and the rear end of the main body. The water stop means 11, 12 is pushed out of the main body 2 along with the expansion and expansion of the main body 2, hits the hole wall 43 of the bore hole 40, deforms, blocks the gap between the hole wall 43 and the main body 2, and stops the flow of the spring water. Then, the spring water is prevented from being discharged into the tunnel space 31 from the natural ground 30 around the pipe-type rock bolt 1 including the back of the hole. Therefore, the tunnel space 31 is not flooded and the natural ground 30 is not loosened by spring water, and the pipe-type rock bolt 1 is firmly fixed to the natural ground 30 by friction (shown by the arrow P in FIG. 8 (2)). The pressure of the main body and the ground indicated by the arrow Q are fixed by the pressing force), and the internal pressure of the ground 30 is increased by the pressing force, and an appropriate ground support effect by the pipe-type lock bolt is exhibited.

  Note that a fixing material may be further injected into the main body after the expansion of the main body 2 (arrow D in FIG. 7 (4)). When injecting the fixing material or the injection material for the natural ground 30 also outside the main body, after forming a discharge hole (not shown) at the front end of the main body by an appropriate means such as a drill (at this time, a front end sleeve is attached if necessary) It may be broken) and injection is performed. Since the fixing solution is injected into the borehole from the discharge hole at the tip of the main body (arrow E in FIG. 7 (4)), the space behind the hole of the borehole 40, that is, the water groove, is blocked with a fixing material, thereby making the spring water more complete. Water can be stopped, and natural ground can be reinforced.

  According to this embodiment, since the hole diameter D2 of the bore hole 40 is 3% smaller than the diameter D1 of the steel pipe material 20 for manufacturing the main body 2 (that is, the peripheral length of the bore hole 40 is 3% shorter than the peripheral length of the main body 2). ) When the pipe-type lock bolt 1 is driven into the bore hole 40 and expanded and expanded in diameter, the outer peripheral surface of the main body comes into close contact with and presses the hole wall 43 of the bore hole 40. At this time, the concave portion 3 does not completely expand even after the expansion and expansion of the main body 2, and remains as a shallow concave portion 3 a, but the water stop means 11, 12 is a gap between the hole wall 43 and the main body 2. To block the flow of spring water. Therefore, the tunnel space 31 is not flooded, and the natural ground 30 is not loosened by the spring water, and the pipe-type rock bolt 1 is firmly fixed to the natural ground 30 and the internal pressure of the natural ground 30 by the pressing force. As a result, the ground support effect of the pipe-type rock bolt 1 is exhibited. Further, even when the fixing material is injected after the main body 2 expands and expands, caulking work (installing a packer or packing waste) is not required at the mouth of the bore hole to stop water, and workability is improved.

9 is an external plan view of a pipe type rock bolt showing a second embodiment of the present invention, FIG. 10 is a horizontal sectional view of the pipe type rock bolt of FIG. 9, and FIG. 11 is taken along the line XI-XI ′ of FIG. The same components as those in FIGS. 1 to 3 are denoted by the same reference numerals. Although FIG. 1 shows the case where the water stop means is provided at two locations near the center in the axial direction of the main body and near the rear end, in the example of FIG. 9, the water stop means is provided over almost the entire length in the axial direction of the main body. Show the case.
9 to 11, the water stop means 13 is attached to the recessed portion 10 of the recessed portion 3 over substantially the entire length of the main body 2 of the pipe-type lock bolt 1 </ b> A in the axial direction. By doing in this way, when the main body 2 is inflated and expanded, the water stop means 13 closes the gap between the main body and the borehole hole wall over substantially the entire length of the main body 2, so that the water stop effect is further enhanced. The other components of the pipe-type lock bolt 1A are configured in exactly the same way as the pipe-type lock bolt 1 of FIG.

  FIG. 12 is a cross-sectional view of a pipe-type rock bolt showing a third embodiment of the present invention. The same components as those of the pipe-type rock bolt 1 of FIG. In FIG. 12, the water stop means 14 provided in the recessed part 10 of the recessed part 3 of the main body 2 of the pipe-type rock bolt 1B is a viscoelastic material such as silicon rubber, and the recessed part 3 accompanying the expansion and expansion of the main body 2. According to this deformation, the gap is freely deformed and the gap between the outer periphery of the main body and the hole wall 43 is closed so as to enter the crack of the hole wall 43 of the bore hole 40 (FIG. 13).

  FIG. 14 is a cross-sectional view of a pipe-type rock bolt showing a fourth embodiment of the present invention. The same components as those of the pipe-type rock bolt 1 of FIG. In FIG. 14, the concave portion 3C of the main body 2C of the pipe-type lock bolt 1C has a narrow groove-shaped concave portion 10C, but the water stop means 14 is a viscoelastic material, and the main body 2C of the lock bolt 1C is By filling the concave portion 3C after processing, it can be stored in a narrow space without a gap. The water stop means 14 is freely deformed in accordance with the deformation of the concave portion 3C accompanying the expansion and expansion of the main body 2C, and enters the gap of the hole wall 43 of the bore hole 40 so that a gap between the outer periphery of the main body and the hole wall is formed. It closes (FIG. 15).

  FIG. 16 is an external perspective view of a pipe-type lock bolt according to a fifth embodiment of the present invention, in which a part of the pipe-type lock bolt is omitted. Components identical to those of the pipe-type lock bolt 1 of FIG. is there. In FIG. 16, the water stopping means 15 of the pipe-type lock bolt 1D is a rubber body of synthetic rubber or natural rubber formed in a substantially cylindrical shape so as to go around the outer periphery of the main body 2, and a protruding portion 15a protruding inwardly. Is inserted into the recessed portion 10 of the recessed portion 3 of the main body 2. When the diameter of the main body 2 is expanded and expanded, the cylindrical portion 15b of the water stop means 15 expands and comes into close contact with the hole wall of the bore hole, and the protrusion 15a does not come off from the concave portion 3 that becomes a water channel. As a result, the water stop means 15, the gap between the outer periphery of the main body and the hole wall is reliably closed.

  FIG. 17 is an explanatory view of the operation of the pipe-type rock bolt according to the sixth embodiment of the present invention. The same components as those of the pipe-type rock bolt 1 of FIG. The water stop means 16 provided in the concave portion 10 of the concave portion 3 of the main body 2 of the pipe-type lock bolt 1E includes a resin capsule 17 that is crushed when an external force is applied, and a hardening material 18 that is housed in the resin capsule 17. After the pipe-type lock bolt 1E is placed in the bore hole 40 (FIG. 17 (1)), when the diameter of the resin capsule 17 expands and expands, the resin capsule 17 strikes the hole wall 43 and is crushed (FIG. 17 (2)). The hardener 18 mixes around the main body while undergoing a curing reaction, and is filled as a filler 19 in the gap with the hole wall 43 to stop water (FIG. 17 (3)).

  In each of the embodiments shown above, a borehole is drilled with a rock drill or the like, and then a pipe-type lock bolt 1 is driven into the borehole. May be provided. In this case, the lock bolt itself is used as a drilling rod and is drilled while drilling a bore hole in the ground pile 30. After the placement, the pressure fluid is supplied into the main body to perform the expansion and expansion operation as in the above embodiment. Each water stop means can exhibit the same water stop effect.

  It can be used to support natural ground around the tunnel in tunnel construction, support natural ground in front of the mirror, support natural ground improvement, and strengthen slopes and retaining walls.

It is an external appearance top view of the pipe type rock bolt concerning the 1st example of the present invention (example 1). FIG. 2 is a horizontal sectional view of the pipe-type lock bolt of FIG. 1. FIG. 3 is a cross-sectional view taken along line III-III ′ in FIG. 2. It is explanatory drawing of the manufacturing method of a pipe-type rock bolt. It is explanatory drawing of tunnel construction. FIG. 6 is a cross-sectional view taken along line VI-VI ′ of FIG. 5. It is explanatory drawing of the construction method of a pipe-type rock bolt. It is operation | movement explanatory drawing of a water stop means. It is an external appearance top view of the pipe-type rock bolt concerning the 2nd example of the present invention (example 2). FIG. 10 is a horizontal sectional view of the pipe-type lock bolt of FIG. 9. It is sectional drawing along the XI-XI 'line | wire of FIG. It is sectional drawing of the pipe type rock volt | bolt which concerns on the 3rd Example of this invention (Example 3). It is operation | movement explanatory drawing of the pipe type rock volt | bolt of FIG. It is sectional drawing of the pipe type rock volt | bolt which concerns on the 4th Example of this invention (Example 4). It is operation | movement explanatory drawing of the pipe type rock volt | bolt of FIG. (Example 5) which is the external appearance perspective view which abbreviate | omitted one part of the pipe type rock volt | bolt which concerns on the 5th Example of this invention. It is operation | movement explanatory drawing of the pipe type rock volt | bolt which concerns on the 6th Example of this invention.

Explanation of symbols

1, 1A, 1B, 1C, 1D, 1E Pipe-type lock bolt 2, 2C main body 3, 3C concave portion 10, 10C concave portion 11, 12, 13, 14, 15, 16 Water stop means 17 Resin capsule 18 Curing material

Claims (5)

Pipe type that has a main body with a concave part in the cross-sectional shape, and supports the natural mountain by placing it in a bore hole drilled in the natural mountain at the time of construction and pressurizing the inside of the main body to expand and expand the diameter to the side In the lock bolt,
When the main body is expanded and enlarged in the borehole at substantially the entire length in the axial direction of the main body or at least one of the concave portions of the predetermined one or a plurality of locations, the gap between the main body and the borehole hole wall is blocked. Provided water stop means to stop water,
A pipe-type rock bolt characterized by The water stop means includes at least one of a viscoelastic material and a water-swellable material;
The pipe type rock bolt according to claim 1 characterized by things. The water-stop means includes a resin capsule that is crushed when an external force is applied, and a curing material that reacts and hardens with a resin capsule piece that is previously stored in the resin capsule and crushed,
The pipe type rock bolt according to claim 1 characterized by things. A pipe-type lock bolt having a main body having a concave portion formed in a cross-sectional shape and a water stop means provided at substantially the entire axial length of the main body or at least one concave portion of the predetermined concave portion is provided. And
Drill a borehole with a circumference of at least 3% smaller than the circumference of the body of the pipe-type rock bolt in the natural ground,
A pipe-type lock bolt is placed in the bore hole and the inside of the main body is pressurized to expand and expand to the side.
By this expansion and expansion, the outer periphery of the main body is pressed against the hole wall of the borehole, and the gap between the main body and the borehole is closed with the water stop means,
A pipe-type rock bolt construction method characterized by A main body in which a concave portion is formed in a cross-sectional shape, and a water stop means provided at substantially the entire length in the axial direction of the main body or at least a recessed portion of one or more predetermined concave portions, and the water stop means Prepares a pipe-type lock bolt containing a resin capsule that is crushed when external force is applied, and a hardener that reacts with and hardens the resin capsule pieces that are stored in advance and crushed in the resin capsule,
Drill a borehole with a circumference of at least 3% smaller than the circumference of the body of the pipe-type rock bolt in the natural ground,
A pipe-type lock bolt is placed in the bore hole and the inside of the main body is pressurized to expand and expand to the side.
By this expansion and expansion, the outer periphery of the main body is pressed against the hole wall of the borehole, and the resin capsule is crushed between the outer periphery of the main body and the hole wall, and the resin capsule piece and the curing material are reacted to cause a contact between the main body and the borehole. To close the gap,
A pipe-type rock bolt construction method characterized by

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