KR100754927B1 - Ground reinfrocing bar and leading end fixing apparatus for it - Google Patents

Abstract

A ground reinforcing bar having an end anchorage is provided to increase pull-out strength by heightening the binding strength with the ground using an end anchorage having expansion pieces. A rock bolt as a ground reinforcing bar is provided with an end anchorage(14) fixed to the ground and composed of a body(15) having plural projecting supports(18) to couple the body and the ground more strongly, projecting joints(17) to function as a lever to push out a steel bar when a steel bar is inserted to the body and plural expansion pieces(16) to widen radially to drive the projecting supports in a side wall of a perforated hole, and a steel bar(10) inserted/couple to the end anchorage and provided with a thread(11) to couple with a thread formed on the body of the end anchorage strongly.

Description

Ground reinfrocing bar and leading end fixing apparatus for it}

1 is a schematic diagram of an embodiment of a conventional rock bolt.

Figure 2 is an exploded cross-sectional view showing the structure of the rock bolt according to the present invention.

Figure 3 is a cross-sectional view showing the structure of the rock bolt according to the present invention.

4 is an exploded perspective view of the rock bolt according to the present invention.

5 is a combined perspective view of the rock bolt according to the present invention.

6 is a perspective view of a middle rod having a passage and a discharge hole formed therein;

Figure 7 is a schematic view of the state in which the steel rod and the tip anchorage is coupled.

8 is a schematic view of an embodiment of a rock bolt according to the present invention.

9 is a structural diagram of a tip anchorage including a collapsible loop.

10 is a schematic view when the extension is deployed at a limited angle.

11 is a plan view of the folding means.

12 is a side view when the folding means is attached.

<Description of Symbols for Major Parts of Drawings>

10: steel bar 11: screw structure

12 discharge hole 13 passage

14: front end stop 15: body

16: extension 17: protruding jaw

18: protrusion support 19: slit

20: middle peak 21: ground

22: punched hole 23: cement milk

24: pressure plate 25: nut

26: folding means 27: fixing means

28: longevity

The present invention relates to a ground reinforcing rod and its tip anchoring hole, and more particularly, to be inserted into a drilling hole formed in the ground, and to drill a rock bolt used to strengthen the ground, and to strengthen the bonding force between the ground and the rock bolt. It relates to a tip anchoring mouth having an extension piece that is inserted into and then expanded to engage the ground.

In general, rock bolt is a kind of support ball that supports the original ground by using the strength of the ground itself in civil construction work, especially in the construction of tunnels, etc., and it is suture action, beam formation action, pressure resistance action, arch formation action and ground reinforcement action. Do it.

FIG. 1 illustrates an example of a conventional rock bolt, in which drilling holes 2 are excavated to have a diameter larger than that of rock bolts 3 using a drill or the like in the ground 1, and the rock bolts 3 are drilled in the drilling holes 2. ) And fix the rock bolt (3) to the ground (1) by supplying cement milk (4), which is a fixing material for fixing the rock bolt (3) to the ground (1) using an injection hose (7). Let's go. Then, by using the fastening means such as the nut (6) to install the pressure plate 5 in close contact with the excavation surface or shotcrete surface.

However, such a conventional rock bolt was difficult to place the rock bolt in the center of the drilling hole, the rock bolt is easy to be separated from the drilling hole during the installation process, there is a high risk of injury to the operator, troublesome installation, there is a problem of coupling force with the ground There was a problem that a large number of rock bolts had to be installed to strengthen the ground.

The present invention in order to solve the above problems by installing a rock bolt to strengthen the ground, by using the tip fixing hole with an extension piece to increase the coupling strength of the rock bolt and the ground to increase the pull strength, and also rock bolt By forming pre-stress or post-stress on the ground to increase the effect of the ground strengthening by rock bolts, the number of rock bolts can be reduced, and the rock bolts are not separated from the drilled holes to improve the work efficiency. To make it possible.

The ground fixing rod tip anchoring hole of the present invention for achieving the above object is in the shape of a cylinder and the protruding support portion and the inner circumferential surface of the body is formed of a screw structure, and is connected to the rear edge of the body is formed It characterized in that it comprises a plurality of extension pieces formed to be separated from each other by a protruding jaw formed to protrude in the inward direction to have an inscribed circle smaller than the inner diameter of the body.

Ground reinforcing rod of the present invention is characterized in that it comprises a steel rod coupled to the inner circumferential surface of the front end fitting and the body of the front end fitting and pushing the protruding jaw in the outward direction to expand the extension piece radially.

The steel rod has a central passage through which the cement milk can pass, and a plurality of discharge holes for discharging the cement milk passing through the inside of the steel rod to the outside of the steel rod may be formed at the waist of the steel rod. In addition, a screw structure may be formed on an outer circumferential surface of the steel bar.

The front end of the body may further include a plurality of protruding supports, and the front end of the body may be substantially shielded.

A screw structure may be formed on an inner side surface of the extension piece, and a folding means may be further included at a boundary between the body and the extension piece.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

2 and 3 are exploded and combined cross-sectional view showing the structure of the rock bolt according to the invention, Figures 4 and 5 are exploded and combined perspective view of the rock bolt according to the present invention.

The rock bolt of the present invention is composed of the tip anchoring hole 14 and the steel rod 10, the steel rod 10 is inserted into the tip anchoring hole 14 and coupled to the tip anchoring hole 14, the tip anchoring hole 14 is expanded (16) is provided and is fixed to the ground (21) by the extension piece (16).

The steel bar 10 is made of a metal material such as stainless steel or rebar, etc., which is manufactured in the shape of a cylinder, and a screw structure 11 is formed on the outer circumferential surface thereof so as to form a screw structure 11 formed in the body 15 of the tip fitting 14. By combining with the front end fitting (14). However, if necessary, the screw structure 11 may be formed on only one outer peripheral surface thereof. Here, the screw structure 11 is preferably formed of a screw thread and a screw thread which completely constitutes a screw line, but includes a fastening protrusion form that can be fastened to a female thread or a male thread.

As shown in FIG. 6, instead of the steel rod 10, a middle rod 20 having a central passage 13 through which cement milk 23 used as a fixing material for rock bolts can pass may be used. A discharge hole 12 may be formed at the waist to discharge the cement milk 23 supplied through the central passage 13 to the outside of the middle rod 20. That is, one end of the middle rod 20 is inserted into the body 15 is shielded, and the cement milk 23 is continuously injected through the passage 13 from the other end direction through the discharge hole 12. 23) is to be discharged. As a result, unlike the embodiment of the conventional rock bolt of FIG. 1 having a separate injection hose to supply the cement milk 23, it is possible to supply the cement milk 23 only by the rock bolt itself. This becomes even easier. At this time, even if one end of the middle bar 20 is not necessarily shielded, the discharge of the cement milk 23 is possible.

At this time, the discharge hole 12 is preferably formed in the middle portion of the middle rod 20, It is preferable to form a gap between the discharge holes 12 so that the cement milk 23 can be uniformly discharged around the middle rod 20.

Hereinafter, both the steel rods 10 and the middle rods 20 may be referred to as steel rods 10, and the middle rods 20 may be understood as a special case in which the central passage 13 is formed in the steel rods 10.

The tip fixing hole 14 fixed to the ground 21 is composed of a body 15, a projection jaw 17 and a plurality of extension pieces 16.

The body 15 is a portion that forms a screw connection with the steel bar 10, the front end is shielded, and the rear end is preferably in the shape of a cylindrical opening corresponding to the shape of the steel bar 10. A screw structure 11 is formed on the inner circumferential surface of the body 15 to be screwed with the steel bar 10. However, the tip portion may not be completely shielded, but may form a ventilation hole or the like, or may allow both sides to be opened.

A plurality of protruding supports 18 may be formed at the leading end of the body 15 to strengthen the coupling of the body 15 and the ground 21, and in particular, as shown in FIGS. Therefore, it can be formed, the shape is preferably wedge shape. As a result, when the tip anchoring hole 14 is inserted into the drilling hole 22 formed in the ground 21, the protrusion support 18 is embedded in the drilling surface of the inner ground 21 of the drilling hole 22 so as to be coupled with the rock bolt. The coupling of the ground 21 can be further strengthened, and furthermore, the steel rod 10 and the body 15 can prevent the rotation of the tip anchoring hole 14 while screwing, thereby making the operation easier. . At this time, it is preferable to form a gap between each projecting support 18 so that the bonding force between the body 15 and the ground 21 can be evenly distributed.

The extension piece 16 is expanded in the outward direction in the process of inserting the steel rod 10 into the body 15 and fixed to the ground 21 to increase the coupling force between the rock bolt and the ground 21, which will be described later. It has a protruding jaw 17 and is formed at the rear end of the body 15, but in the state before expansion, the slits are formed to extend substantially parallel to the longitudinal direction of the body 15, and a slit between each extension piece 16 is provided. 19) is formed so that the extension piece 16 can be expanded radially. At this time, it is preferable to make the spacing of the slits 19 uniform so that the bonding force between the extension piece 16 and the ground 21 can be uniformly transmitted to the rock bolt. In addition, a screw structure 11 may be formed on the inner surface of the extension piece 16 so as to be firmly coupled to the steel bar 10 inserted into the body 15. The expansion process of the extension piece 16 is made through the protruding jaw 17 and the steel rod 10 to be described below.

As shown in FIGS. 2 and 4, the protruding jaw 17 protrudes inside the extension piece 16 and is located close to the boundary with the body 15. Protruding jaw 17 is inclined in contact with the tip portion is smaller than the inner diameter of the body 15 takes the form of a peak that forms a gentle slope from the inner diameter to the tip. Therefore, the inscribed circle of the portion in which the protruding jaw 17 is formed is smaller than the outer diameter of the steel bar 10 to be screwed with the body 15, so that the steel bar 10 is inserted into the body 15 in the process of being inserted into the body 15. As a result, the protruding jaw 17 acts as a lever and pushes outward, and as a result, a plurality of pieces 16 of the protruding jaws 17 connected to each other are radially expanded.

The steel bar 10 which pushes the protruding jaw 17 in the outward direction is then screwed with the body 15 while being rotated so as to be firmly coupled with the tip fixing hole 14 so as not to fall out.

Hereinafter, an embodiment of the rock bolt of the present invention will be described with reference to FIGS. 7 to 8.

First, as shown in FIG. 7, the tip anchoring hole 14 of the present invention is introduced into the drilling hole 22 temporarily temporarily coupled to one end of the steel bar 10. The temporary coupling state is that the steel bar 10 and the extension piece 16 are screwed in the state in which the extension piece 16 is not expanded, and the steel bar 10 is only up to the previous position of the portion where the protruding jaw 17 is formed. It is inserted.

However, as discussed above, the screw piece 11 may not be formed in the extension piece 16. In this case, the temporary coupling may apply pressure to the steel bar 10, thereby protruding the steel bar 10 from the protruding jaw 17. It only consists of inserting up to the previous position of the formed part.

Introduced by the front end fitting 14 and the steel rod 10 into the drilling hole 22 and then rotating the steel rod 10, the steel rod by the screw structure 11 formed in the steel rod 10 and the extension piece 16 10 is continuously inserted into the tip anchoring hole 14, in the process, the steel rod 10 pushes the protruding jaw 17 outward, and as a result, the extension 16 is radially expanded. At this time, in the process of rotating the steel rod 10, the tip fixing opening 14 is pressed into the inner ground 21 of the drilling hole 22 so that the protruding support 18 is on the excavation surface of the inner ground 21 of the drilling hole 22 As well as being supported by being lodged, the expanded piece 16 is embedded in the side wall of the drilled hole 22 to be coupled to resist pulling force.

However, when the screw structure 11 for provisional coupling is not formed in the extension piece 16, the protruding jaw 17 is introduced in the process of being introduced into the drilling hole 22 and then applying pressure to the steel rod 10. It is pushed outward and the extension of the extension piece 16 is made while the protrusion support 18 is embedded in the side wall of the drilling hole 22 is coupled.

Since the steel bar 10 pushed out the protrusion jaw is screwed with the body 15 is completed the structure of the rock bolt.

8 shows a state in which the installation of the rock bolt is completed by the above process. In the interior of the drilling hole 22 formed in the ground 21 is inserted into the lock bolt 14 and the steel rod 10 is coupled, the protruding support 18 formed on the outer surface of the body 15 is It is fixed to the surface of the ground 21, the extension piece 16 is also expanded and coupled with the ground 21, between the rock bolt and ground 21, which is composed of the tip fixing hole 14 and the steel bar 10 Cement milk 23 is filled. The cement milk 23 is supplied through the passage 13 and the tip anchoring hole 14 formed in the steel bar 10, and in the case where the discharge hole 12 is formed in the steel rod 10, It is supplied through the discharge hole 12. Of course, when the passage 13 is not formed inside the steel rod 10, the cement milk 23 may be injected in the same manner as in the related art.

In addition, the pressure plate 24 is installed and the nut plate 25 is used to fix the pressure plate 24 in close contact with the excavation surface or shotcrete surface, which can be easily performed by those skilled in the art by a conventional method. will be.

In the above, the body 15 and the extension piece 16 are integrally formed so as to be enlarged by a permanent deformation in which a boundary between the body 15 and the extension piece 16 is bent, but as shown in FIGS. 9 to 10. 15) and the extension piece 16 are manufactured separately and the extension piece 16 is connected to the rotation of the steel rod 10 by connecting the body 15 and the extension piece 16 by using a folding means 26 such as a hinge. It can also take the form of expansion.

In this case, an inclination is formed on at least one of the cross sections of the body 15 and the extension pieces 16 connected by the folding means 26 so that the extension pieces 16 can be enlarged, and according to the size of the inclination angle The angle at which the extension piece 16 is expanded is changed. Therefore, it is preferable to adjust the angle of the inclination angle in consideration of the diameter of the drilling hole 22 into which the rock bolt is to be inserted, so that the extension piece 16 can be secured to the ground 21 after expansion.

11 is a plan view of the folding means 26, and FIG. 12 is a sectional view when the folding means 26 is attached to the body 15 and the extension piece 16. As shown in FIG.

The folding means 26 is attached to the body 15 and the extension piece 16 by fixing means 27 such as rivets, and a long hole 28 is formed at the portion attached to the extension piece 16 so that the extension piece is extended. When 16 is expanded, the relative position of the fixing means 27 in the long hole 28 is moved in the rearward direction.

Folding means 26 is not limited to the above embodiment, of course, various modifications are possible.

In the case of using the folding means 26, the temporary coupling of the tip fitting opening 14 and the steel rod 10 is performed by fixing with a fastener surrounding the outside of the extension piece 16, and the steel rod 11 is inserted therein. If a force exceeding the breaking strength of the fastener is applied outward in the process, the extension 16 is developed while the fastener is released.

In the state in which the extension piece 16 is expanded, the cross sections of the body 15 and the extension piece 16 make surface contact with each other, and the extension piece 16 is no longer enlarged by the size of the drilling diameter of the drilling hole 22. This results in a strong pull resistance structure.

Although described above with reference to the rock bolt, of course, it can be applied to the ground reinforcing rod including a soil reinforcement nail (soil nail) having a similar function.

As described above, the present invention increases the pullout strength by strengthening the coupling force between the rock bolt and the ground by using the tip anchoring hole with extension pieces in strengthening the ground using the rock bolt. By forming a compressed area on the ground by acting post-stress, the effect of the ground strengthening can be increased to reduce the number of rock bolts, and the rock bolts can be removed from the drilled hole to improve the work efficiency. In addition, by forming the central passage and the discharge hole for supplying the cement milk to the steel rod constituting the rock bolt of the present invention to simplify the structure of the rock bolt can lead to a reduction in the manufacturing cost, installation work of rock bolt To make it easier.

Claims (12)

The inner circumferential surface has a cylindrical shape and has a screw structure formed therein, a plurality of protruding support portions formed at the front end portion of the body, and are connected to the rear edge of the body and have an inscribed circle smaller than the inner diameter of the body. A protruding jaw having a protruding jaw and protruding the ground reinforcing rod including a plurality of pieces formed to be separated from each other by the slit. The method of claim 1, Ground fixing rod end fitting characterized in that the screw structure is formed on the inner surface of the extension piece. delete The method according to claim 1 or 2, Tip fixing part for ground reinforcing rods, characterized in that the front end of the body is substantially shielded. The method according to claim 1 or 2, A front anchoring stop for ground reinforcing rods, characterized in that it further comprises a folding means at the boundary of the body and the extension piece. The inner circumferential surface has a cylindrical shape and has a screw structure formed therein, a plurality of protruding support portions formed at the front end portion of the body, and are connected to the rear edge of the body and have an inscribed circle smaller than the inner diameter of the body. A front end fitting having a protruding jaw formed to protrude and including a plurality of extension pieces separated from each other by slits; And Ground reinforcing rod comprising a; a screw structure is formed on the outer circumferential surface is coupled to the inner circumferential surface of the body of the tip fixing port to push the protruding jaw outwards so that the extension piece is radially expanded. delete The method of claim 6, The steel rod has a central passage through which the cement milk can pass, and a plurality of discharge holes are formed at the waist of the steel rod to discharge cement milk passing through the steel rod to the outside of the steel rod. Ground reinforcing rod delete The method according to claim 6 or 8, Ground reinforcing rods, characterized in that further comprising a folding means at the boundary of the body and the extension piece. The method of claim 5, Wherein the folding means is fixed to one side of the body or the extension piece, the other side is the ground reinforcing rod front end fitting characterized in that the flow or coupled to the other side of the extension piece. The method of claim 10, The folding means is a ground reinforcing rod, characterized in that one side is fixedly coupled to one of the body or the extension piece, the other side is fluidly coupled to the other side of the body or the extension piece.

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