KR100297930B1 - Rock bolt buried fixing device and rock bolt fixing method - Google Patents

Abstract

The present invention effectively anchors rock bolts buried to stabilize the excavated wall surface of artificially excavated underground cavities, and significantly improves rock bearing capacity around the excavated wall surface, and rock bolt embedding fixing device using the same The technical configuration of the present invention is characterized in that the connection piece is formed to extend in the periphery of the outer end of the metal disc (A) made to fit in the excavation hole (2) perforated in the excavating wall surface of the underground cavity 10 and the attachment pieces 20 extending shortly outwardly between the connecting pieces as a unitary body with the connecting pieces 10 and radially elastically spreading, and installed at the ends of the connecting pieces 10, respectively. And the fixing pieces 30 which are divided to form a variable cylindrical body which is reduced or expanded to an arbitrary diameter, and arranged to flow inside the fixing pieces 30. Come on the fixing side of reduction, it gives the widening operation by the fixing bolt for rock embedded consisting of a hwakgyeong means 40 hayeoseo tip is formed of a binder assembly hole (41) of the lock bolt 3 and the center device;

Drill the excavation hole 2 to a predetermined length through the boring process on the excavation wall surface of the underground cavity, and attach the prepared fixing device 1 to the distal end of the excavation hole 2 by attaching it to the distal end of the rock bolt 3. Insert and pull the lock bolt 3 primarily from the outside of the excavation hole 2 so that the fixing device 1 is fixed to the excavation hole 2, and then the rock bolt 3 outside the excavation hole 2. By pulling the secondary to ensure that the fixing device (1) is completely settled in the excavation hole (2), the prestress is applied to the rock bolt (3) bound by the fixing device (1) fixed in the excavation hole (2) The rock bolt 3 is embedded in the excavation hole 2 so that the rock bolt 3 is embedded so as to compress the rock around the excavation wall surface of the underground cavity.

Description

Rock bolt buried fixing device and rock bolt fixing method

The present invention effectively anchors rock bolts buried to stabilize the excavated wall surface of artificially excavated underground cavities, and significantly improves rock bearing capacity around the excavated wall surface, and rock bolt embedding fixing device using the same It relates to the settlement method of.

Rocks around the excavation wall of underground tunnels or tunnels artificially excavated underground rock layers have their own weak bearing capacity, so there is a risk of collapse and falling rocks.Concrete Lin to stabilize the excavation walls of these underground cavity ing) and NATM (New Austrian Tunnel Method) methods have been actively used.

In the concrete lining method, the construction period is extended and construction cost is increased due to the burden of repeatedly installing or dismantling the groundwork and formwork when constructing the perforated wall of the underground cavity to the reinforcement wall of the required thickness. On the other hand, the NATM method is recognized to have advantages of reducing construction costs while shortening the construction period because of excellent construction, because it stabilizes the excavation wall itself by using shotcrete together with rock bolts.

In order to effectively stabilize the excavation wall surface of the underground cavity as the NATM method, it is necessary to firmly fix the rock bolts that are inserted into the excavation hole drilled in the excavation wall surface. Because rock bolts should be buried to exert pre-stress to compress the rock around the excavation wall after penetrating into the excavation hole of the excavation wall surface, the rock bolts inserted in the excavation hole of the excavation wall can bear the stress It must be settled.

In order to fix the rock bolt as described above, rock bolt embedding fixing devices of various structures and shapes have been developed, and one of them is formed as a glass having low hardness and is formed as a cylindrical body having an empty space therein. A rock bolt embedding fixing device is known, which is composed of a capsule and a foamable fixing resin in a gel state accommodated in an empty space inside the capsule, to fix rock bolts introduced into a drilling hole drilled in an excavation wall surface of an underground cavity.

The rock bolt embedding fixing device is pushed into the rock bolt to be positioned at the distal end of the drilled hole in the excavating wall surface of the underground cavity, and then, when the rock bolt is impacted and forcibly broken, it flows out from the inside of the capsule. The gel-like expandable fixing resin was cured while being filled in the excavation hole, thereby restraining the fixation by restraining the tip of the rock bolt inserted into the excavation hole.

However, such a conventional rock bolt embedding fixing device has some problems in that rock bolts cannot be firmly fixed in the excavation hole.

That is, in the conventional rock bolt embedding fixing device, in the process of inserting the rock bolt embedding fixing device into the excavation hole and inserting it, the rock bolt embedding fixing device does not reach the end of the excavation hole and is made of glass material in the middle. Since the capsules are easily broken, the foam fixing resin flowing out from the broken capsules is lost, and thus the operation of fixing the rock bolts could not be performed.

Secondly, in view of the fact that we always maintain the wet state by the leachate in the excavation hole of the excavation wall surface, the adhesive force of the foamed fixing resin itself filled in the excavation hole is lowered, and thus the original function is not faithfully exhibited. The rock bolts penetrated into the ball could not be firmly settled,

Third, in the case of an excavation hole drilled in the vertical direction on the ceiling which forms the excavation wall surface of the underground cavity, if the capsule is placed at the distal end of the excavation hole forcibly damaged, the foamed fixing resin flowing into the broken capsule flows down the excavation hole. It is pointed out that there is a problem such as unable to settle the rock bolt.

Therefore, due to the problems pointed out above, the conventional rock bolt embedding fixing device fails to effectively give prestress to the rock bolt fixed in the excavation hole, thereby compressing and stabilizing the rock around the excavation wall of the underground cavity. The result is a significant degradation of functionality.

The present invention is configured to fix the rock bolts more firmly without regard to the form or conditions of the perforated holes drilled in the excavation wall of the underground cavity, so that the pre-stress given by the rock bolts set in the excavation hole can be efficiently handled. The purpose of the present invention is to provide a fixing device for rock bolt embedding and a method for fixing a rock bolt using the same, which greatly increases the bearing capacity for the rock around the excavation wall through the rock bolt.

Figure 1 shows an example of applying the fixing device for embedding rock bolt of the present invention

Figure 2 is an exploded perspective view showing a fixing device for embedding rock bolt of the present invention

Figure 3a, Figure 3b is a cross-sectional view showing the operating state of the anchoring device for embedding rock bolt of the present invention

Figure 4 is a partial perspective view showing a modified example of the anchoring device for embedding rock bolt of the present invention

Figure 5 is a side cross-sectional view of Figure 4

6A, 6B, 6C, 6D, 6E, and 6F illustrate step by step fixing methods of the present invention rock bolt.

Shown

<Description of the symbols for the main parts of the drawings>

A: metal disc B: reinforced metal plate 10: connecting piece

20: Family Arrival 21: Rivet 30: Settlement

31: engaging jaw 32: binding groove 33: rivet

40: expansion means 41: assembly hole

Rock bolt embedding fixing device 1 of the present invention is a connecting piece that is elongated at regular intervals around the outer end of the metal disk (A) made to be fitted in the excavation hole (2) perforated to the excavating wall surface of the underground cavity ( 10) and housed pieces 20 extending shortly outwardly between the connecting pieces as a unitary body with the connecting pieces 10 and radially unfolding, and installed at the ends of the connecting pieces 10, respectively. Fixing pieces 30 divided to form a variable cylindrical body which is reduced in diameter or expanded to an arbitrary diameter, and are arranged to flow in the fixing pieces 30 so that the fixing pieces can be reduced and expanded and locked in the center portion. It has the technical structure comprised by the diameter expansion means 40 formed by forming the assembly hole 41 which the front-end | tip of the bolt 3 binds.

The present invention configured as described above, as shown in Figure 3, the end portion of the excavation hole (2) is assumed to be fitted into the mounting pieces (10) radially spread between the connecting pieces 10, the ends of the connecting pieces (10) Locked to the expansion means 40, so that the fixing pieces 30, which are expanded by the expansion means 40, which are respectively installed and flowed from the inside, are engaged while being in close contact with the inner wall of the excavation hole 2, respectively. The tip of the bolt 3 is restrained and fixed firmly.

Therefore, not only the excavation hole 2 drilled in the horizontal direction on the excavation wall surface of the underground cavity, but also the prestress provided with the rock bolt 3 firmly fixed to the distal end in the excavation hole 2 drilled in the vertical direction to the ceiling. Because it can efficiently handle, it will be able to significantly increase the support for the rock around the excavation wall.

In the figure, reference numeral 4 is an acupressure plate.

Hereinafter, each component will be described in more detail with reference to specific embodiments of the present invention.

Embodiments of the present invention shown in Figs. 1 to 2 also extends at equal intervals around the outer end of the metal disc (A) made to fit in the excavation hole (2) perforated to the excavating wall surface of the underground cavity 10 and the attachment pieces 20 extending shortly outwardly between the connecting pieces as a unitary body with the connecting pieces 10 and radially elastically spreading, and installed at the ends of the connecting pieces 10, respectively. And the fixing pieces 30 which are divided to form a variable cylindrical body which is reduced or expanded to an arbitrary diameter, and are arranged to flow in the fixing pieces 30 so as to reduce and expand the fixing pieces. The technical concept of the present invention is realized in that it includes a technical configuration having an enlarged diameter means 40 formed by forming an assembly hole 41 at which the tip of the rock bolt 3 is engaged.

The connecting pieces 10 are formed to extend at regular intervals at equal intervals around the outer end of the metal disc A, so that the fixing pieces 30 are fixedly connected to the ends of the respective connecting pieces 10.

These connecting pieces 10 are end portions of the connecting pieces 10 when the metal disc A pushed by the expansion-expansion means 40 fastened to the distal end of the lock bolt 3 is inserted into the excavation hole 2. Towing the fixing piece (30) connected to the part.

Here, the metal disk A on which the connecting pieces 10 are formed is made of a high strength metal plate, so that it is prevented from being deformed when the work is inserted into the excavation hole 2.

The fixing pieces 20 are formed to extend shortly from the outer end of the metal disc A to be located between the connecting pieces 10, so that the fixing pieces 20 are radially formed on the inner wall surface of the excavation hole 2 as a whole. Resiliently hooked to stay home.

And, it is important that the housed pieces 20 are bent downwardly inclined at a predetermined angle. The reason for this is that the insertion pieces 20 are not disturbed in the advancing direction when they are inserted into the excavation hole 2, and when they are fixed in the excavation hole 2, they hang on the inner wall surface of the excavation hole 2. The purpose of this is to increase the family's attachment ability by performing the role of a hooked hook.

4 and 5, the connecting pieces 20 are connected to each other from the outer end of the reinforcing metal plate B which is integrally fixed to the inner surface of the metal disc A by the same diameter size. Note that it may be formed so as to be located between (10). At this time, the reinforcing metal plate (B) abuts on the metal disc (A) is to be firmly attached and fixed as a rivet 21 through.

The reinforcing metal plate (B) is to be provided in the excavation hole (2) to reinforce the metal disc (A) while allowing the original fitting pieces 20 to be formed at the outer end of the reinforcing metal plate to perform the original function. At the same time, it can expect the side benefit of preventing deformation.

The fixing pieces 30 are respectively installed at the ends of the connecting pieces 10 to be divided to form a variable cylindrical body, so as to be reduced in diameter when fitted into the drilling hole (2), the home fitting piece at the distal end of the drilling hole (2) In the state assumed by the (20) while being expanded by the diameter expansion means 40 to be in close contact with the inner wall of the excavation hole (2).

In addition, the fixing pieces 30 are formed such that a plurality of engaging jaws 31 are formed to be stepped downward on each outer surface thereof, so that the fixing pieces 30 can be more securely engaged to the inner wall of the excavation hole 2. Do.

Here, the fixing pieces 30 are each formed with a binding groove 32 on the outer surface of the upper end, by inserting the end of the connecting piece 10 in the binding groove 32 and fastened as a rivet 33 through To be fixed.

The expansion means 40 is fastened to the front end of the lock bolt (3) and positioned to flow in the fixing pieces (30), when it is inserted into the excavation hole (2) is raised to push the metal disc (A) To reach the distal end of the excavation hole (2), and in the state assumed by the home attachment piece (20) is lowered to operate the fixing pieces (30) to be able to be hooked to the inner wall of the excavation hole (2) .

The expansion means 40 has an assembling hole 41 which extends up and down in the center thereof, so that the distal end of the lock bolt 3 is assembled through the assembling hole 41.

In the embodiment of the present invention, each of the fixing pieces 30 has a cross-sectional shape gradually thickening from the upper end to the lower end so that the fixing pieces 30 are formed so that the inner diameter of the upper and lower narrowing as a whole, the fixing piece 30 The expansion means (40) flowing in the inside of the) is formed as a cylindrical body having an outer diameter of the shape of the upper and lower narrow, the fixing piece 30 by the expansion means 40 flowing in the fixing piece (30) It is exemplified to improve the settlement ability by allowing them to widen and widen.

The rock bolt embedding fixing device 1 configured as described above is fixed in the following manner, as shown in Figs. 6A to 6B.

First, drill the excavation hole (2) by a predetermined length through the boring process in the excavation wall surface of the underground cavity,

Secondly, the fixing device 1 prepared by mounting on the distal end of the rock bolt 3 is inserted to reach the distal end of the excavation hole 2,

Third, after pulling the lock bolt 3 first from the outside of the excavation hole (2) to be fixed to the excavation hole (2),

Fourth, by pulling the lock bolt (3) to the outside of the excavation hole (2) to make the fixing device (1) completely fixed in the excavation hole (2),

Fifth, prestressing and tensioning the rock bolt (3) bound by the fixing device (1) fixed in the excavation hole (2),

Sixth, the construction is completed by installing a rock bolt (3) to compress the rock around the excavation wall surface of the underground cavity by injection-hardening the grout in the excavation hole (2).

As seen from the rational view, the present invention fixes rock bolts more firmly in the excavation hole drilled in the excavation wall of the underground cavity, so that the rock bolt fixed in the excavation hole can efficiently handle the prestress given by the rock bolt. By greatly increasing the support capacity for the rock around the excavation wall through the construction quality will have an excellent effect.

Claims (6)

Connection pieces 10 extending at equal intervals around the outer end of the metal disc A made to fit in the excavation hole 2 perforated to the excavating wall surface of the underground cavity, and the connecting piece 10 and the unitary body Shortly extending to the outside between the connecting pieces as the outer elastically stretched housed pieces 20, respectively, is installed on the ends of the connecting pieces 10 to form a variable cylindrical body reduced or enlarged to an arbitrary diameter The assembly holes 41 are arranged to flow in the divided fixing pieces 30 and the fixing pieces 30 to reduce and expand the fixing pieces, and the end of the lock bolt 3 is fastened to the center thereof. Fixing device for embedding the rock bolt, characterized in that consisting of a diameter-expansion means 40 by forming a. The fixing device for rock bolt embedding of claim 1, wherein the fixing pieces (20) are bent downwardly at a predetermined angle. The connecting pieces 10 according to claim 1 or 2, wherein the attachment pieces 20 are joined to the inner surface of the metal disc A by the same diameter size and are fixed integrally with each other from the outer end of the reinforcing metal plate B. Locking bolt buried fusing device characterized in that formed so as to be positioned between. According to claim 1, wherein the fixing piece 30 is a lock bolt embedding fixing device, characterized in that a plurality of engaging jaw (31) formed to be stepped downward on the respective outer surface is formed. According to claim 1, wherein the fixing pieces 30 each have a cross-sectional shape gradually thickening from the upper end to the lower end so that the fixing pieces 30 are formed so that the inner diameter as a whole of the upper and lower narrowing, the fixing piece 30 The expansion means (40) flowing in the inside of the) is formed as a cylindrical body having an outer diameter of the shape of the upper and lower narrow, the fixing piece 30 by the expansion means 40 flowing in the fixing piece (30) A rock bolt buried fusing device, characterized in that to improve the fixing capacity by allowing them to widen and widen. Drill the excavation hole 2 to a predetermined length through the boring process on the excavation wall surface of the underground cavity, and attach the prepared fixing device 1 to the distal end of the excavation hole 2 by attaching it to the distal end of the rock bolt 3. Insert and pull the lock bolt 3 primarily from the outside of the excavation hole 2 so that the fixing device 1 is fixed to the excavation hole 2, and then the rock bolt 3 outside the excavation hole 2. By pulling the secondary to ensure that the fixing device (1) is completely settled in the excavation hole (2), the prestress is applied to the rock bolt (3) bound by the fixing device (1) fixed in the excavation hole (2) And a rock bolt (3) is installed to compress the rock around the excavation wall surface of the underground cavity by injection-hardening the grout in the excavation hole (2).