HU208357B - Device for making anchor particularly rock anchor and liquid afterhardening matter for injecting into rock or/and soil mass - Google Patents

Abstract

The hydraulic self drilling rock anchor, is used esp. for drilling loose rock of practically the same compressive strength. It can consolidate the rock through injection and make safe the voids. It consists of a tube deformed along its length by an involuted slot (1), and having at one end a coupling sleeve (4) with a side filler opening (10), and at the other end a closure sleeve (3) with a drill cutter. There is a central axial boring (9) which carries the fluid for injection. USE/ADVANTAGE - System combines the drilling and injection processes for producing a rock anchor.

Description

FIELD OF THE INVENTION The present invention relates to a process for making an anchor, in particular a rock anchor, and injecting a liquid curing agent into soil or rock mass.

In mining, tunneling, and other civil engineering work, there are many cases in which drilling is required using a variety of manually or mechanically operated electrically compressed air or hydraulically driven drilling equipment that can be rotated or hammered. The mechanical properties of the rock to be drilled generally determine the type of drilling: rotary drilling equipment is used in soft, low, unidirectional rocks, while drilling rigs are used in harder, high, triaxial rocks.

The energy from the rotary motor or the hammer drill to the drill bit is transmitted by the drill rod, which is also responsible for conveying the rinsing medium, liquid or some liquid mixture. The drill rod is usually cylindrical or hexagonal or spiral and has a generally smooth surface; it can be extensible or it can be integrated with the crown. The wall of the hole drilled into very low unidirectional compressive strength rocks loses its stability within a very short time after the extraction of the tool; often, even the retraction of the drill bit is prevented by a collapsed hole wall.

Two fundamentally important ways of injecting rock masses, such as those in mining, that surround subterranean spaces, namely rock consolidation and water or gas containment.

Rock consolidation is required if the cut (tunnel) mantle or its immediate surroundings is a rock of low strength that, despite the installation of conventional securing equipment, remains unstable. However, water or gas barrier injection is used when the casing of the cut or its immediate surroundings is so cracked that it does not provide protection against the risk of water or gas intrusion.

The injection is carried out by means of an injection tool inserted into a hole drilled to a sufficient depth in the rock, after which the tool is pressed (e.g. mechanically) against the wall of the hole, thereby eliminating the risk of backflow of the injection material.

Rock anchors, which are known in many versions, are used to secure mining spaces (cavities) and to perform various civil engineering tasks. For example, it is known to have a closed-gauge tubular groove into which high-pressure fluid is introduced, thereby expanding the cross-sectional area of the tubing so as to create a frictional connection between the outer wall of the tubular anchor and the rock to be secured. In the pre-expansion state, the tubular anchor comprises at least one longitudinally extending passage which is plastically ejected by the hydraulic pressure of the fluid being introduced, and the periphery of the tubular anchor is resting on the wall of the pre-drilled hole, following its irregularities. The fluid pressure is provided by an external auxiliary device. The pre-made hole in the rock should be of such a diameter that the pipe anchor can be easily inserted. The pipe anchor is of medium toughness, which is capable of plastic deformation under 100-300 bar fluid pressure. One end of the anchor is provided with a suitably designed filling head and the other end is provided with a reinforcing sleeve to prevent the anchor bursting.

The pipe anchor described above is available in a variety of sizes from 1 to 3 meters, but often requires anchors over 6 meters in length, but due to the difficulty and complexity of attaching the anchor parts to each other only at an expense and time and labor. A further disadvantage of the discussed pipe anchor is that it prevents the drainage of the mining water in the rock cavities and cracked rocks, and does not allow post-solidifying liquids, such as cement milk, to solidify the rock. Another disadvantage is that the anchoring head cannot be lowered into the cut wall or the base of the cut, in other words it cannot function as a recessed anchor, which greatly limits the use of, for example, wheeled conveyors in the cuts.

A solution to overcome these drawbacks is described in patent application HU 196 477. The pipe structure discussed herein, which is suitable for both hydraulic rock anchoring and fluid transfer, has a fluidized-pressure fluid wall pipe having an end with a reinforcing sleeve surrounding the pipe and extending to the inner wall of the pipe by means of a seam-welded end. is closed and a switching element is connected to the other end. The most important feature of this tubular structure is that this coupling element is formed by a threaded coupling pin with a through hole extending into the inside of the pipe.

The hydraulic rock anchors described above are used to provide looser, low unidirectional rock strengths. Depending on the hardness of the particular rock, a hole with a diameter of approximately 5-8 mm in diameter must be drilled for their installation. The great advantage of this type of anchor is that after an increase in diameter ("inflating") as a result of the hydraulic pressure, the anchor creates a secondary stress along its entire length in the center casing of the cut. With the help of anchors built at the proper density, the load-bearing capacity of the initially low-strength rock jacket can be significantly increased, however, the most advanced versions of hydraulic anchors also have drawbacks. Anchor making always requires a separate set of tools: first, as a stand-alone operation, separately

EN 208 357 Β is used to drill holes, and in very loose, low unidirectional rocks, the drilling operation itself may be problematic. Due to the low stability of the puncture wall, insertion of the injection device or anchor body into the hole is difficult and time consuming, and in many cases, when the puncture wall collapses, is impossible.

It is an object of the present invention to provide a structure whereby the drilling, injection and rock-anchoring operations can be carried out without the use of additional tools and separate technological operation (s), thus eliminating the problem of low perforation stability.

The present invention is based on the discovery that the anchoring tubular structure of anchor can be adapted to be connected to a drilling machine by inserting a suitable spacer in such a way that the flushing medium is passed from the filling end to the drilling crown and thus made suitable for drilling. It will further be appreciated that the filler end of the tube assembly may be adapted to be connected to an anchor pump so that the tube assembly may be inflated as a hydraulic anchor and, at a predetermined position, weaken the tube wall at a predetermined position of inflating the tube. Finally, it has been discovered that the filling end of the tubular structure may be adapted to be connected to an injection pump so that the injection material may flow through the tubular structure and may be injected into the surrounding rock through the expansion opening, i.e. the anchor tube.

Based on the above findings, the object of the present invention has been solved by the use of a rock anchor device having an anchor shaft having a longitudinal infiltration tube, a filling sleeve fixed at one end and a locking sleeve fixed at the other end. that a drilling device, preferably a drill fork, is attached to the sealing sleeve having a longitudinally extending hole in the tube communicating at one end with an internal channel delimited by a crease and at the other end extending from the drilling device; a connecting piece for providing a torque transfer connection to the outer end of the filling sleeve having a hole extending from one end thereof and approaching said inner channel at the other end; the device having a releasable connection to the connection piece on the one hand and to the drill and having a fluid passageway therebetween, and the wall of the tube forming part of the anchor rod being broken at least at one point relative to the rest of the wall weakening.

Thus, the above-defined structure is essentially a self-drilling injection hydraulic anchor, since the structure is suitable for making a hole in loose rock and, as originally intended, can be anchored into the hole as an anchor and then used as an injection device. Thus, three technological processes - drilling, tensioning and injection - can be performed in a single structure, which of course results in significant time and cost savings. The structure also makes it possible to install anchors in loose rocks that would otherwise be unsuitable for anchoring. In addition, anchoring enhances the effectiveness of rock consolidation achieved by injection. It should be emphasized that, for the purposes of this description, the term "rock" should be interpreted as broadly as possible, obviously including "soils".

A preferred embodiment of the device according to the invention is characterized in that the connecting piece is a rectangular body made of steel in which the fluid through hole is centrally located. According to another feature of the invention, the fluid through hole in the drill, preferably the drill, is centrally located.

Another preferred embodiment of the structure is that the tube is weakened by milling at one or more locations close to the sealing sleeve, preferably facing each other on the shoulders delimiting the gap. It may also be desirable for the drill sleeve to have an insert having a cavity shaped to fill the anchor rod, which cavity has a larger diameter cylindrical outer cavity extending to the front face of the insert, and a cylindrical inner cavity connecting them preferably. in the continuation of the inner cavity, a recess is formed in relation to the outer cavity, having the shape of a connecting piece fixed to the filling sleeve, and having a stem connecting to the insert having one end extending into the nest and the other end a channel extending through the forming coupling head. In this case, it is advantageous to have holes in the cylindrical wall defining the outer cavity for the insertion of a spring-locking fork for releasing contact with the drill. Finally, it is also expedient to illustrate an embodiment in which a plate-shaped washer is placed on the anchor shaft. As a result of this action, the structure of the present invention is capable of performing the full function of the rock anchor.

The invention will now be described in more detail with reference to the accompanying drawings, which illustrate a preferred embodiment of the structure and illustrate the most important stages of its application. In the drawings, Figure 1 is a schematic side view of the anchor leg of the structure;

Figure 2 is a sectional view of a drill sleeve of the structure on a larger scale;

Figure 3 is a larger cross-sectional view taken along the line I-I in Figure 1;

Figure 4 is a perspective view of the arrow II in Figure 1;

Figure 5 shows a frame 3 in the state of preparation of the anchor shaft of Figure 1 for the blow operation

HU 208 357 Β seen from the side, partly in section;

Figure 6 is a schematic side view of the anchor leg of Figure 1 in its ready state for the expansion operation; Fig. 7 is a schematic side view of the anchor leg of Fig. 1 in the state of the injection operation.

Figure 1 is a schematic side elevational view of the anchor shaft x of the entire structure, denoted by 27, with its longitudinal geometric center axis. The main parts of the anchor shaft 27 are the tube 28, the drill head 1 and the filling head 6, which have a plunging 28a of substantially the entire length. The drill bit 1 has, within practical limits, a drill fork 1a, which has a longitudinal through hole 3 and is connected to a sealing sleeve 4 which terminates at the end of the tube 28 of any length. The latter travels with an inner channel 15 delimited by the inflow 28a of the tube 28 shown in larger scale. Due to the presence of clogging 28a, there are recesses 16 in the wall 28 of the outer trough 5 (Fig. 3) extending along the length of the tube 28, near the sealing sleeve 4, which at this point weakens the tube wall, i.e. weakening the cross section. It will be noted that as shown in FIG. 3, said inner channel 15 does not communicate with the interior 28b of tube 28.

Returning to Figure 1; the filling head 6 of the tube 28 has a filling sleeve 6a that fits on the end of the tube. At the end of this filling sleeve 6a a connection piece 8 is provided by means of a welding seam 17 having a central longitudinal through hole 9 (see FIG.

4). The latter passes through the inner channel 15 of the tube 28. Also, a filling opening 7 is formed in the wall of the filling sleeve 6a which extends into the inner space 28b of the tube 28 shown in FIG. The inner channel 15 formed in the tube 28 as well as the holes 3 and 9 (preferably holes) are located in the longitudinal geometric central axis x of the anchor shaft 27.

Figure 2 is a larger sectional view of the drill sleeve, which is part of the structure of the present invention and is designated by reference numeral 29. The drill sleeve 29 has an insert 10, which may be made from a cylindrical block of steel, for example, and which contains a cylindrical inner cavity 20 of smaller diameter d and an outer cavity 19 of larger diameter D extending to the face of the insert. The inner cavity 20 is connected to the outer cavity 19 by the conical transition space 30. Connected to the end of the inner cavity 20 opposite the transition space 30 is a smaller recess 18, which is recessed into the inner surface of the insert 10 and has the shape of a connecting piece 8 for the filling head 6. The inner cavity 20 and the outer cavity 19 are designed to receive the filling sleeve 6a and are shaped accordingly. In the cylindrical wall of the insert 10, which defines the outer cavity 19, there are two through holes 11 which are to be used again.

On the end face of the insert 10 opposite to the outer cavity 19 is attached the welding seam 13 by a welding seam 13 in which a centrally longitudinal channel 14 extends, one end of which extends into the above-mentioned socket 18 and the other end ; the function of the latter will be described later. The longitudinal geometric center axis of the entire drill bit 29 is shown in FIG. 2 with reference letter x '.

In Figure 5, where the previously used reference numerals have been used to denote like parts, the structure of the present invention is illustrated in a state prepared for drilling operations. Accordingly, the anchor shaft 27 is inserted into the drill sleeve 29 with its filling head 6 and secured therewith by inserting a spring fork 21 through the holes 11, and the drill sleeve 29 is guided into the drill 22, known per se. (The longitudinal geometric center axes x, x coincide.) The transmission of torque from the drill 22 to the anchor 27, which will also serve as the drill bit with the drill bit 1 at its end, is provided on the coupling head 31 and the socket 8 , columnar body). The flushing fluid reaches its destination from the drill 22 through channel 14, inner channel 15 of pipe 28 (Figure 3), and longitudinal hole 3. The spring-locking fork 21 allows the anchor shaft 27 to be moved back and forth (in and out of the hole) in order to remove the drill hole faster and to prevent the hole 3 from blocking.

In Figure 6 (where reference numerals have already been used to denote the structural elements previously described), the structure of the present invention is illustrated in an assembled state for anchor assembly operation. In this case, the anchor rod 27 with its filling head 6 fits into the known anchor assembly 23. By this time, the hole 33 in the rock 32 is already complete, the anchor shaft 27 is located there, and the structure is ready for the expansion operation.

Figure 7 illustrates an embodiment of the structural injection operation of the present invention; By this time the expansion process has been completed, the cavity 28a of the tube 28 has been depressed (Fig. 3), the bores 16, the weakened wall portions, have been ruptured and gaps 26 have formed in the wall of the tube 28; the tube 28 itself, having a circular cross-section, fills the hole 32 in the rock 32, at the end of which the drill bit 1 is located (and remains there permanently as a losing structure). The filling head 6 is now connected to an injection device 24 known per se, and the filling sleeve 6a lies on the base wall 25 on which the opening 25a is formed; this is located in the longitudinal geometric central axis x of the anchor rod 27. The washer 25 is preferably manufactured for the anchor rod 27

EN 208 357 Β before welding the drill fork la.

Using the structure described above, the ground anchor is prepared as follows:

In the first step, the anchor shaft 27 with the drill head 1 according to Fig. 1 is prepared for making a final anchor structure in the rock by inserting the drill sleeve 29 shown in Fig. 2 into the opposite end of the anchor numbers 27. the connecting piece 8 is inserted into the socket 18 and the anchor shaft 27 and the drill sleeve 29 are secured to each other by pushing the spring fork 21 into the through hole 11. The connecting rod 13 of the drill sleeve 29 is then connected to the known drilling machine 22, also with a releasable connection, as shown in Figure 5. In the rock, drilling is then performed using the anchor shaft 27 as a drill while the flushing medium (liquid) can flow freely through a continuous stream of channels 14, 9, 15, and 3, as shown in Figures 1, 2, 4, and 5. via a duct (cavity) outside the la fork, that is to its destination.

After completion of the bore of the desired length, the drilling machine 22 (Fig. 5) is dismounted from the rock mass end of the anchor rod 27 and the known anchor-building device 23 is connected to the exposed filling head 6 as shown in Fig. 6. its interior 28b is "puffed", i.e. filled with pressurized fluid (hundreds of bars) above atmospheric to straighten inflow 28a. The pressurized fluid (working fluid) may be any suitable medium. For example, the swelling operation may be carried out in the same manner as described in U.S. Patent No. 1,967,477. Upon completion of the expansion process, when the pressure in the inner space 28a of the tube 28 (FIG. 3) reaches about 250-280 bar, the cut-outs 16 are ruptured to form the slits 26 of FIG. The person performing this puffing operation senses a sudden drop in pressure. After the formation of the slots 26, an injection device 24 is now connected to the filling head 6 of the anchor shaft 27 which is suitable for injection from the rock 32, after disassembling the anchor-building device, and from there through the filling opening 7 is injected and injected. into the 32 rocks. After the injection operation is carried out in a manner known per se, the injection device 24 is removed from the outer end of the anchor stem 27 and the protruding anchor shaft end is finalized, thereby completing the injection and anchor making with a tool, essentially in a single process.

Advantageous effects of the invention may be summarized as follows:

it is an essential advantage of the invention that it allows the possibility of incorporating rock anchors into loose rock masses where it would otherwise be difficult, if not impossible, to insert the rock anchor into the bore due to its tendency to collapse. In such loose rocks, it is generally extremely advantageous to perform injection and anchor construction simultaneously, which the structure of the present invention allows, since the efficiency of injection-based rock consolidation is greatly enhanced by the simultaneous application of rock anchoring. The fact that drilling, rock anchoring and injection operations can be carried out with the same structure is advantageous, while not only eliminating the risk of borehole drilling, but also making it possible to significantly reduce the time needed to secure the rock mass at a given location, , reduce labor costs). The cost of constructing the structure, taking into account its multi-purpose use, is advantageously low and can be produced using materials and tools commonly known in mining and civil engineering. It is a significant advantage that the most suitable drill fork for drilling a given rock is always used in the structure, as well as the connecting rod (plug end) corresponding to the drill available at all times.

The invention is, of course, not limited to the embodiment described above, but may be practiced in various ways within the scope of the claims.

Claims (7)

A device for making an anchor, in particular a rock anchor, and injecting a liquid curing agent into a soil or / and rock mass having a sealing sleeve having a sealing sleeve having a longitudinal furrow tube, a filling sleeve fixed at one end thereof and a closing sleeve (4) is provided with a drilling device, preferably a drilling fork (1a), in which a longitudinally extending hole (15) in the tube (28) is connected to an internal channel (15) delimited at one end by a recess (28a); ) is; a connecting piece (8) for providing a torque transfer connection to the outer end of the filling sleeve (6a), which has a hole (9) extending therefrom at one end and communicating with said inner channel (15) at the other end; the device further having a releasable connection to the connection piece (8) on the one hand and to the drilling machine (22) having a fluid transfer passage (29) and the wall (28) of the tube forming part of the anchor rod (27) relative to the remainder, for example, is weakened by a burst (16) that can be disrupted by pressure created in the tube (28). Device according to Claim 1, characterized in that the connecting piece (8) is made of a rectangular steel part, in which the fluid through hole (9) is centrally located. The device according to claim 1 or 2, characterized in that the fluid guide hole (3) in the drilling device, preferably in the drilling fork (1a), is centrally located. HU 208 357 B 4. A device according to any one of claims 1 to 5, characterized in that the tube (28) is weakened at one or more locations near the sealing sleeve (4), preferably by opposing recesses (16) on the shoulders defining the gap (5) extending along the crease. 5. A device according to any one of claims 1 to 4, characterized in that the drill sleeve (29) has a spacer (10) having a cavity in the shape of the filling sleeve (6a) of the anchor rod (27), which cavity extends to the front face of the spacer (10). forming a cylindrical outer cavity (19), a cylindrical inner cavity (20) of smaller diameter (d), and preferably a conical transition space (30) connecting them, and a socket extending from the outer cavity (19) to extend the inner cavity (20). (18) having the shape of a connecting piece (8) fixed to the filling sleeve (6a) and having a shank (13) for attaching to the insert (10), in which At one end, a channel (14) extends through the coupling head (31) which is inserted into the nest (18) and through the coupling head (31) which forms part of the connecting rod (13). Device according to claim 5, characterized in that the outer cavity (19) of the insert (10) In the cylindrical wall 10 of the boundary there are holes (11) suitable for introducing a spring-locking fork (21) for releasing contact with the drilling machine (22). 7. A device according to any one of claims 1 to 3, characterized in that the anchor shank (27) is provided with a le15 washer.