EP1828487A1

EP1828487A1 - Method for installing anchors and an anchor which can be used according to said method

Info

Publication number: EP1828487A1
Application number: EP05809165A
Authority: EP
Inventors: Mark Bernthaler
Original assignee: Atlas Copco Mai GmbH
Current assignee: Atlas Copco Mai GmbH
Priority date: 2004-12-23
Filing date: 2005-11-24
Publication date: 2007-09-05
Also published as: AT501441A3; CA2552700A1; JP4146878B2; KR20070089895A; CN1922365A; AT501441A2; WO2006066288A1; US20080110640A1; JP2007519838A; IL176115A0; AU2005300238A1; BRPI0506590A; RU2317374C1; ZA200604867B

Abstract

The invention relates to an anchor comprising a pipe (1) which is folded in the longitudinal direction and an end piece (13) which can be opened under pressure and which is provided on the end of the anchor which is arranged inside the borehole. Said anchor is introduced into the borehole and is enlarged by using internal pressure which unfolds the pipe (1) until said pipe (1) is arranged on the friction fit and/or form fit on the borehole. Then, the pressure in the anchor is increased such that the front end (15) of the end piece (13) is separated and the hardened material is injected through the anchor into the borehole in order to fill the cavities in the region of the end of the anchor which is arranged in the base of the borehole and in the base (ground, rock) wherein the anchor is fixed, and cavities or crevices are located in the adjacent base. A hydraulically binding material based on cement can be used, in particular, as a hardened material.

Description

Method for setting anchors and anchors usable in this method

The invention relates to a method for setting anchors, such as ground anchors and rock anchors, with the features of the introductory part of claim 1.

The invention further relates to an anchor which can be used in the method according to the invention.

From US Pat. No. 4,459,067 A, a method of the type mentioned at the outset is known.

In this known method, an anchor (rock bolt or rock bolt) having a longitudinally inwardly folded tube is introduced into a borehole and expanded by increasing the pressure inside the folded tube, so that the outer surface of the tube to the inner surface of the borehole and thus fixes the anchor in the borehole.

In the known rock anchor the front end of the pipe is closed and the rear end of the pipe, that is the end adjacent to the opening of the borehole (the outer end of the borehole), is connected with a hose or pipe via the pressurized fluid (FIG. in particular water) in the interior of the tube for expanding the same can be introduced, connected.

A disadvantage of the known method and the known rock anchor is that this is determined solely by friction and positive fit in the hole, but the positive side effects of a Inj ektionsankers, such as solidification of the borehole surrounding soil or mountains are not given.

The invention is based on the object of specifying a method of the type mentioned in the beginning and an anchor which can be used in this method, which does not have the described disadvantages and wherein a quickly achieved and permanently secure hold of the anchor is achieved.

This object is achieved, as far as the method is concerned, with the features of the main claim of the method, and as far as the armature is concerned, with the characteristics of the independent, ^{* directed} to the anchor claim.

Preferred and advantageous embodiments of the invention are the subject of the dependent claims.

An anchor set by the method according to the invention sits securely and permanently firmly, as it firmly against the inner surface of the Bore hole is applied because the wall of the expanded tube of the anchor deformed a positive and friction resulting in gaps, joints and / or areas with softer material into it, but also has the advantage that the mountains or the soil in which the anchor is inserted , is solidified in the area of the borehole deepest end of the borehole by the introduced, hardening mass and possibly in the borehole deep existing columns or cracks are filled with the mass.

The anchor according to the invention is a further development of the known Reibrohranker, as they are known for example from the above-mentioned US 4, 459, 067 A and which are also referred to as "Swellex". In the anchor according to the invention, the power transmission takes place in the subsoil both by friction and by mechanical (form-fitting) connection with the ground. The anchor according to the invention also has the advantage that the anchor can also be used as an injection lance for soil improvement. Soil improvement at certain depths or above a certain depth is of particular importance if soil layers overlying the surface of the day or rock layers lying in front of it under tunneling would be affected by the pressure in such a way that under certain circumstances the entire stability of the structure would be jeopardized.

As a hardening mass (Inj ektionsgut) anchor mortar, Portland cements and other cements with sufficiently small particle size but also synthetic resins and other Inj can be used in the context of the invention in principle.

The hardening composition used in the process according to the invention may also be a hydraulically setting compound, such as injection (essentially a mixture of water, cement and optionally fine aggregates, such as fly ash) or a mortar (essentially a mixture of water, Cement and aggregates with small grain size). In this case, the inventive method has the advantage that the interior of the anchor is protected by the hardened mass from corrosion. As hardening mass and plastics can be used, the z. B. introduced molten and solidify by cooling or harden after introduction by chemical reaction.

In general terms, the procedure used in the method according to the invention can be described as follows: It becomes a borehole in the required length and in each case manufactured for the product in question (anchor) required diameter. In this hole, the expandable anchor is introduced. This is then connected in particular using an adapter with a pump, filled with water and pressurized until the profile of the anchor unfolds and the tube fits snugly against the borehole wall. Subsequently, the profile expands in such a way that also irregularities in the borehole diameter are filled. In fractures or cavities, the profile expands to its maximum diameter, which also creates a mechanical (positive locking) anchoring relative to the limited expansion in the regular wellbore. After this has been achieved, the pressure is further increased until the tip, in particular in the region of a groove provided for this purpose, opens and is cut off in the wellbore deepest. Now, the adapter previously used, was introduced through the water, replaced by a Inj ektionsadapter and introduced the injection material through the severed tip of the anchor in the ground. Also, the introduction of the pressed material (injection material) is carried out under pressure, wherein the pressure due to the friction and the mechanical connection anchor ground of the correspondingly dimensioned armature is intercepted so that the armature is not pushed out of the borehole in the manner of a piston.

The anchor which can be used in the method according to the invention has at its front end, that is to say at the end, with which it is introduced into the borehole, an end piece which is fastened, for example, to a sleeve provided there, which is connected to the pipe, wherein the tail opens at a pressure higher than that of expanding the pipe to apply it to the inside of the wellbore so that hardening mass can then be injected through the pipe and the then open end into the wellbore.

The armature according to the invention can carry at its end lying on a borehole an anchor plate which is supported on the ground or rock side on the outer end sleeve of the armature. Anchors according to the invention can also be combined with Inj ectonsbohrankern. This has the advantage that the anchor according to the invention a rapid load capacity and the Inj ektionsanker ensure the continuous load capacity.

Further details, features and advantages of the invention will become apparent from the following description with reference to the attached drawings.

It shows: Fig. 1 is a schematic plan view of a rock anchor, FIG. 2 the pipe of the rock anchor in the middle section, Fig. FIG. 3 shows the pipe of the rock bolt in section in the region of one end thereof, FIG. FIG. 4 shows an end piece at the front end of the rock bolt in a first embodiment, FIG. Fig. 5 schematically shows a tube of a rock bolt, widened in abutment with the inner surface of a borehole, FIG. 6 shows the end piece of the rock bolt in a second embodiment, FIG. 7 an adapter receptacle piece provided at the rear end of the rock bolt, that is, adjacent to the open end of the borehole, FIG. 8 an adapter for the introduction of a pressure medium for expanding the tube of the rock anchor, Fig. 9 an adapter for introducing the hardening mass into the borehole, Fig. 10 an anchor partially in section and Fig. 11 a further embodiment of an anchor partially in section.

Although in the following the invention will be described mainly by the example of rock anchors, as they are also shown in the drawings, it should be noted that the invention in principle for all types of anchors, especially those of the aforementioned type, is applicable, including for the Use in soils and the like soft ground.

An in Fig. 1 shown rock anchor has a tube 1, which in its central region in FIG. 2 has cross-sectional shape shown in section. The tube 1 thus has an inwardly directed longitudinal fold 3, wherein the inwardly folded part of the wall of the tube 1 in the middle region (FIG. 2) looks somewhat omega-shaped, whereas in the region of the ends of the tube 1 the longitudinally folded longitudinal fold 3 has two substantially mutually parallel wall parts 5 (Fig. 3). With the ends of the tube 1, which as mentioned in FIG. 3 have shown cross-sectional shape, are inserted through these ends sleeves 7 and 9 connected. In particular, the sleeves 7, 9 are connected to the ends of the tube 1 by welds 11.

With the inner end of the tube 1, in particular with the sleeve 9 connected to this end of the tube 1, an end piece 13 is connected.

The end piece 13 is closed, but designed so that it opens at a certain pressure (a pressure which is higher than the pressure required to expand the tube 1) and the access to the interior of the end piece 13 or. of the tube 1 releases. Possible embodiments for end pieces 13 are shown in FIGS. 4 and

6 and 10 and 11 are shown.

In the in Fig. 4 embodiment, the end piece 13 has a tapered end 15 which is connected to the tubular part of the end piece 13 by a groove 17, that is a weakening point. Upon reaching a certain pressure inside the tube 1, the wall of the end piece 13 breaks in the region of the groove 17, so that the end of the tube 1 connected to the sleeve 9, for example by a weld 10, is open. In the in Fig. 6 shown embodiment, the end piece 13 is formed as a tube, the free end 19 is provided with an internal thread. In the internal thread a plug 21 is screwed in, so that the end piece 13 of FIG. 6 embodiment is initially closed. Upon reaching a certain internal pressure in the pipe 1 or. in the sleeve 9, the plug 21 is pushed out of the plug holder designed as end 19 of the end piece 13, so that in this embodiment, the interior of the tube 1 with the environment, ie with the interior of the wellbore is connected. With the other, in Fig. 7, the inner end of the tube 1 with the sleeve 7 and the end piece 13 opposite end of the tube 1 is connected via the sleeve 7, an adapter receptacle piece 31. For example, the adapter receptacle 31 is with the sleeve

7 connected by a weld 33. The adapter receiving piece 31 is arranged in the region of the open end of the borehole in which the rock anchor is to be fixed. The adapter receptacle 31 may be provided with a check valve 34 which opens into the tube 1 only in the direction of flow and thus prevents the escape of pressurized fluid and hardening mass from the rock bolt. Into the adapter receptacle 31 may be either a in Fig. 8 shown adapter 35 for the introduction of pressurized fluid, in particular water, are connected to the interior of the tube 1. Alternatively, an adapter 37 can be attached to the adapter receptacle 31, which can be seen in FIG. 9 is shown and for impressing hardening mass, in particular hydraulically setting mass, such as injection or mortar, is used.

The adapter 37 of FIG. 9 may be equipped with a quick-release coupling 38, so that a hose coming from a pump, which conveys the hardening mass, can be connected quickly. The adapters 35 and 37 can be provided with an external thread 39 which can be screwed into an internal thread 41 of the adapter receptacle 31.

Components such as ring bolts (DIN 580) can be fastened to the adapter receptacle 31 after the rock bolt has been fixed in a borehole, as will be described below.

To set the described rock anchor (rock bolt) in a borehole proceed as follows: First, the rock anchor is introduced with its end 13 ahead in a previously generated wellbore. Once this is done, pressurized fluid (e.g., water at a pressure of the order of 100-500 bar) is introduced into the interior of the tube 1 via the adapter 35 attached to the adapter receiving piece 31 by screwing. Under the effect of the pressure prevailing in the interior of the tube 1, the tube 1 expands while opening its longitudinal fold 3, so that it is pressed with its outer surface close to the inner surface of the borehole (FIG. 5). Once this is done, the adapter 35 can be removed from the adapter receptacle 31 by unscrewing it and replaced with the adapter 37 (Figure 9) by screwing this adapter 37 into the adapter receptacle 31. By means of the adapter 37 (FIG. 9), a hardening mass, in particular injection or a mortar, which is conveyed from a corresponding pump, is now pressed in under pressure. In this case, the pressure in the hardening mass is higher than the pressure previously prevailing during the expansion of the tube 1 by the fluid, so that the end piece 13 opens by either (FIG. 4) the tip 15 of the end piece 13 by breaking the wall in the region of the groove 17 is cut off or (FIG. 6) the plug 21 is pushed out of the plug holder 19. Once this is done, first enters the fluid that has been used to expand the tube 1, in particular water, and then enters the hardening mass of the tube ^ 1 through the sleeve 9 and the end piece 13 in the borehole. The hardening, in particular hydraulically setting, mass now fills the remaining after the expansion of the tube 1 space 8 between the rest of the fold 3 and the inner surface of the borehole (Fig. 5). In addition, hardening mass penetrates into cracks or fractures emanating from the front end of the borehole, and thus solidifies the material (mountains, rocks or the like) into which the rock anchor has been set, especially in the area where the rock anchor is located Drill hole deep surrounds.

In a modified mode of operation, it is also possible to proceed in such a way that initially with the adapter 35 of FIG. 8 pressure is generated, which is sufficient for the expansion of the tube 1 while opening its fold 3, so that the tube 1 with its outer surface to the borehole applies (Figure 5), whereupon then the pressure in the fluid is increased, so the end piece 13 opens and only then the adapter 35 of FIG. 8 against the adapter 37 of FIG. 9 is replaced. In addition, the procedure described offers the advantage that the interior of the rock anchor, which consists in particular of steel, is protected from corrosion. In the event that a cement-based hydraulically setting mass is used, an alkaline environment is additionally ensured, which is an advantage. With the operation of the invention and the use of the invention rock anchor in combination with Inj ektionsbohrankern (so-called "hybrid anchor"), the benefits of using internal pressure expandable rock anchors (rapid strength and tight fit) with the advantages of hardening, z. B. The hardening mass fills any clearances in the area of the borehole between the outside of the injection well anchor and also penetrates into cracks or fissures, which emanate from the borehole, and thus the rock, the soil respectively . generally solidified a ground around the wellbore around.

In the in Fig. 10, the anchor again consists of a profile tube 1 and the two provided at its ends sleeves 7 and 9. The sleeves 7 and 9 are connected to the profile tube 1 of the anchor by pressing and welding. To the sleeve 7 is in the in Fig. 10 embodiment, an end piece 31 welded, in which the in Figs. 8 and 9 can be selectively screwed adapter shown. For this purpose, the end piece 31 has an internal thread via which the in Fig. 8 shown coupling piece for the expansion of the profile tube 1 can be screwed. About this coupling water is introduced under pressure to expand the profile tube 1 and then blasting off the tip of the armature.

To the end piece 31 and the injection adapter according to FIG. 9 are connected to the anchor (screwed) after the coupling of FIG. 8 has been removed, so then the the At the front end of the armature, an end piece 13 is connected via the sleeve 9 with a tip 15 via a weld 10. In the wall of the end piece 13, an outwardly open groove 14 is provided near the base of the tip 15. About this groove 14 material breach is enforced after exceeding the Aufweitdruckes and subsequently caused the blasting of the tip 15, so that then the ground-binding mass can be injected by the anchor.

In the in Fig. 11, the anchor again has the profile tube 1, which at the ends of the profile tube 1 by pressing and / or welding attached sleeves 7 and 9 and connected to the sleeve 7 (welded) end piece 31. To the front sleeve 9 is connected via a Weld 55 an externally threaded coupling piece 54 is connected. About this coupling piece 54, an internally threaded coupling piece 53 is screwed to the weld 10, the end piece 13 is connected to the tip 15. In the in Fig. 11, the groove 17 at the foot of the tip 15 to the inside of the end piece 13 is open. The tip 15 may be formed at different angles than the embodiment shown in the drawings. It can also end pieces 13 with curved front end (cambered) or be used with flat front end.

In summary, an embodiment of the invention can be described as follows:

An armature having a longitudinally-folded tube 1 and a downhole end 13 of the anchor is inserted into a borehole and expanded by applying internal pressure to unfold the tube 1 until the tube 1 is frictionally locked / or positive fit rests against the borehole, whereupon the pressure in the armature is increased, so that the front tip 15 of the end piece 13 is separated. Then hardening mass is pressed by the anchor into the well to fill cavities in the area of the well located in the wellbore end of the anchor and the ground (soil, rock) in which the anchor is fixed, and located in the adjacent subsurface cavities or cracks. In particular, a hydraulically setting mass based on cement can be used as the hardening mass.

Claims

Claims :

Method for setting anchors with a tube (1) folded at least once, wherein the tube (1) is expanded by applying internal pressure after it has been inserted into a borehole, characterized in that after expansion of the tube (1 ) the internal pressure is increased until an end piece (13) provided at the inner end of the armature opens and releases a connection between the interior space of the pipe (1) of the armature and the borehole, and then that hardening mass is pressed through the pipe (1), that the hardening mass is filled with clearances (8) between the front end of the pipe (1) and the borehole, crevices and cracks emanating from the borehole and finally allowing the hardening mass to harden.

2. The method according to claim 1, characterized in that a hydraulically setting compound is used as the hardening mass.

3. The method according to claim 2, characterized in that is used as the hardening mass of a hydraulically setting mass based on cement.

4. The method according to claim 1, characterized in that a plastic is used as the hardening mass.

5. The method according to claim 4, characterized in that a hardening by chemical reactions plastic is used.

6. The method according to claim 5, characterized in that an epoxy resin is used.

7. The method according to claim 4, characterized in that a plastic is used as the hardening mass, which is pressed in molten.

8. The method according to any one of claims 1 to 7, characterized marked, that for the expansion of the tube (1) in the tube (1) of the anchor, a fluid, in particular water under a pressure of 100-500 bar, is introduced.

9. The method according to claim 8, characterized in that the pressure in the for expanding the tube (1) introduced fluid after the expansion of the tube (1) is increased to open the end piece (13).

10. The method according to any one of claims 1 to 9, characterized in that the end piece (13) by breaking in the region of a predetermined breaking point (groove 17) is opened.

11. The method according to any one of claims 1 to 9, characterized in that the end piece (13) by pressing out of a closure plug (21) is opened.

12. An anchor for use in carrying out the method according to any one of claims 1 to 11, comprising a tube (1), the at least one Longitudinal fold (3), characterized in that at the rear end of the tube (1) to be inserted first into a borehole an initially closed end piece (13) is provided, and in that the end piece (13) under the action of the tube (1) the prevailing pressure is obvious.

13. Anchor according to claim 12, characterized in that at both ends of the tube (1) sleeves (7, 9) are provided, which are connected to the tube

(1) are tightly connected.

14. An anchor according to claim 13, characterized in that the end piece (13) with the at the inner end of the tube (1) of the anchor provided sleeve (9) is connected.

15. An anchor according to any one of claims 12 to 14, characterized in that the end piece (13) at its closed end (15) has a predetermined breaking point (groove 17).

16. An anchor according to claim 15, characterized in that the outside of the predetermined breaking point (groove 17) lying end of the end piece (13) has a tip (15).

17. An anchor according to any one of claims 12 to 16, characterized in that the end piece (13) has a in its outer end (19) inserted set graft (21).

18. An anchor according to claim 17, characterized in that the plug (21) in the region of an internally threaded end (19) of the end piece (13) is inserted, in particular screwed.

19. An anchor according to any one of claims 12 to 18, characterized marked, that the end piece (13) is a tube which is connected to the inner sleeve

(9) of the anchor is connected.

20. An anchor according to any one of claims 12 to 19, characterized in that at the end piece (13) opposite the outer end of the tube (1) of the anchor, an adapter receptacle piece (31) is provided in which optionally an adapter (35) for the introduction of pressurized fluid and an adapter (37) for introducing hardening, in particular hydraulically setting mass can be fixed.

21. An anchor according to claim 20, characterized in that the adapter receptacle piece (31) carries an internal thread (41) and that the adapter (35, 37) with external thread (39) in the adapter receptacle piece (31) are screwed.

22. An anchor according to claim 20 or 21, characterized in that the adapter (37) for the introduction of hardening mass carries a quick coupling (38) for the connection of a delivery hose for heir- ing mass.

23. An anchor according to any one of claims 19 to 22, characterized in that in the adapter receiving piece (31) a check valve (34) is provided.