WO2001011194A1

WO2001011194A1 - Method for fixing a spreading anchor and spreading anchor

Info

Publication number: WO2001011194A1
Application number: PCT/AT2000/000202
Authority: WO
Inventors: Josef Mocivnik; Karl BÖHM
Original assignee: Techmo Entwicklungs- Und Vertriebs Gmbh; 'alwag' Tunnelausbau Gesellschaft M.B.H.
Priority date: 1999-08-06
Filing date: 2000-07-21
Publication date: 2001-02-15
Also published as: AU6253200A; EP1206625A1; ATA135899A; US20020081160A1; AT409785B; EP1206625B1; DE50002854D1; TWM271971U; JP2003506604A

Abstract

The invention relates to a method for fixing a spreading anchor (1) in a bore hole (2). After inserting the spreading anchor (1), at least one expandable spreading element (3) which is arranged on the anchor rod (4) of the spreading anchor (1) is expanded until it rests against the bore hole inner wall. According to the invention, the anchor rod (4) and the expandable spreading element (3) are advanced or withdrawn via the free end, which is pointed toward the open end of the bore hole (2), as the spreading element (3) expands toward the open end of the bore hole (2). The invention also relates to a spreading anchor (1), especially for use in mining, whereby at least one expandable spreading element (3) is provided on the outer side of the spreading anchor (1) that has an anchor rod. According to the invention, the spreading element (3) is held in a retaining element (13) fixed on the anchor rod (4), in an adjacent position when inserting the spreading anchor (3) into a hole (2). In addition the spreading element (3) can be expanded by displacing the anchor rod (4) toward the opening of the bore hole (2) caused by the interaction of the spreading element (3) with a stop element (9) anchored in the bore hole (2).

Description

METHOD FOR DETERMINING A SPREADING ANCHOR AND SPREADING ANCHOR

The present invention relates to a method for fixing an expansion anchor in a borehole, wherein after insertion of the expansion anchor, at least one expandable expansion element arranged on the anchor rod of the expansion anchor is applied in contact with the inner wall of the borehole, and to an expansion anchor, in particular for mining, at least one expandable expansion element being provided on the outside of the expansion anchor having an anchor rod.

In connection with the fixing or anchoring of an expansion anchor in a borehole, it is known to insert such an expansion anchor with at least one expandable element arranged on its circumference in the front section in a previously completed borehole and then to fix the expansion element by expanding the expandable element To allow expansion anchors in the borehole or to allow the expandable element to rest against the borehole wall, which in most cases is followed by an additional introduction of a curable suspension. Such embodiments can be found, for example, in AT-PS 339 239, EP-A 0 354 760, WO 94/05900 or US Pat. No. 4,305,687. In these known embodiments, after the expansion anchor has been introduced, a plurality of expandable expansion elements provided on the circumference of the expansion anchor are widened, for example by a screwing movement of the anchor, as a result of which there is an interaction with the expandable expansion elements on the threaded anchor rod of the anchor screwable element interacts and the expansion of the expandable expansion elements against the wall of the previously completed borehole possible. Such a system on the borehole wall provides a provisional securing of such an anchor against failure, so that a suspension can subsequently be introduced. By widening the expandable elements in this way, which, moreover, usually have a corresponding longitudinal extension in the axial direction of the borehole and are provided with rib-like elevations to increase the securing or anchoring effect, only one, in particular in the case of loose rock, can actually be achieved Provide provisional and short-term ^■ securing that prevents the expansion anchor from being inadvertently pulled out or falling out when it is installed in a vertically upward borehole, but does not allow the anchor to be adequately anchored to absorb larger loads.

The present invention now aims to provide, starting from a method and an expansion anchor of the type mentioned, the possibility of securing and fixing such an expansion anchor in a borehole beyond a provisional anchoring effect by a corresponding penetration or insertion of the at least one to allow an expandable expansion element.

To achieve this object, the method according to the invention is essentially characterized in that the anchor rod and the expandable expansion element are also open

End of the borehole-pointing, free end are acted upon or withdrawn during the expansion of the expansion element in the direction of the open end of the borehole. Because not only does the expansion element expand in contact with the borehole wall, but also in addition, during the expansion of the expansion element, the anchor rod and the expandable expansion element are acted upon or withdrawn in the direction of the open end of the borehole, not only does the expandable element rest securely on the borehole wall, but this backward movement also leads to an additional entry or penetration the free end, which faces the wall of the borehole, into the borehole wall, so that a correspondingly good anchoring effect can be achieved. By entering or seizing the free end of the expandable element in the borehole wall in this way, a sufficient anchoring effect of the expansion anchor can only be achieved by widening the expandable element, the anchoring effect subsequently being able to be increased accordingly, for example by introducing a curable suspension. An additional anchoring effect that can be achieved by the backward movement of the anchor rod and the associated expandable element when entering the borehole wall makes it possible, for example, to advance the expansion in a provisional expansion immediately after the anchor has been set and the curable suspension has been introduced, because of the seizure of the expandable expansion element, a sufficient anchoring effect is achieved and there is no need to wait for the hardening of the hardenable suspension to continue with the finishing work, so that overall a considerable time advantage can be achieved for carrying out such finishing work.

For a particularly effective and efficient expansion of the expandable expansion element, it is also preferably proposed according to the inventive method that the expansion of the expandable expansion element by screwing the anchor rod relative to one in the borehole fixed stop element and a cooperation of the expandable expansion element with the stop element is made. As a result, correspondingly high forces can be introduced during the screwing movement of the anchor rod and a correspondingly high or good anchoring effect can be achieved.

For a particularly simple fixing of the stop element in the borehole, which is subsequently used for anchoring and widening the expandable expansion element, it is proposed according to a further preferred embodiment of the method according to the invention that the stop element interacts with a cladding tube, which after a preceding drilling operation is withdrawn and fixed slightly at least by the length of a holding element with the expandable expansion element and the stop element. It is thus easy to use a cladding tube used in a previous drilling process directly for positioning the stop element of the expansion anchor, so that after removing the drill head and the drill rod from the cladding tube and slightly withdrawing the cladding tube, the expansion anchor is immediately set with at least an expandable expansion element can be made through the cladding tube and by positioning the stop element in front of the cladding tube, a secure positioning and definition of the position of the stop element can be achieved for the subsequent process of fixing the expansion anchor while expanding the at least one expandable expansion element.

To solve the problems mentioned above, an expansion anchor of the type mentioned is essentially characterized in that the expansion element in a holding element fixed to the anchor rod in is held in position when the expansion anchor is in a hole and that the expansion element can be expanded by a movement of the anchor rod in the direction of the opening of the borehole by cooperation of the expansion element with a stop element anchored in the borehole. Because, according to the invention, the expandable expansion element is held in an adjacent position in a holding element, the expansion anchor can be introduced in a simple manner together with the at least one expandable element, whereupon the expandable expansion element by moving the anchor rod is expandable in the direction of the opening of the borehole by cooperation of the expansion element with a stop element anchored in the borehole. It can thus be found with a structurally simple and accordingly robust and stable construction which is sufficient to achieve the desired, secure anchoring by widening the at least one expandable expansion element when the free end thereof enters the borehole wall by pulling back the anchor rod together with the expandable

Achieve expansion element.

For a particularly simple positioning and holding of the expandable expansion element on the anchor rod during the introduction thereof, it is proposed according to a further preferred embodiment that the holding element for the expansion element is formed by a sleeve element surrounding the anchor rod.

For the expansion of the expansion element provided after the expansion anchor has been introduced into the borehole, it is proposed according to a further preferred embodiment that the expandable expansion element is guided or pivotably mounted in the holding element, such articulation being effected, for example, by a simple joint or a correspondingly simple and robust guide can be formed.

For simple placement of the expandable expansion element on the anchor rod while the expansion anchor is being introduced into the borehole, it is also provided according to a further preferred embodiment that the expansion element is held by a retaining ring in the region of the holding element.

For a proper opening or unfolding movement of the expandable expansion element, provision is also made for the expansion element in its end received in the holding element to be designed with at least one bevel or flattening, as corresponds to a further preferred embodiment of the expansion anchor according to the invention. Such a bevel or flattening allows sufficient space for the expansion element during the pivoting movement when expanding or unfolding and entering the borehole wall.

For a proper and easily controllable expansion movement during the retraction of the anchor rod together with the at least one expandable expansion element, it is also preferably provided that the expandable expansion element is designed with a further bevel or profile at its end facing the stop element, which is provided with a complementary bevel or profiling on the stop element interacts. Such bevels or profiles both on the free end of the expandable expansion element and on the stop element can be designed with appropriate inclinations in order to obtain the desired anchoring effect by expanding the expansion element, knowing the material of the borehole while allowing the free end to penetrate into the area of the borehole wall.

For a uniform application of high anchoring forces over the circumference of the expansion anchor, it is provided according to a further preferred embodiment according to the invention that a plurality of expandable expansion elements are arranged substantially uniformly distributed over the circumference of the expansion anchor. In addition to such an equalization of the forces to be introduced over the circumference of the expansion anchor according to the invention, to further increase the anchoring forces it can be provided that a plurality of expandable expansion elements are provided on the circumference of the expansion anchor at different distances from the tip of the expansion anchor, as is preferred by another Embodiment of the expansion anchor according to the invention corresponds. By means of expandable elements arranged in this way at a different distance from the tip of the expansion anchor, a correspondingly secure anchoring of the expansion anchor can thus be achieved over a greater length, in particular in the tip region of the expansion anchor, when the expandable expansion elements are expanded, so that, if appropriate, especially in the case of loose elements Rock at least some of the expansion elements arranged at different distances from the tip of the expansion anchor ensure secure and reliable anchoring.

According to a structurally particularly simple embodiment, it is preferably proposed in this context that spreading elements arranged at different distances from the tip are arranged offset in the circumferential direction from one another.

As already indicated above, if bevels or profiles are provided, they can both be at the free end of the expandable expansion elements as well as on the expansion element interacting therewith achieve control of the expansion process, for example depending on the rock in which the expansion anchor is to be used. In this context, it is proposed according to a particularly preferred embodiment that spreading elements arranged at different distances from the tip are provided with different bevels or profiles for interaction with complementarily designed bevels or profiles of the associated stop element, so that depending on, for example, the distance from the tip of the expansion anchor with different opening movements of the individual, expandable elements can achieve a targeted anchoring effect. For example, it can be aimed at the fact that expandable expansion elements located in the area of the tip are provided with steeper bevels or profiles, which can be adequately secured with shorter, expandable expansion elements, while at a greater distance from the tip of the

Anchored, expandable spreading elements allow for a slower overall opening movement and additional securing by providing flatter bevels, without influencing the entry of the expandable spreading elements in the tip area. With such flatter inclinations of the bevels, correspondingly longer, expandable expansion elements can also be used.

For further adjustment to an anchoring effect to be achieved, especially in loose rock, it is proposed according to a further preferred embodiment that the expansion element can be changed in length, in particular telescoped, so that it is partially independent of the nature of the rock and even when present of cavities in the region of the borehole which are not readily known beforehand, nevertheless a secure anchoring effect can be achieved.

For a further equalization of the forces to be exerted on the circumference of the expansion anchor, it is proposed according to a further preferred embodiment that an expansion element divided in the circumferential direction surrounds the anchor rod in an umbrella-like manner and is formed from, in particular, plate-like elements connected to one another in an articulated manner. Such an umbrella-like element, similar to a panel construction, can also be achieved by retracting the anchor rod and the expansion element by interacting with a stop element, making the expandable expansion element essentially continuous over the entire circumference of the expansion anchor.

For a particularly simple fixing of the stop element in the borehole, it is proposed according to a further preferred embodiment of the expansion anchor according to the invention that the stop element interacts via a spring washer with a cladding tube arranged in the borehole during a previous drilling operation, with the simple introduction of the expansion anchor by using such a spring washer Such a cladding tube can be achieved, the exact position of the stop element in the borehole on the cladding tube being carried out by automatically widening the spring ring after the expansion anchor has been fully inserted, after which the widening and entry of the expandable elements, which are associated with this, then take place immediately by unscrewing the anchor rod the expansion anchor is anchored in the borehole wall. The invention is explained in more detail below with reference to exemplary embodiments of expansion anchors according to the invention which are shown schematically in the accompanying drawing for carrying out the method according to the invention. In this show:

1 shows a schematic side view, partly in section, of a first embodiment of an expansion anchor according to the invention for carrying out the method according to the invention; 2 shows, in a representation similar to FIG. 1, a modified embodiment of an expansion anchor according to the invention for performing the method according to the invention with a plurality of expandable expansion elements arranged at different distances from the tip of the expansion anchor; and

3 shows a front view of the expansion anchor according to the invention with partially extended expandable expansion elements in the direction of arrow III of FIG. 2.

1 generally shows the foremost section of an expansion anchor 1 which has been inserted into a borehole 2, a plurality of expandable expansion elements 3 being arranged on the circumference of the expansion anchor, one of which is shown in detail in FIG. 1. The expansion anchor 1 also has an anchor rod, indicated schematically by 4, which, as is also indicated schematically, is provided with a thread 5. In the retracted position of the expandable expansion elements, shown in solid lines in FIG. 1, the expansion anchor 1 is introduced through a cladding tube 6 located in the borehole 2, which after completion of a preceding drilling operation after removal of the rod assembly together with the drill head is slightly different from the Tip 7 of the borehole has been withdrawn in accordance with the foremost section of the expansion anchor. After performing the expansion anchor through the cladding tube 6 is achieved by automatically expanding a spring ring 8, a stop element 9 on the end face 10 of the cladding tube 6 and thus an exact positioning of the expansion anchor in the insertion position shown in Fig. 1 with solid lines.

To expand the expandable expansion elements 3 provided on the circumference at regular intervals, the anchor rod 4 is screwed in the direction of the arrow 11 in the stop element 9, as a result of which an end element 12 which is connected to the foremost region of the anchor rod 4 and which is connected in a rotationally fixed manner to the anchor rod is, acts directly on a holding element or sleeve element 13 for the pivotable and expandable expansion elements 3. By unscrewing the anchor rod 4 in the direction of arrow 11, by sliding a bevel or a profile 14 of the expandable expansion element in a complementary bevel 15 of the stop element 9, the expandable expansion element is unfolded or widened, with not only abutment of the free end or the tip 16 of the expandable element to the borehole wall 2, but penetration of the tip into the material in the region of the borehole wall 2 takes place by further screwing movement in the direction of arrow 11, as shown in FIG. 1 by the tip 16 'of the expanded or opened spreading element 3 'is indicated. The expandable spreading element is mounted in the holding element 13 about a joint indicated schematically by 17.

Depending in particular on the material in which the borehole 2 is formed, the expandable expansion elements can be securely anchored by penetrating the free tip 16 ′ into the surrounding material. elements 3 by the backward movement of the foremost section by screwing the anchor rod 4 in the direction of arrow 11 in the fixed in the borehole 2 stop element.

In the modified embodiment shown in FIG. 2, a plurality of expandable expansion elements 3 are fixed at different distances from the tip of the expansion anchor 1. In addition to the different spacing of the expandable expansion elements 3 from the front section 12 of the expansion anchor, it can be seen in particular from FIG. 3 that the expansion elements arranged in different radial planes are also each offset from one another, in FIG. 3 those closer to the tip Spreading elements, which are denoted in each case by 3 ′ in the expanded state in FIG. 2, are arranged at 0 °, 90 °, 180 ° and 270 ° in the coordinate system selected in FIG. 3, while they lie at a greater distance from the tip 12 expandable expansion elements, which are denoted by 3 "in FIG. 2, are each arranged between these elements 3 '. In the illustration according to FIG. 2, the expandable expansion elements 3' and 3" shown in section are thus 45 ° shown rotated against each other.

In this embodiment too, after the expansion anchor 1 has been introduced into a borehole 2 and a fixed positioning of a stop element, again designated 9, via a spring ring fixed to a cladding tube, the individual rods are expanded by screwing the anchor rod 4 back in the direction of arrow 11. expandable spreading elements 3 into the position shown again with dashed lines at 3 'and 3 ". Instead of the joint 17 shown in FIG. 1 for the individual expandable spreading elements, retaining rings 18 are indicated in FIG. 2, which allow a proper insertion of the expandable expansion elements 3 by abutment against the respective holding elements 13, whereupon a suitable guidance in holding elements 13 during the movement of the anchor rod 4 together with the foremost section 12 shortens the respective distance between the holding elements 13 and the stop elements 9 and the expandable expansion elements are expanded.

From Fig. 2 it can be seen that the spreader elements closer to the tip, which are denoted by 3 'in the expanded state, each have bevels 14' with a greater inclination compared to the spreader elements 3 "which are further away and have bevels 14", whereby naturally the associated stop elements 9 also have bevels which are matched thereto and have different inclinations. Due to the different inclinations, correspondingly different extension or opening movements of the expandable elements 3 can be achieved when the anchor rod is screwed on, so that, for example, the elements closer to the tip and having a shorter length are first anchored in position 3 'and by a correspondingly delayed movement of the elements a larger length spreading elements in position 3 ".

From Fig. 3 it can be seen that the staggered arrangement of expansion elements arranged in different radial planes essentially a complete coverage of the entire circumference of the expansion anchor can be achieved by the expandable expansion elements 3 and thus distributed correspondingly high anchoring over the entire circumference of the expansion anchor - And security forces can be brought in. Instead of such an arrangement of a plurality of expansion elements both at a distance from one another in the circumferential direction and at a different distance from the tip of the expansion anchor, appropriately divided expansion elements can be arranged essentially in a radial plane 1, again by unscrewing the anchor rod 4 according to the arrow 11 and cooperation with a stationary stop element, an aperture-like expansion element is expanded and a simultaneous contact is made over the entire circumference of the expansion anchor with the expansion elements entering the material of the borehole wall 2.

Claims

Patent claims

1. Procedure for setting an expansion anchor (1) in one

Borehole (2), wherein after the expansion anchor (1) has been introduced, at least one is expanded on the anchor rod

(4) of the expansion anchor (1) arranged, expandable expansion element (3) in contact with the inner wall of the borehole, characterized in that the anchor rod

(4) and the expandable expansion element (3) with the free end pointing towards the open end of the borehole (2) during the

Widening of the expansion element (3) towards the open one

End of the borehole (2) are applied or withdrawn.

2. The method according to claim 1, characterized in that the expansion of the expandable expansion element (3) by screwing the anchor rod (4) relative to a in the borehole (2) fixed stop element (9) and cooperation of the expandable expansion element (3) with the stop element (9) is made.

3. The method according to claim 1 or 2, characterized in that the stop element (9) cooperates with a cladding tube (6), which after a preceding drilling operation slightly at least by the length of a holding element (13) with the expandable expansion element ( 3) and the stop element (9) is withdrawn from the borehole (2) and fixed.

4. expansion anchor, in particular for mining, wherein on the outside of the anchor rod (4) having expansion anchor (1) at least one expandable expansion element (3) is provided, characterized in that the expansion element (3) in a on the anchor rod (4th ) fixed holding element (13) in when inserting the expansion anchor (1) in a hole (2) is held in position and that the expansion element (3) by moving the anchor rod (4) towards the opening of the borehole (2) by interaction of the expansion element (3) with a stop element anchored in the borehole (2) ( 9) is expandable.

5. Expansion anchor according to claim 4, characterized in that the holding element (13) for the expansion element (3) is formed by a sleeve element surrounding the anchor rod (4).

6. Expansion anchor according to claim 4 or 5, characterized in that the expandable expansion element (3) in the holding element (13) is guided or pivotally mounted.

7. expansion anchor according to claim 6, characterized in that the expansion element (3) in the region of the holding element (13) is held by a retaining ring (18).

8. expansion anchor according to one of claims 4 to 7, characterized in that the expansion element (3) in its holding element (13) received end is formed with at least one bevel or flattened.

9. Expansion anchor according to one of claims 4 to 8, characterized in that the expandable expansion element (3) is formed at its end facing the stop element (9) with a further bevel or profile (14), which with a complementary bevel or Profiling (15) on the stop element (9) interacts.

10. Expansion anchor according to one of claims 4 to 9, characterized in that a plurality of expandable expansion elements (3) is arranged distributed substantially uniformly over the circumference of the expansion anchor (1).

11. Expansion anchor according to one of claims 4 to 10, characterized in that a plurality of expandable expansion elements (3) are provided at different distances from the tip of the expansion anchor (1) on the circumference of the expansion anchor (1).

12. Expansion anchor according to claim 11, characterized in that expansion elements (3) arranged at different distances from the tip are arranged offset to one another in the circumferential direction.

13. Expansion anchor according to claim 11 or 12, characterized in that at different distances from the top arranged expansion elements (3) with different bevels or profiles (14) for cooperation with complementary bevels or profiles (15) of the associated stop element ( 9) are provided.

14. Expansion anchor according to one of claims 4 to 13, characterized in that the expansion element (3) is variable in length, in particular telescopic.

15. Expansible anchor according to one of claims 4 to 14, characterized in that a circumferentially divided expansion element (3) surrounds the anchor rod (4) like an umbrella and is formed from in particular articulated, plate-like elements.

16. Expansion anchor according to one of claims 4 to 15, characterized in that the stop element (9) cooperates via a spring ring (8) with a casing tube (6) arranged in the borehole (2) of a preceding drilling operation.