Abstract
The disclosure relates to a hollow rod composite anchor for stabilizing rock strata in mining, tunnel construction, underground construction, and rock construction, at least having an anchor base with one or more outlet channels, a hollow rod which is arranged behind the anchor base and contains a static mixing device and an adhesive cartridge with a press-out piston, said adhesive cartridge being arranged on the static mixing device via a cylindrical seal device with at least one bursting surface, wherein the outer diameter of the seal device substantially corresponds to the inner diameter of the hollow rod, the area of the bursting surface is greater than or equal to 15% and less than or equal to 90% of the cylinder cross-section of the seal device, and the ratio of the area of the bursting surface to the area of the hollow rod wall cross-section is greater than or equal to 0.1 and less than or equal to 25. The disclosure additionally relates to an improved method for setting hollow rod composite anchors.
Claims
1. A hollow rod composite anchor for stabilizing rock strata in mining, tunnel construction, civil engineering and rock construction, at least comprising an anchor base comprising one or more outlet channels, a hollow rod arranged behind the anchor base and including a static mixing device and an adhesive cartridge comprising a squeezing plunger, wherein the adhesive cartridge is disposed via a cylindrical sealing device comprising at least one bursting surface at the static mixing device, wherein the outer diameter of the sealing device essentially corresponds to the inner diameter of the hollow rod and the bursting surface is greater than or equal to 15% and less than or equal to 90% of the cylindrical cross section of the sealing device, wherein the ratio of the bursting surface to the area of the hollow rod wall cross-section, expressed as the bursting surface divided by the wall area of the hollow rod cross-section, is greater than or equal to 0,1 and less than or equal to 25.
2. The hollow rod composite anchor according to claim 1, wherein the cylindrical sealing device comprises two bursting areas separated from each other.
3. The hollow rod composite anchor according to claim 2, wherein the cylindrical sealing device is configured symmetrically and the two bursting surfaces are arranged separately from one another at the sealing device via a web extending along the diameter of the cylindrical sealing device.
4. The hollow rod composite anchor according to claim 3, wherein the bursting surfaces are configured as bursting sails and the ratio of the holding force of the bursting sails at the web to the holding force of the bursting sails at the outer circumference of the sealing device, expressed as the holding force at the web divided by the holding force at the outer circumference, is greater than or equal to 1.5 and less than or equal to 5.
5. The hollow rod composite anchor according to claim 3, wherein the bursting surfaces in the area of the outer circumference of the sealing device are connected to the sealing device via holding points.
6. The hollow rod composite anchor according to claim 1, wherein the total bursting area of the sealing device is greater than or equal to 50% and less than or equal to 90% of the cylinder cross-section.
7. The hollow rod composite anchor according to claim 1, wherein the ratio of the bursting surface to the area of the hollow rod wall cross-section is greater than or equal to and less than or equal to 3.
8. The hollow rod composite anchor according to claim 1, wherein the material of the hollow rod has a breaking load (tension) according to DIN EN ISO 6892-113:2009-12 of 80 kN and less than or equal to 800 kN.
9. The hollow rod composite anchor according to claim 3, wherein the width of the web is greater than or equal to 1% and less than or equal to 15% with respect to the diameter of the cylindrical sealing device.
10. The hollow rod composite anchor according to claim 1, wherein the static mixing device is spaced apart from the cylindrical sealing device by greater than or equal to 20% and less than or equal to 70% with respect to the diameter of the cylindrical sealing device.
11. The hollow rod composite anchor according to claim 1, wherein the contact surface of the adhesive cartridge on the cylindrical sealing device is greater than or equal to 20% and less than or equal to 55% of the cross-sectional area of the cylindrical sealing device.
12. The hollow rod composite anchor according to claim 1, wherein the adhesive cartridge is divided into two compartments by a partition wall and the squeezing plunger is designed in two parts corresponding to the compartment division, wherein a cutting device is arranged between the two parts of the squeezing plunger.
13. A method for setting a hollow rod composite anchor in a rock layer, wherein the method comprises at least the steps of: a) drilling a hole in a rock stratum to be stabilized; b) setting a hollow rod composite anchor according to claim 1; and c) squeezing the chemical fastening agents from the two compartments through the static mixer and the anchor base by pressurization.
14. The method according to claim 13, wherein in method step c) the pressure load over time per squeezing operation is recorded and digitally stored.
15. The method according to claim 13, wherein the area ratio of diameter of the hole drilled in method step a) to hollow rod composite anchor inner diameter, calculated as hole diameter divided by hollow rod composite anchor inner diameter, is greater than or equal to 1.5 and less than or equal to 2.5, preferably greater than or equal to 1.8 and less than or equal to 2.5.
Description
DRAWINGS
[0042] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.
[0043] Further advantages and advantageous embodiments of the subject matter according to the disclosure are illustrated in the drawings and explained in the following description. It should be noted that the drawings are descriptive only and are not intended to limit the disclosure in any way.
[0044] In the figures:
[0045] FIG. 1 schematically shows the structure of a hollow rod composite anchor according to the disclosure;
[0046] FIG. 2 schematically shows the structure of an anchor base with one or more outlet channels which can be used in the hollow rod composite anchor according to the disclosure;
[0047] FIG. 3 schematically shows a static mixing device that can be used in the hollow rod composite anchor according to the disclosure and consists of several mixing elements arranged one behind the other in a three-part mixing row combination;
[0048] FIG. 4 schematically shows a static mixing device which can be used in the hollow rod composite anchor according to the disclosure and consists of several mixing elements arranged one behind the other in a two-mixing row combination;
[0049] FIG. 5 shows a possible design of the mixing device which can be used in the hollow rod composite anchor according to the disclosure;
[0050] FIG. 6 schematically shows the structure of a squeezing plunger usable in the hollow rod composite anchor according to the disclosure;
[0051] FIG. 7 schematically shows the structure of a cylindrical sealing device usable in the hollow rod composite anchor according to the disclosure in an oblique view from below;
[0052] FIG. 8 schematically shows the structure of a cylindrical sealing device usable in the hollow rod composite anchor according to the disclosure in an oblique view from above; and
[0053] FIG. 9 schematically shows a top view of the structure of a cylindrical sealing device usable in the hollow rod composite anchor according to the disclosure.
[0054] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.
DETAILED DESCRIPTION
[0055] Example embodiments will now be described more fully with reference to the accompanying drawings.
[0056] FIG. 1 shows a possible embodiment of a hollow rod composite anchor 1 according to the disclosure. Starting from the deepest end of the borehole, the hollow rod composite anchor 1 comprises an anchor base 3, which comprises one or more outlet channels (not shown) for the outlet of a fastening agent from the hollow rod composite anchor 1. Via the outlet channels of the anchor base 3, fastening agent is pressed between the hollow rod composite anchor 2 and the borehole, and the hollow rod composite anchor 1 is thus anchored in the borehole. At the anchor base 3 the hollow rod 2 is arranged, which extends over the further functional parts (4, 5, 6, 17) of the hollow rod composite anchor 1 located in the interior. Inside the hollow rod 2, adjacent to the anchor base 3, the static mixing device 4 is disposed, in which the fastening agent, for example a two-component adhesive, is mixed before exiting through the anchor base 3. The adhesive is contained in a cartridge 5 divided into two compartments by a partition wall, which cartridge is squeezed out by a squeezing plunger 6 via pressurization. Between cartridge 5 and static mixer 4 the cylindrical sealing device 17 is arranged, which controls the supply of fastening agent to the static mixer 4. For example, this sealing device can prevent unintentional inflow of fastening agent into the static mixer during transport. In the application, the hollow rod composite anchor 1 is inserted into the borehole and the extrusion plunger 6 is moved forward, for example via water pressure, in the hollow rod 2 from the far end of the borehole 7 through the cartridge 5 toward the anchor base 3. The forces exerted press the adhesive out of the cartridge 5 through the sealing device 17, while opening the bursting surfaces, and into the static mixing device 4. In the mixing device 4, the adhesive is intimately mixed and enters the borehole via the outlet channel(s) of the anchor base 3 and anchors the hollow rod composite anchor 1 in the borehole via the outer anchor walls.
[0057] FIG. 2 shows a possible design of an anchor base 3. The anchor base 3 can comprise an anchor tip in which one or more outlet channels 8 for the fastening means are arranged.
[0058] FIG. 3 shows a side view of an arrangement of successive mixing elements 16 of the static mixing device 4 according to the disclosure. In this embodiment, the individual mixing elements 16 are combined to form three mixing element rows 9, wherein the row centers form a triangle relative to the direction of the force flow. This means that the mixing element rows 9 with the respective mixing elements 16 connected in series are arranged offset to each other, wherein the two different geometries for the individual mixing elements 16 are shown in this illustration. The flow of the fastening agent around the mixing elements 16 and rows 9 results in that the flow direction of the fastening means is deflected twice by approximately 180° between entry and exit from the static mixer (4). From the point of view of the force effect, the individual mixing element rows 9 and thus also the mixing elements 16 can be arranged offset from one another, so that different starting points of the mixing element rows 9 are obtained in the direction of the force effect.
[0059] FIG. 4 shows a side view of an arrangement of mixing elements 16 of the static mixing device 4 disposed one behind the other according to the disclosure. In this configuration, the individual mixing elements 16 are combined to form two mixing element rows 9, and the rear mixing element row of FIG. 3 has been omitted for the sake of clarity. The individual mixing element rows 9 are each composed of two different mixing elements 10, 11. These two designs 9, 10 of mixing elements 16 can contribute to an optimized mixing result without a large increase in flow resistance. Relatively large quantities of highly viscous fastening agents can also be processed with good mixing performance and an output pressure that is not too high.
[0060] FIG. 5 shows a possible enclosure of the static mixing device 4 within the hollow rod (not shown). The mixing elements, which may optionally be arranged in mixing rows, can be easily and securely inserted into and anchored in the hollow rod 2 by means of this enclosure. The opening 12 of the mixing device points in the direction of the anchor base 3 and the rear side 13 of the mixing device 4 points in the direction of the cartridge 5 divided into two compartments (not shown).
[0061] FIG. 6 shows a possible embodiment according to the disclosure of one half of a two-part squeezing plunger 6 according to the disclosure. The second half, which is not shown, is mirror-symmetrical to the first half 6 and is fixed to the first half 6 by means of a cutting device which is arranged between the two halves 6. In this figure, the upper and lower guide lips 15 and the central sealing lips 14 of the two-part squeezing plunger 6 are shown. By means of this embodiment, even highly viscous fastening agents can be safely squeezed out by the static mixing device 4. In particular, the risk is reduced that fastening means presses past the squeezing plunger 6 in the direction of the mouth of the borehole and thus can no longer contribute to fix the anchor in the borehole. In particular, the guide lips 15 can contribute to a smoother movement of the squeezing plunger 6, preventing canting even at high squeezing pressures or during rapid setting processes.
[0062] FIG. 7 schematically shows an embodiment of a cylindrical sealing device 17 according to the disclosure from the underside. In this case, the term “underside” means that the cylindrical sealing device 17 faces with this side in the direction of the static mixing device 4. The overall cylindrical configuration of the sealing device 17 with a substantially round circumference can be seen. The figure shows the cylindrical design of the sealing device 17 with a round circumference, which substantially abuts the inner wall of the hollow rod 2. The sealing device comprises a central web 18 and two bursting surfaces 19 separated thereby. Only by means of the bursting surfaces 19 the fastening agent can pass from the cartridge 5 in the direction of the static mixing device 4. The center web 18 extends along the diameter of the cylindrical sealing device 17 and ensures that the cylindrical sealing device 17 comprises bursting surfaces 19 separated from one another.
[0063] FIG. 8 schematically shows an embodiment of the sealing device 17 according to the disclosure in a view from “above”. The term “above” in this case means that the cylindrical sealing device 17 points with this side in the direction of the adhesive cartridge 5. In this view, the central web 18 and the two bursting surfaces 19 separated by it are also shown. In addition, the contact surface 20 of the adhesive cartridge can be seen in this view, which is held and guided by two annular guides 21, 22. The adhesive cartridge 5 is pressed into the contact surface 20 of the adhesive cartridge by pressurization during the anchor setting process and is held in this position by the annular guides 21, 22. When the adhesive cartridge 5 is squeezed out by the plunger 6, adhesive is forced out of the adhesive cartridge 5 through the two bursting surfaces 19 in the direction of the static mixing device 4. The mixed adhesive exits the static mixing device 4 through the outlet channels 8 of the anchor base 3. The adhesive is pressed in the direction of the borehole mouth and bonds the outer sides of the hollow rod composite anchor 1 to the surrounding rock.
[0064] FIG. 9 shows the design of a cylindrical sealing device according to the disclosure 17 in plan view. The two bursting surfaces 19 can be seen, which are configured symmetrically and separated from each other by a central web 18. The sealing device 17 comprises an outer diameter 24 which corresponds essentially to the inner diameter of the hollow rod 2. In this embodiment, the sealing device comprises an outer protrusion with an inner diameter 25 which stabilizes the sealing device against the hollow rod 2. The available bursting area can be determined on the basis of the circular diameter 23, from which circular area the area of the central web 18 must still be subtracted.
[0065] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are gener-ally not limited to that particular embodiment, but, where applicable, are inter-change-able and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure
