Strand pressure-pipe anchor

Abstract

A strand pressure-pipe anchor comprises a compression anchor base element, a tension strand or a plurality of tension strands, and at least one sheath, in which the tension strand or at least one of the tension strands is received. The tension strand or at least one of the tension strands is provided, at the end thereof associated with the compression anchor base element, with a crimp sleeve, which is provided with an external thread, which, in a connected state of the tension strand and the compression anchor base element where the tension strand is connected to the compression anchor base element to pass on the anchoring forces to the surrounding substratum, is in screw engagement with an internal thread of the compression anchor base element.

Claims

1. A strand pressure-pipe anchor, comprising: a compression anchor base element, a tension strand or a plurality of tension strands, at least one sheath, in which the tension strand or at least one of the tension strands is received, wherein the tension strand or at least one of the plurality of tension strands is provided, at an end thereof associated with the compression anchor base element, with a crimp sleeve, which is provided with an external thread, which, in a connected state of the tension strand or at least one of the plurality of tension strands and the compression anchor base element where the tension strand or at least one of the plurality of tension strands is connected to the compression anchor base element to pass on anchoring forces to a surrounding substratum, is in screw engagement with an internal thread of the compression anchor base element, wherein the sheath or at least one of the sheaths is connected to the compression anchor base element in a sealing manner, wherein the sheath or at least one of the sheaths is screwed to the compression anchor base element.

2. The strand anchor according to claim 1, wherein a direction of lay of the tension strand or at least one of the plurality of tension strands is the same as a rotational direction of the thread of the crimp sleeve arranged at a free end of the crimp sleeve.

3. The strand anchor according to claim 1, wherein the compression anchor base element comprises, on a surface thereof facing the tension strand or the plurality of tension strands, a depression for the sheath or at least one of the sheaths, into which depression a free end of an associated sheath can be inserted.

4. The strand anchor according to claim 1, wherein if the plurality of tension strands are provided, a specific sheath is associated with at least one tension strand.

5. The strand anchor according to claim 1, further comprising at least one pressure body, which cooperates with the compression anchor base element in passing the anchoring forces to the surrounding substratum.

6. The strand anchor according to claim 5, wherein a plurality of ribs extending in a peripheral direction are provided on an outer face of the at least one pressure body.

7. The strand anchor according to claim 5, wherein the at least one pressure body is formed free of ribs extending in a peripheral direction at a point where a through-opening, intended for passing the tension strand or one of the tension strands therethrough, is located.

8. The strand anchor according to claim 5, wherein the at least one pressure body encloses the tension strand or the plurality of tension strands, and has an end face thereof which faces the compression anchor base element and is positioned, in a planar manner, against the compression anchor base element or a further pressure body.

9. The strand anchor according to claim 5, wherein, on an outer peripheral face thereof, the at least one pressure body has at least one depression extending substantially in parallel with a longitudinal extension direction of the tension strand or the plurality of tension strands.

10. The strand anchor according to claim 1, wherein the at least one sheath is dimensioned or formed, at least at an end portion thereof adjacent to the compression anchor base element, in such a way that, during introduction into the at least one sheath connected to the compression anchor base element, the external thread of the crimp sleeve of the associated tension strand or at least one of the plurality of tension strands is inserted into the internal thread of the compression anchor base element by insertion movement of the tension strand or at least one of the plurality of tension strands.

11. A strand pressure-pipe anchor, comprising: a compression anchor base element, a tension strand or a plurality of tension strands, at least one sheath, in which the tension strand or at least one of the tension strands is received, wherein the tension strand or at least one of the plurality of tension strands is provided, at an end thereof associated with the compression anchor base element, with a crimp sleeve, which is provided with an external thread, which, in a connected state of the tension strand or at least one of the plurality of tension strands and the compression anchor base element where the tension strand or at least one of the plurality of tension strands is connected to the compression anchor base element to pass on anchoring forces to a surrounding substratum, is in screw engagement with an internal thread of the compression anchor base element, further comprising at least one pressure body, which cooperates with the compression anchor base element in passing the anchoring forces to the surrounding substratum, wherein a plurality of ribs extending in a peripheral direction are provided on an outer face of the at least one pressure body.

12. The strand anchor according to claim 11, wherein the at least one pressure body encloses the tension strand or the plurality of tension strands, and has an end face thereof which faces the compression anchor base element and is positioned, in a planar manner, against the compression anchor base element or a further pressure body.

13. The strand anchor according to claim 11, wherein, on an outer peripheral face thereof, the at least one pressure body has at least one depression extending substantially in parallel with a longitudinal extension direction of the tension strand or the plurality of tension strands.

14. The strand anchor according to claim 11, wherein the sheath or at least one of the sheaths is connected to the compression anchor base element in a sealing manner.

15. The strand anchor according to claim 14, wherein the compression anchor base element comprises, on a surface thereof facing the tension strand or the plurality of tension strands, a depression for the sheath or at least one of the sheaths, into which depression a free end of an associated sheath can be inserted.

16. The strand anchor according to claim 11, wherein a direction of lay of the tension strand or at least one of the plurality of tension strands is the same as a rotational direction of the thread of the crimp sleeve arranged at a free end of the crimp sleeve.

17. The strand anchor according to claim 11, wherein if the plurality of tension strands are provided, a specific sheath is associated with at least one of the plurality of tension strands.

18. The strand anchor according to claim 11, wherein the at least one pressure body is formed free of ribs extending in a peripheral direction at a point where a through-opening, intended for passing the tension strand or one of the tension strands therethrough, is located.

19. The strand anchor according to claim 11, wherein the at least one sheath is dimensioned or formed, at least at an end portion thereof adjacent to the compression anchor base element, in such a way that, during introduction into the at least one sheath connected to the compression anchor base element, the external thread of the crimp sleeve of the associated tension strand or at least one of the plurality of tension strands is inserted into the internal thread of the compression anchor base element by insertion movement of the tension strand or at least one of the plurality of tension strands.

Description

(1) In the following, the invention will be described in greater detail by way of embodiments with reference to the accompanying drawings, in which:

(2) FIG. 1 is a partially sectional perspective view of a first embodiment of a strand pressure-pipe anchor according to the invention, which comprises three strands;

(3) FIG. 2 is a side view of the strand pressure-pipe anchor of FIG. 1;

(4) FIG. 3 is a sectional view of the strand pressure-pipe anchor of FIGS. 1 and 2, taken along the lines III-III, in other words in the region of a pressure body;

(5) FIG. 4 is a sectional view of the strand pressure-pipe anchor of FIGS. 1 and 2, taken along the lines IV-IV, in other words in the region of the foot box;

(6) FIG. 5 is a sectional view of the foot box of FIG. 4, taken along the lines V-V;

(7) FIG. 6 is a perspective view of a pressure body;

(8) FIG. 7 is a longitudinal section through the base body of a crimp sleeve;

(9) FIG. 8 is a longitudinal section through an insertion sleeve, which, when inserted into the base body, forms the crimp sleeve together therewith;

(10) FIG. 9 is a drawing illustrating inserting a strand into the crimp sleeve;

(11) FIG. 10 is a drawing illustrating pressing the crimp sleeve onto the strand;

(12) FIG. 11 to 13 are views similar to FIG. 1 to 3 of a second embodiment of a strand pressure-pipe anchor according to the invention, which comprises four strands;

(13) FIG. 14 to 16 are views similar to FIG. 1 to 3 of a second embodiment of a strand pressure-pipe anchor according to the invention, which comprises seven strands.

(14) In FIGS. 1 and 2, a strand pressure-pipe anchor according to the invention is denoted completely generally as 10. It comprises a foot box 12, which forms the compression anchor base element according to the invention, three strands 14, which are fixed in the foot box 12 by way of crimp sleeves 16, three sheaths 18, each of which encloses one of the strands 14, and pressure bodies 20, to which the foot box 12 passes on the tensile forces, transmitted thereto from the strands 14, as compressive forces.

(15) As can be seen in particular from FIGS. 4 and 5 viewed in conjunction, for each of the three strands 14 the foot box 12 has a stepped receiving hole 22, having a portion 24 that has a smaller diameter, is arranged so as to be deeper in the foot box and is provided with an internal thread 24a, and having a portion 26 that has a larger diameter, is arranged so as to be adjacent to the surface 12a of the foot box 12 and is also provided with an internal thread 26a. The portion 24 having a smaller diameter is used to fix the crimp sleeve 16, which is pressed onto the associated strand 14 and provided with an external thread 16a, whilst the portion 26 having a larger diameter is used to fix the sheath 18 enclosing the associated strand.

(16) To manufacture the strand pressure-pipe anchor 10 according to the invention, it is possible for example to proceed as follows.

(17) In a first step, the crimp sleeves 16 are pressed onto the associated strands 14. Each crimp sleeve 16 comprises a base body 28 (see FIG. 7), made of a deformable material, for example bright steel, machining steel or tempering steel, and an insertion sleeve 30, which ensures secure retention of the base body 28 on the strand 14. For this purpose, the insertion sleeve 30 is formed with a toothing both on the inner face thereof and on the outer face thereof. When the crimp sleeve 16 is pressed onto the strand 14, these two toothings dig into the material of the base body 28, on the one hand, and into the material of the strand 14, on the other hand. Further, the insertion sleeve 30 may be formed as a longitudinally slotted sleeve, in such a way that it can be positioned fully against the outer surface of the strand 14 when the crimp sleeve 16 is pressed onto the strand 14, without actually experiencing significant plastic deformation. The insertion sleeve 30 may for example be made of bright steel, machining steel or tempering steel.

(18) To press the crimp sleeves 16 onto the associated strands 14, initially the insertion sleeves 30 are inserted into the base body 28 from the left in FIG. 7. This is facilitated by an insertion ramp 28a. Subsequently, the crimp sleeve 16 thus formed is placed on the associated strand 14 from the left in FIG. 9 until the strand 14 projects out from the crimp sleeve 16 slightly on the other side, for example by between approximately 5 mm and approximately 10 mm. Thereupon, the actual pressing-on can be achieved by plastic deformation of the base body 28. In this context, as can be seen from a comparison of FIGS. 9 and 10, the base body 28 is both reduced in external diameter and lengthened slightly. Finally, the external thread 16a is cut into the outer peripheral face of the base body 28 of the crimp sleeve 16.

(19) In a second step, the strands 14 thus prepared are inserted into the associated sheath 18. Advantageously, the sheaths 18, which are preferably made of plastics material, for example polyethylene (PE), are also provided with an external thread 18a at the end from which the crimp sleeves 16 project.

(20) In a third step, the desired number of strands 14, in the present embodiment therefore three strands 14, are combined, and the required number of pressure bodies 20 are slid onto the strands 14.

(21) Subsequently, for mounting the strands 14, the strands 14 are guided in succession to the foot box 12. To fix a strand 14 in the foot box 12, the external thread 16a of the crimp sleeve 16 pressed onto the strand 14 is screwed into the internal thread 24a of the portion 24 having a smaller diameter. Subsequently, the external thread 18a of the sheath 18 is screwed into the internal thread 26a of the portion 26 having a larger diameter, resulting in a sealing engagement between the foot box 12 and the sheath 18, in particular an engagement which seals against the penetration of cement mortar.

(22) In an alternative embodiment, in the foot box 12 the formation of the internal thread 26a in the portion 26 having a larger diameter could be omitted, and on the sheath 18 the formation of the external thread 18a could be omitted. In this case, the sealing engagement between the foot box 12 and the sheath 18 could be provided using a press fit between the foot box 12 and the sheath 18.

(23) Subsequently, the pressure bodies 20 are further slid onto the foot box 12, until they are positioned, at the end faces, against this or against the respectively adjacent pressure bodies 20 for the subsequent transmission of compressive forces. This state is secured by a securing unit 32, for example an adhesive tape, a shrink sleeve, an electrofusion coupler or the like. This securing unit 32 may further have the object of preventing or at least impeding the penetration of cement mortar between the sheath 18 and the pressure body 20.

(24) In the state thus obtained, the strand pressure-pipe anchor 10 is prepared for insertion into and anchoring in the drill hole provided therefor at the construction site.

(25) The removable strand pressure-pipe anchors 10 are preassembled at the factory, wound up and delivered to the construction site. After drilling, the pre-prepared anchors can be inserted into the drill hole immediately. In principle, it is also conceivable to assemble the strand pressure-pipe anchors on the construction site. However, preassembly at the factory has the advantage that additional operations on the construction site, which could impede activity on the building site, are avoided.

(26) Once the strand pressure-pipe anchor 10 has been inserted into the drill hole, which is usually sloped down into the soil, said anchor should subsequently be fixed therein, for example using cement mortar. To be able to ensure that the foot box 12 and the pressure body 20 are fully embedded in cement mortar, the pressure bodies 20 are formed, as can best be seen from FIGS. 3 and 5, with longitudinal depressions 20a, into which supply lines (not shown) for cement mortar can be laid. If desired, these longitudinal depressions may also continue in the outer peripheral face of the foot box 12, as can be seen in FIG. 1. Further, the pressure bodies 20 are formed with peripheral ribs 20b, which provide better anchoring of the pressure bodies 20 in the cement mortar.

(27) Once the cement mortar is cured, to secure the construction pit, the strand pressure-pipe anchor 10 can be braced using a supporting wall provided for this purpose. During the grouting using cement mortar, the sheaths 18 and the sealing engagement thereof with the foot box 12 ensure that the strands 14 do not come into contact with the cement mortar. The tensile forces applied to the strands 14 used as tension elements are therefore fully transmitted to the foot box 12, which passes them on via the end face 12a thereof to the pressure bodies 20 as compressive forces. From the foot box 12 and the pressure bodies 20, the forces are subsequently dissipated to the surrounding soil via the grout body, in other words the cured cement mortar.

(28) Once it is no longer necessary to secure the construction pit, the strands 14 and the sheaths 18 enclosing them can be fully removed again. For this purpose, it is merely necessary to release the threaded engagement between the external thread 16a of the crimp sleeve 16 pressed onto the strand 14 and the internal thread 24a of the portion 24 having a smaller diameter of the foot box 12. This threaded engagement can be released in a particularly simple manner if the direction of lay R1 of the strands 14 (see FIG. 1) is the same as the rotational direction R2 of the thread 16a of the crimp sleeve 16 (see FIG. 10). In this development of the invention, the strands 14 contract when being pulled out from the foot box 12, in such a way that the wires of each strand 14 do not open, but instead are pressed more tightly together and support one another. The strand 14 thus has greater torsional rigidity over the entire length thereof, and can be unscrewed from the foot box 12 in a simple manner, for which purpose it need only be gripped at the end thereof remote from foot box 12.

(29) Even though the two directions R1 and R2 are right-handed in the embodiment shown, in other words the external wires extend in the direction of clockwise rotation during movement along the strands 14, a left-handed lay of the strands in conjunction with a left-handed thread in the foot box is also conceivable.

(30) At this point, it should be noted that, although the strands 14 are each formed from seven wires 14a in the embodiment shown, the present invention is not limited to strands of this type. Strands having a smaller number of wires, for example three wires, or a larger number of wires, for example nineteen wires, may equally be used.

(31) It should further be noted that the foot box 12, the pressure bodies 20 and the sheath 16 are left in the soil after the removal of the strands 14. So as not to unnecessarily impede subsequent construction activities on the plot in the soil of which these elements are left, the pressure bodies 20 are formed with predetermined break points 20c and 20d. For this purpose, radially inwardly on the floor of the longitudinal depressions 20a (at 20c in FIG. 3) and radially outwardly centrally between two adjacent longitudinal depressions 20a (at 20d in FIG. 3), the wall thickness thereof has a smaller value than the respectively adjacent wall portions.

(32) It should also further be noted that the foot box 12 may preferably be made of steel or cast material.

(33) FIG. 11 to 13 show a second embodiment of a strand pressure-pipe anchor according to the invention, which substantially corresponds to the embodiment of FIG. 1 to 10. Therefore, in FIG. 11 to 13, analogous parts are provided with the same reference numerals as in FIG. 1 to 10, but increased by 100. Further, the strand pressure-pipe anchor 110 of FIG. 11 to 13 is only described in the following insofar as it differs from the strand pressure-pipe anchor 10 of FIG. 1 to 10, to the description of which reference is hereby otherwise expressly made.

(34) First, the strand pressure-pipe anchor 110 differs from the strand pressure-pipe anchor 10 in that, instead of having three tension strands, like the strand pressure-pipe anchor 10, it has four tension strands 114. Each of these tension strands 114 may however be formed identically to the tension strands 14, in particular as regards forming the crimp sleeve 116 and pressing it onto the strand 114.

(35) Second, the strand pressure-pipe anchor 110 differs from the strand pressure-pipe anchor 10 in that, instead of a specific sheath being associated with each of the strands 114, all four strands 114 are received in a shared sheath 118. Accordingly, the foot box 112 also comprises merely a single portion 126 having a larger diameter. As in the embodiment of FIG. 1 to 10, the sheath 118 can be screwed to the foot box 112 or connected thereto in a sealing manner using a press fit.

(36) Because of the embodiment using a single sheath 118 and the need to minimise the diameter of the required drill hole, the pressure bodies 120 do not have longitudinal depressions corresponding to the longitudinal depressions 20a, in which supply lines for cement mortar could be laid. In this variant, the cement mortar is filled in and grouted via the drill pipe.

(37) FIGS. 14 to 16, analogous parts are provided with the same reference numerals as in FIGS. 1 to 10, but increased by 200, in other words increased by 100 with respect to FIGS. 11 to 13 (e.g., sheath 218 is analogous to sheaths 18, 118). Further, the strand pressure-pipe anchor 210 of FIGS. 14 to 16 is only described in the following insofar as it differs from the strand pressure-pipe anchor 10 of FIGS. 1 to 10, to the description of which reference is hereby otherwise expressly made.

(38) First, the strand pressure-pipe anchor 210 differs from the strand pressure-pipe anchor 10 in that, instead of having three tension strands, like the strand pressure-pipe anchor 10, it has seven tension strands 214. Each of these tension strands 214 may however be formed identically to the tension strands 14, in particular as regards forming the crimp sleeve 216 and pressing it onto the strand.

(39) Second, the strand pressure-pipe anchor 210 differs from the strand pressure-pipe anchor 10 in that, because of the need to minimise the diameter of the required drill hole, the pressure bodies 220 do not have longitudinal depressions corresponding to the longitudinal depressions 20a, in which supply lines for cement mortar could be laid. To grout the cement mortar, it is therefore necessary to proceed in the same manner as for the embodiment of FIG. 11 to 13.

(40) Alternatively, however, a modification is also conceivable in which merely six strands are provided, and the space provided for the seventh strand, for example the central strand, is used for laying a supply line for cement mortar. The receiving hole 222 associated with this supply line should thus be formed as a through-hole, in such a way that the cement mortar sufficiently encloses the foot box 212 and the pressure body 220 on the outer face thereof.