ONSHORE ANCHORING SYSTEM

Abstract

The present invention relates to an anchoring system (1) comprising an anchor pile (2) configured to be embedded in a borehole (30) drilled in a ground surface. The anchor pile (2) comprises an elongate main body (3) having a longitudinal axis (L) and comprising an upper end (4) and a lower end (5). The cross section of the elongate main body (3) increases along a portion of the longitudinal axis (L) in the direction from the upper end (4) to the lower end (5) defining at least one bearing surface (7a, 7b) such that in use an annular gap (32) for receiving locking media is defined between the at least one bearing surface (7a, 7b) and the adjacent portions of the borehole (30). The anchor pile (2) is locked in position within the borehole (30) on receipt of locking media within the annular gap (32) and abutment of the loose material with the bearing surface (7a, 7b).

Claims

1. Anchoring system (1) comprising: an anchor pile (2) configured to be received within a borehole (30) drilled in a ground surface, the anchor pile (2) comprising an elongate main body (3) optionally comprising one or more joints formed along the elongate main body (3), the elongate main body (3) having a longitudinal axis (L) and comprising an upper end (4) and a lower end (5), wherein the upper end is configured in use to be fully received within the borehole (30); and one or more portions located on the elongate main body (3) of the anchor pile (2), the one or more portions each having a cross section greater than the cross section of the elongate main body (3) and the optionally one or more joints formed thereon, and in which the cross section of the one or more portions increases along a portion of the longitudinal axis (L) in the direction from the upper end (4) to the lower end (5) defining at least one bearing surface (7a, 7b) such that in use an annular gap (32) for receiving locking media is defined between the at least one bearing surface (7a, 7b) and the adjacent portions of the borehole (30), and in which the anchor pile (2) is locked in position within the borehole (30) on receipt of locking media within the annular gap (32) as a result of sufficient frictional resistance arising from the abutment of the locking media with the bearing surface (7a, 7b) and suitable load bearing soil layers of the borehole (30).

2. Anchoring system (1) according to claim 1, in which the bearing surface (7a, 7b) comprises at least one tapered section.

3. Anchoring system (1) according to either of claims 1 and 2, wherein the elongate main body (3) comprises at least one protruding section (6a, 6b) projecting outwardly from the elongate main body (3) and/or at least one angled face sloping down outwardly from the elongate main body (3).

4. Anchoring system (1) according to any preceding claim, wherein the elongate main body (3) comprises at least one conduit (11a, 11b) arranged essentially parallel to the longitudinal axis (L), such that the conduit (11a, 11b) extends along the portion of the longitudinal axis (L) of the elongate main body (3) along which the cross section of the elongate main body (3) increases, the at least one conduit (11a, 11b) defining a channel between an upper section and a lower section of the elongate main body (3) thereby.

5. Anchoring system (1) according to any of the previous claims, wherein the elongate main body (2) comprises: a first conical portion (8a, 8b) coaxial with the longitudinal axis (L) of the elongate main body (3), wherein along the first conical portion (8a, 8b) the cross section of the elongate body (11) increases in the direction from the upper end (4) to the lower end (5); a second conical portion (10a, 10b) coaxial with the longitudinal axis (L) of the elongate main body (3), wherein along the second conical portion (10a, 10b) the cross section of the main body (3) decreases in the direction from the upper end (4) to the lower end (5); and a tubular portion (9a, 9b) coaxial with the longitudinal axis (L) of the elongate main body (3), extending between the first conical portion (8a, 8b) and the second conical portion (10a, 10b).

6. Anchoring system (1) according to claim 5, wherein the taper angle of the first conical portion (8a, 8b) is smaller than the taper angle of the second conical portion (10a, 10b).

7. Anchoring system (1) according to either of claims 5 and 6, wherein the first conical portion (8a, 8b) extends along a greater length of the elongate main body (3) than the second conical portion (10a, 10b).

8. Anchoring system (1) according to any one of claims 4 to 7, wherein the elongate main body (3) comprises at least one conduit (11a, 11b) arranged essentially parallel to the longitudinal axis (L) of the elongate main body (3), the conduit (11a, 11b) extending along: at least a portion of the first conical portion (8a, 8b); the tubular section (9a, 9b); and at least a portion of the second conical portion (10a, 10b).

9. Anchoring system (1) according to any of the previous claims, wherein at least a portion of the elongate main body (3) of the anchor pile (2) comprises a cohesive high friction coating configured to increase friction between the elongate main body (3) and locking media received within the annular gap (32).

10. Anchoring system (1) as claimed in claim 9, in which the cohesive high friction coating comprises bitumen, a similar material or a sheet material bonded to the elongate main body (3).

11. Anchoring system (1) according to either of claims 9 and 10, wherein the at least one tapered section comprises a cohesive high friction coating.

12. Anchoring system (1) according to any of the previous claims, wherein at least a section of the elongate main body (3) comprises fixing means (12), configured for being driven outwardly from the elongate main body (3) for penetrating the borehole (30) wall, such that a fixed connection is established thereby.

13. Anchoring system (1) as claimed in claim 10 in which the fixing means (12) are cone point bolts.

14. Anchoring system (1) according to either of claims 12 and 13, wherein the elongate main body (3) comprises a plurality of fixing means (12) spaced apart from each other along the length of the elongate main body (3).

15. Anchoring system (1) according to claim 14, in which one or more of the plurality of fixing means (12) are configured to extend at different angles with respect to the longitudinal axis of the elongate main body (3).

16. Anchoring system (1) according to any of the previous claims, wherein the elongate main body (3) of the anchor pile (2) is shaped as an essentially tubular hollow body comprising a plurality of ports (14a, 14b, 14c) arranged over at least a portion of its length, the ports (14a, 14b, 14c) being configured for establishing a fluidic communication between an inner volume of the elongate main body (3) and the annular gap (32) defined between the elongate main body (3) and the borehole (30).

17. Anchoring system (1) according to any of the previous claims, wherein a attachment line termination point of a attachment line (40) is integrally connected to the upper end (4) of the elongate main body (5) of the anchor pile (2), such that the attachment line (40) is concentric and axially aligned with the longitudinal axis (L) of the elongate main body (3).

18. Anchoring system (1) according to any of the previous claims further comprising a guide collar (20) configured for being arranged at the opening of the borehole, the guide collar (20) providing a guide channel (22) configured in use to be aligned with the borehole (30) and to enable the anchor pile (2) to pass therethrough into the borehole (30), and in which the guide collar (20) is configured to be removable from the anchor pile (2) once positioned within the borehole (30).

19. Anchoring system (1) according to claim 18, in which the guide collar (20) comprises a first end configured to contact the borehole (30), and a second opposed end, and in which the guide collar (20) further comprises a slot extending between the first and second ends thereof, and in which the slot is in communication with the guide channel (22).

20. Anchoring system (1) according to claim 19, in which the slot extends essentially parallel to the longitudinal axis of the guide collar (20).

21. Anchoring system (1) according to any one of claims 18 to 20, wherein at least the guide collar (20) is made of a brittle or deformable material.

22. Method of installing an anchor pile (2) into a borehole (30) drilled in a ground surface for creating an anchorage, the method comprising the steps of: i. providing an anchoring system (1) according to any of claims 1 to 21; and ii. at least partially filling the annular gap (32) defined between the bearing surface (7a, 7b) of the elongate main body (3) of the anchor pile (2) and the adjacent borehole (300) wall with locking media to lock the anchor pile (2) in place.

23. Method of installing an anchor pile (2) as claimed in claim 22, further comprising running the anchor pile (2) through the borehole (30) until the anchor pile (2) is entirely received within the borehole (30) prior to insertion of locking media.

24. Method of installing an anchor pile (2) as claimed in either of claims 22 and 23, further comprising: iii. introducing the lower end (5) of the elongate main body (3) through a guide channel of a guide collar (20), into the borehole (30); and iv. removing the guide collar (20) from the anchor pile (2).

25. Method according to any one of claims 22 to 24, wherein in the locking media is provided in a fluid medium directly into the annular gap (32) from an upper section of the borehole (30).

26. Method according to claim 25 wherein the elongate main body (3) of the anchor pile (2) is shaped as an essentially tubular hollow body, wherein the locking media is provided as fluid and/or slurry pumped through the hollow tubular main body and into the annular gap (32) between the elongate main body (3) and the borehole (30).

27. Method according to claim 26, wherein the elongate main body (3) comprises a plurality of ports (14a, 14b, 14c) arranged over at least a portion of its length, the ports (14a, 14b, 14c) being configured for establishing a fluidic communication between an inner volume of the elongate main body (3) and the annular gap (32) and wherein the locking media is provided in a fluid medium through the upper end (4) of the hollow elongate main body (3), the fluid being pumped through the inner volume of the elongate main body (3) through the ports (14a, 14b, 14c) to provide the locking media in a fluid medium into the annular gap (32).

28. Method according to claim 27, in which the elongate main body (3) comprises a plurality of ports (14a, 14b, 14c) arranged over at least a portion of its length, in which the size of the ports (14a, 14b, 14c) decreases with distance away from the lower end (5) of the elongate main body (3).

29. Method according to any of claims 22 to 28 further comprising the step of providing cement grout aggregate material into the borehole (30) prior to inserting the anchor pile (2) into the borehole (30).

Description

[0091] These and other aspects of the present invention will now be described, by way of example, only with reference to the accompanying figures, in which:

[0092] FIG. 1 shows a schematic illustration of a cross-sectional view of an anchoring system according to one embodiment of the present invention;

[0093] FIG. 2 shows a schematic illustration of the anchoring system of FIG. 1 within a borehole;

[0094] FIG. 3 shows a schematic illustration of an outwardly extending member of an anchoring system according to one embodiment of the present invention;

[0095] FIG. 4 shows a schematic illustration of the flowpath of locking media introduced via the anchoring system of FIG. 1;

[0096] FIG. 5 shows a schematic illustration of the flowpath of locking media introduced via the anchoring system of FIG. 1 within the borehole;

[0097] FIG. 6 shows a schematic illustration of the flowpath of locking media introduced via the anchoring system of FIG. 1 towards the lower end of the anchoring system;

[0098] FIG. 7 shows a schematic illustration of the flowpath of locking media introduced via the anchoring system of FIG. 1 towards a central region of the elongate body member of the anchoring system;

[0099] FIG. 8 shows a schematic illustration of the flowpath of locking media introduced via the anchoring system of FIG. 1 towards the upper end of the anchoring system;

[0100] FIG. 9 shows a schematic illustration of the guide collar according to one embodiment of the present invention;

[0101] FIG. 10 shows a schematic illustration of progression over time of the anchoring system of FIG. 1 secured within a borehole.

DETAILED DESCRIPTION

[0102] With reference to the Figures, the anchoring system 1 comprises an anchor pile 2 configured to be embedded in a borehole 30 drilled in a ground surface. The anchor pile 2 comprises an elongate main body 3 having a longitudinal axis and comprising an upper end 4 and a lower end 5.

[0103] The elongate main body 3 comprises two spaced apart outwardly extending members 6a, 6b. The two outwardly extending body members 6a, 6b can be seen to be approximately equidistantly spaced along the length of the elongate main body 3. It is however to be understood that the members 6a, 6b may be provided at any suitable locations on the elongate main body 3.

[0104] It can be seen that the cross section of the elongate main body 3 increases at each of these two outwardly extending body members 6a, 6b in a direction extending along the longitudinal axis from the upper end 4 to the lower end 5 thereof.

[0105] Although the illustrated embodiment has two spaced apart outwardly extending body portions 6a, 6b, it is to be understood that the anchoring system 1 may comprise any suitable number of outwardly extending body portions 6a, 6b. For example, the system 1 may comprise a single outwardly extending body member, or more than two outwardly extending body members, for example three or four or five, depending on the particular requirements for the anchoring system, such as for example the depth of the borehole 30.

[0106] Each of the two spaced apart outwardly extending body members 6a, 6b provides a bearing surface 7a, 7b such that in use an annular gap 32 for receiving locking media is defined between the bearing surfaces 7a, 7b and the adjacent portions of the borehole 30.

[0107] Each outwardly extending body member 6a, 6b comprises a first conical portion 8a, 8b, a tubular portion 9a, 9b, and a second conical portion 10a, 10b coaxial with the longitudinal axis (L) of the elongate main body 3.

[0108] Along the first conical portion 8a, 8b of each body member 6a, 6b the cross section of the elongate main body 3 increases in the direction from the upper end 4 to the lower end 5;

[0109] Along the second conical portion 10a, 10b of each body portion 6a, 6b the cross section of the elongate main body 3 decreases in the direction from the upper end 4 to the lower end 5.

[0110] The tubular portion 9a, 9b is located between the first conical portion 8a, 8b and the second conical portion 10a, 10b.

[0111] The first and second conical portions 8a, 8b, 10a, 10b define tapered sections provided the bearing surface 7a, 7b. It is however to be understood that the projecting members 6a, 6b may have any suitable shape or configuration to provide a bearing surface 7a, 7b suitable of supporting, abutting and retaining locking media.

[0112] Each of the first conical portion and second conical portion 8a, 8b, 10a, 10b provides a tapered section which extends at an angle to (i.e. defining the taper angle) the longitudinal axis (L) of the elongate main body 3.

[0113] In the illustrated embodiment, the first conical portion 8a, 8b is smaller than the taper angle of the second conical portion 10a, 10b. It is however to be understood that the taper angles of the first and second conical portions 8a, 8b, 10a, 10b may have any suitable angle depending on the particular requirements of the anchoring system 1.

[0114] Each conical portion 8a, 8b, 10a, 10b has a first free end and a second opposed end located at or adjacent the tubular portion 9a, 9b. The length of each conical portion 8a, 8b, 10a, 10b is measured between the first free end and the second opposed end thereof. It can be seen from FIGS. 1 and 3 that the first conical portion 8a, 8b has a greater length than the second conical portion 10a, 10b. It is however to be understood that each conical portion may have any suitable length depending on the particular requirements of the anchoring system.

[0115] In the illustrated embodiment, the cross-sectional dimensions of the second opposed ends of each conical portion 8a, 8b, 10a, 10b are substantially the same as the cross-sectional dimension of the tubular portion 9a, 9b. This helps to ensure that the anchoring system 1 can be inserted smoothly into the bore hole.

[0116] Each outwardly extending member 6a, 6b further comprises a plurality of spaced apart conduits 11a, 11b provided on outer surfaces thereof. The conduits 11a, 11b extend in a direction substantially parallel to the longitudinal direction L of the elongate main body 3. The conduits 11a, 11b extend along at least a portion of the first conical portion 8a, 8b, the tubular section 9a, 9b, and at least a portion of the second conical portion 10a, 10b.

[0117] In the illustrated embodiment, the conduits 11a, 11b are provided as channels. The channels 11a of the first projection member 6a are aligned with the channels 11b of the second projection member 6b. It is however to be understood that the channels may be located at any suitable position and can for example be offset from channels provided on other, for example adjacent, projecting members.

[0118] A cohesive high friction coating, such as for example bitumen, is provided on the tapered bearing surfaces 7a, 7b of the projecting members 6a, 6b. The cohesive high friction coating is configured to increase friction between the elongate main body 3 and locking media received within the annular gap.

[0119] With reference to FIG. 3, in one embodiment, the outwardly extending body member 6a of the elongate main body 3 comprises fixing means 12 operative to penetrate an adjacent portion of a borehole 30 wall to establish a fixed connection therewith. It can be seen that the fixing means 12 are provided on the tubular section 9a of the member 6a. Although FIG. 3 only illustrates the fixing means to be present on a single outwardly extending member 6a, it is to be understood that one or more, for example each, of the outwardly extending members 6a, 6b may comprise fixing means 12.

[0120] The fixing means 12 are operative to be driven outwardly or away from the elongate main body 3 to penetrate an adjacent portion of a borehole wall 30.

[0121] In the illustrated embodiment, the fixing means 12 are cone point bolts. It is however to be understood that the fixing means 12 may be any suitable fixing means 12 capable of being driven outwardly to penetrate a borehole wall 30.

[0122] The elongate main body 3, for example the or each outwardly extending body member 6a, 6b, may comprise one or more, preferably a plurality of, fixing means 12. The fixing means 12 may be spaced apart from each other along the length of the elongate main body 3, for example along the length of the outwardly extending body member 6a, 6b (or tubular section 9a, 9b).

[0123] One or more of the plurality of fixing means 12 is configured to extend at different angles with respect to the longitudinal axis of the corresponding elongate main body 3. The fixation of the elongate means has been found to be improved by the use of fixing means 12 which extend at a plurality of different angles from the elongate main body 3.

[0124] In use, as shown in FIGS. 4 to 9, the method of installing an anchor pile 2 into a borehole 30 drilled in a ground surface for creating an anchorage, comprises running the anchor pile 2 as herein described through the borehole 30 until the anchor pile 2 is entirely received within the borehole 30 prior to insertion of locking media. The upper end 4 of the elongate main body 3 is entirely received within the borehole 30 and located at a predetermined depth beneath the surface of the ground. In one embodiment, the anchor pile 2, for example the lower end 5 of the elongate main body 3, contacts the bottom of the borehole 30.

[0125] During installation, a guide collar 20 providing a guide channel 21 extending therethrough is placed in position at the opening of the borehole 30. The guide channel 21 is aligned within the borehole 30. The anchor pile 2 is aligned with and inserted through the guide channel 21 of the guide collar 20 into the opening of the borehole 30. The anchor pile 2 is then driven into the borehole 30. The guide collar 20 is then removed from the anchor pile 2.

[0126] The locking media may be provided in a fluid medium directly into the annular gap 32 from an upper section of the borehole 30. Alternatively, or in addition, the locking media may be provided in a fluid medium into the annular gap 32 from a lower portion of the elongate main body 3. The elongate main body 3 of the anchor pile 2 is shaped as an essentially tubular hollow body, as shown in FIGS. 4 to 8, and the locking media is provided as fluid and/or sediments pumped from inside the borehole 30 through the hollow tubular main body 3.

[0127] As shown in FIGS. 4 to 8, the elongate main body 3 comprises a plurality of, ports 14a, 14b, 14c arranged over its length. Each port 14a, 14b, 14c is configured for establishing a fluidic communication between an inner volume of the elongate main body 3 and the adjacent annular gap 32. Locking media may be provided into the annular gap in a fluid medium through the elongate main body 3. In the illustrated embodiment, locking media is provided through the upper end 4 of the elongate main body 3 (for example hollow tubular main body) towards the lower end 5 thereof. The fluid may for example be pumped through the inner volume of the main body 3 through the port(s) 14a, 14b, 14c to provide the locking media in a fluid medium into the annular gap 32.

[0128] It can be seen from FIGS. 6 to 8 that the size of the ports 14a, 14b, 14c decreases with distance away from the lower end 5 of the elongate main body 3. The ports 14a provided towards the lower end 5 of the elongate main body 3 (as shown in FIG. 6) are larger in dimension than the ports 14b provided towards a central region of the elongate main body 3 (as shown in FIG. 7). Furthermore, the ports 14b provided towards a central region of the elongate main body 3 (as shown in FIG. 7) are larger in dimension than the ports 14c provided towards the upper end 4 of the elongate main body 3 (as shown in FIG. 8). This arrangement enables the anchoring system 1 of the present invention to provide unique fluid placement methodology in which the locking media is provided to fill the borehole 30, and the annular gap(s) 32 preferentially and sequentially from the lower end 5 of the anchor pile 2 sequentially upwards towards the upper end of the anchor pile 2. With this arrangement, the supplied locking media preferentially exits the elongate main body 3 through the largest ports 14a located towards the lower end 5 of the elongate main body 3. As the locking media fills the annular gap 32 at or adjacent the largest ports 14a towards the lower end 5 of the elongate main body 3, the increased pressure causes the locking media to exit through slightly smaller ports 14b provided further along the elongate main body 3 in a direction towards the upper end 4 thereof. As the locking media fills the annular gap 32 at or adjacent the slightly smaller ports 14b, the increased pressure causes the locking media to exit through progressively smaller ports 16c located along the elongate main body 3 towards the upper end 4 thereof, sequentially filling the adjacent annular gaps 32. The present invention therefore provides an anchoring system 1 which can be used to efficiently and reliably fill annular gaps formed between multiple bearing surfaces located along the length of the elongate main body 3 and adjacent portions of the borehole 30. The present invention is therefore able to securely fix the anchor pile 2 in position within the borehole 30.