Soft ground anchor device for anchoring one or more structures and method for placing an anchor in soft ground - Patents.com

Abstract

A soft ground anchoring device (1) for fastening multiple structures and a method for placing an anchor in soft ground is provided, the soft ground anchoring device (1) comprising, when viewed in a vertical operating position, an elongated continuous inner open box structure (2) having a triangular cross section with a first wall surface (3), a second wall surface (4) and a third wall surface (5), and a continuous outer open box structure (10) having a shorter vertical length than the elongated continuous inner open box structure (2) and having a triangular cross section constituted by a first outer wall surface (11), a second outer wall surface (12) and a third outer wall surface (13), the vertical central area of ​​the first outer wall surface, the second outer wall surface and the third outer wall surface being defined by a first outer wall surface (14), a second outer wall surface (15) and a third outer wall surface (16), the first outer wall surface (16) and the third outer wall surface being defined by a second outer wall surface (17), the second outer wall surface (18) and the third outer wall surface being defined by a third outer wall surface (19), the second outer wall surface (20) and the third outer wall surface being defined by a third outer wall surface (21), the third outer wall surface (22) and the third outer wall surface being defined by a first outer wall surface (19), the second outer wall surface (23) and the third outer wall surface being defined by a third outer wall surface (24), the third outer wall surface (25) and the third outer wall surface being defined by a first outer wall surface (19), the second outer wall surface (26) and the third outer wall surface being defined by a third outer wall surface (27), the third outer wall surface (28) and the third outer wall surface being defined by a third outer wall surface (29), the third outer wall surface (30) and the third outer wall surface being defined by a third outer wall surface (31), the third outer wall surface (32) and the third outer wall surface being defined by a third outer wall surface (33). (14) is connected to the elongated continuous inner open box structure (2) in an outer edge region between the first wall surface (3) and the second wall surface (4), an outer edge region between the second wall surface (4) and the third wall surface (5), and a lower region of the outer edge region between the third wall surface (5) and the first wall surface (3), and an anchor bracket (20) is placed in the lower outer region of the soft ground anchor device (1), where the soft ground anchor device comprising the elongated continuous inner open box structure (2) and the continuous outer open box structure (10) is lowered to a desired depth into the soft ground.

Description

[Technical field]

[0001] The present invention relates to a soft ground anchoring device for anchoring one or more structures. The present invention further relates to a method for placing anchors in soft ground for anchoring one or more structures using the soft ground anchoring device. The anchoring device is preferably configured to be driven into the seabed using conventional piling frame equipment or possibly by a vibro hammer. [Background technology]

[0002] Within the scope of the present invention, a variety of anchor types are known today, some examples of which are discussed below.

[0003] Conventional plate anchors or ship anchors, e.g. the "Vryhof" type. These are designed so that a vessel with a high towing force pulls the anchor, thereby digging into the seabed. These anchor types are widely used, but they also have some drawbacks. In some cases, the nature of the soft ground is such that the anchor cannot be pulled down deep enough to achieve the required holding force.

[0004] Anchor piles, usually designed as steel pipe piles. They are installed using a pile hammer. These anchors usually have a small diameter and may have too low a holding resistance. Furthermore, they have a constant cross-sectional area and consume a relatively large amount of material in the upper soil layer with little holding resistance.

[0005] Suction anchors. These are installed by means of a mechanical pump that is attached to the pile and sucked into the ground. These anchors have a certain cross-sectional area and, as a result, consume a relatively large amount of material in the upper soil layer with almost no holding resistance. Furthermore, they require a cap on top to establish suction. They also require a special mechanical system to allow installation in soft ground by suction.

[0006] SEPLA anchors. These are formed as plate anchors and are forced into the uncompressed mass by suction anchors. This usually results in a complicated operation.

[0007] EP 0 312 198 A1 discloses a pile with high resistance to tension when used as an anchor for horizontal or near-horizontal guidance. The pile has an elongated hollow body with a cross-sectional profile in the form of a closed figure that is asymmetric about at least one axis, preferably a triangle, in particular an equilateral triangle with an equal angle in the range of 20 to 45 degrees. The pile body is preferably made of plate material, where at least the lower end is open so that it can be easily driven into a carrier material (for example the seabed). A beam-like reinforcing member preferably extends throughout the interior of the pile body over the entire vertical length of the pile body in order to strengthen the pile against bending when used in an anchor. A connecting element such as a hook is arranged on the edge of the pile, preferably the reinforcing beam. In a preferred form of the pile, the vertical reinforcing beam forms the apex of an equilateral triangle with an equal angle of 35 degrees between its equal sides, the connecting element being at the apex at approximately the middle length of the pile. A strong marine anchoring system using the pile is also disclosed.

[0008] US Patent 3,850,128 discloses an anchor assembly for sinking in a layer below a body of water, the anchor assembly comprising an anchor section with an elongated hollow shaft and a radially extending tapered plate attached to its lower end, a vibratory drive unit and a releasable coupling for connecting said drive unit to said shaft. Vibratory forces cause the seabed to fluidize, whereby the anchor tends to sink under its own weight. After sinking, the coupling is deactivated, allowing recovery of the drive. Summary of the Invention

[0009] It is therefore an object of the present invention to provide a soft ground anchoring device that overcomes the drawbacks and problems of known anchor types as discussed above.

[0010] Another objective is that the anchoring device should be manufacturable and transportable in a cost-effective manner.

[0011] A further object is that the anchoring device should be installable in the exact predetermined position by standard framing equipment for piles.

[0012] A further object is that the soft ground anchoring device should achieve high anchoring capacity in deeper soft ground.

[0013] Yet another objective is that the anchoring device should be adapted and dimensioned so that the anchor has maximum holding capacity in at least three directions, thereby allowing the anchor to be used as a common anchor for multiple structures.

[0014] The object of the invention is achieved by a soft ground anchoring device for anchoring one or more structures, which soft ground anchoring device, when viewed in a vertical working position, has: The soft ground anchor device comprises an elongated, continuous inner open box structure having a triangular cross section with a first wall surface, a second wall surface and a third wall surface; and a continuous outer open box structure having a shorter vertical length than the elongated, continuous inner open box structure and a triangular cross section formed by a first outer wall surface, a second outer wall surface and a third outer wall surface, wherein vertical central regions of the first outer wall surface, the second outer wall surface and the third outer wall surface are connected to the elongated, continuous inner open box structure at an outer edge region between the first wall surface and the second wall surface, an outer edge region between the second wall surface and the third wall surface, and a lower region of the outer edge region between the third wall surface and the first wall surface, respectively, and an anchor pile is disposed in a lower outer region of the soft ground anchor device, and the soft ground anchor device comprising the elongated, continuous inner open box structure and the continuous outer open box structure is lowered to a desired depth into the soft ground.

[0015] Preferred embodiments of the soft ground anchoring device are detailed in claims 2-12.

[0016] The object of the present invention is further achieved by a method for placing anchors in soft ground for anchoring one or more structures, in which a soft ground anchoring device according to any one of claims 1 to 12 is used, the method comprising: Attaching an anchor line to a soft ground anchor device; Lowering the soft ground anchor device with the anchor line attached to it so that its lower end region is toward the soft ground; and The method includes driving the soft ground anchor device into the soft ground using conventional frame equipment for pile driving or by using a vibro hammer.

[0017] A preferred embodiment of the method is further detailed in claim 14. In the following, three embodiments of a soft ground anchoring device for anchoring one or more (multiple) structures according to the invention are described with reference to the accompanying drawings. [Brief description of the drawings]

[0018] [Figure 1] 1 shows an embodiment of a soft ground anchoring device for anchoring multiple structures according to the present invention; [Diagram 2] 2 shows a second embodiment of the soft ground anchoring device according to FIG. 1; [Diagram 3] 3 shows a third embodiment of a soft ground anchoring device according to the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Referring initially to Figures 1 and 2, a soft ground anchoring device 1 for anchoring a number of structures is shown. The soft ground anchoring device 1 is shown in a vertical working position. The soft ground anchoring device 1 is constituted by an elongated continuous open box structure 2 with a triangular cross section comprising a first wall plate 3, a second wall plate 4 and a third wall plate 5. A continuous outer open box structure 10, having a shorter vertical length than the inner box structure 2 and with a triangular cross section constituted by a first outer wall plate 11, a second outer wall plate 12 and a third outer wall plate 13, is connected to the elongated continuous inner open box structure 2 in its lower region. The vertical central regions 14 of the first, second and third outer walls are connected to the outer edge regions between the first wall surface 3 and the second wall surface 4, between the second wall surface 4 and the third wall surface 5 and between the third wall surface 5 and the first wall surface 3, respectively. 1, an anchor bracket 20 is disposed at each of the connection regions between the first outer wall surface 11 and the second outer wall surface 12, between the second outer wall surface 12 and the third outer wall surface 13, and between the third outer wall surface 13 and the first outer wall surface 11. Further, referring to FIG. 2, an anchor bracket 20 is disposed at each of the connection regions between the inner box structure 2 and the outer box structure 10. The anchor brackets 20 may also be disposed at both the corners of the outer box structure 10 and the vertical center regions of the outer walls 11, 12, 13.

[0020] With reference to Fig. 3, a third embodiment of the soft ground anchoring device 1 is shown. The soft ground anchoring device 1 herein comprises a continuous further outer open box structure 25 having a triangular cross section arranged outside the continuous outer open box structure 10. The further outer open box structure 25 comprises a first further outer wall surface 26, a second further outer wall surface 27 and a third further outer wall surface 28. A vertical central area 29 of each of the first, second and third further outer wall surfaces 26, 27, 28 is connected to a lower connection area between the first outer wall surface 11 and the second outer wall surface 12, a lower connection area between the second outer wall surface 12 and the third outer wall surface 13 and a lower connection area between the third outer wall surface 13 and the first outer wall surface 11, respectively. Here, an anchor bracket 20 is shown arranged in each of the vertical central areas 29 of each of the first, second and third further outer wall surfaces 26, 27, 28.

[0021] The soft ground anchoring device 1 according to the embodiment of Fig. 3 is further provided with a reinforcing wall 30 extending from the vertical central region 14 of the first, second and third outer wall 11, 12, 13 to the first, second and third further outer wall 26, 27, 28, respectively. The reinforcing wall 30 in this embodiment forms angles in the range of 60° and 120° with the first, second and third further outer wall 26, 27, 28, respectively. The further outer box structure 25 in this embodiment has a shorter vertical length than the outer box structure 10. It should be noted in this connection that the further outer box structure 25 does not necessarily extend as deep as the outer box structure 10. The elongated continuous inner open box structure 2, the continuous outer open box structure 10 and the continuous further outer open box structure 25 each have a cross section in the form of an equilateral triangle. The box structures 2, 10, 25 may also have a triangular cross section that is not an equilateral triangle.

[0022] The anchor bracket 20 for the anchor line is fixed to the bottom of the soft ground anchoring device 1, where the sum of the resulting holding resistances from adjacent soil masses acts based on the distribution of the ground resistance over the height of the anchoring device. In this way the soft ground anchoring device 1 can utilize the horizontal ground resistance.

[0023] Depending on the required holding force and the local ground conditions, the anchoring device 1 can be shaped by modifying its geometry, for example: i) the length / height of the elongated continuous open box structure 2 and at least one continuous outer box structure 10, 25 can be varied; ii) the cross-sectional shape of the continuous open box structure can be either an equilateral or non-equidistant triangle; iii) The anchor brackets 20 can be selected based on the distribution of ground resistance over the height of the anchor device, whereby the anchor brackets 20 can also be placed at the corners of the outer box structure 10, at a level directly above the further outer box structure 25.

[0024] The soft ground anchoring device 1 is formed from a straight plate offering a simple and cost-effective manufacturing method, as shown in Figure 1. The anchoring device can be manufactured and transported in a lying position.

[0025] The soft ground anchoring device 1 with its triangular box structure cross section means that the forces from the anchor line are distributed into the surrounding soft ground over the full height of the anchoring device 1 due to the inherent properties of the open box structure as a continuous beam.

[0026] The anchor structure 1 is suitable for anchor sharing, e.g. in a wind farm many floats are connected to the same anchor. In such a case the anchor device 1 has to be loaded from different directions. The anchor device 1 is made to be loaded in three directions, and furthermore the best holding capacity is achieved deep in the ground, and most of the material of the structure (steel, concrete) is placed in this area. The principle is that there is a larger holding capacity deep in the ground, and therefore it is advantageous to use more material deep below, while the top of the anchor device 1 is for pushing the anchor device 1 into the ground. The triangular box structure 2, 10, 25 facilitates large dimensions at the bottom and at the same time minimal dimensions at the top, which contributes little to the holding capacity.

[0027] As mentioned above, the soft ground anchoring device 1 is formed for being driven down to the seabed by conventional pile driving frame equipment. The frame equipment can be, for example, a conventional pile hammer (drop weight or hydraulic hammer) or a vibro hammer. To facilitate the use of the pile driving equipment, reinforcing plates 7 are arranged on the inside of the upper areas of the corners of the continuous inner box structure 2. The pile driving equipment can, as an advantage, be mounted on the anchoring device 1 on board a suitable installation vessel and lowered as a unit to the seabed. The further driving of the anchoring device 1 into the soft ground takes place similarly to the framing of the self-supporting pile.

[0028] After use, it becomes possible to lift the anchoring device 1 for reuse or use of the vibro hammer in combination with an upward pulling force.

[0029] The soft ground anchoring device 1 is formed in such a way that its installation is not limited with respect to the soil profile. Different soil profiles therefore do not limit the use of the soft ground anchoring device 1. Soil profiles often show an increase in hardness with depth. The soft ground anchoring device 1 of the invention is formed in such a way as to use as little construction material as possible in the upper soil layers, but more construction material in the deeper and harder soil layers, as mentioned before. There is no need to use specially made auxiliary equipment other than a standard pile hammer for installation. The anchoring device 1 can be installed in the exact predefined position.

[0030] Finally, it must be mentioned that, although previously known anchoring solutions each have one or more of the properties and advantages that the anchoring device 1 according to the invention has, the soft ground anchoring device 1 according to the invention makes it possible to integrate all these properties into a new anchoring concept.

Claims

1. A soft ground anchoring device (1) for anchoring one or more structures, said soft ground anchoring device (1) having, when viewed in a vertical working position: an elongated continuous inner open box structure (2) having a triangular cross section with a first wall (3), a second wall (4) and a third wall (5); a continuous outer open box structure (10) having a vertical length shorter than said elongated continuous inner open box structure (2) and having a triangular cross section defined by a first outer wall surface (11), a second outer wall surface (12), and a third outer wall surface (13); Equipped with a vertical central region (14) of the first outer wall surface, the second outer wall surface and the third outer wall surface are connected to the elongated continuous inner open box structure (2) at an outer edge region between the first wall surface (3) and the second wall surface (4), at an outer edge region between the second wall surface (4) and the third wall surface (5) and at a lower region of the outer edge region between the third wall surface (5) and the first wall surface (3), respectively; An anchor bracket (20) is disposed in the lower outer region of the soft ground anchor device (1); The soft ground anchoring device (1), characterized in that the soft ground anchoring device comprising the elongated continuous inner open box structure (2) and the continuous outer open box structure (10) is lowered into the soft ground to a desired depth.

2. 2. The soft ground anchoring device (1) according to claim 1, characterized in that the anchor brackets (20) are arranged in each of the connection areas between the elongated continuous inner open box structure (2) and the continuous outer open box structure (10).

3. 2. The soft ground anchor device (1) according to claim 1, characterized in that the anchor brackets (20) are arranged in each of the connection regions between the first outer wall surface (11) and the second outer wall surface (12), the connection region between the second outer wall surface (12) and the third outer wall surface (13), and the connection region between the third outer wall surface (13) and the first outer wall surface (11).

4. The soft ground anchoring device (1) comprises a continuous further outer open box structure (25) having a triangular cross section arranged outside the continuous outer open box structure (10), the continuous further outer open box structure (25) comprising: a first further outer wall surface (26), a second further outer wall surface (27) and a third further outer wall surface (28), wherein a vertical central region (29) of each of said first further outer wall surface (26), said second further outer wall surface (27) and said third further outer wall surface (28) is connected to a lower connection region between said first outer wall surface (11) and said second outer wall surface (12), a lower connection region between said second outer wall surface (12) and said third outer wall surface (13), and a lower connection region between said third outer wall surface (13) and said first outer wall surface (11), 2. The soft soil anchoring device (1) according to claim 1, characterized in that the anchor brackets (20) are arranged in the vertical central regions (29) of the first further outer wall surface (26), the second further outer wall surface (27) and the third further outer wall surface (28), respectively.

5. 5. The soft ground anchoring device (1) according to claim 4, characterized in that a reinforcing wall (30) extends from the vertical central region (14) of the first outer wall (11), the second outer wall (12) and the third outer wall (13) to the first further outer wall (26), the second further outer wall (27) and the third further outer wall (28), respectively.

6. 6. The soft ground anchoring device (1) according to claim 5, characterized in that the reinforcing wall surface (30) forms angles in the range of 60° and 120° with the first further outer wall surface (26), the second further outer wall surface (27) and the third further outer wall surface (28), respectively.

7. The soft ground anchoring device (1) according to any one of claims 4 to 6, characterized in that the continuous further outer open box structure (25) has a shorter vertical length than the continuous outer open box structure (10).

8. 8. The soft ground anchoring device (1) according to any one of claims 1 to 7, characterised in that the triangular cross sections of the elongated continuous inner open box structure (2), the continuous outer open box structure (10) and the continuous further outer open box structure (25) are equilateral triangles.

9. The soft ground anchoring device (1) according to any one of claims 1 to 7, characterised in that the triangular cross sections of the elongated continuous inner open box structure (2), the continuous outer open box structure (10) and the continuous further outer open box structure (25) are non-equilateral triangles.

10. 10. The soft ground anchoring device (1) according to any one of claims 1 to 9, characterized in that the anchor bracket (20) is arranged in a lower region of the soft ground anchoring device (1), in which the sum of the resulting holding resistances from adjacent soil masses is such that it is selected based on the distribution of ground resistances over the height of the soft ground anchoring device (1).

11. 11. The soft ground anchoring device (1) according to any one of claims 1 to 10, characterized in that the geometry of the soft ground anchoring device (1) is varied with respect to the vertical length of the elongated continuous inner open box structure (2), the at least one outer open box structure (10) and the continuous further outer open box structure (25), the triangular cross-section of the elongated continuous inner open box structure (2), the at least one outer open box structure (10) and the continuous further outer open box structure (25) and the arrangement of the anchor brackets (20) which is selected based on the distribution of the ground resistance over the length of the soft ground anchoring device (1).

12. The soft ground anchoring device (1) according to any one of claims 1 to 11, characterised in that the soft ground anchoring device (1) is made of steel.

13. A method for placing anchors in soft ground for anchoring one or more structures, comprising the steps of: Attaching an anchor line to the soft ground anchor device (1); Lowering the soft ground anchor device (1) with the anchor line attached to it so that its lower end area is toward the soft ground; and driving the soft ground anchoring device (1) into the soft ground with conventional frame equipment for pile driving or by using a vibro hammer.

14. The method is further characterized in that 14. The method according to claim 13, characterized in that the soft ground anchoring device (1) is released and lifted from the soft ground by using a vibro hammer in combination with an upward pulling force.

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