Anchor device, anchor system, and method for installing anchor system

Abstract

This anchor device (20) comprises a shaft member (22) which extends along a central axis (A) and which has a tension member (85) attached thereto, and a first plate member (30) and a second plate member (40) that are configured to be capable of rotating relative to one other about the central axis (A), wherein: the first plate member (30) has a first rear end portion (31) that is farthest from the center axis (A) in a direction in which the first plate member (30) extends and in a direction orthogonal to the center axis (A); the second plate member (40) has a second rear end portion (41) that is farthest from the central axis (A) in a direction in which the second plate member (40) extends and in a direction orthogonal to the central axis (A); and the anchor device (20) is configured to be capable of changing from a folded state in which the first rear end portion (31) and the second rear end portion (41) are close to each other to an unfolded state in which the first rear end portion (31) and the second rear end portion (41) are separated from each other.

Description

Anchor device, anchor system, and anchor system installation method

[0001] The present invention relates to an anchoring device, an anchoring system and a method for installing an anchoring system.

[0002] Wind turbines that are used while floating on the ocean are known. Such wind turbines are also called floating offshore wind turbines. A floating offshore wind turbine includes a floating structure and a mooring system. The floating structure includes blades that rotate in response to wind, a nacelle that houses a generator, a tower that supports the nacelle, and a support for supporting the tower. The mooring system is a system for mooring the floating structure to the ground. The mooring system includes anchors that are placed in the ground and mooring lines that connect the floating structure and the anchors. The mooring lines are, for example, wires that connect the support for the floating structure to the anchors. An example of a mooring system is disclosed in JPS61-7493U.

[0003] Known anchors included in mooring systems include pile anchors, suction anchors, drag anchors, and suction embedded anchors. Pile anchors and suction anchors have the advantage of being relatively large and capable of exerting a large holding force, but they have the disadvantage of requiring large ships and large construction machinery to install, which increases installation costs and takes a long time. Drag anchors and suction embedded anchors have the advantage of not requiring large ships and large construction machinery to install, but they have the disadvantage of being relatively small and therefore difficult to exert a large holding force. Holding force refers to the force that resists the anchor moving, sliding, or being pulled out of the ground where it is installed, generated when a pulling force acts on the anchor via the mooring line.

[0004] The present invention has been made in consideration of these points, and an object of the present invention is to provide an anchor device, an anchor system, and an installation method for an anchor system that can be made compact during installation and can exert a large gripping force after installation.

[0005] The anchor device according to the present invention is an anchor device that is configured to be able to change from a folded state in which the first rear end and the second rear end are close to each other to an unfolded state in which the first rear end and the second rear end are separated from each other.

[0013] The anchor device according to the present invention is: [1] An anchor device that includes: an axial member that extends along a central axis and to which a tension member is attached; and a first plate member and a second plate member that are configured to be rotatable relative to each other around the central axis, wherein the first plate member has a first rear end that is farthest from the central axis in the direction in which the first plate member extends and in a direction perpendicular to the central axis, and the second plate member has a second rear end that is farthest from the central axis in the direction in which the second plate member extends and in a direction perpendicular to the central axis, and

[0006] The anchor device according to the present invention is the anchor device described in [1], [2] wherein the first plate member has a first outer surface facing away from the second plate member in the folded state, the second plate member has a second outer surface facing away from the first plate member in the folded state, the first outer surface includes a first inclined outer surface that approaches the second plate member as it approaches the axis member in the folded state, and the second outer surface includes a second inclined outer surface that approaches the first plate member as it approaches the axis member in the folded state.

[0007] The anchor device according to the present invention is the anchor device according to [1] or [2], [3] wherein the first rear end includes a first inclined end surface that approaches the second plate member as it approaches the shaft member in the folded state, and the second rear end includes a second inclined end surface that approaches the first plate member as it approaches the shaft member in the folded state.

[0008] The anchor device according to the present invention is the anchor device according to any one of [1] to [3], further including: [4] a third plate member connected to the first plate member and configured to be rotatable relative to the first plate member; and a fourth plate member connected to the second plate member and configured to be rotatable relative to the second plate member.

[0009] The anchor device according to the present invention is [5] the anchor device according to any one of [1] to [4], which has a restricting portion that restricts the angle between the first plate member and the second plate member to a predetermined angle or less in the deployed state.

[0010] The anchor device according to the present invention is the anchor device described in [5], [6] wherein the regulating portion includes a contact portion that comes into contact with the first plate member and the second plate member when the angle between them becomes the predetermined angle.

[0011] The anchor device according to the present invention is [7] the anchor device according to [5] or [6], wherein the restricting portion includes a connecting member that connects the first plate member and the second plate member to each other.

[0012] The anchor device according to the present invention is an anchor device [8] comprising: an axial member extending along a central axis and to which a tension member is attached; first and second frame members configured to be rotatable relative to each other about the central axis; and a pressure-receiving member stretched across the first and second frame members, wherein the first frame member has a first rear end portion that is furthest from the central axis in a direction perpendicular to the central axis, and the second frame member has a second rear end portion that is furthest from the central axis in a direction perpendicular to the central axis, and wherein the anchor device is configured to be changeable from a folded state in which the first rear end portion and the second rear end portion are close to each other, to an unfolded state in which the first rear end portion and the second rear end portion are separated from each other.

[0013] The anchor device according to the present invention is the anchor device described in [8], further including: [9] a third frame member connected to the first frame member and configured to be rotatable relative to the first frame member; and a fourth frame member connected to the second frame member and configured to be rotatable relative to the second frame member.

[0014] The anchor device according to the present invention is

[10] the anchor device according to [8] or [9], which has a restricting portion that restricts the angle between the first frame member and the second frame member to a predetermined angle or less in the deployed state.

[0015] The anchor device according to the present invention is

[11] the anchor device according to

[10] , wherein the restricting portion includes a connecting member that connects the first frame member and the second frame member to each other.

[0016] An anchor system according to the present invention is an anchor system comprising:

[12] the anchor device according to any one of [1] to

[11] ; and a tension member attached to the shaft member.

[0017]

[13] A method for installing an anchor system according to the present invention includes the steps of: placing the anchor device of the anchor system according to

[12] in the folded state within a ground layer; and pulling the tension member to change the anchor device from the folded state to the unfolded state.

[0018] According to the present invention, it is possible to provide an anchor device, an anchor system, and an installation method for an anchor system that can be made compact when installed and can exert a large gripping force after installation.

[0019] FIG. 1 is a diagram for explaining a first embodiment of the present invention, showing an example of a wind turbine generator and an anchor system. FIG. 2 is a side view showing an example of an anchor device of the anchor system in a folded state. FIG. 3 is a side view showing the anchor device of FIG. 2 in a state in the middle of being deployed. FIG. 4 is a side view showing the anchor device of FIG. 2 in a deployed state. FIG. 5 is a plan view showing the anchor device of FIG. 4 in a deployed state. FIG. 6 is a diagram showing an example of a method of installing the anchor system. FIG. 7 is a diagram showing an example of a method of installing the anchor system. FIG. 8 is a diagram showing an example of a method of installing the anchor system. FIG. 9 is a diagram showing an example of a method of installing the anchor system. FIG. 10 is a diagram showing an example of a method of installing the anchor system. FIG. 11 is a side view showing a modified anchor device in a folded state. FIG. 12 is a side view showing the anchor device of FIG. 11 in a deployed state. FIG. 13 is a side view showing another modified anchor device in a folded state. FIG. 14 is a side view showing the anchor device of FIG. 13 in a deployed state. FIG. 15 is a side view showing yet another modified anchor device in a folded state. Fig. 16 is a side view showing the anchoring device of Fig. 15 in a state in the middle of deployment. Fig. 17 is a side view showing the anchoring device of Fig. 15 in a state in the deployed state. Fig. 18 is a side view showing yet another modified anchoring device in a state in the deployed state. Fig. 19 is a side view showing yet another modified anchoring device in a folded state. Fig. 20 is a side view showing the anchoring device of Fig. 19 in a state in the middle of deployment. Fig. 21 is a side view showing the anchoring device of Fig. 19 in a state in the middle of deployment. Fig. 22 is a side view showing the anchoring device of Fig. 19 in a deployed state. Fig. 23 is a side view showing the anchoring device used in an experiment conducted by the present inventors in a folded state. Fig. 24 is a side view showing the anchoring device of Fig. 23 in a state in the middle of deployment. Fig. 25 is a graph showing the relationship between the pull-out amount and the deployment angle of the anchoring device of Fig. 23. Fig. 26 is a graph showing the angle θ of anchoring device 20. ２ 27 is a graph showing the relationship between the withdrawal amount S (mm) of the anchor device 20 and the deployment angle θ (degrees) when the angle θ of the anchor device 20 is changed. ２ is fixed at 20 degrees, and the angle θ ３28 is a graph showing the relationship between the withdrawal amount S (mm) of the anchor device 20 and the deployment angle θ (degrees) when the angle θ is changed. ２ The angle θ of the anchor device 20 when the angle is fixed at 20 degrees ３ and the pull-out amount S when the deployment of the anchor device 20 has converged. Fig. 29 is a plan view showing an example of an attachment position of a tension member in the anchor device. Fig. 30 is a side view showing the anchor device of Fig. 29 in a folded state. Fig. 31 is a plan view showing another example of an attachment position of a tension member in the anchor device. Fig. 32 is a plan view showing yet another example of an attachment position of a tension member in the anchor device. Fig. 33 is a diagram for explaining a second embodiment of the present invention, showing an example of an anchor device in a deployed state. Fig. 34 is a cross-sectional view showing the anchor device of Fig. 33 in a folded state. Fig. 35 is a cross-sectional view showing the anchor device of Fig. 33 in a deployed state. Fig. 36 is a plan view showing another example of the anchor device of the second embodiment in a deployed state. Fig. 37 is a cross-sectional view showing the anchor device of Fig. 36 in a folded state. Fig. 38 is a cross-sectional view showing the anchor device of Fig. 36 in a deployed state. Fig. 39 is a plan view showing yet another example of the anchor device of the second embodiment in a deployed state. Figure 40 is a cross-sectional view showing the anchor device of Figure 39 in a folded state. Figure 41 is a cross-sectional view showing the anchor device of Figure 39 in an unfolded state. Figure 42 is a top view showing an example of the arrangement of a wind turbine generator and an anchor device.

[0020] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings attached to this specification, the scale and aspect ratios of the actual objects have been appropriately changed and exaggerated for the sake of convenience in illustration and understanding.

[0021] 1 is a diagram for explaining a first embodiment of the present invention, showing an example of a wind turbine generator 10 and an anchor system 80. The wind turbine generator 10 of this embodiment is a so-called floating offshore wind turbine generator, and generates power while floating on a water layer W. The water layer W is, for example, a layer of seawater or freshwater. That is, the wind turbine generator 10 of this embodiment is arranged so as to float on the surface of the sea, a lake, or the like.

[0022] The wind turbine generator 10 has blades 11 that rotate when exposed to wind, a nacelle 12 that houses a generator, a tower 13 that supports the nacelle 12, and a support 14 that supports the tower 13. The blades 11 are connected to the generator housed in the nacelle 12 via a mechanism such as gears. In the wind turbine generator 10, the wind rotates the blades 11, causing the generator to generate electricity. The generated electricity is sent to a substation located on land or elsewhere via a cable (not shown).

[0023] The anchor system 80 of this embodiment is used to hold the wind turbine generator 10 in a predetermined position. The anchor system 80 may also be used to hold other devices or structures in a predetermined position other than the wind turbine generator 10. That is, the anchor system 80 may be used to hold other devices or structures in a predetermined position that are placed on or floating in the water layer W. The anchor system 80 may also be used to maintain the position or attitude of devices or structures placed on land or floating in the atmosphere. For example, the anchor system 80 may be used to maintain the attitude of tower- or column-shaped structures, such as power transmission towers and chimneys, placed on land.

[0024] The anchor system 80 includes an anchor device 20 and a tension member 85. The tension member 85 is used as a so-called mooring line that applies a tension force to the anchor device 20 placed in the ground layer G. The tension member 85 is attached to a shaft member 22 (described later) of the anchor device 20. The tension member 85 may be a wire, a rod, a plate-like member, or the like, without any particular limitation. The tension member 85 may be a flexible member or a rigid body.

[0025] Fig. 2 is a side view showing an example of anchoring device 20 in a folded state. Fig. 3 is a side view showing anchoring device 20 in a state in the middle of deployment. Fig. 4 is a side view showing anchoring device 20 in a deployed state. Fig. 5 is a plan view showing anchoring device 20. Note that the tension member 85 is not shown in Figs. 2 and 5.

[0026] The anchor device 20 includes a shaft member 22, a first plate member 30, and a second plate member 40. The first plate member 30 and the second plate member 40 have a generally plate-like shape. The shaft member 22 has a cylindrical shape and extends along a central axis A. The central axis A is the axis of rotation of the first plate member 30 and the second plate member 40 relative to each other. The central axis A extends along the plate surfaces of the first plate member 30 and the second plate member 40. The plate surface of the first plate member 30 refers to the surface that coincides with the direction in which the first plate member 30 extends when viewed as a whole. Similarly, the plate surface of the second plate member 40 refers to the surface that coincides with the direction in which the second plate member 40 extends when viewed as a whole. The first plate member 30 and the second plate member 40 are each attached to the shaft member 22. The first plate member 30 and the second plate member 40 are configured to be rotatable relative to each other around the central axis A. In this embodiment, the first plate member 30 and the second plate member 40 are configured like hinges that rotate relative to each other around the central axis A.

[0027] The first plate member 30 has a first rear end portion 31. The first rear end portion 31 is the end portion of the first plate member 30 that is farthest from the central axis A. More specifically, the first rear end portion 31 is the end portion that is farthest from the central axis A in the direction in which the first plate member 30 extends and in a direction perpendicular to the central axis A. The second plate member 40 has a second rear end portion 41. The second rear end portion 41 is the end portion of the second plate member 40 that is farthest from the central axis A in the direction in which the second plate member 40 extends and in a direction perpendicular to the central axis A.

[0028] The anchoring device 20 of this embodiment is configured to be able to change from a folded state to an unfolded state. The folded state is the state in which the anchoring device 20 is most closed. In other words, the folded state is the state in which the first rear end 31 and the second rear end 41 are closest to each other. In the folded state, the first rear end 31 and the second rear end 41 may or may not be in contact with each other. The unfolded state is the state in which the anchoring device 20 is most unfolded. In other words, the unfolded state is the state in which the first rear end 31 and the second rear end 41 are farthest from each other.

[0029] The first plate member 30 has a first inner surface 35 and a first outer surface 37. The first inner surface 35 is a surface that faces the second plate member 40 in the folded state. The first outer surface 37 is a surface that faces away from the second plate member 40 in the folded state. The second plate member 40 has a second inner surface 45 and a second outer surface 47. The second inner surface 45 is a surface that faces toward the first plate member 30 in the folded state. The second outer surface 47 is a surface that faces away from the first plate member 30 in the folded state. In the folded state, the first inner surface 35 and the second inner surface 45 face each other, and the first outer surface 37 and the second outer surface 47 face generally opposite each other.

[0030] One end of the tension member 85 is attached to the shaft member 22. The tension member 85 is preferably attached to a plurality of locations on the shaft member 22. For example, the tension member 85 may be attached to two locations on both ends of the shaft member 22 (see FIGS. 29 and 30 ). Furthermore, the tension members 85 attached to the two locations on both ends of the shaft member 22 may be connected to each other and configured to be pulled by a single tension member 85.

[0031] A method for installing the anchor system 80 of this embodiment will be described with reference to FIGS.

[0032] Fig. 2 shows the anchor device 20 in a folded state. In the example shown in Fig. 2, in the folded state, the first inner surface 35 and the second inner surface 45 face each other and are in contact with each other. In the folded state, the anchor device 20 has the smallest projected area when viewed from below (from below in Fig. 2).

[0033] In this embodiment, the anchor device 20 is placed in the ground layer G in a folded state (see FIGS. 2 and 6 ). In the example shown in FIG. 6 , the anchor device 20 in the folded state is inserted into the ground layer G using a suction pile 17. The suction pile 17 is suspended by a wire 18 from a work boat 16 floating on a water layer W. In this embodiment, the anchor device 20 can be inserted into the ground layer G in the folded state, which has the smallest projected area when viewed from below. This significantly reduces the resistance force that the anchor device 20 receives from the ground layer G. Therefore, the anchor device 20 can be placed in the ground layer G without using a large ship or large construction machine. Thereafter, as shown in FIG. 7 , the suction pile 17 is pulled up by pulling the wire 18 with the work boat 16.

[0034] Next, the tension member 85 is pulled by the work boat 16, thereby deploying the anchor device 20 (see FIGS. 3 and 8). As the tension member 85 is pulled, the shaft member 22 is pulled by the tension member 85. At this time, soil and sand that make up the ground layer G enter the space between the first plate member 30 and the second plate member 40, causing the first plate member 30 and the second plate member 40 to move away from each other.

[0035] Further tension on the tension member 85 causes the anchoring device 20 to expand (see FIGS. 4 and 9). That is, the anchoring device 20 expands to its fullest extent. The angle θ between the first inner surface 35 and the second inner surface 45 in the expanded state １ The angle θ may be, for example, 90 degrees or more and 180 degrees or less. １ is measured in a plane perpendicular to the central axis A. Also, the angle θ １ is the angle that does not include the plate members 30 and 40 of the two angles formed between the first inner surface 35 and the second inner surface 45 .

[0036] In particular, if the ground layer G is composed of sand, the anchor device 20 may be subjected to a large resistance force from the ground layer G when it is deployed. In order to reduce the resistance force from the ground layer G, the anchor device 20 may be vibrated or water may be sprayed onto the ground layer G around the anchor device 20 when it is deployed. This increases the fluidity of the ground layer G around the anchor device 20, thereby reducing the resistance force from the ground layer G that the anchor device 20 receives when it is deployed. In order to vibrate the anchor device 20, a vibrator may be attached to the anchor device 20. In addition, in order to spray water onto the ground layer G around the anchor device 20, a hose may be placed along the tension member 85, and water may be sprayed through the hose from the work vessel 16.

[0037] 10, the tension member 85 is connected to the wind turbine generator 10. In this state, one end of the tension member 85 is connected to the anchor device 20, and the other end is connected to the support portion 14 of the wind turbine generator 10. Although Fig. 10 shows a state in which one anchor system 80 is connected to the wind turbine generator 10, in reality, the wind turbine generator 10 is moored to the ground layer G by a plurality of anchor systems 80 (e.g., three or more).

[0038] In the deployed state, anchoring device 20 has the largest projected area when viewed from the opposite side of tensioning member 85 (downward in Figures 4 and 9). Therefore, when tensioning member 85 is tensioned in Figures 4, 9, and 10, anchoring device 20 generates a large gripping force.

[0039] The anchor device 20 of this embodiment comprises an axial member 22 that extends along the central axis A and to which a tension member 85 is attached, and a first plate member 30 and a second plate member 40 that are configured to be rotatable relative to each other around the central axis A, wherein the first plate member 30 has a first rear end portion 31 that is farthest from the central axis A in the direction in which the first plate member 30 extends and in a direction perpendicular to the central axis A, and the second plate member 40 has a second rear end portion 41 that is farthest from the central axis A in the direction in which the second plate member 40 extends and in a direction perpendicular to the central axis A, and is configured to be changeable from a folded state in which the first rear end portion 31 and the second rear end portion 41 are close to each other, to an unfolded state in which the first rear end portion 31 and the second rear end portion 41 are separated from each other.

[0040] The anchoring system 80 of this embodiment includes the anchoring device 20 described above and a tension member 85 attached to the shaft member 22 .

[0041] The method for installing the anchor system 80 of this embodiment includes the steps of placing the anchor device 20 of the anchor system 80 in a folded state within the ground layer G, and pulling the tension member 85 to change the anchor device 20 from the folded state to the unfolded state.

[0042] According to the anchor device 20, anchor system 80, and installation method of the anchor system 80, the anchor device 20 can be inserted into the ground layer G in a folded state in which the projected area when viewed from below is smallest. This makes it possible to significantly reduce the resistance force that the anchor device 20 receives from the ground layer G. Therefore, the anchor device 20 can be placed in the ground layer G without using a large vessel or large construction machine. Furthermore, in the unfolded state, the projected area of ​​the anchor device 20 is largest when viewed from the opposite direction of the tension member 85. Therefore, when the tension member 85 is pulled in the unfolded state, the anchor device 20 generates a large holding force. In other words, according to the anchor device 20, anchor system 80, and installation method of the anchor system 80, the anchor device 20 can be easily placed in the ground layer G and can exert a large holding force after installation.

[0043] Various modifications can be made to the above-described embodiment. Modifications of the above-described embodiment will be described below with reference to the drawings as appropriate. In the following description and the drawings used in the following description, parts that can be configured similarly to the above-described embodiment will be designated by the same reference numerals as those used for the corresponding parts in the above-described embodiment, and duplicated descriptions will be omitted.

[0044] Fig. 11 is a side view showing a modified anchor device 20 in a folded state, and Fig. 12 is a side view showing the anchor device 20 in an unfolded state. Note that the tension member 85 is not shown in Fig. 11.

[0045] In the anchor device 20 of this modified example, the first outer surface 37 of the first plate member 30 includes a first inclined outer surface 38. The first inclined outer surface 38 is a surface that approaches the second plate member 40 as it approaches the shaft member 22 in the folded state. Furthermore, the second outer surface 47 of the second plate member 40 includes a second inclined outer surface 48. The second inclined outer surface 48 is a surface that approaches the first plate member 30 as it approaches the shaft member 22 in the folded state. In particular, the anchor device 20 of this modified example includes the first inclined outer surface 38 and the second inclined outer surface 48.

[0046] Because the anchor device 20 has the first inclined outer surface 38 and / or the second inclined outer surface 48, the anchor device 20 has an overall tapered shape. Specifically, in the side view shown in FIG. 11 , the width (thickness) of the anchor device 20 decreases toward the shaft member 22. This reduces the resistance force that the anchor device 20 receives from the ground layer G when inserting the anchor device 20 into the ground layer G. Furthermore, because the first rear end portion 31 and the second rear end portion 41 are configured to be wide, when a tensile force is applied to the anchor device 20, although the resistance force that the anchor device 20 receives from the ground layer G increases, the rear end portions 31, 41 can more easily capture the soil and sand that make up the ground layer G, which is expected to facilitate deployment.

[0047] The angle between the inner surface 35 and the inclined outer surface 38 and the angle between the inner surface 45 and the inclined outer surface 48 are respectively defined as θ ２ The angle θ ２The angle θ may be, for example, 5 degrees or more and 30 degrees or less. ２ is measured in a plane perpendicular to the central axis A. Also, the angle θ ２ is the angle formed within the plate members 30, 40 of the two angles formed between the inner surfaces 35, 45 and the inclined outer surfaces 38, 48.

[0048] In the anchor device 20 of this modified example, the first plate member 30 has a first outer surface 37 that faces away from the second plate member 40 in the folded state, the second plate member 40 has a second outer surface 47 that faces away from the first plate member 30 in the folded state, the first outer surface 37 includes a first inclined outer surface 38 that approaches the second plate member 40 as it approaches the axial member 22 in the folded state, and the second outer surface 47 includes a second inclined outer surface 48 that approaches the first plate member 30 as it approaches the axial member 22 in the folded state.

[0049] With such an anchor device 20, it is possible to reduce the resistance force that the anchor device 20 receives from the ground layer G when inserting the anchor device 20 into the ground layer G. Furthermore, although the resistance force that the anchor device 20 receives from the ground layer G increases when a tensile force is applied to the anchor device 20, it is expected to have the effect of making it easier to deploy. Therefore, it is possible to more easily place the anchor device 20 in the ground layer G without using a large ship or large construction machine.

[0050] Fig. 13 is a side view showing another modified example of anchor device 20 in a folded state, and Fig. 14 is a side view showing anchor device 20 in an unfolded state. Note that tension member 85 is not shown in Fig. 13.

[0051] The anchor device 20 of this modified example includes a first inclined end surface 33 of the first plate member 30. The first inclined end surface 33 is a surface that approaches the second plate member 40 as it approaches the shaft member 22 in the folded state. Furthermore, the second rear end portion 41 of the second plate member 40 includes a second inclined end surface 43. The second inclined end surface 43 is a surface that approaches the first plate member 30 as it approaches the shaft member 22 in the folded state. In particular, the anchor device 20 of this modified example includes the first inclined end surface 33 and the second inclined end surface 43.

[0052] In this modification, the shaft member 22 is pulled via the tension member 85, causing the soil and sand that make up the ground layer G to flow along the first inclined end face 33 and / or the second inclined end face 43 into the space between the first inner face 35 and the second inner face 45. Therefore, the anchor device 20 can be deployed with a small amount of displacement.

[0053] Angle θ between the inner surface 35, 45 and the inclined end surface 33, 43 ３ The angle θ may be, for example, 45 degrees or more and 90 degrees or less. ３ is measured in a plane perpendicular to the central axis A. Also, the angle θ ３ is the angle formed on the outside of the plate member 30, 40 of the two angles formed between the inner surface 35, 45 and the inclined end surface 33, 43.

[0054] In this modified anchor device 20, the first rear end portion 31 includes a first inclined end face 33 that approaches the second plate member 40 as it approaches the shaft member 22 in the folded state, and the second rear end portion 41 includes a second inclined end face 43 that approaches the first plate member 30 as it approaches the shaft member 22 in the folded state.

[0055] According to such an anchor device 20, when the anchor device 20 is deployed, the shaft member 22 is pulled via the tension member 85, causing the soil and sand that make up the ground layer G to flow along the first inclined end face 33 and / or the second inclined end face 43 into the space between the first inner face 35 and the second inner face 45. Therefore, the anchor device 20 can be easily deployed.

[0056] In another modified example (not shown), the first plate member 30 and the second plate member 40 may have a shape in which the intermediate portion thereof is bent toward the first outer surface 37 and the second outer surface 47, respectively, in other words, in the direction in which the first rear end portion 31 and the second rear end portion 41 are separated when in the folded state. In such a shape, when the tension member 85 is pulled, soil and sand constituting the ground layer G enters the space between the first inner surface 35 and the second inner surface 45 of the bent portion. Therefore, the anchor device 20 can be deployed with a small amount of displacement.

[0057] Fig. 15 is a side view showing yet another modified example of anchor device 20 in a folded state, Fig. 16 is a side view showing anchor device 20 in a state in the middle of being deployed, and Fig. 17 is a side view showing anchor device 20 in the deployed state. Note that tension member 85 is not shown in Fig. 15.

[0058] The anchor device 20 of this modified example has a restricting portion 70. The restricting portion 70 restricts the angle between the first plate member 30 and the second plate member 40 to a predetermined angle or less in the deployed state.

[0059] 15 to 17 , the restricting portion 70 has a contact portion 72. The contact portion 72 is a portion that comes into contact with the first plate member 30 and the second plate member 40 when the angle between them becomes a predetermined angle. The contact portion 72 includes a protrusion 39 and a recess 49. In the illustrated example, the first plate member 30 has the protrusion 39, and the second plate member 40 has the recess 49. However, this is not limiting, and the first plate member 30 may have the recess 49, and the second plate member 40 may have the protrusion 39.

[0060] 15 to 17, when anchoring device 20 is in the deployed state, protrusion 39 enters recess 49, and protrusion 39 and recess 49 come into contact with each other. In this state, angle θ between first inner surface 35 and second inner surface 45 １ The convex portion 39 and the concave portion 49 are configured so that the angle between the first plate member 30 and the second plate member 40 becomes a predetermined angle when the convex portion 39 and the concave portion 49 come into contact with each other. This restricts the angle between the first plate member 30 and the second plate member 40 to be equal to or less than the predetermined angle.

[0061] The anchor device 20 of this modified example has a restricting portion 70 that restricts the angle between the first plate member 30 and the second plate member 40 to a predetermined angle or less in the deployed state.

[0062] Furthermore, in the anchor device 20 of this modified example, the restricting portion 70 includes a contact portion 72 that comes into contact with the first plate member 30 and the second plate member 40 when the angle between them reaches a predetermined angle.

[0063] With such an anchor device 20, the angle between the first plate member 30 and the second plate member 40 can be restricted to a predetermined angle or less. This allows the angle between the first plate member 30 and the second plate member 40 to be regulated so that the anchor device 20 exerts a large holding force when installed in the ground layer G.

[0064] FIG. 18 is a side view showing yet another modified example of anchor device 20 in a deployed state.

[0065] 18, the restricting portion 70 includes a connecting member 74. The connecting member 74 connects the first plate member 30 and the second plate member 40 to each other. The length of the connecting member 74 is determined by the angle θ between the first inner surface 35 and the second inner surface 45 when the connecting member 74 is fully extended (tensioned). １ The angle between the first plate member 30 and the second plate member 40 in the deployed state (the angle θ １ The connecting member 74 is not particularly limited, but may be formed of, for example, a wire, a chain, a rod, or the like.

[0066] In the anchor device 20 of this modified example, the restricting portion 70 includes a connecting member 74 that connects the first plate member 30 and the second plate member 40 to each other.

[0067] This anchor device 20 also makes it possible to restrict the angle between the first plate member 30 and the second plate member 40 to a predetermined angle or less. This allows the angle between the first plate member 30 and the second plate member 40 to be regulated so that the anchor device 20 exerts a large holding force when the anchor device 20 is installed in the ground layer G.

[0068] Fig. 19 is a side view showing yet another modified example of anchor device 20 in a folded state, Fig. 20 is a side view showing anchor device 20 in a state in the middle of deployment, Fig. 21 is a side view showing anchor device 20 in a state in the middle of deployment, and Fig. 22 is a side view showing anchor device 20 in a deployed state. Note that tension member 85 is omitted from Figs. 19 and 20.

[0069] In the example shown in Figures 19 to 22, the anchor device 20 includes a third plate member 50 and a fourth plate member 60 in addition to the first plate member 30 and the second plate member 40. The third plate member 50 is connected to the first plate member 30 and configured to be rotatable relative to the first plate member 30. In particular, the third plate member 50 is configured to be rotatable relative to the first plate member 30 about a rotation axis 52. The rotation axis 52 has a central axis extending parallel to the central axis A. The rotation axis 52 is the axis of rotation about which the first plate member 30 and the third plate member 50 rotate relative to each other. The fourth plate member 60 is connected to the second plate member 40 and configured to be rotatable relative to the second plate member 40. In particular, the fourth plate member 60 is configured to be rotatable relative to the second plate member 40 about a rotation axis 62. The rotation axis 62 has a central axis extending parallel to the central axis A. The rotation axis 62 is the axis of relative rotation between the second plate member 40 and the fourth plate member 60 .

[0070] 19 to 22, the length of the third plate member 50 in the direction perpendicular to the central axis A in the folded state is shorter than the length of the first plate member 30. Furthermore, the length of the fourth plate member 60 in the direction perpendicular to the central axis A in the folded state is shorter than the length of the second plate member 40. The rotation angle of the third plate member 50 relative to the first plate member 30 may be restricted to within a predetermined angle. Furthermore, the rotation angle of the fourth plate member 60 relative to the second plate member 40 may be restricted to within a predetermined angle.

[0071] In this modification, when the tension member 85 is pulled in the state shown in Fig. 19 , soil and sand constituting the ground layer G enter the space between the third plate member 50 and the fourth plate member 60. As a result, as shown in Fig. 20 , the third plate member 50 rotates around the rotation axis 52, and the fourth plate member 60 rotates around the rotation axis 62. Specifically, the third plate member 50 rotates in the opposite direction to the second plate member 40, and the fourth plate member 60 rotates in the opposite direction to the first plate member 30. At this time, because the lengths of the third plate member 50 and the fourth plate member 60 are shorter than the lengths of the first plate member 30 and the second plate member 40, the third plate member 50 and the fourth plate member 60 rotate relative to the first plate member 30 and the second plate member 40 with a relatively small force. In this modified example, in the state shown in FIG. 20, the third plate member 50 and the fourth plate member 60 are configured not to rotate any further relative to the first plate member 30 and the second plate member 40.

[0072] 20, when the tension member 85 is further pulled, the soil and sand that make up the ground layer G moves along the inner surfaces of the third plate member 50 and the fourth plate member 60 toward the space between the first plate member 30 and the second plate member 40. As a result, the soil and sand that make up the ground layer G enters the space between the first plate member 30 and the second plate member 40, and the anchor device 20 deploys as shown in Fig. 21. When the tension member 85 is further pulled, the anchor device 20 deploys as shown in Fig. 22.

[0073] The anchor device 20 of this modified example further includes a third plate member 50 connected to the first plate member 30 and configured to be rotatable relative to the first plate member 30, and a fourth plate member 60 connected to the second plate member 40 and configured to be rotatable relative to the second plate member 40.

[0074] With this anchor device 20, when the tension member 85 is pulled, a relatively small force causes the third plate member 50 and the fourth plate member 60 to rotate relative to the first plate member 30 and the second plate member 40. This allows the soil and sand that make up the ground layer G to easily enter the space between the third plate member 50 and the fourth plate member 60. The soil and sand that has entered the space between the third plate member 50 and the fourth plate member 60 is guided by the inner surfaces of the third plate member 50 and the fourth plate member 60 and enters the space between the first plate member 30 and the second plate member 40. This makes it possible to easily deploy the anchor device 20.

[0075] The anchor device 20 of this modified example may be provided with the first inclined end surface 33 and / or the second inclined end surface 43. The anchor device 20 of this modified example may also be provided with the first inclined outer surface 38 and / or the second inclined outer surface 48.

[0076] Next, an experiment conducted by the present inventors will be described with reference to Figures 23 to 25. Figure 23 is a side view showing anchor device 20 used in this experiment in a folded state, and Figure 24 is a side view showing anchor device 20 in a state in the middle of being deployed.

[0077] The anchor device 20 used in this experiment has a first inclined end surface 33 and a second inclined end surface 43. Meanwhile, the first inner surface 35 and the first outer surface 37 of the first plate member 30 are parallel to each other. The second inner surface 45 and the second outer surface 47 of the second plate member 40 are parallel to each other. The total length L (see FIG. 23 ) of the first plate member 30 and the second plate member 40 along a direction perpendicular to the central axis A was 40 mm. The thickness T of the first plate member 30 and the second plate member 40 was 3 mm. The depth of the first plate member 30 and the second plate member 40 in the direction parallel to the central axis A (the direction perpendicular to the plane of the paper in FIG. 23 ) was 40 mm.

[0078] As shown in Figure 24, the angle between the first inner surface 35 and the second inner surface 45 during deployment is defined as θ. Also, in Figure 24, the angle between the central axis of the tension member 85 and the first inner surface 35 is defined as θ. Ｌ and the angle between the central axis of the tension member 85 and the second inner surface 45 is θ Ｒ The angles θ and θ Ｌ and θＲ are all measured in a plane perpendicular to the central axis A.

[0079] A large number of quartz particles were mixed with a fluid having the same refractive index as the quartz particles to create a transparent ground. This transparent ground simulates a ground layer G and is configured so that the inside of the ground can be seen from the outside. The anchor device 20 shown in Figures 23 and 24 was buried in this ground with the shaft member 22 positioned downward. A tension member 85 extending vertically was attached to each end of the shaft member 22. The anchor device 20 was pulled upward via the tension member 85 while a camera was used to photograph the anchor device 20 from the direction in which the shaft member 22 extended. The amount of pulling out of the anchor device 20 (mm) and the deployment angles θ, θ of the anchor device 20 at this time were measured. Ｌ , θ Ｒ The relationship between the deployment angles θ and θ is shown in Figure 25. The pull-out amount (mm) was measured by measuring the vertical displacement of the member connected to the tension member 85 using a laser displacement meter. Ｌ , θ Ｒ (degrees) was measured from an image taken by a camera.

[0080] From the experimental results shown in FIG. 25, as the withdrawal amount increases, the deployment angles θ and θ Ｌ , θ Ｒ In other words, it was confirmed that the anchor device 20 can be properly deployed from the folded state simply by pulling the anchor device 20 upward via the tension member 85. Also, the angle θ Ｌ and angle θ Ｒ were approximately the same size throughout the entire process of pulling out the anchor device 20. This also confirmed that by configuring the first plate member 30 and the second plate member 40 to have a symmetrical shape and pulling out the anchor device 20 in the same direction as the extension direction of the first plate member 30 and the second plate member 40 in the folded state, the first plate member 30 and the second plate member 40 can be unfolded approximately symmetrically.

[0081] Next, another experiment conducted by the present inventors will be described with reference to Figures 26 to 28. The anchor device 20 used in this experiment is the anchor device 20 described with reference to Figures 11 to 14. θ is the deployment angle between the first inner surface 35 and the second inner surface 45 during deployment. θ ２ is the angle between the inner surface 35 and the inclined outer surface 38, and the angle between the inner surface 45 and the inclined outer surface 48. ３ is the angle between the inner surface 35, 45 and the inclined end surface 33, 43. Therefore, the angle θ ３ = 90 degrees, the anchoring device 20 is similar to the anchoring device 20 described with reference to Figures 11 and 12. ３ 26 shows the angle θ of the anchoring device 20. ２ 27 is a graph showing the relationship between the withdrawal amount S (mm) of the anchor device 20 and the deployment angle θ (degrees) when the angle θ of the anchor device 20 is changed. ２ is fixed at 20 degrees, and the angle θ ３ 28 is a graph showing the relationship between the withdrawal amount S (mm) of the anchor device 20 and the deployment angle θ (degrees) when the angle θ of the anchor device 20 is changed. ２ When the angle is fixed at 20 degrees, ３ 10 is a graph showing the relationship between the amount of pull-out S when the deployment of the anchor device 20 has converged and the amount of pull-out S when the deployment of the anchor device 20 has converged.

[0082] FIG. 26 shows the angle θ ２ is changed to 0 degrees, 5 degrees, 10 degrees, 15 degrees, and 20 degrees, and the angle θ ３ 1 shows the relationship between the withdrawal amount S (mm) of the anchor device 20 and the deployment angle θ (degrees) between the first inner surface 35 and the second inner surface 45 during deployment when the angle θ is fixed at 90 degrees. ２ and angle θ ３ From the experimental results shown in FIG. 26, the angle θ ２Except for the case where S is 0 degrees, the deployment angle θ also increases with an increase in the withdrawal amount S, and after a certain amount of withdrawal (withdrawal amount S<100 mm), it can be seen that the angle converges to an arbitrary angle. From Figure 26, it can be seen that the increase in the deployment angle θ with respect to the withdrawal increment is proportional to the angle θ ２ It can be seen that the probability of deployment (the probability that the deployment angle θ>120° when the withdrawal amount S<100 mm) also increases with the angle θ ２ In particular, the angle θ ２ It was confirmed that the anchor device 20 can be reliably deployed from the folded state to a withdrawal amount S<80 mm simply by pulling the anchor device 20 upward via the tension member 85 at angle S=20 degrees.

[0083] FIG. 27 shows the angle θ ２ is fixed at 20 degrees and the angle θ ３ 1 shows the relationship between the withdrawal amount S (mm) of the anchor device 20 and the deployment angle θ (degrees) between the first inner surface 35 and the second inner surface 45 during deployment when the angle θ is changed to 90 degrees, 80 degrees, 70 degrees, and 50 degrees. ２ and angle θ ３ Three pull-out experiments were conducted for each combination of the above. From the experimental results shown in Figure 27, it can be seen that in all cases, the deployment angle θ increases as the pull-out amount S increases, and the anchor device 20 is deployed reliably (the deployment angle θ is greater than 160 degrees when the pull-out amount S is less than 100 mm). From Figure 27, it can be seen that the final deployment angle θ is the angle θ ３ It was confirmed that the relationship between the angle of deployment θ and the increment of withdrawal is 160 degrees < θ < 180 degrees. ３ It can be seen that the tendency for this to increase with the decrease in

[0084] FIG. 28 shows the relationship between the angle θ and the increment of the withdrawal amount S when the deployment angle θ is greater than 150 degrees. ３ The withdrawal amount S when the increment of the angle θ becomes less than 1 degree / mm and the deployment converges is defined as ３ From FIG. 28, the angle θ ３It has been confirmed that by reducing the pull-out amount S, the anchor device 20 can be deployed with a smaller pull-out amount S, which leads to improved workability.

[0085] FIG. 29 is a plan view showing an example of the attachment position of tension member 85 in anchor device 20, and FIG. 30 is a side view showing anchor device 20 of FIG. 29 in a folded state.

[0086] 29 and 30 , the tension member 85 is attached to two locations on both ends of the shaft member 22. More specifically, as shown in Fig. 30 , the tension member 85 is attached to two locations on both ends of the shaft member 22 by rotating attachment members 87. One end of the tension member 85 is fixed to the corresponding attachment member 87. The attachment member 87 may be fixed to the shaft member 22 so as not to rotate about the central axis A relative to the shaft member 22. Alternatively, the attachment member 87 may be attached to the shaft member 22 so as to be rotatable about the central axis A.

[0087] Figure 31 is a plan view showing another example of the attachment position of the tension member 85 in the anchor device 20. In the example shown in Figure 31, the tension member 85 is attached to one location in the center of the shaft member 22. The tension member 85 may also be attached to the shaft member 22 via the attachment member 87 described with reference to Figure 30.

[0088] Figure 32 is a plan view showing yet another example of the attachment position of tension member 85 in the anchor device. The anchor device 20 in the example shown in Figure 32 is the anchor device 20 described with reference to Figure 18. Tension member 85 may be attached to shaft member 22 via attachment member 87 described with reference to Figure 30.

[0089] Second Embodiment Figure 33 is a diagram for explaining a second embodiment of the present invention, and is a plan view showing an example of anchor device 20 in an unfolded state. Figure 34 is a diagram showing anchor device 20 of Figure 33 in a folded state, and is a cross-sectional view corresponding to line A-A in Figure 33. Figure 35 is a diagram showing anchor device 20 of Figure 33 in an unfolded state, and is a cross-sectional view corresponding to line A-A in Figure 33. In the second embodiment, parts that can be configured similarly to the first embodiment will be given the same reference numerals as those used for the corresponding parts in the first embodiment, and duplicated explanations will be omitted.

[0090] The anchor device 20 includes a shaft member 22, a first frame member 130, a second frame member 140, a pressure-receiving member 110, and a restricting portion 70. The first frame member 130 and the second frame member 140 have a generally frame-like shape. The shaft member 22 has a cylindrical shape and extends along a central axis A. The central axis A is the axis of rotation for relative rotation of the first frame member 130 and the second frame member 140. The first frame member 130 and the second frame member 140 are each attached to the shaft member 22. The first frame member 130 and the second frame member 140 are configured to be rotatable relative to each other about the central axis A.

[0091] The first frame member 130 has a first rear end portion 131. The first rear end portion 131 is the end portion of the first frame member 130 that is farther from the central axis A. The second frame member 140 has a second rear end portion 141. The second rear end portion 141 is the end portion of the second frame member 140 that is farther from the central axis A. The anchor device 20 of this embodiment is configured to be able to change from a folded state to an unfolded state, similar to the first embodiment.

[0092] In the example shown in FIG. 34 , the first frame member 130 and the second frame member 140 each have a shape bent at the middle portion. The first frame member 130 includes a first portion 130a and a second portion 130b. The first portion 130a and the second portion 130b are fixed to each other. That is, the angle between the first portion 130a and the second portion 130b is always constant. One end of the first portion 130a is rotatably connected to the shaft member 22, and the other end of the first portion 130a is fixed to the second portion 130b. One end of the second portion 130b is fixed to the other end of the first portion 130a, and the other end of the second portion 130b is a free end.

[0093] The second frame member 140 includes a first portion 140a and a second portion 140b. The first portion 140a and the second portion 140b are fixed to each other. That is, the angle between the first portion 140a and the second portion 140b is always constant. The angle between the first portion 140a and the second portion 140b in the second frame member 140 may be the same as or different from the angle between the first portion 130a and the second portion 130b in the first frame member 130. One end of the first portion 140a is rotatably connected to the shaft member 22, and the other end of the first portion 140a is fixed to the second portion 140b. One end of the second portion 140b is fixed to the other end of the first portion 140a, and the other end of the second portion 140b is a free end.

[0094] 34 , the first portion 130a of the first frame member 130 and the first portion 140a of the second frame member 140 extend generally parallel to each other. The second portion 130b of the first frame member 130 extends in a direction oblique to the first portion 130a so as to move away from the second frame member 140 as it moves away from the shaft member 22. Furthermore, the second portion 140b of the second frame member 140 extends in a direction oblique to the first portion 140a so as to move away from the first frame member 130 as it moves away from the shaft member 22.

[0095] There are no particular limitations on the respective lengths of the first portion 130a and the second portion 130b of the first frame member 130 and the respective lengths of the first portion 140a and the second portion 140b of the second frame member 140. The length of the first portion 130a of the first frame member 130 and the length of the first portion 140a of the second frame member 140 may be the same as or different from each other. Furthermore, the length of the second portion 130b of the first frame member 130 and the length of the second portion 140b of the second frame member 140 may be the same as or different from each other.

[0096] However, the present invention is not limited to this, and the first frame member 130 and the second frame member 140 do not have to have a shape that is bent at the middle portion. For example, the first frame member 130 and the second frame member 140 may have a linear shape when viewed from a direction along the central axis A of the shaft member 22.

[0097] The first frame member 130 has a first inner surface 135 and a first outer surface 137. The first inner surface 135 is a surface that faces the second frame member 140 in the folded state. The first outer surface 137 is a surface that faces away from the second frame member 140 in the folded state. The second frame member 140 has a second inner surface 145 and a second outer surface 147. The second inner surface 145 is a surface that faces toward the first frame member 130 in the folded state. The second outer surface 147 is a surface that faces away from the first frame member 130 in the folded state. In the folded state, the first inner surface 135 and the second inner surface 145 face each other, and the first outer surface 137 and the second outer surface 147 face generally opposite each other.

[0098] Although not shown in the present embodiment, a tension member 85 is attached to the shaft member 22. The tension member 85 can be attached to the shaft member 22 in the same manner as in the example described with reference to Figures 29 to 32, for example.

[0099] The pressure-receiving member 110 is suspended across the first frame member 130 and the second frame member 140. The pressure-receiving member 110 has the function of receiving pressure acting on the anchor device 20 from the ground layer G. The pressure-receiving member 110 is fixed to the first frame member 130 and the second frame member 140 at its peripheral edge. In particular, it is preferable that the pressure-receiving member 110 be fixed to the first frame member 130 and the second frame member 140 over the entire length of its peripheral edge. In this embodiment, the pressure-receiving member 110 has a rectangular shape in a plan view. In this case, all four sides of the pressure-receiving member 110 are fixed to the first frame member 130 and the second frame member 140.

[0100] The pressure-receiving member 110 is made of a material that can withstand the pressure received from the ground layer G. Such a pressure-receiving member 110 can be made of a flexible material (flexible material) or a non-flexible material (non-flexible material). As the flexible material, for example, a sheet-like material or a mesh-like material can be used. As the non-flexible material, for example, a plate-like material can be used.

[0101] The restricting portion 70 of the present embodiment includes a connecting member 74. The connecting member 74 connects the first frame member 130 and the second frame member 140 to each other. In particular, in the present embodiment, the restricting portion 70 includes two connecting members 74.

[0102] The anchor system 80 including the anchor device 20 of this embodiment is installed in the same manner as the installation method described with reference to FIGS. 6 to 10 in the first embodiment.

[0103] Figure 34 shows the anchor device 20 in a folded state. In the example shown in Figure 34, in the folded state, the first inner surface 135 and the second inner surface 145 face each other and are close to each other. At this time, the pressure-receiving member 110 is folded between the first inner surface 135 and the second inner surface 145. In the folded state, the anchor device 20 has the smallest projected area when viewed from below (from below in Figure 34).

[0104] As in the first embodiment, the anchor device 20 is placed in the ground layer G in the folded state. Next, the tensioning member 85 is pulled by the work boat 16. This causes the anchor device 20 to deploy. As the tensioning member 85 is pulled, the shaft member 22 is pulled by the tensioning member 85. At this time, soil and sand that make up the ground layer G enters the space between the folded pressure-receiving members 110, and the first frame member 130 and the second plate member 140 move away from each other.

[0105] When the tension member 85 is further pulled, the connecting member 74 is fully stretched, and the angle θ between the first inner surface 135 and the second inner surface 145 １ reaches a predetermined angle (see Figure 35). At this time, the anchor device 20 is in an expanded state. That is, the anchor device 20 is in its most expanded state. At this time, the tension member 85 is pulled, and the pressure that the anchor device 20 receives from the ground layer G acts on the pressure-receiving member 110. That is, the pressure-receiving member 110 receives the pressure that acts on the anchor device 20 from the ground layer G.

[0106] 34, when the first frame member 130 and the second frame member 140 each have a shape bent at the middle portion, pulling the tension member 85 causes the soil and sand that make up the ground layer G to enter the space between the first inner surface 135 and the second inner surface 145 along the second portion 130b of the first frame member 130 and / or the second portion 140b of the second frame member 140. Therefore, the anchor device 20 can be deployed with a small amount of displacement.

[0107] In addition, the angle θ between the first inner surface 135 and the second inner surface 145 in the deployed state １ is θ in the first embodiment １ may be set similarly.

[0108] The anchor device 20 of this embodiment comprises an axial member 22 that extends along the central axis A and to which the tension member 85 is attached, a first frame member 130 and a second frame member 140 that are configured to be rotatable relative to each other around the central axis A, and a pressure-receiving member 110 that is suspended between the first frame member 130 and the second frame member 140, wherein the first frame member 130 has a first rear end portion 131 that is furthest from the central axis A in a direction perpendicular to the central axis A, and the second frame member 140 has a second rear end portion 141 that is furthest from the central axis A in a direction perpendicular to the central axis A, and is configured to be changeable from a folded state in which the first rear end portion 131 and the second rear end portion 141 are close to each other, to an unfolded state in which the first rear end portion 131 and the second rear end portion 141 are separated from each other.

[0109] With this anchor device 20, too, the anchor device 20 can be inserted into the ground layer G in the folded state, which has the smallest projected area when viewed from below. This makes it possible to significantly reduce the resistance force that the anchor device 20 receives from the ground layer G. Therefore, the anchor device 20 can be placed in the ground layer G without using a large vessel or large construction machine. Furthermore, in the unfolded state, the anchor device 20 has the largest projected area when viewed from the opposite direction of the tension member 85. Therefore, when the tension member 85 is pulled in the unfolded state, the anchor device 20 generates a large holding force. In other words, with this anchor device 20, the anchor device 20 can be easily placed in the ground layer G and can exert a large holding force after installation.

[0110] The anchor device 20 of this embodiment has a restricting portion 70 that restricts the angle between the first frame member 130 and the second frame member 140 to a predetermined angle or less in the deployed state.

[0111] In the anchor device 20 of this embodiment, the restricting portion 70 includes a connecting member 74 that connects the first frame member 130 and the second frame member 140 to each other.

[0112] According to such an anchor device 20, the angle between the first frame member 130 and the second frame member 140 can be restricted to a predetermined angle or less. As a result, when the anchor device 20 is installed in the ground layer G, the angle between the first frame member 130 and the second frame member 140 can be regulated so that the anchor device 20 exerts a large holding force.

[0113] Figure 36 is a plan view showing another example of anchoring device 20 of the second embodiment in an unfolded state. Figure 37 is a view showing anchoring device 20 of Figure 36 in a folded state, and is a cross-sectional view corresponding to line B-B in Figure 36. Figure 38 is a view showing anchoring device 20 of Figure 36 in an unfolded state, and is a cross-sectional view corresponding to line B-B in Figure 36.

[0114] 36 to 38, the anchor device 20 further includes a third frame member 150 and a fourth frame member 160. The pressure-receiving member 110 spans across the first frame member 130, the second frame member 140, the third frame member 150, and the fourth frame member 160.

[0115] The third frame member 150 is connected to the first frame member 130 and is configured to be rotatable relative to the first frame member 130. In particular, the third frame member 150 is configured to be rotatable relative to the first frame member 130 about a rotation axis 152. The rotation axis 152 has a central axis that extends parallel to the central axis A. The rotation axis 152 is the axis of relative rotation between the first frame member 130 and the third frame member 150.

[0116] The fourth frame member 160 is connected to the second frame member 140 and is configured to be rotatable relative to the second frame member 140. In particular, the fourth frame member 160 is configured to be rotatable relative to the second frame member 140 about a rotation axis 162. The rotation axis 162 has a central axis that extends parallel to the central axis A. The rotation axis 162 is the axis of relative rotation between the second frame member 140 and the fourth frame member 160.

[0117] In the example shown in Figures 37 and 38, the third frame member 150 has a tapered shape in which its thickness decreases with increasing distance from the rotation shaft 152. Furthermore, the fourth frame member 160 has a tapered shape in which its thickness decreases with increasing distance from the rotation shaft 162. In particular, in the folded state shown in Figure 37, the inner surface 151 of the third frame member 150 extends in an inclined direction so as to move away from the fourth frame member 160 with increasing distance from the rotation shaft 152. Furthermore, in the folded state, the inner surface 161 of the fourth frame member 160 extends in an inclined direction so as to move away from the third frame member 150 with increasing distance from the rotation shaft 162. However, this is not limited thereto, and the third frame member 150 may have a constant thickness regardless of the distance from the rotation shaft 152. Furthermore, the fourth frame member 160 may have a constant thickness regardless of the distance from the rotation shaft 162.

[0118] 36 to 38, the length of the third frame member 150 along the direction perpendicular to the central axis A in the folded state is shorter than the length of the first frame member 130. Furthermore, the length of the fourth frame member 160 along the direction perpendicular to the central axis A in the folded state is shorter than the length of the second frame member 140. The rotation angle of the third frame member 150 relative to the first frame member 130 may be restricted to within a predetermined angle. Furthermore, the rotation angle of the fourth frame member 160 relative to the second frame member 140 may be restricted to within a predetermined angle.

[0119] There are no particular limitations on the lengths of the first frame member 130, the second frame member 140, the third frame member 150, and the fourth frame member 160. The lengths of the first frame member 130 and the second frame member 140 may be the same as or different from each other. Furthermore, the lengths of the third frame member 150 and the fourth frame member 160 may be the same as or different from each other.

[0120] The third frame member 150 and the fourth frame member 160 of this embodiment function in the same manner as the third plate member 50 and the fourth plate member 60 of the first embodiment, and therefore detailed description thereof will be omitted.

[0121] The anchor device 20 of this modified example further includes a third frame member 150 connected to the first frame member 130 and configured to be rotatable relative to the first frame member 130, and a fourth frame member 160 connected to the second frame member 140 and configured to be rotatable relative to the second frame member 140.

[0122] With this anchor device 20, when the tension member 85 is pulled, a relatively small force causes the third frame member 150 and the fourth frame member 160 to rotate relative to the first frame member 130 and the second frame member 140. This allows the soil and sand that make up the ground layer G to easily enter the space between the folded pressure-receiving member 110. The soil and sand that enters the space between the third frame member 150 and the fourth frame member 160 is guided by the portions of the pressure-receiving member 110 that overlap with the third frame member 150 and the fourth frame member 160, and enters the space between the portions that overlap with the first frame member 130 and the second frame member 140. This makes it possible to easily deploy the anchor device 20.

[0123] 37 , in the folded state, if the inner surface 151 of the third frame member 150 and / or the inner surface 161 of the fourth frame member 160 extend in an inclined direction, the pulling of the tension member 85 causes soil and sand that make up the ground layer G to enter the space between the first inner surface 135 and the second inner surface 145 of the inner surface 151 of the third frame member 150 and / or the inner surface 161 of the fourth frame member 160. Therefore, the anchor device 20 can be deployed even more easily.

[0124] Figure 39 is a plan view showing yet another example of anchoring device 20 of the second embodiment in an unfolded state. Figure 40 is a view showing anchoring device 20 of Figure 39 in a folded state, and is a cross-sectional view corresponding to line CC in Figure 39. Figure 41 is a view showing anchoring device 20 of Figure 39 in an unfolded state, and is a cross-sectional view corresponding to line CC in Figure 39.

[0125] 33 to 35 in that the pressure-receiving member 110 is configured from a combination of a flexible member and a non-flexible member. In particular, in this modification, a portion of the pressure-receiving member 110 that is close to the shaft member 22 is formed from a flexible member, and a portion that is separated from the shaft member 22 is formed from a non-flexible member.

[0126] With this anchor device 20, too, the anchor device 20 can be inserted into the ground layer G in the folded state, which has the smallest projected area when viewed from below. This makes it possible to significantly reduce the resistance force that the anchor device 20 receives from the ground layer G. Therefore, the anchor device 20 can be placed in the ground layer G without using a large vessel or large construction machine. Furthermore, in the unfolded state, the anchor device 20 has the largest projected area when viewed from the opposite direction of the tension member 85. Therefore, when the tension member 85 is pulled in the unfolded state, the anchor device 20 generates a large holding force. In other words, with this anchor device 20, the anchor device 20 can be easily placed in the ground layer G and can exert a large holding force after installation.

[0127] FIG. 42 is a top view showing an example of the arrangement of the wind turbine generator 10 and the anchor system 80.

[0128] 42, a plurality of wind turbine generators 10 and a plurality of anchor devices 20 are arranged. One wind turbine generator 10 is fixed to the ground layer G by a plurality of anchor devices 20. Furthermore, one anchor device 20 fixes a plurality of wind turbine generators 10 to the ground layer G.

[0129] Many conventional anchor devices are tension-installed in a manner that is horizontally offset from the point where the anchor device is embedded in the ground layer G. Therefore, there are cases where the anchor device is unable to provide sufficient anchoring function against tensile forces from multiple directions. In contrast, in the present invention, the anchor device 20 is deployed by pulling the tension member 85 at the point where the anchor device 20 is embedded in the ground layer G, and the pressure-receiving surface of the anchor device 20 extends approximately perpendicular to the extension direction of the tension member 85. This makes it possible to install the anchor device 20 in any position while ensuring that the pressure-receiving surface of the anchor device 20 extends approximately perpendicular to the extension direction of the tension member 85 when the tension member 85 is pulled. Therefore, the anchor device 20 of the present invention can be highly effective against tensile forces from multiple directions.

Claims

1. An anchor device comprising: an axis member extending along a central axis and having a tension member attached thereto; and a first plate member and a second plate member configured to be rotatable relative to each other about the central axis, wherein the first plate member has a first rear end that is furthest from the central axis in the direction in which the first plate member extends and in a direction perpendicular to the central axis, and the second plate member has a second rear end that is furthest from the central axis in the direction in which the second plate member extends and in a direction perpendicular to the central axis, and configured to be changeable from a folded state in which the first rear end and the second rear end are close to each other, to an unfolded state in which the first rear end and the second rear end are separated.

2. An anchor device as described in claim 1, wherein the first plate member has a first outer surface facing away from the second plate member in the folded state, the second plate member has a second outer surface facing away from the first plate member in the folded state, the first outer surface includes a first inclined outer surface approaching the second plate member as it approaches the axis member in the folded state, and the second outer surface includes a second inclined outer surface approaching the first plate member as it approaches the axis member in the folded state.

3. An anchor device as described in claim 1, wherein the first rear end includes a first inclined end surface that approaches the second plate member as it approaches the shaft member in the folded state, and the second rear end includes a second inclined end surface that approaches the first plate member as it approaches the shaft member in the folded state.

4. The anchor device of claim 1, further comprising: a third plate member connected to the first plate member and configured to be rotatable relative to the first plate member; and a fourth plate member connected to the second plate member and configured to be rotatable relative to the second plate member.

5. The anchor device according to claim 1, further comprising a restricting portion that restricts the angle between said first plate member and said second plate member to a predetermined angle or less in said deployed state.

6. An anchor device according to claim 5, wherein the regulating portion includes a contact portion that comes into contact with the first plate member and the second plate member when the angle between them becomes the predetermined angle.

7. The anchor device according to claim 5, wherein the restricting portion includes a connecting member that connects the first plate member and the second plate member to each other.

8. An anchor device comprising: an axis member extending along a central axis and to which a tension member is attached; first and second frame members configured to be rotatable relative to each other about the central axis; and a pressure-receiving member suspended between the first and second frame members, wherein the first frame member has a first rear end portion that is furthest from the central axis in a direction perpendicular to the central axis; and the second frame member has a second rear end portion that is furthest from the central axis in a direction perpendicular to the central axis, and configured to be changeable from a folded state in which the first and second rear end portions are close to each other, to an unfolded state in which the first and second rear end portions are separated.

9. The anchor device of claim 8, further comprising: a third frame member connected to the first frame member and configured to be rotatable relative to the first frame member; and a fourth frame member connected to the second frame member and configured to be rotatable relative to the second frame member.

10. The anchor device according to claim 8, further comprising a restricting portion that restricts the angle between said first frame member and said second frame member to a predetermined angle or less in said deployed state.

11. The anchor device according to claim 10, wherein the restricting portion includes a connecting member that connects the first frame member and the second frame member to each other.

12. An anchor system comprising an anchor device according to any one of claims 1 to 11 and a tension member attached to the shaft member.

13. A method of installing an anchor system comprising the steps of: placing the anchor device of the anchor system according to claim 12 in the folded state within a ground layer; and changing the anchor device from the folded state to the deployed state by tensioning the tension member.