Mooring method and mooring line replacement method for offshore floating structure

Abstract

The present invention relates to a mooring method for an offshore floating structure for forming an offshore floating structure mooring system including the offshore floating structure, an anchor body, and a mooring line. The anchor body includes an anchor concrete structure having: a mooring line pass-through passage for passing the mooring line through formed on the inside; and a compressed air chamber that is closed on the top and sides. The mooring line is supported in a middle portion by the anchor body while passing through the mooring line pass-through passage, and both ends of the mooring line are connected to the offshore floating structure. Accordingly, the coupling force between the anchor concrete structure and the mooring line can be increased, and underwater work related to installation and replacement of the mooring line becomes unnecessary.

Description

Mooring methods and mooring line replacement methods for offshore floating structures

[0001] The present invention relates to a mooring method for mooring various types of marine floating structures floating on the sea surface or in seawater, and a method for replacing mooring lines, and more particularly, to a technology using a concrete structure for an anchor and a mooring line connected thereto.

[0002] Various types of floating marine structures are known, floating on the sea surface or in the seawater. Floating foundations for floating offshore wind power are a prime example.

[0003] Such floating marine structures can be moored by being connected to an anchor body fixed to the seabed by mooring lines.

[0004] As a type of anchor for marine floating structures, it can be divided into gravity anchor, drag-embedment anchor, and suction anchor.

[0005] Gravity anchors maintain floating marine structures in a fixed position through friction between the anchor's weight and the seabed. Gravity anchors have the advantage of being the lowest cost.

[0006] A drag-embedment anchor is one in which the anchor penetrates the seabed and has horizontal support in the main installation direction.

[0007] Other known devices include suction anchors.

[0008] Meanwhile, offshore floating structures utilize various types of mooring systems.

[0009] For example, SPAR type marine floating structures use taut mooring or semi-taut mooring, and TLP type marine floating structures use TLP mooring using tensioned legs.

[0010] The TLP mooring method is a method of mooring a buoyant marine floating structure in the sea by applying strong tensile force to vertical mooring lines called 'tendons'. Compared to the typical taut mooring or semi-taut mooring, it has the advantage of being able to stably maintain the marine floating structure even in rough sea conditions.

[0011] In the case of the TLP mooring method, vertical tensile force is applied to the mooring line, so the drag-embedment anchor method, which is vulnerable to vertical tensile force, is not suitable.

[0012] Gravity anchors have the advantage of being able to withstand vertical tensile forces and are very economical compared to other methods.

[0013] However, as gravity anchors become larger, the difficulty of manufacturing and installation increases significantly.

[0014] Meanwhile, as gravity anchors become larger, the problem of how to connect the anchor and mooring line becomes a problem.

[0015] As a technology related to this, Korean Patent No. 10-1572938, “Gravity mooring device for floating structure” (registered on November 24, 2015) has been proposed.

[0016] Conventional technology involves providing a metal ring on a gravity anchor, which is a concrete structure, and connecting a mooring line to the metal ring.

[0017] However, this method has limitations in the bonding strength between the metal ring and the concrete structure, so there is a risk that the metal ring may detach from the concrete structure if excessive tensile force is applied to the metal ring.

[0018] In addition, since mooring lines are usually made of metal materials such as wire rope or chain, the thickness of the mooring line must be selected taking into account corrosion that occurs when the mooring line is in contact with seawater for a long period of time.

[0019] If a mooring line is to be used only for a short period of time when corrosion does not occur, the mooring line is designed with tensile stress in mind and can be relatively thin. However, if a mooring line is to be used for a long period of time when corrosion does occur, the mooring line must be designed with corrosion in mind along with tensile stress and must be considerably thicker.

[0020] Furthermore, even when selecting a thick mooring line, it is necessary to replace it after a certain period of use. However, this requires the diver to disconnect the old mooring line from the deep-water mooring anchor and then reconnect a new mooring line to the anchor at a greater depth. Consequently, mooring line replacement is a relatively difficult task, making it difficult to perform on a frequent basis.

[0021] As mentioned above, because the replacement of mooring lines is difficult, mooring lines are replaced at relatively long intervals, and therefore, the mooring lines must be very thick to take into account corrosion that occurs during the long interval.

[0022] Since such very thick mooring lines do not bend easily, there is a problem in that it is not easy to connect the mooring lines to mooring anchors located in deep water.

[0023] The present invention has been devised to solve the problems of the prior art as described above, and to provide a mooring system for a marine floating structure that increases the bonding strength between the anchor concrete structure and the mooring line by forming a mooring line penetration passage inside the anchor concrete structure, and also does not require underwater work related to installation and replacement of the mooring line.

[0024] In order to solve the above problems, the present invention comprises a manufacturing step of manufacturing an anchor concrete structure in which a compressed air chamber is formed in a form in which the upper surface and the side surface are closed and the lower surface is open, a mooring line penetration passage is formed inside, and a compressed air pipe for injecting or discharging compressed air into or out of the compressed air chamber is provided; a transport step of injecting compressed air into the compressed air chamber of the anchor concrete structure to float the anchor concrete structure on the water surface and transporting the anchor concrete structure to an installation site using a tugboat; after the transport step, the compressed air in the compressed air chamber of the anchor concrete structure is discharged to the outside through the compressed air pipe to sink the anchor concrete structure to the seabed, and after the anchor concrete structure has sunk to the seabed, the air and water in the compressed air chamber are discharged through the compressed air pipe to allow the side surface of the anchor concrete structure to penetrate the seabed, thereby settling the anchor concrete structure on the seabed; The present invention is characterized by comprising: a mooring line installation step of installing a mooring line to an anchor concrete structure so that the middle portion of the mooring line passes through a mooring line penetration passage of the manufactured anchor concrete structure; and a mooring step of connecting both ends of the mooring line to a marine floating structure floating on the sea surface or in seawater by buoyancy after the anchor concrete structure is settled on the seabed, thereby mooring the marine floating structure.

[0025] In the above, the mooring line penetration passage may be formed in a U shape with both ends open upward.

[0026] In the above: the anchor concrete structure includes a concrete block assembly formed by a plurality of concrete blocks, a plurality of concrete columns formed vertically to connect the plurality of concrete blocks, and a topping concrete formed on the upper part of the concrete block assembly by a casting-on-site method; a crane lifting wire rope penetration pipe formed in a U shape is provided in each of the concrete blocks; and an auxiliary connecting passage forming the mooring line penetration passage together with the crane lifting wire rope penetration pipe of the concrete block arranged at the top of the concrete block assembly may be formed in the topping concrete.

[0027] In another aspect of the present invention, there is provided a method for replacing a first mooring line of a marine floating structure mooring system constructed by the above marine floating structure mooring method with a second mooring line that is a new installation target, including a marine floating structure that floats on the sea surface or in seawater by buoyancy, an anchor body settled on the seabed, and a first mooring line connecting the marine floating structure and the anchor body to moor the marine floating structure, wherein: the anchor body includes an anchor concrete structure having a mooring line passage formed therein for passing the first mooring line; the first mooring line is supported by the anchor body while its middle portion passes through the mooring line passage, and both ends are connected to the marine floating structure; It is characterized by including a first step of connecting the other end of the second mooring line to one end of the first mooring line, a second step of pulling the other end of the first mooring line after the first step so that the first mooring line is detached from the anchor body and the middle portion of the second mooring line passes through the mooring line passage so that both ends of the second mooring line are positioned above the marine floating structure, and a third step of removing the first mooring line after the second step and connecting both ends of the second mooring line to the marine floating structure.

[0028] In another aspect of the present invention, there is provided a manufacturing step of manufacturing an anchor concrete structure in which a compressed air chamber having a closed upper surface, side surfaces, and lower surfaces is formed, a seawater distribution port is formed to connect the lower portion of the compressed air chamber with the outside, a mooring line penetration passage is formed inside, and a compressed air pipe for injecting or discharging compressed air into the compressed air chamber is provided; a transport step of injecting compressed air into the compressed air chamber of the anchor concrete structure so that the upper space of the compressed air chamber is filled with compressed air and the lower space of the compressed air chamber is filled with water that is connected to the outside water through the seawater distribution port, thereby transporting the anchor concrete structure to an installation site using a tugboat in a state of floating on the water surface; After the above-mentioned transporting step, the compressed air of the compressed air chamber is discharged to the outside through the compressed air pipe of the anchor concrete structure, thereby causing external water to flow into the compressed air chamber through the seawater distribution port and fill the compressed air chamber with water, thereby sinking the anchor concrete structure to the seabed, and after the anchor concrete structure has sunk to the seabed, a settling step is formed by filling the compressed air chamber with a filler material through the compressed air pipe to settle the anchor concrete structure on the seabed; a mooring line installation step is formed by installing a mooring line to the anchor concrete structure so that the middle portion of the mooring line passes through the mooring line penetration passage of the manufactured anchor concrete structure; and a mooring step is formed by connecting both ends of the mooring line to a marine floating structure floating on the sea surface or in seawater by buoyancy after the anchor concrete structure has been settled to the seabed, thereby mooring the marine floating structure.

[0029] In the above, it is preferable that the mooring line penetration passage be formed in a U shape with both ends open upward.

[0030] In the above: the anchor concrete structure includes a concrete block assembly formed by a plurality of concrete blocks, a plurality of concrete columns formed vertically to connect the plurality of concrete blocks, and a topping concrete formed on the upper part of the concrete block assembly by a casting-on-site method; a crane lifting wire rope penetration pipe formed in a U shape is provided in each of the concrete blocks; and an auxiliary connecting passage forming the mooring line penetration passage together with the crane lifting wire rope penetration pipe of the concrete block arranged at the top of the concrete block assembly is formed in the topping concrete; this is preferable.

[0031] In the above, prior to the anchor concrete structure settling step, a foundation ground preparation step of preparing a foundation ground on the seabed for settling the anchor concrete structure may be further included.

[0032] In another aspect of the present invention, there is provided a method for replacing a first mooring line of a marine floating structure mooring system constructed by the above marine floating structure mooring method, which comprises a marine floating structure floating on the sea surface or in seawater by buoyancy, an anchor body settled on the seabed, and a first mooring line connecting the marine floating structure and the anchor body to moor the marine floating structure, with a second mooring line to be newly installed: the anchor body includes an anchor concrete structure having a mooring line passage formed therein for passing the first mooring line; the first mooring line is supported by the anchor body while its middle portion passes through the mooring line passage, and both ends are connected to the marine floating structure; It is characterized by including a first step of connecting the other end of the second mooring line to one end of the first mooring line, a second step of pulling the other end of the first mooring line after the first step so that the first mooring line is detached from the anchor body and the middle portion of the second mooring line passes through the mooring line passage so that both ends of the second mooring line are positioned above the marine floating structure, and a third step of removing the first mooring line after the second step and connecting both ends of the second mooring line to the marine floating structure.

[0033] As described above, the present invention can dramatically increase the bonding strength between the anchor concrete structure and the mooring line by forming a passage through the anchor concrete structure.

[0034] In addition, the present invention eliminates the need for underwater work in connection with the installation and replacement of mooring lines, thereby significantly reducing the overall installation and replacement costs of mooring lines.

[0035] In addition, the present invention can be freed from corrosion problems because the replacement cost of mooring lines is reduced and the mooring lines can be replaced at frequent intervals, and as a result, only the mooring tensile force can be considered in the design of the mooring line thickness, so the mooring lines can be made thinner.

[0036] In addition, since the present invention can reduce the thickness of the mooring line, the work of connecting the mooring line to a concrete structure for anchoring or a marine floating structure becomes very easy.

[0037] Figure 1 is a perspective view of a concrete structure for an anchor according to a first embodiment of the present invention.

[0038] Figure 2 is a cross-sectional view of Figure 1;

[0039] Figure 3 is a conceptual diagram of a state in which a mooring line is installed on the concrete structure for anchoring in Figure 2.

[0040] Figure 4 is a conceptual diagram of the anchor concrete structure of Figure 3 floating on the water surface.

[0041] Figure 5 is a conceptual diagram of the anchor concrete structure of Figure 4 being installed on the seabed.

[0042] Figure 6 is a conceptual diagram of a state in which a floating marine structure is moored after Figure 5.

[0043] Figures 7 to 10 are drawings sequentially showing a method for replacing a mooring line.

[0044] Figures 11 to 14 are drawings sequentially showing the process of manufacturing a concrete structure for an anchor according to a second embodiment of the present invention.

[0045] Figure 15 is a cross-sectional view of a concrete structure for an anchor according to a third embodiment of the present invention.

[0046] Figure 16 is a conceptual diagram of the anchor concrete structure of Figure 15 floating on the water surface.

[0047] Figure 17 is a conceptual diagram of the anchor concrete structure of Figure 16 placed on the seabed.

[0048] Below, with reference to the attached drawings, embodiments of the present invention are described in detail so that those skilled in the art can easily implement them. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein. In the drawings, irrelevant parts have been omitted for clarity of description, and similar reference numerals have been assigned to similar parts throughout the specification.

[0049] Throughout the specification, whenever a part is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise stated.

[0050] Below, a method for mooring a floating marine structure according to a first embodiment of the present invention is sequentially described.

[0051] 1. Production stage

[0052] A concrete structure (110) for an anchor such as FIG. 1 and FIG. 2 is manufactured.

[0053] The concrete structure (110) for anchoring has a compressed air chamber (111) and a mooring line penetration passage (112) formed inside it.

[0054] The compressed air chamber (111) is closed at the top and sides and open at the bottom.

[0055] In this embodiment, the mooring line penetration passage (112) is formed in a U shape with both ends open toward the top.

[0056] Such a mooring line penetration passage (112) is formed with a relatively large curvature to facilitate the passage of the mooring line (200) described later.

[0057] A concrete structure (110) for anchoring is provided with a compressed air pipe (111a) for injecting or discharging compressed air into or from a compressed air chamber (111). The compressed air pipe (111a) includes a valve that can open and close the compressed air pipe (111a).

[0058] 2. Mooring line installation steps

[0059] After the concrete structure (110) for anchoring is manufactured as shown in Fig. 2, a plurality of mooring lines (200) are installed on the concrete structure (110) for anchoring as shown in Fig. 3.

[0060] Accordingly, the mooring line (200) is arranged so that its middle part passes through the mooring line penetration passage (112) of the anchor concrete structure (110), and both ends of the mooring line (200) are arranged on the outside of the anchor concrete structure (110).

[0061] In other words, the installation of the mooring line (200) is not done underwater, but in a land environment.

[0062] Meanwhile, buoys (201) are installed at both ends of the mooring line (200).

[0063] 3. Transport stage

[0064] After the mooring line (200) is installed on the anchor concrete structure (110) as shown in Fig. 3, the anchor concrete structure (110) is floated on the water surface as shown in Fig. 4.

[0065] When compressed air is injected into the compressed air chamber (111) through the compressed air pipe (111a), the air pressure inside the compressed air chamber (111) increases, and at the same time, the water level inside the compressed air chamber (111) decreases compared to the external water level, allowing the anchor concrete structure (110) to float on the water surface.

[0066] After compressed air is injected, the compressed air pipe (111a) is closed.

[0067] The concrete structure (110) for anchoring floating on the water surface is transported to the installation site using a tugboat, etc.

[0068] 4. Settlement Stage

[0069] As shown in Fig. 5, the concrete structure (110) for anchoring transported to the installation point is sunk into the seabed and secured to the seabed.

[0070] When the compressed air in the compressed air chamber (111) is discharged, the anchor concrete structure (110) sinks to the seabed.

[0071] In addition, after the anchor concrete structure (110) has sunk to the seabed, if the air and water in the compressed air chamber (111) are completely discharged through the compressed air pipe (111a), the side of the anchor concrete structure (110) can penetrate the seabed as shown in FIG. 5.

[0072] Afterwards, the compressed air pipe (111a) is kept closed.

[0073] That is, the concrete structure (110) for anchoring of the present embodiment functions as a type of suction anchor.

[0074] The concrete structure (110) for anchoring, which is settled on the seabed in this way, functions as an anchor body (100).

[0075] Meanwhile, since a mooring line (200) is already installed on the concrete structure (110) for anchoring and buoys (201) are installed on both ends of the mooring line (200), the middle part of the mooring line (200) sinks to the seabed together with the concrete structure (110) for anchoring, but both ends of the mooring line (200) are located on the water surface together with the buoys (201).

[0076] 5. Pending stage

[0077] As shown in Fig. 5, after the concrete structure (110) for anchoring is settled on the seabed, i.e., after the anchor body (100) is installed, as shown in Fig. 6, both ends of the mooring line (200) are connected to the marine floating structure (300) to moor the marine floating structure (300).

[0078] That is, each mooring line (200) is connected to the upper part of a marine floating structure (300) with both ends positioned above the water surface, and the middle part of each mooring line (200) is supported on an anchor body (100) while passing through a mooring line penetration passage (112).

[0079] In this way, a mooring system for a marine floating structure (300) is completed.

[0080] A marine floating structure (300) floats on the sea surface or in seawater due to buoyancy.

[0081] Although this embodiment illustrates a TLP mooring method utilizing tension angles, the present invention can also be applied to taut mooring or semi-taut mooring methods.

[0082] A mooring structure like this can dramatically increase the bonding strength between the anchor concrete structure (110) and the mooring line (200) by forming a mooring line penetration passage (112) inside the anchor concrete structure (110).

[0083] In addition, the installation of the mooring line (200) is performed above the water surface, eliminating the need for underwater work, thereby reducing overall costs.

[0084] 6. How to replace mooring lines

[0085] Figure 7 illustrates a first mooring line (200A) for mooring a marine floating structure and a concrete structure (110) for anchoring an anchor body (100).

[0086] The first mooring line (200A) is usually made of wire rope, etc., so it corrodes when in contact with seawater, and must be replaced after a certain period of use.

[0087] A method of replacing a mooring line is described using FIGS. 7 to 10.

[0088] For convenience of understanding, the illustrations of marine floating structures are omitted in Figures 7 to 10.

[0089] The mooring line to be removed is called the first mooring line (200A), and the mooring line to be newly installed is called the second mooring line (200B).

[0090] Step 1:

[0091] As shown in Fig. 8, the other end of the second mooring line (200B) is connected to one end of the first mooring line (200A) at the top of the marine floating structure.

[0092] In this way, the first mooring line (200A) and the second mooring line (200B) form a continuous line.

[0093] Step 2:

[0094] After the first step, the other end of the first mooring line (200A) (the end opposite to the end connected to the second mooring line (200B)) is pulled as shown in Fig. 9.

[0095] Accordingly, the first mooring line (200A) is detached from the anchor body (100), and the middle part of the second mooring line (200B) passes through the mooring line penetration passage (112) of the anchor body (100) under the guidance of the first mooring line (200A), so that both ends of the second mooring line (200B) are positioned on the upper part of the marine floating structure (300).

[0096] Step 3:

[0097] After the second step, as shown in Fig. 10, the first mooring line (200A) is removed, both ends of the second mooring line (200B) are connected to the marine floating structure (300), and the marine floating structure (300) is moored.

[0098] The aforementioned first, second, and third steps are all performed on top of the floating marine structure (300). This means that underwater work is unnecessary.

[0099] Therefore, the present invention can significantly reduce the cost of replacing mooring lines.

[0100] < Fabrication of concrete structures for anchors >

[0101] In order for the anchor concrete structure (110) to function as a gravity anchor, it is desirable for the anchor concrete structure (110) to be enlarged. For this reason, if the anchor concrete structure (110) is enlarged, the anchor concrete structure (110) may have a weight that cannot be lifted by a general crane.

[0102] Therefore, in the manufacturing method of the concrete structure (110) for anchoring, a work method that does not require crane lifting work is required, and for this purpose, two methods can be considered.

[0103] 1) Method of manufacturing in one piece

[0104] An integral anchor concrete structure (110) can be manufactured in a dry dock or a large barge. That is, after installing formwork, etc. in a dry dock or a large barge to manufacture an anchor concrete structure (110), the completed anchor concrete structure (110) can be floated.

[0105] This method is very inefficient because it requires the continuous use of a dry dock or a large barge during the construction period of the concrete structure (110) for anchoring, which significantly increases the construction cost.

[0106] 2) Manufactured in the form of a combination of concrete blocks

[0107] The inventor of the present invention has proposed a method of manufacturing a concrete block structure by combining concrete blocks underwater in accordance with Korean Patent Registration No. 10-2292821, and by applying the above-mentioned conventional technology, a concrete structure (110) for an anchor can be manufactured.

[0108] The above prior art is incorporated into this specification, and this specification mainly describes contents not suggested in the above prior art.

[0109] Figures 11 to 14 are drawings sequentially illustrating the process of manufacturing a concrete structure (110) for an anchor according to a second embodiment of the present invention.

[0110] First, a plurality of concrete blocks (11, 12) required for the production of a concrete structure (110) for anchoring on land are manufactured.

[0111] Each concrete block (11, 12) is provided with a crane lifting wire rope penetration pipe (11a, 12a) formed in a U shape.

[0112] The technology regarding a wire rope penetration pipe for crane lifting is a technology described in Korean Patent No. 10-1220995 proposed by the inventor of the present invention, and therefore, its description is omitted in this specification.

[0113] Using a wire rope penetration pipe (11a, 12a) for crane lifting, a concrete block (11, 12) manufactured on land is lifted by a crane and installed underwater, thereby forming a concrete block assembly (10).

[0114] Figures 11 and 12 illustrate a process of forming a concrete block assembly (10) using concrete blocks (11, 12).

[0115] The concrete block (11) is a concrete block placed at the bottom, and the concrete block (12) is a concrete block forming a wall.

[0116] Both concrete blocks (11, 12) have a central part that is open in the vertical direction.

[0117] A watertight packing (11b, 12b) is provided on the upper surface of each concrete block (11, 12).

[0118] A plurality of column reinforcing bar assemblies (11c) are provided in the concrete block (11) that extend vertically upward from the lower portion connected to the interior of the concrete block (11).

[0119] A concrete block (12) is formed with a column penetration hole (12c) into which a plurality of column reinforcing bar assemblies (11c) are inserted.

[0120] Additionally, an opening (11d, 12d) for a compressed air chamber is formed in the center of the concrete block (11, 12). The opening (11d, 12d) for a compressed air chamber of the concrete block (11, 12) forms a compressed air chamber (111) of the concrete structure (110) for anchoring.

[0121] When a concrete block assembly (10) is formed as shown in Fig. 12, the upper part of the column reinforcing bar assembly (11c) protrudes upwards from the concrete block (12) placed at the top.

[0122] After the concrete block assembly (10) is formed in this way, concrete is poured into the pillar penetration hole (12c) as shown in Fig. 13 to form a concrete pillar (20) extending vertically.

[0123] After forming a concrete pillar (20), as shown in Fig. 14, a concrete structure (110) for anchoring is completed by forming a top-place concrete (30) on top of a concrete block assembly (10) using a cast-in-place method. In other words, the concrete structure (30) is not a concrete block, but is formed using a formwork and cast-in-place.

[0124] At this time, the upper part of the column reinforcing bar assembly (11c) is connected to the internal reinforcing bar (31) of the top concrete (30).

[0125] When forming the top concrete (30), a compressed air pipe (111a) and an auxiliary connecting passage (32) extending in the vertical direction are formed.

[0126] The auxiliary connecting passage (32) is formed to communicate with the crane lifting wire rope penetration pipe (12a) of the concrete block (12) placed at the top of the concrete block assembly (10), thereby forming a mooring line penetration pipe (112) together with the crane lifting wire rope penetration pipe (12a).

[0127] That is, the mooring line penetration passage (112) is formed when the crane lifting wire rope penetration pipe (12a) of the concrete block (12) and the auxiliary connecting passage (32) of the on-site poured concrete (30) are connected to each other.

[0128] In order to form an auxiliary connecting passage (32), a vertical pipe (32a) extending vertically is provided on the lower part of the upper concrete (30), and a concrete protection device (32b) having a trumpet shape with a top-down and bottom-up angle is provided on the upper part of the upper concrete (30).

[0129] That is, the vertical pipe (32a) and the concrete protection device (32b) are connected to each other to form an auxiliary connecting passage (32), and the lower end of the vertical pipe (32a) is connected to the wire rope penetration pipe (12a) for crane lifting of the concrete block (12).

[0130] The concrete protection device (32b) is intended to prevent damage to the mooring line (200) or the anchor concrete structure (110) due to friction between the mooring line (200) and the anchor concrete structure (110) while the marine floating structure (300) is moored by the mooring line (200).

[0131] In this structure, the mooring line penetration passage (112) is formed along the uppermost concrete block (12) and the top-mounted concrete (30), and the top-mounted concrete (30) is connected to the lowest concrete block (11) via a concrete pillar (20). Consequently, the mooring line (200) passing through the mooring line penetration passage (112) can exert a very large supporting force.

[0132] After the anchor concrete structure (110) is manufactured in this way, when compressed air is injected into the compressed air chamber (111), the anchor concrete structure (110) floats on the water surface as shown in FIG. 4.

[0133] This method of manufacturing concrete blocks (11, 12) on land and using the concrete blocks (11, 12) to manufacture a concrete structure (110) for anchoring underwater is very economical because it does not require a dry dock or a large barge.

[0134] Hereinafter, a third embodiment of the present invention will be described.

[0135] Fig. 15 is a cross-sectional view of a concrete structure for an anchor according to a third embodiment of the present invention, Fig. 16 is a conceptual diagram of the concrete structure for an anchor of Fig. 15 floating on the water surface, and Fig. 17 is a conceptual diagram of the concrete structure for an anchor of Fig. 16 settled on the seabed.

[0136] 1. Production stage

[0137] A concrete structure (110) for an anchor, such as that shown in Fig. 15, is manufactured.

[0138] The concrete structure (110) for anchoring has a compressed air chamber (111) and a mooring line penetration passage (112) formed inside it.

[0139] The compressed air chamber (111) is closed on the top, sides, and bottom.

[0140] In this embodiment, four compressed air chambers (111) are formed. Since Fig. 15 is a cross-sectional view, only two compressed air chambers (111) are shown.

[0141] In each compressed air chamber (111), a compressed air pipe (111a) for injecting or discharging compressed air into or from the compressed air chamber (111) and a seawater distribution port (111b) for connecting the lower part of the compressed air chamber (111) to the outside are provided.

[0142] In this embodiment, the seawater distribution port (111b) is illustrated as including a valve for opening and closing the seawater distribution port (111b), but depending on the embodiment, the seawater distribution port (111b) may be a hole formed in a concrete structure (110) for anchoring.

[0143] Meanwhile, the concrete structure (110) for anchoring of Fig. 15 can also be manufactured by applying the manufacturing method of Figs. 11 to 14.

[0144] 2. Mooring line installation and transportation stages

[0145] After the concrete structure (110) for anchoring is manufactured as shown in Fig. 15, a plurality of mooring lines (200) are installed on the concrete structure (110) for anchoring as shown in Fig. 16, and buoys (201) are installed at both ends of the mooring lines (200).

[0146] In addition, after the anchor concrete structure (110) is manufactured as shown in Fig. 15, the anchor concrete structure (110) is floated on the water surface as shown in Fig. 16.

[0147] When compressed air is supplied to the compressed air chamber (111) through the compressed air pipe (111a), the water level inside the compressed air chamber (111) becomes lower than the water level outside, allowing the anchor concrete structure (110) to float on the water surface. That is, when compressed air is injected into the compressed air chamber (111), the water inside the compressed air chamber (111) is discharged to the outside through the seawater distribution port (111b). That is, by injecting compressed air into the compressed air chamber (111), the upper space of the compressed air chamber (111) is filled with compressed air, the lower space of the compressed air chamber (111) is filled with water, and the water filled in the lower space of the compressed air chamber (111) is in communication with the outside water through the seawater distribution port (111b).

[0148] The concrete structure (110) for anchoring floating on the water surface is transported to the installation site using a tugboat, etc.

[0149] 3. Settlement and mooring stages

[0150] As shown in Fig. 17, the concrete structure (110) for anchoring transported to the installation point is sunk into the seabed and secured to the seabed.

[0151] When the compressed air in the compressed air chamber (111) is discharged, the anchor concrete structure (110) sinks to the seabed. Specifically, the compressed air in the compressed air chamber (111) is discharged to the outside through the compressed air pipe (111a) of the anchor concrete structure (110), and as a result, the pressure in the compressed air chamber (111) is lowered, and external water flows into the compressed air chamber (111) through the seawater distribution port (111b), filling the compressed air chamber (111) with water, thereby sinking the anchor concrete structure (110) to the seabed.

[0152] Meanwhile, before installing the anchor concrete structure (110) on the seabed, a foundation ground preparation step may be performed to prepare a foundation ground on the seabed in advance for installing the anchor concrete structure (110).

[0153] The foundation ground preparation stage refers to the process of placing foundation stones on the seabed and leveling the foundation for purposes such as leveling.

[0154] After the concrete structure (110) for anchoring has sunk, a filler (120) (sand) is injected into the compressed air chamber (111) through the compressed air pipe (111a) so that the compressed air chamber (111) is filled with the filler (120), and the concrete structure (110) for anchoring settled on the seabed functions as an anchor body (100).

[0155] In this way, after the anchor concrete structure (110) is settled on the seabed, i.e., after the anchor body (100) is installed, the marine floating structure (300) can be moored using both ends of the mooring line (200) in the same manner as in FIG. 6.

[0156] 4. How to replace the mooring line

[0157] After mooring the marine floating structure (300) as described above, the mooring line can be replaced in the same manner as in FIGS. 7 to 10.

[0158] The scope of the present invention is indicated by the claims set forth below rather than the detailed description above.

[0159] The present invention can be used to moor various types of marine floating structures floating on the sea surface or in seawater.

Claims

1. A manufacturing step for manufacturing an anchor concrete structure in which a compressed air chamber is formed with the upper surface and side surfaces closed and the lower surface open, a passage for passing a mooring line is formed inside, and a compressed air pipe for injecting or discharging compressed air into the compressed air chamber is provided; A transport step of transporting the anchor concrete structure to the installation site using a tugboat by injecting compressed air into the compressed air chamber of the anchor concrete structure to float the anchor concrete structure on the water surface; After the above transport step, the compressed air in the compressed air chamber of the anchor concrete structure is discharged to the outside through the compressed air pipe to sink the anchor concrete structure to the seabed, and after the anchor concrete structure has sunk to the seabed, the air and water in the compressed air chamber are discharged through the compressed air pipe to allow the side of the anchor concrete structure to penetrate the seabed, thereby settling the anchor concrete structure to the seabed; A mooring line installation step of installing the mooring line into the anchor concrete structure so that the middle part of the mooring line passes through the mooring line penetration passage of the above-mentioned anchor concrete structure; A mooring step of mooring a marine floating structure by connecting both ends of the mooring line to a marine floating structure floating on the sea surface or in seawater by buoyancy after the above anchor concrete structure is settled on the seabed; A method for mooring a marine floating structure, characterized in that it includes a .

2. In paragraph 1, A method for mooring a marine floating structure, characterized in that the above mooring line penetration passage is formed in a U shape with both ends open toward the top.

3. In paragraph 1: The above anchor concrete structure includes a concrete block assembly formed by a plurality of concrete blocks, a plurality of concrete columns formed vertically to connect the plurality of concrete blocks, and top-place concrete formed by a casting-on-site method on the upper part of the concrete block assembly; A crane lifting wire rope penetration pipe formed in a U shape is provided in each of the above concrete blocks; In the above-mentioned concrete, an auxiliary connecting passage is formed to form the mooring line passage together with a crane lifting wire rope penetration pipe of the concrete block placed at the top of the concrete block assembly; A method for mooring a marine floating structure characterized by:

4. A method for replacing a first mooring line of a marine floating structure mooring system constructed by the marine floating structure mooring method of claim 1 with a second mooring line that is a new installation target, including a marine floating structure floating on the sea surface or in seawater by buoyancy, an anchor body settled on the seabed, and a first mooring line connecting the marine floating structure and the anchor body to moor the marine floating structure: The above anchor body includes an anchor concrete structure having a mooring line penetration passage formed therein for penetrating the first mooring line; The first mooring line is supported on the anchor body while the middle part passes through the mooring line passage, and both ends are connected to the marine floating structure; A first step of connecting the other end of the second mooring line to one end of the first mooring line; After the first step, the other end of the first mooring line is pulled so that the first mooring line is detached from the anchor body, and the middle part of the second mooring line passes through the mooring line passage, and the second step is made so that both ends of the second mooring line are positioned on the upper part of the marine floating structure, and A third step comprising removing the first mooring line after the second step and connecting both ends of the second mooring line to the marine floating structure; A method for replacing a mooring line of a marine floating structure mooring system characterized by .

5. A manufacturing step for manufacturing an anchor concrete structure in which a compressed air chamber is formed with the upper surface, side surfaces, and lower surface all closed, a seawater distribution port is formed to connect the lower part of the compressed air chamber to the outside, a mooring line penetration passage is formed inside, and a compressed air pipe for injecting or discharging compressed air into the compressed air chamber is provided; A transport step of transporting the anchor concrete structure to an installation site using a tugboat by injecting compressed air into the compressed air chamber of the anchor concrete structure so that the upper space of the compressed air chamber is filled with compressed air and the lower space of the compressed air chamber is filled with water that is connected to external water through the seawater distribution port, thereby floating the anchor concrete structure on the water surface; After the above transport step, the compressed air in the compressed air chamber is discharged to the outside through the compressed air pipe of the anchor concrete structure, thereby causing external water to flow into the compressed air chamber through the seawater distribution port and filling the compressed air chamber with water, thereby sinking the anchor concrete structure to the seabed, and after the anchor concrete structure has sunk to the seabed, the compressed air chamber is filled with a filler material through the compressed air pipe to settle the anchor concrete structure to the seabed; A mooring line installation step of installing the mooring line into the anchor concrete structure so that the middle part of the mooring line passes through the mooring line penetration passage of the above-mentioned anchor concrete structure; A mooring step of mooring a marine floating structure by connecting both ends of the mooring line to a marine floating structure floating on the sea surface or in seawater by buoyancy after the above anchor concrete structure is settled on the seabed; A method for mooring a marine floating structure, characterized in that it includes a .

6. In paragraph 5, A method for mooring a marine floating structure, characterized in that the above mooring line penetration passage is formed in a U shape with both ends open toward the top.

7. In paragraph 5: The above anchor concrete structure includes a concrete block assembly formed by a plurality of concrete blocks, a plurality of concrete columns formed vertically to connect the plurality of concrete blocks, and top-place concrete formed by a casting-on-site method on the upper part of the concrete block assembly; A crane lifting wire rope penetration pipe formed in a U shape is provided in each of the above concrete blocks; In the above-mentioned concrete, an auxiliary connecting passage is formed to form the mooring line passage together with a crane lifting wire rope penetration pipe of the concrete block placed at the top of the concrete block assembly; A method for mooring a marine floating structure characterized by:

8. In paragraph 5, A method for mooring a marine floating structure, characterized in that it further includes a step of creating a foundation ground on the seabed for creating a foundation ground for the anchoring of the concrete structure for the anchor before the step of installing the concrete structure for the anchor.

9. A method for replacing the first mooring line of a marine floating structure mooring system constructed by the marine floating structure mooring method of paragraph 5 with a second mooring line that is a new installation target, including a marine floating structure floating on the sea surface or in seawater by buoyancy, an anchor body settled on the seabed, and a first mooring line connecting the marine floating structure and the anchor body to moor the marine floating structure: The above anchor body includes an anchor concrete structure having a mooring line penetration passage formed therein for penetrating the first mooring line; The first mooring line is supported on the anchor body while the middle part passes through the mooring line passage, and both ends are connected to the marine floating structure; A first step of connecting the other end of the second mooring line to one end of the first mooring line; After the first step, the other end of the first mooring line is pulled so that the first mooring line is detached from the anchor body, and the middle part of the second mooring line passes through the mooring line passage, and the second step is made so that both ends of the second mooring line are positioned on the upper part of the marine floating structure, and A third step comprising removing the first mooring line after the second step and connecting both ends of the second mooring line to the marine floating structure; A method for replacing a mooring line of a marine floating structure mooring system characterized by .

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