KR102636337B1 - Method for mooring of marine structure, and method for replacing mooring cable of marine structure - Google Patents

Abstract

The present invention manufactures a concrete structure for an anchor in which a mooring line passage is formed inside and a buoyancy chamber is formed, a mooring line is installed in the mooring line penetration passage of the anchor concrete structure, and the buoyancy chamber of the anchor concrete structure is used. The anchor concrete structure is transported to the installation point using a tugboat while floating on the water surface, and filler is placed in the buoyancy chamber of the anchor concrete structure transported to the installation point to place the anchor concrete structure on the sea floor. It relates to a method of mooring the marine floating structure by connecting both ends of the mooring line to a marine floating structure floating on the sea surface or in sea water after the anchor concrete structure is seated on the sea floor. This can increase the bonding strength between the anchor concrete structure and the mooring line, and also eliminates the need for underwater work in relation to the installation and replacement of the mooring line.

Description

Method for mooring marine floating structures and method for replacing mooring lines in marine floating structure mooring systems {METHOD FOR MOORING OF MARINE STRUCTURE, AND METHOD FOR REPLACING MOORING CABLE OF MARINE STRUCTURE}

The present invention relates to a mooring method for mooring various types of marine floating structures floating on the sea surface or in sea water, and a method for replacing mooring lines. Specifically, the present invention relates to an anchor body composed of a concrete structure for an anchor and a filling material; It is about technology using a mooring line connected to this.

Various types of marine floating structures floating on or in sea water are known.

Such marine floating structures can be moored by being connected to an anchor fixed to the sea floor by a mooring line.

Types of anchors for marine floating structures can be divided into gravity anchors, drag-embedding anchors, suction anchors, etc.

Gravity anchors maintain marine floating structures in a certain position by friction with the seafloor due to the anchor's own weight. Gravity anchors have the advantage of being the lowest cost.

A drag-embedding anchor is an anchor that penetrates the seafloor and has horizontal bearing capacity in the main installation direction.

Other suction anchors and the like are known.

Meanwhile, marine floating structures use various types of mooring systems.

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. get drunk

The TLP mooring method is achieved by applying a strong tensile force to vertical mooring lines called 'tandems' in mooring a buoyant marine floating structure in the ocean, and is usually referred to as taut mooring or semi-turt mooring. Compared to semitaut mooring, it has the advantage of stably maintaining marine floating structures even in rough sea conditions.

In the case of the TLP mooring method, vertical tension is applied to the mooring line, so the drag-embedment anchor method, which is vulnerable to vertical tension, is not suitable.

Gravity anchors not only have the advantage of being able to withstand tensile force in the vertical direction, but are also very economical compared to other methods.

However, in the case of gravity anchors, the larger they become, the more difficult they are to manufacture and install.

Meanwhile, when gravity anchors become larger, the problem becomes how to connect the anchor and mooring line.

As a related technology, Korea Patent No. 10-1572938, “Gravity mooring device for floating structures” (registered on November 24, 2015) has been proposed.

In the conventional technology, a metal ring is provided on a gravity anchor, which is a concrete structure, and a mooring line is connected to the metal ring.

However, because this method has limitations in the adhesion between the metal ring and the concrete structure, there is a risk that the metal ring may be separated from the concrete structure if excessive tensile force is applied to the metal ring.

In addition, since wire rope is usually used as a mooring line, the thickness of the mooring line must be selected in consideration of corrosion that occurs when the mooring line is in contact with seawater for a long period of time.

If you want to use the mooring line only for a short period of time without corrosion, the mooring line can be relatively thin as it is designed primarily for tensile stress. However, if you want to use the mooring line for a long period of time when corrosion occurs, the mooring line must be considerably thick to take corrosion into account.

In addition, no matter how thick the mooring line is selected, it is necessary to replace the mooring line after proper use. In this case, the diver must disconnect the old mooring line from the anchor located in deep water, and the diver can install a new mooring line in deep water. There is a difficulty in connecting to the anchor. Therefore, replacing mooring lines becomes a relatively difficult task and is difficult to carry out on a frequent basis.

Because it is difficult to replace the mooring line as described above, the mooring line is replaced at a relatively long cycle, and therefore, considering corrosion that occurs during a long cycle, the mooring line must have a very thick thickness.

Since this very thick mooring line does not bend easily, there is a problem in that it is not easy to connect the mooring line to an anchor located in deep water.

Republic of Korea No. 10-1572938 “Gravity mooring device for floating structures” (registered on November 24, 2015) Republic of Korea Patent Registration No. 10-2292821 “Floating concrete block structure and method of manufacturing the same” (registered on August 18, 2021)

The present invention was developed to solve the problems of the prior art as described above, and a mooring line penetrating passage is formed inside the anchor concrete structure to increase the bonding force between the anchor concrete structure and the mooring line. In addition, the mooring line The aim is to provide a method of mooring marine floating structures that does not require underwater work in relation to the installation and replacement of .

In order to solve the above problem, the present invention includes the steps of manufacturing a concrete structure for an anchor in which a mooring line passage is formed inside and a buoyancy chamber with an open upper surface is formed; Installing the mooring line on 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; Transporting the anchor concrete structure to an installation point using a tugboat while floating on the water surface using the buoyancy chamber of the anchor concrete structure; An anchor concrete structure seating step of seating the anchor concrete structure on the sea floor by inserting filler into the buoyancy chamber of the anchor concrete structure transported to the installation point; After the anchor concrete structure is seated on the sea floor, connecting both ends of the mooring line to a marine floating structure floating on the sea surface or in sea water by buoyancy to moor the marine floating structure; It is characterized by including.

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In the above, the mooring line penetration passage is preferably formed in a U-shape with both ends open upward within the anchor concrete structure.

In the above: the concrete structure for the anchor includes a concrete block assembly formed by a plurality of concrete blocks, a plurality of concrete columns formed in a vertical direction to connect the plurality of concrete blocks, and a cast-in-place structure on top of the concrete block assembly. It includes bed concrete formed in a manner; A wire rope penetration pipe for crane lifting formed in a U shape is provided in each of the concrete blocks; It is preferable that an auxiliary connection passage forming the mooring line passage is formed in the placed concrete along with a wire rope passage for crane lifting of the concrete block disposed at the top of the concrete block assembly.

In the above, before the step of seating the concrete structure for the anchor, a basic ground preparation step of creating a foundation ground on the sea floor for seating the concrete structure for the anchor may be further included.

In another idea of the present invention, a marine floating structure floating on the sea surface or in sea water by buoyancy, an anchor body seated on the sea floor, and a first mooring connecting the marine floating structure and the anchor body to moor the marine floating structure. In the method of replacing the first mooring line of the marine floating structure mooring system, which includes a line and is created by the marine floating structure mooring method, with a second mooring line to be newly installed: the anchor body, the first mooring line A mooring line penetration passage for penetration of the anchor is formed inside and is formed by a concrete structure for an anchor having a buoyancy chamber with an open upper surface and a filler material introduced into the buoyancy chamber of the concrete structure for an anchor; The first mooring line has a middle portion that passes through the mooring line passage and is supported by the anchor body, 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, and after the first step, the other end of the first mooring line is pulled so that the first mooring line is separated from the anchor body and the second mooring line is separated from the anchor body. A second step in which the middle part of the second mooring line passes through the mooring line passage and both ends of the second mooring line are located at the top of the marine floating structure, and after the second step, the first mooring line is removed. Comprising a third step of connecting both ends of the second mooring line to the marine floating structure; It is characterized by .

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

In addition, the present invention eliminates the need for underwater work in relation to the installation and replacement of mooring lines, thereby significantly reducing the overall installation and replacement costs of mooring lines.

In addition, the present invention reduces the replacement cost of the mooring line and allows the mooring line to be replaced at frequent intervals, thereby eliminating corrosion problems. As a result, only the mooring tension force can be considered in designing the thickness of the mooring line, so the mooring line can be The thickness can be made thinner.

In addition, since the present invention can reduce the thickness of the mooring line, it becomes very easy to connect the mooring line to the concrete anchor structure or marine floating structure.

1 is a perspective view of a concrete structure for an anchor according to an embodiment of the present invention;
Figure 2 is a cross-sectional view of Figure 1;
Figure 3 is a conceptual diagram of a state in which a mooring line is installed on the concrete anchor structure of Figure 2;
Figure 4 is a conceptual diagram of the concrete anchor structure of Figure 3 floating on the water surface;
Figure 5 is a conceptual diagram of a state in which filler is added to the anchor concrete structure of Figure 4 and placed on the seafloor;
Figure 6 is a conceptual diagram of the state in which the marine floating structure is moored after Figure 5;
Figures 7 to 10 are diagrams sequentially showing a method of replacing a mooring line;
11 to 14 are diagrams sequentially showing the process of manufacturing a concrete structure for an anchor according to an embodiment of the present invention.

Below, with reference to the attached drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. In order to clearly explain the present invention in the drawings, parts that are not related to the description are omitted, and similar parts are given similar reference numerals throughout the specification.

Throughout the specification, when a part is said to “include” a certain element, this means that it may further include other elements rather than excluding other elements, unless specifically stated to the contrary.

Hereinafter, a method of mooring an offshore floating structure according to an embodiment of the present invention will be sequentially described.

1. Concrete structure manufacturing steps for anchors

A concrete structure 110 for an anchor as shown in FIGS. 1 and 2 is manufactured.

The anchor concrete structure 110 has a buoyancy chamber 111 with an open upper surface, and a mooring line penetration passage 112 is formed inside the anchor concrete structure 110.

In this embodiment, the mooring line passage 112 is formed in a U shape with both ends open upward.

Such a mooring line passage 112 is formed with a relatively large curvature and can facilitate smooth passage of the mooring line 200, which will be described later.

2. Mooring line installation steps

After the anchor concrete structure 110 is manufactured as shown in FIG. 2, a plurality of mooring lines 200 are installed on the anchor concrete structure 110 as shown in FIG. 3.

Accordingly, the mooring line 200 is arranged so that its middle portion penetrates the mooring line penetration passage 112 of the anchor concrete structure 110, and both ends of the mooring line 200 are outside the anchor concrete structure 110. It is placed.

That is, the installation of the mooring line 200 is not performed underwater but in a land environment.

Meanwhile, buoys 201 are installed at both ends of the mooring line 200.

3. Transport stage of concrete structure for anchor

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.

The anchor concrete structure 110 can float on the water surface due to the buoyancy chamber 111.

The anchor concrete structure 110 floating on the water is transported to the installation point using a tugboat or the like.

4. Concrete structure seating stage for anchors

As shown in FIG. 5, filler material 120 such as sand, gravel, or riprap is placed in the buoyancy chamber 111 of the anchor concrete structure 110 transported to the installation point, and the anchor concrete structure 110 is submerged in water. It sits down and settles on the sea floor.

When the buoyancy chamber 111 is filled with the filler 120, the anchor concrete structure 110 loses buoyancy and sinks in the water.

In this way, the concrete structure for anchors 110, which is seated on the sea floor by adding the filler 120 to the buoyancy chamber 111, functions as the anchor body 100.

On the other hand, since the mooring line 200 is already installed in the anchor concrete structure 110 and the buoys 201 are installed at both ends of the mooring line 200, the middle part of the mooring line 200 is the anchor concrete structure ( Although it sinks to the sea floor together with 110), both ends of the mooring line 200 are located on the water surface together with the buoy 201.

Meanwhile, before seating the anchor concrete structure 110 on the seafloor, a basic ground preparation step may be performed in which the foundation ground is previously created on the seafloor for seating the anchor concrete structure 110.

The basic ground preparation stage refers to dropping basic riprap stones on the sea floor and leveling the foundation for leveling, etc.

5. Marine floating structure mooring steps

After the anchor concrete structure 110 is seated on the sea floor as shown in FIG. 5, that is, after the anchor body 100 is installed, both ends of the mooring line 200 are connected to the marine floating structure 300 as shown in FIG. 6. The marine floating structure 300 is moored.

That is, both ends of each mooring line 200 are connected to the upper part of the marine floating structure 300 located on the water, and the middle part of each mooring line 200 penetrates the mooring line passage 112 and anchor body 100. ) is supported.

As a result, the mooring system for the marine floating structure 300 is completed.

The marine floating structure 300 floats on the sea surface or in sea water by buoyancy.

Although this embodiment shows a TLP mooring method using tensile angles, the invention can also be applied to taut mooring or semi-taut mooring methods.

In this type of mooring structure, a mooring line penetration passage 112 is formed inside the anchor concrete structure 110, thereby dramatically increasing the bonding force between the anchor concrete structure 110 and the mooring line 200.

In addition, installation of the mooring line 200 is performed on the water surface and no underwater work is required, thereby reducing overall costs.

6. How to replace mooring line

Figure 7 shows the first mooring line 200A for mooring a marine floating structure and the concrete structure 110 for anchor of the anchor body 100.

Since the first mooring line (200A) is usually made of wire rope, etc., corrosion occurs when it comes in contact with seawater, so it must be replaced after being used for a certain period of time.

A method of replacing a mooring line will be described using FIGS. 7 to 10.

In FIGS. 7 to 10 , illustrations of marine floating structures are omitted for convenience of understanding.

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).

Step 1:

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.

As a result, the first mooring line 200A and the second mooring line 200B form a continuous line.

Step 2:

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

As a result, the first mooring line 200A is separated from the anchor body 100, and the middle portion of the second mooring line 200B is guided by the first mooring line 200A through the mooring line penetration passage of the anchor body 100. While passing through (112), both ends of the second mooring line (200B) are located on the upper part of the marine floating structure (300).

Step 3:

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

The above-mentioned first step, second step, and third step are all performed at the top of the marine floating structure 300. In other words, underwater work becomes unnecessary.

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

<Manufacture of concrete structures for anchors>

In order for the anchor concrete structure 110 to function as a gravity anchor, it is preferable that the anchor concrete structure 110 is enlarged. For this reason, when the anchor concrete structure 110 is enlarged, the anchor concrete structure 110 is It has a weight that makes it impossible to lift with a typical crane.

Therefore, a method of manufacturing the anchor concrete structure 110 that does not require crane lifting work is needed, and for this purpose, two methods can be considered.

1) How to manufacture in one piece

The concrete structure 110 for an integrated anchor can be manufactured in a dry dock or a large barge. That is, after manufacturing the anchor concrete structure 110 by installing a form, etc. on a dry dock or a large barge, the manufactured anchor concrete structure 110 can be floated.

This method is very inefficient because a dry dock or large barge must be used continuously during the manufacturing period of the anchor concrete structure 110, resulting in a significant increase in manufacturing costs.

2) Manufactured in the form of a combination of concrete blocks

The present inventor has proposed a floating concrete block structure in which concrete blocks are combined according to Korean Patent Registration No. 10-2292821, and the concrete structure 110 for an anchor can be manufactured by applying the above-described prior art.

The prior art is integrated into this specification, and this specification mainly explains content that is not proposed in the prior art.

Figures 11 to 14 are diagrams sequentially showing the process of manufacturing the concrete structure 110 for an anchor according to an embodiment of the present invention.

First, a plurality of concrete blocks 11 and 12 necessary for manufacturing the anchor concrete structure 110 on land are manufactured.

Each concrete block (11, 12) is provided with a U-shaped wire rope penetration pipe (11a, 12a) for crane lifting.

Since the technology related to the wire rope penetration pipe for crane lifting is described in Korean Patent No. 10-1220995 proposed by the present inventor, its description is omitted in this specification.

Concrete blocks (11, 12) manufactured on land are lifted by a crane using wire rope penetration pipes (11a, 12a) for crane lifting and installed underwater, thereby forming a concrete block assembly (10).

11 and 12 show the process of forming a concrete block assembly 10 using concrete blocks 11 and 12.

The concrete block 11 is a concrete block placed at the bottom to form the floor, and the concrete block 12 is a concrete block forming the wall.

Watertight packing (11b, 12b) is provided on the upper surface of each concrete block (11, 12).

The concrete block 11 is provided with a plurality of column reinforcing bar assemblies 11c extending vertically upward from the lower end connected to the interior of the concrete block 11.

The concrete block 12 is formed with a column through-hole 12c into which a plurality of column rebar assemblies 11c are inserted.

Additionally, an opening 12d for a buoyancy room is formed in the central part of the concrete block 12. The buoyancy chamber opening 12d of the concrete block 12 forms the buoyancy chamber 111 of the anchor concrete structure 110.

When the concrete block assembly 10 is formed as shown in FIG. 12, the upper end of the column rebar assembly 11c protrudes above the concrete block 20 disposed at the uppermost level.

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 in the vertical direction.

After forming the concrete pillar 20, the concrete structure 110 for the anchor is completed by forming the concrete 30 on top of the concrete block assembly 10 using a cast-in-place method, as shown in FIG. 14. In other words, the standing concrete 30 is not a concrete block, but is formed using formwork and casting in situ.

At this time, the upper end of the column reinforcing bar assembly (11c) is connected to the internal reinforcing bar (31) of the upper concrete (30).

In addition, when forming the upper concrete 30, an auxiliary connection passage 32 extending in the vertical direction is formed.

The auxiliary connection passage 32 is formed to communicate with the wire rope penetration pipe 12a for crane lifting of the concrete block 20 disposed at the top of the concrete block assembly 10, and the wire rope penetration pipe 12a for crane lifting ) together with the mooring line to form a passage 112.

That is, the mooring line penetration passage 112 is formed by the wire rope penetration pipe 12a for crane lifting of the concrete block 20 and the auxiliary connection passage 32 of the placed concrete 30 that is cast in situ.

In order to form the auxiliary connection passage 32, a vertical pipe (32a) extending vertically is provided at the lower part of the upper concrete 30, and a concrete protector in the form of a fallopian tube of the upper and lower cavities is provided at the upper part of the upper concrete 30. 32b) is prepared.

That is, the vertical pipe (32a) and the concrete protector (32b) are connected to each other to form an auxiliary connection passage (32), and the lower end of the vertical pipe (32a) is a wire rope penetration pipe (12a) for crane lifting of the concrete block (20). is connected to

The concrete protector 32b is designed to cause the mooring line 200 to rub against the anchor concrete structure 110 while the marine floating structure 300 is moored by the mooring line 200, thereby causing the mooring line 200 or the anchor concrete. This is to prevent the structure 110 from being damaged.

In this structure, the mooring line penetration passage 112 is formed along the uppermost concrete block 12 and the upper concrete 30, and the upper concrete 30 is connected to the lowermost concrete block 11 via the concrete pillar 20. ), so the mooring line 200 passing through the mooring line penetration passage 112 can exert a very large support force.

After manufacturing the anchor concrete structure 110 in this way, when the water inside the buoyancy chamber 111 is drained, the anchor concrete structure 110 floats on the water surface as shown in FIG. 4.

In this way, the method of manufacturing concrete blocks 11 and 12 on land and using concrete blocks 11 and 12 to manufacture concrete structures 110 for anchors underwater does not require a dry dock or large barge. Very economical.

The description of the present invention described above is for illustrative purposes, and those skilled in the art will understand that the present invention can be easily modified into other specific forms without changing the technical idea or essential features of the present invention. will be. Therefore, the embodiments described above should be understood in all respects as illustrative and not restrictive. For example, each component described as unitary may be implemented in a distributed manner, and similarly, components described as distributed may also be implemented in a combined form.

The scope of the present invention is indicated by the claims described below rather than the detailed description above, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention. do.

10: Concrete block assembly
11: Concrete block 11c: Rebar assembly for column
12: Concrete block 12a: Wire rope penetration pipe for crane lifting
12c: Through hole for pillar 12d: Opening hole for buoyancy room
20: Concrete pillar
30: Top concrete 32: Auxiliary connection passage
32a: Vertical pipe 32b: Concrete protector
100: anchor body
110: Concrete structure for anchor
111: Buoyancy room
112: Mooring line penetration passage
120: Filling material
200: mooring line
201: Buoy
300: Marine floating structure

Claims (9)

delete delete delete delete Manufacturing a concrete structure for an anchor in which a mooring line passage is formed inside and a buoyancy chamber with an open upper surface is formed;
Installing the mooring line on 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;
Transporting the anchor concrete structure to an installation point using a tugboat while floating on the water surface using the buoyancy chamber of the anchor concrete structure;
An anchor concrete structure seating step of seating the anchor concrete structure on the sea floor by inserting filler into the buoyancy chamber of the anchor concrete structure transported to the installation point;
After the anchor concrete structure is seated on the sea floor, connecting both ends of the mooring line to a marine floating structure floating on the sea surface or in sea water by buoyancy to moor the marine floating structure;
A method of mooring an offshore floating structure comprising a.
According to claim 5,
A method of mooring a marine floating structure, including the mooring line passage being formed in a U shape with both ends open to the top.
According to clause 5:
The anchor concrete structure includes a concrete block assembly formed by a plurality of concrete blocks, a plurality of concrete columns formed in a vertical direction to connect the plurality of concrete blocks, and a cast-in-place method on the upper part of the concrete block assembly. Includes overlying concrete;
A wire rope penetration pipe for crane lifting formed in a U shape is provided in each of the concrete blocks;
An auxiliary connection passage forming the mooring line passage is formed in the placed concrete together with a wire rope passage for crane lifting of the concrete block disposed at the top of the concrete block assembly;
A method of mooring an offshore floating structure, characterized by:
According to claim 5,
A method of mooring an offshore floating structure, characterized in that it further comprises a foundation ground creation step of creating a foundation ground on the sea floor for seating the anchor concrete structure before the anchor concrete structure seating step.
It includes a marine floating structure floating on the sea surface or in sea water due to buoyancy, an anchor body seated on the sea floor, and a first mooring line connecting the marine floating structure and the anchor body to moor the marine floating structure, and according to claim 5. In the method of replacing the first mooring line of the marine floating structure mooring system created by the marine floating structure mooring method with the second mooring line to be newly installed:
The anchor body is formed by a concrete structure for an anchor having a buoyancy chamber with an open upper surface and a mooring line penetration passage for penetration of the first mooring line formed therein, and a filling material introduced into the buoyancy chamber of the concrete structure for the anchor. It is done;
The first mooring line has a middle portion that passes through the mooring line passage and is supported by the anchor body, 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, the first mooring line is separated from the anchor body, and the middle portion of the second mooring line penetrates the mooring line passage and both ends of the second mooring line are separated from the anchor body. A second step to be located on top of the marine floating structure, and
Comprising 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;
A method of replacing mooring lines in an offshore floating structure mooring system, characterized by: