JP7614434B1 - Process Planning Method - Google Patents

Abstract

An object of the present invention is to provide a construction project process planning method capable of shortening the process of a construction project.
[Solution] A process planning method for planning the processes of a monopile foundation construction project, comprising: a structural analysis process SA3 in which a computer performs a structural analysis of a model of the monopile foundation multiple times; and a first production process SB1 that is started after completion of the earthquake response analysis included in the first structural analysis process SA3 and before completion of the earthquake response analysis included in the second structural analysis process SA3, wherein the first production process SB1 does not produce an interface flange of the transition piece, but produces parts of the transition piece other than the interface flange, and the first production process SB1 produces a connection part of the monopile body that is connected to the transition piece in a state that overlaps with it when viewed horizontally, and does not produce parts of the monopile body other than the connection part.
[Selected figure] Figure 5

Description

This disclosure relates to a process planning method.

Conventionally, structures are manufactured in a factory and then assembled and installed at a construction site.
Patent Document 1 discloses a method of constructing a vertical structure in which a unit structure, which is prefabricated in a factory, consists of a single smooth metal plate and has horizontal reinforcing ribs welded to its outer surface.

Japanese Unexamined Patent Publication No. 62-86273

The conventional construction method described above poses challenges in shortening the construction project schedule.

This disclosure has been made in consideration of the above-mentioned circumstances, and aims to provide a process planning method that can shorten the process of a construction project.

A process planning method according to one aspect of the present disclosure is a process planning method for planning the process of a construction project of a monopile foundation that has a monopile body and a transition piece and supports the tower of an offshore wind turbine, comprising: a structural analysis step in which a computer performs structural analysis of a model of the monopile foundation multiple times; and a first manufacturing step in which at least a part of the components that constitute the monopile foundation is manufactured after completion of an earthquake response analysis included in the first structural analysis step and before completion of an earthquake response analysis included in the second structural analysis step, the first manufacturing step manufacturing the transition piece, the first manufacturing step not manufacturing an interface flange of the transition piece, and manufacturing a part of the transition piece other than the interface flange, the first manufacturing step manufacturing the monopile body, the first manufacturing step manufacturing a connection part of the monopile body that is connected in a state where it overlaps with the transition piece in a horizontal view, and not manufacturing a part of the monopile body other than the connection part.

This disclosure provides a process planning method that can shorten the construction project process.

FIG. 1 is a diagram showing a first example of a marine structure according to an embodiment. FIG. 2 is a diagram showing a state in which a plurality of the marine structures shown in FIG. 1 are installed. 3 is a cross-sectional view of the monopile body in the III-III direction shown in FIG. 1. FIG. 2 is an enlarged view of a portion IV shown in FIG. 3 is a flow chart of a process planning method according to an embodiment.

Hereinafter, an offshore structure and a process planning method for an offshore structure according to an embodiment of the present disclosure will be described with reference to the drawings.
The marine structure according to this embodiment is a foundation structure that supports the tower of an offshore wind turbine. The marine structure may be, for example, a jacket foundation, a monopile foundation, or any other structure.

(Regarding marine structures)
FIG. 1 is a diagram showing a first example of a marine structure 1 according to an embodiment.
FIG. 2 is a diagram showing a state in which a plurality of marine structures 1 shown in FIG. 1 are installed.
As shown in Fig. 1, in this embodiment, the marine structure 1 is a monopile foundation. As shown in Fig. 2, a plurality of marine structures 1 may be present in the same wind farm or sea area (hereinafter, installation site A), for example.

In this embodiment, the marine structure 1, which is a monopile foundation, has a monopile body 10, a transition piece 20, and an auxiliary facility 30, as shown in FIG.
The monopile body 10 is a cylindrical member that is driven into the seabed OF. In this embodiment, the monopile body 10 refers to, for example, a steel pipe at least a part of which is embedded in the ground. In this embodiment, at least one of the inner and outer surfaces of the monopile body 10 may be coated with an anti-corrosive coating.
In this embodiment, the monopile body 10 is formed by connecting a plurality of unit cylindrical bodies 11, which are cylindrical members having any length, in the longitudinal direction, as shown in Fig. 1. The monopile body 10 may be made of steel or any other material.
In addition, in this embodiment, as described above, multiple marine structures 1 installed at the same installation location A may have part or all of the shape of the monopile body 10 in common, or the shape may be set individually as appropriate to suit the conditions such as the ground and water depth at the respective installation locations of the multiple marine structures 1.

FIG. 3 is a cross-sectional view of the monopile body 10 taken along the line III-III shown in FIG.
In this embodiment, the monopile body 10 may be formed so that its cross section has a circular shape as shown in Fig. 3. The tubular unit 11 having such a cross-sectional shape may be formed, for example, by connecting ends of a plurality of curved plates 11A as shown in Fig. 3, by bending a steel plate, or by integrally molding a tubular member.
Alternatively, the monopile body 10 may be formed to have an elliptical cross-sectional shape, or any other cross-sectional shape.

As described above, the monopile body 10 is formed by connecting multiple unit tubular bodies 11 in the longitudinal direction. At this time, the portion of the monopile body 10 that is installed underground, and in particular the portion close to the surface (seabed surface) of the seabed OF, may be subjected to a relatively large bending moment compared to other portions. For this reason, the unit tubular bodies 11 located in these portions may have a greater plate thickness than the unit tubular bodies 11 located in other portions.

FIG. 4 is an enlarged view of part IV shown in FIG.
A cable C may be provided inside the monopile body 10 as shown in Fig. 4. The cable C is, for example, a cable for connecting various devices (not shown) provided inside the offshore wind turbine WM with a submarine cable (not shown) laid on the seabed OF. In order to enable the submarine cable (not shown) to be connected to the cable C shown in Fig. 4, a hole (not shown) may be provided in a side wall of the monopile body 10 near the seabed surface. When the cable C and the submarine cable (not shown) are connected by a joint (not shown), the boundary between the cable C and the submarine cable (not shown) may be confirmed by the location of the joint (not shown). Also, the boundary between the cable C and the submarine cable (not shown) may be confirmed by understanding that the cable that has landed on the seabed is the submarine cable (not shown).

The transition piece 20 is disposed on the upper part of the monopile body 10, as shown in Figures 1 and 4. Specifically, the transition piece 20 is provided so as to overlap a part of the monopile body 10 including its upper end when viewed in the horizontal direction. That is, the upper part of the monopile body 10 is inserted into the transition piece 20 from below. As shown in Figure 4, the part of the monopile body 10 including its upper end and the transition piece 20 are preferably cone-shaped. That is, the part of the monopile body 10 including its upper end and the transition piece 20 are preferably truncated cones whose diameter decreases from the bottom to the top.
4 , a portion of the monopile body 10 including its upper end and the transition piece 20 may be fixed by grout G in a state in which they are arranged so as to overlap each other when viewed in the horizontal direction. The grout G is injected into the gap (annular space) between the upper part of the monopile body 10 and the transition piece 20.
The transition piece 20 may be made of, for example, steel, or any other material.
The transition piece 20 disposed on the upper part of the monopile body 10 as described above connects the monopile body 10 to the tower T of the offshore wind turbine WM. The tower T extends upward from the connection position with the transition piece 20. The offshore wind turbine WM is installed on the ocean.
In this embodiment, the transition piece 20 has an interface flange IF as shown in Fig. 4. The interface flange IF is provided at the upper end of the transition piece 20. In this embodiment, a similar interface flange IF is also provided at the lower end of the tower T of the offshore wind turbine WM. The connection between the transition piece 20 and the tower T of the offshore wind turbine WM is achieved by joining the interface flanges IF provided on the transition piece 20 and the tower T of the offshore wind turbine WM with bolts B as shown in Fig. 4. Note that the transition piece 20 may have a function of adjusting the connection angle with the tower T. With this configuration, the tower T of the offshore wind turbine WM can be adjusted to extend in the vertical direction when connected to the lower end of the tower T of the offshore wind turbine WM.
A cable C may be provided inside the transition piece 20 as shown in Fig. 4. A hole H having a circular, elliptical or any other shape may be provided inside the transition piece 20 in order to pass the cable C through. As described above, a plurality of marine structures 1 may exist at the same installation site A as shown in Fig. 2. In this case, it is preferable that the shape of the hole H provided inside the transition piece 20 in the plurality of marine structures 1 is the same.
In this embodiment, the transition pieces 20 may have a common structure or may be different in the marine structures 1 that are installed in the same installation location A as described above.

The auxiliary facilities 30 are provided to enable workers to move and perform various operations on the marine structure 1. In this embodiment, the auxiliary facilities 30 include a mooring facility 31, a ladder 32, a landing 33, a work platform 34, and a passageway 35, as shown in Fig. 4 for example. Each of the auxiliary facilities 30 may be made of steel, for example, or may be made of any other material.
In this embodiment, the auxiliary equipment 30 may have a common structure for multiple marine structures 1 installed at the same installation site A as described above, or may be different.

The mooring equipment 31 is a member for mooring a work boat in the marine structure 1. In this embodiment, the mooring equipment 31 shown in Fig. 4 has, for example, a pair of rod-shaped members extending in the vertical direction. With the work boat moored to the mooring equipment 31, a worker moves from the work boat to the marine structure 1.
The ladder 32 is used for a worker who has moved to the marine structure 1 to move up and down. In this embodiment, the ladder 32 shown in Fig. 4 is provided between a pair of rod-shaped members of the mooring equipment 31, for example.
As shown in Fig. 4, the landing 33 is provided at the upper end of the ladder 32. In this embodiment, the landing 33 is a place where a worker who moves from the work boat to the marine structure 1 and moves upward using the ladder 32 gets off.
The work floor 34 is a place where workers perform various tasks. For example, as shown in Fig. 4, the work floor 34 may be provided with a davit crane DC for lifting materials.
The passage 35 is a portion where a worker moves. In this embodiment, the passage 35 includes the ladder 32 and the landing 33. In other words, in this embodiment, the ladder 32 and the landing 33 may be collectively referred to as the passage 35.
The marine structure 1 according to this embodiment is constituted by the above-mentioned components.

(About the process planning method)
Next, a process planning method according to this embodiment will be described. The process planning method according to this embodiment is a method for planning the process of a construction project of an offshore structure 1 that supports the tower T of an offshore wind turbine WM. The process planning method described below is applied to the manufacture of the offshore structure 1 according to this embodiment. The offshore structure 1 according to this embodiment is manufactured through a process based on the process planning method, and installed offshore.
In this embodiment, manufacturing the marine structure 1 includes procuring materials, processing the materials to form various components, and assembling the various components to form the marine structure 1.

FIG. 5 is a flow chart of a process planning method according to the embodiment.
As shown in FIG. 5, the process planning method according to this embodiment includes a design review flow SA and a production flow SB.
The design review flow SA is a flow for reviewing the shape of the marine structure 1. As shown in Fig. 5, the design review flow SA includes a preliminary investigation process SA1, a shape review process SA2, and a structure analysis process SA3.

The preliminary investigation process SA1 is a process of investigating specific conditions, including ground conditions and wave conditions, at the installation site A where the marine structure 1 and the offshore wind turbine WM will be installed. Specifically, in the preliminary investigation process SA1, for example, wind observation, geological investigation, bathymetry, indoor soil testing, etc. are performed. The results of the various investigations in the preliminary investigation process SA1 are reflected in the analysis conditions in, for example, the shape consideration process SA2 and the structure analysis process SA3.
In addition, a pre-first production process SB1a (described later) in the production flow SB may be started before or after the preliminary inspection process SA1.

The shape examination process SA2 is a process for examining the shape of the marine structure 1 and creating a model of the marine structure 1. Specifically, for example, the diameter and thickness of the monopile body 10 and the diameter and thickness of the transition piece 20 of the marine structure 1, which is a monopile foundation, are examined, and a model to be used in the structural analysis process SA3 is created.

Here, in this embodiment, in the first pre-fabrication process SB1a (described later), materials constituting the monopile body 10 and the transition piece 20 that are highly versatile may be secured in advance as inventory. That is, for example, multiple types of steel pipes with different diameters, plate thicknesses, and materials may be procured in advance as materials constituting the monopile body 10 and the transition piece 20. In such a case, the diameters and plate thicknesses of the multiple types of steel pipes change in predetermined numerical increments. The predetermined numerical values may be, for example, any numerical values as appropriate. The predetermined numerical values are, for example, discrete values.
At this time, in this embodiment, a plurality of shapes of the marine structure 1 may be considered in the shape consideration step SA2. In the shape consideration step SA2, the diameters and plate thicknesses of the monopile body 10 and the transition pieces 20 are preferably set in predetermined numerical increments in accordance with the steel pipes secured as inventory. Moreover, the predetermined numerical values are preferably discrete values in accordance with the steel pipes secured as inventory, for example. This makes it easier to perform, for example, the structural analysis step SA3 described below. Also, it makes it easier to prevent excess inventory when procuring materials for the monopile body 10 and the transition pieces 20 (details will be described later).
After the shape of the marine structure 1 is considered in the shape consideration step SA2, the first intermediate manufacturing step SB1b (described later) in the manufacturing flow SB is started and the process proceeds to the structural analysis step SA3. However, the start of the first intermediate manufacturing step SB1b is not essential. In other words, whether or not to start the first intermediate manufacturing step SB1b is determined appropriately.

The structural analysis step SA3 is a step of performing a structural analysis of the model of the marine structure 1. In this embodiment, the structural analysis step SA3 may be performed multiple times. In other words, in this embodiment, the structural analysis step SA3 may be a step in which a computer performs a structural analysis of the model of the marine structure 1 multiple times.
The structural analysis process SA3 is performed based on the shape of the marine structure 1 considered in the shape consideration process SA2. As shown in Fig. 5, the structural analysis process SA3 includes an analysis implementation step SA3a, a first confirmation step SA3b, a second confirmation step SA3c, a third confirmation step SA3d, and a review step SA3e.

The analysis execution step SA3a is a step of performing a structural analysis of the model of the marine structure 1. In this embodiment, for example, eigenvalue analysis, wind-wave integrated analysis, earthquake response analysis, etc. are performed in the analysis execution step SA3a. The eigenvalue analysis, wind-wave integrated analysis, and earthquake response analysis may be performed by frame structure analysis or finite element analysis. It is also preferable that the wind-wave integrated analysis and earthquake response analysis are performed by time history response analysis. In the analysis execution step SA3a, a static analysis may be performed on the auxiliary equipment 30. In the static analysis, for example, wave load, ship docking load, towing load, etc. may be considered as loads.
When multiple shapes of the marine structure 1 are considered in the shape consideration step SA2, for example, an analysis is performed for each shape in the analysis implementation step SA3a.

The first confirmation step SA3b is a step for confirming the result of the analysis performed in the analysis performing step SA3a. Specifically, in the first confirmation step SA3b, it is confirmed whether or not all the members of the marine structure 1 can be finalized based on the overall shape of the model of the marine structure 1 when the analysis performing step SA3a is performed.
When it is determined that all the components of the marine structure 1 can be finalized based on the overall shape of the model of the marine structure 1 (SA3b: Yes), the structural analysis step SA3 is terminated and the shape of the marine structure 1 is finally determined. When it is determined that all the components of the marine structure 1 cannot be finalized (SA3b: No), the process proceeds to a second confirmation step SA3c.

The second confirmation step SA3c is a step of confirming whether or not the shape of a part of the model of the marine structure 1, for which it has been determined that not all components are finalizable, is finalizable. Note that the part of the model of the marine structure 1 refers to either the monopile body 10 or the transition piece 20 in the marine structure 1. In this case, the part of the model of the marine structure 1 may be a part of the monopile body 10 or a part of the transition piece 20.
Of the parts of the model of the marine structure 1, those parts that are determined to be finalizable (SA3c: parts that can be finalized) start the first manufacturing process SB1c (described later) in the manufacturing flow SB. Of the parts of the model of the marine structure 1, those parts that are determined to be not finalizable (SA3c: parts that cannot be finalized) move to the third confirmation step SA3d.

The third confirmation step SA3d is a step of confirming the degree of necessary reinforcement for a member determined not to be finalizable among a part of the model of the marine structure 1. That is, the third confirmation step SA3d is a step of confirming the degree of the need to change the shape of the model of the marine structure 1.
If it is determined that a relatively large-scale shape modification is required for a component that is determined to be incomplete (SA3d: another shape review step is required), the component is transferred to the shape review step SA2, where the shape is reconsidered. If it is determined that a large-scale shape modification is not required for a component that is determined to be incomplete (SA3d: only a review of the component cross section and material is sufficient), the component is transferred to the review step SA3e.

The review step SA3e is a step for reviewing the shape of the model of the corresponding member in the marine structure 1 when it is determined that large-scale shape modification is not necessary for the member determined to be not finalizable. In the review step SA3e, for example, the cross-sectional shape of the model of the corresponding member and the material used are reviewed. For members for which the review step SA3e has been completed, the analysis implementation step SA3a is performed again.
In this embodiment, the shape consideration step SA2 and the structure analysis step SA3 may be repeated until the shape of the marine structure 1 is finally determined.

In this embodiment, for example, when multiple types of steel pipes whose diameters vary in a predetermined numerical increment are secured as stock as materials for constructing the monopile body 10 and the transition piece 20, the structural analysis step SA3 may perform structural analysis of the model of the marine structure 1 only in the predetermined diameter increment. In this case, it is preferable to consider models in the predetermined diameter increments as multiple shapes in the shape consideration step SA2 in accordance with the multiple types of steel pipes secured as stock. In other words, in the structural analysis step SA3, the diameters of the monopile body 10 and the transition piece 20 may be set in the above-mentioned shape consideration step SA2 in the predetermined numerical increments in accordance with the multiple types of steel pipes secured as stock. Specifically, for example, the predetermined diameter is preferably in the range of 7000 mm to 15000 mm in diameter in 500 mm increments, but may be any other numerical value.

In addition, for example, when multiple types of plate materials or steel pipes whose thickness varies in a predetermined numerical increment are secured as materials constituting the monopile body 10 or the transition piece 20, the structural analysis step SA3 may perform structural analysis of the model of the marine structure 1 only in the predetermined plate thickness increment. In this case, it is preferable to consider models with a predetermined plate thickness increment as multiple shapes in the shape consideration step SA2 in accordance with the multiple types of plate materials and steel pipes secured as inventory. In other words, in the structural analysis step SA3, the plate thickness of the monopile body 10 or the transition piece 20 may be set in a predetermined numerical increment in accordance with the multiple types of plate materials and steel pipes secured as inventory in the above-mentioned shape consideration step SA2. Specifically, for example, the predetermined plate thickness is preferably in 5 mm increments in the range from 70 mm to 100 mm, but may be any other numerical value.

As described above, by setting the diameter and plate thickness in the structural analysis step SA3 in predetermined numerical increments in accordance with the multiple types of plate materials and steel pipes secured as inventory, it is possible to easily prevent excess inventory from occurring and also to reduce the number of analyses to be performed at one time in the structural analysis step SA3. This makes it easier to perform the structural analysis step SA3.
In this manner, the design review flow SA is performed.

Here, in the structural analysis step SA3, the various analyses described above may take several months. Furthermore, the shape of the marine structure 1 (e.g., member cross sections, materials, etc.) is often roughly determined at the time of the first structural analysis step SA3. In this case, if the structural analysis step SA3 is performed several times and the manufacture of the marine structure 1 is started after the shape of the marine structure 1 is finally determined, there is room to shorten the process of the construction project of the marine structure 1.
In this embodiment, the manufacturing flow SB is carried out as follows, thereby contributing to shortening the process of a construction project.

The production flow SB is a flow for producing the marine structure 1. Specifically, the production flow SB is a flow for procuring materials that constitute the marine structure 1 and processing the procured materials. As shown in FIG. 5, the production flow SB includes a first production process SB1, a second production process SB2, and an assembly process SB3.

The first manufacturing process SB1 is, for example, the structural analysis process SA3 described above, which is started after the completion of the earthquake response analysis included in the first structural analysis process SA3 and before the completion of the earthquake response analysis included in the second structural analysis process SA3. The first manufacturing process SB1 is a process for manufacturing at least a part of the members constituting the marine structure 1.
Since the analysis results of each component affect each other, production (procurement) would normally begin after all of the above-mentioned structural analysis process SA3 is completed. However, in this embodiment, the first production process SB1 contributes to accelerating the completion of the marine structure 1 by, for example, starting the production of components that are deemed to be finalizable in the above-mentioned structural analysis process SA3 in advance.
In this embodiment, the first manufacturing process SB1 may, for example, manufacture a part of the members constituting the marine structure 1. An example of the part manufactured in the first manufacturing process SB1 will be described later. Alternatively, the first manufacturing process SB1 may manufacture all of the members constituting the marine structure 1.

In this embodiment, the first manufacturing process SB1 has a front first manufacturing process SB1a, a middle first manufacturing process SB1b, and a rear first manufacturing process SB1c. Note that in this embodiment, the first manufacturing process SB1 may include only one or two of these processes. Also, in this embodiment, performing the first manufacturing process SB1 means performing at least one of these processes.

The first pre-fabrication process SB1a is a process that is started before or after the preliminary investigation process SA1 during the first fabrication process SB1. The first pre-fabrication process SB1a is a process for securing in advance as an inventory materials that are highly versatile among the materials that constitute the monopile body 10 and the transition pieces 20. In the first pre-fabrication process SB1a, for example, an order is placed for multiple types of steel pipes with different diameters, plate thicknesses, and materials as materials that constitute the monopile body 10 and the transition pieces 20.
In this case, the diameters and wall thicknesses of the multiple types of steel pipes may be changed in increments of a predetermined value. The predetermined value may be, for example, any value that is appropriately determined. The predetermined value may be, for example, a discrete value.

The first intermediate manufacturing process SB1b is a process in the first manufacturing process SB1 that is started before the start of the structural analysis process SA3. In this embodiment, the first intermediate manufacturing process SB1b is started after the shape of the marine structure 1 is considered in the shape consideration process SA2.
In the first intermediate manufacturing process SB1b, for example, materials that are not procured in the first previous manufacturing process SB1a are procured. Specifically, in the first intermediate manufacturing process SB1b, for example, an order is placed for materials constituting the monopile body 10 or the transition piece 20, the shapes of which have been finalized in the shape review process SA2.

As described above, in the shape consideration process SA2 and the structural analysis process SA3, the diameters and thicknesses of the monopile body 10 and transition pieces 20 of the marine structure 1 are set in predetermined numerical increments to match the plate materials and steel pipes procured in the first manufacturing process SB1a. This makes it possible to start processing the components using appropriate materials as soon as the diameters and thicknesses of the monopile body 10 and transition pieces 20 are determined as the structural analysis process SA3 progresses.

In addition, by setting the diameters and plate thicknesses of the monopile body 10 and the transition pieces 20 as described above, it is possible to reduce the types of materials that need to be prepared in the first front manufacturing process SB1a and the first intermediate manufacturing process SB1b. This makes it easier to prevent excess inventory.
In addition, among the materials having a plurality of diameters and plate thicknesses procured as described above, it is preferable that those not used for the monopile body 10 or the transition piece 20 are diverted to other members, structures, etc. This also makes it possible to more reliably prevent excess inventory from occurring.
In addition, in the first intermediate manufacturing process SB1b, materials to be used for the auxiliary equipment 30 of the marine structure 1 may be procured. However, the materials to be used for the auxiliary equipment 30 of the marine structure 1 may be procured in the first front manufacturing process SB1a or the first rear manufacturing process SB1c.
The first intermediate manufacturing process SB1b can contribute to hastening the completion of the marine structure 1 by procuring materials in advance as described above.

The post-first manufacturing process SB1c is a process in the first manufacturing process SB1 that is started after the start of the structural analysis process SA3. In this embodiment, the post-first manufacturing process SB1c, for example, manufactures a part of the model of the marine structure 1 that is determined to be finalizable (SA3c: possible part) in the second confirmation step SA3c of the structural analysis process SA3. As described above, the part of the model of the marine structure 1 in the second confirmation step SA3c refers to either the monopile body 10 or the transition piece 20 of the marine structure 1. In the post-first manufacturing process SB1c, it is preferable to manufacture either of these that is determined to be finalizable and for which manufacturing can be started.

In the first post-production process SB1c, materials are mainly processed to form various components of the marine structure 1. In this embodiment, it is preferable that the start time of the first post-production process SB1c is appropriately set depending on, for example, the design difficulty of each component, the production process, the offshore construction process, etc. Alternatively, the first post-production process SB1c may be started as soon as the shapes of each of the various components are determined as the structural analysis process SA3 progresses.

In this embodiment, performing the above-mentioned first manufacturing process SB1 contributes to early completion of the offshore wind turbine WM. Note that it is preferable that the members to be manufactured in the first manufacturing process SB1 are appropriately determined after careful consideration.
In this embodiment, the first manufacturing process SB1 manufactures, for example, components that are rate-limiting in the manufacturing process of the marine structure 1. In this embodiment, being rate-limiting means that, for example, it takes a long time to procure materials, or it takes a long time to process and assemble materials, and therefore there is room to shorten the manufacturing process of the marine structure 1.
Below, there will be described several examples of members that are rate-limiting in the manufacturing process of the marine structure 1. In this embodiment, it is preferable to appropriately select any of the members described below and manufacture them in the first manufacturing process SB1.

In the first manufacturing process SB1, for example, a component with a shear key is manufactured. Since shear keys require a relatively large amount of welding, they take a long time to manufacture. For this reason, a component with a shear key may be manufactured in the first manufacturing process SB1.

In the first manufacturing process SB1, for example, the auxiliary equipment 30 may be manufactured. The auxiliary equipment 30 is at least one of the mooring equipment 31, ladder 32, landing 33, work platform 34, and passageway 35. These auxiliary equipment 30 require a relatively large amount of welding, and therefore require a long period of time to manufacture. For this reason, these auxiliary equipment 30 may be manufactured in the first manufacturing process SB1.

In the first manufacturing process SB1, for example, an interface flange IF may be manufactured. The interface flange IF requires time-consuming anti-corrosion processing, and therefore takes a long time to manufacture. For this reason, the interface flange IF may be manufactured in the first manufacturing process SB1.

In the first manufacturing process SB1, for example, the monopile body 10 may be manufactured. As described above, the monopile body 10 is formed by connecting multiple unit cylindrical bodies 11 in the longitudinal direction, and therefore requires a relatively large amount of welding. Also, in the first manufacturing process SB1, at least one of the inner and outer surfaces of the monopile body 10 may be coated with anti-corrosion coating. For this reason, the monopile body 10 takes a long time to manufacture. For this reason, the monopile body 10 may be manufactured in the first manufacturing process SB1.

Also, in the first manufacturing step SB1, for example, the portion of the monopile body 10 that is to be installed underground may be manufactured. As described above, the portion of the monopile body 10 that is to be installed underground, and particularly the portion close to the surface (seabed surface) of the seabed OF, may be subjected to a relatively large bending moment compared to other portions, and therefore a material with a relatively large plate thickness may be used. Such materials require a large amount of welding compared to materials with normal plate thicknesses, and therefore may require a long period of time for processing. For this reason, in the first manufacturing step SB1, the portion of the monopile body 10 that is to be installed underground may be manufactured. More specifically, for example, the material to be used for the portion of the monopile body 10 that is to be installed underground may be procured in advance.
In addition, in the first manufacturing process SB1, a connection portion of the monopile body 10 is manufactured so that it is connected to the transition piece 20 in a state where it overlaps with the transition piece 20 when viewed horizontally, and no portion of the monopile body 10 other than the connection portion is manufactured.

In this embodiment, in the first manufacturing process SB1, in addition to the rate-limiting components described above, a component whose shape is unlikely to change before and after the structural analysis process SA3 may be manufactured. Specifically, for example, the following is performed.
That is, in the first manufacturing process SB1, for example, the transition piece 20 may be manufactured. As described above, the transition piece 20 is disposed so as to overlap the upper part of the monopile body 10. Therefore, the transition piece 20 has a relatively high strength, and is unlikely to change in shape before and after the structural analysis process SA3. Therefore, the transition piece 20 may be manufactured in the first manufacturing process SB1.
In addition, in the first manufacturing process SB1, the interface flange IF of the transition piece 20 may not be manufactured, and a portion of the transition piece 20 other than the interface flange IF may be manufactured. The portion of the transition piece 20 other than the interface flange IF is, for example, a side wall portion of the transition piece 20.

In this embodiment, at least one of the above-mentioned components is manufactured in the first manufacturing process SB1. Also, more than one of the above-mentioned components may be manufactured in the first manufacturing process SB1. Specifically, for example, at least one of the monopile body 10, the transition piece 20, and the auxiliary equipment 30 may be manufactured in the later first manufacturing process SB1c. Alternatively, all of the above-mentioned various components may be manufactured in the first manufacturing process SB1.

Here, multiple marine structures 1 present at the same installation location A may be installed one by one in sequence. Therefore, in this embodiment, it is preferable that the first fabrication process SB1 is performed for at least one of the multiple marine structures 1 present at the same installation location A. In other words, it is preferable that the first fabrication process SB1 is performed only for the first one of the multiple marine structures 1 to be installed, or for some of the marine structures 1 to be installed initially. Then, for marine structures 1 whose turn comes for fabrication after the structural analysis process SA3 is completed, it is preferable to start fabrication after the structural analysis process SA3 is completed without performing the first fabrication process SB1. This makes it possible to prevent the need to redo fabrication of the marine structure 1, for example, when it becomes necessary to change the shape of the marine structure 1 based on the results of the structural analysis process SA3.

The second manufacturing process SB2 is a process for manufacturing the components constituting the marine structure 1 that are not manufactured in the first manufacturing process SB1 after the structural analysis process SA3 is completed. In the second manufacturing process SB2, it is preferable to manufacture components that do not require a long period of time for material procurement and manufacturing, for example. In addition, in the second manufacturing process SB2, it is also possible to manufacture components whose shapes are determined relatively late in the structural analysis process SA3, for example. This is preferable to prevent the need to redo the manufacturing of components due to changes in shape, and to keep costs down.

The assembly process SB3 is a process for assembling the various members manufactured in the first manufacturing process SB1 and the second manufacturing process SB2 described above.
The assembly process SB3 may be performed, for example, at a location such as a factory where the first manufacturing process SB1 and the second manufacturing process SB2 are performed. In this case, the marine structure 1 may be transported to the installation site A and installed there after the assembly process SB3 is completed.
Alternatively, the assembly process SB3 may be performed at the installation site of the marine structure 1. In this case, the marine structure 1 may be installed at the installation site A at the same time as it is assembled in the assembly process SB3.
The process planning method according to this embodiment is carried out through the above-mentioned steps.

The process planning method according to this embodiment may be implemented, for example, by a computer executing a program. In this case, all or part of the functions of the computer may be realized using hardware such as an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), or an FPGA (Field Programmable Gate Array). The program may be recorded on a computer-readable recording medium. Examples of computer-readable recording media include portable media such as flexible disks, optical magnetic disks, ROMs, and CD-ROMs, and storage devices such as hard disks built into computer systems. The program may be transmitted via a telecommunications line.

As described above, the process planning method according to the present embodiment includes a first fabrication process SB1 that is started after completion of the earthquake response analysis included in the first structural analysis process SA3 and before completion of the earthquake response analysis included in the second structural analysis process SA3, and that fabricates at least some of the members that constitute the marine structure 1 (monopile foundation). This allows the fabrication of the members to be started in advance in the first fabrication process SB1. Therefore, for example, the process of the construction project for the marine structure 1 can be shortened compared to the case where the fabrication of the marine structure 1 is started after the structural analysis process SA3 is completed. Therefore, the operation of the offshore wind turbine WM can be started earlier.
Moreover, the first manufacturing process SB1 manufactures the transition piece 20. The first manufacturing process SB1 does not manufacture the interface flange IF of the transition piece 20, but manufactures the portion of the transition piece 20 other than the interface flange IF. This shortens the waiting period for completion of the portion of the transition piece 20 other than the interface flange IF, and shortens the process of the construction project for the marine structure 1. Furthermore, the interface flange IF of the transition piece 20 can easily and flexibly respond to changes in shape that occur in the structural analysis process SA3.
In addition, the first manufacturing process SB1 manufactures the monopile body 10. In the first manufacturing process SB1, a connection portion of the monopile body 10 that is connected to the transition piece 20 in a state where it overlaps with the transition piece 20 in a horizontal view is manufactured, and no portion of the monopile body 10 other than the connection portion is manufactured. This shortens the waiting period for the completion of the connection portion of the monopile body 10, and shortens the process of the construction project for the marine structure 1. In addition, the portion of the monopile body 10 other than the connection portion can be easily and flexibly adapted to changes in shape that occur in the structural analysis process SA3.

In addition, in the structural analysis process SA3, structural analysis is performed using a model of the marine structure 1. Then, in the first manufacturing process SB1, at least some of the components that make up the marine structure 1 are manufactured before the structural analysis process SA3 is completed. This makes it possible to shorten the process of the construction project for the marine structure 1 compared to, for example, a case in which manufacturing of the marine structure 1 begins after the structural analysis process SA3 is completed. This makes it possible to start operation of the offshore wind turbine WM earlier.

The first manufacturing process SB1 also manufactures some of the components that make up the marine structure 1. In this way, by manufacturing some of the components that make up the marine structure 1 in the first manufacturing process SB1 before the structural analysis process SA3 is performed, the process of the construction project for the marine structure 1 can be shortened.

Moreover, the structural analysis step SA3 performs structural analysis of the model of the marine structure 1 only at a predetermined diameter increment. In this way, by managing the diameter of the pipes used in the production of the marine structure 1 at a predetermined diameter increment in accordance with the diameter for which the structural analysis is performed, it is possible to easily manage the inventory of pipes. Specifically, for example, it is possible to prevent the occurrence of pipes of a diameter that are procured in advance and then not used in the production of the marine structure 1 due to the results of the structural analysis, and thus prevent the occurrence of surplus inventory.
In addition, for example, the number of times the structural analysis is performed can be reduced compared to the case where the structural analysis of the model of the marine structure 1 is performed for all possible diameters. Therefore, the structural analysis step SA3 can be shortened.

Moreover, the structural analysis step SA3 performs structural analysis of the model of the marine structure 1 only in predetermined plate thickness increments. In this way, by managing the plate thickness of the plate used in the production of the marine structure 1 in predetermined plate thickness increments according to the plate thickness for which the structural analysis is performed, it is possible to easily manage the plate inventory. Specifically, for example, it is possible to prevent the occurrence of plates of a plate thickness that are procured in advance and then not used in the production of the marine structure 1 due to the results of the structural analysis, and thus to prevent the occurrence of surplus inventory.
In addition, for example, the number of times the structural analysis is performed can be reduced compared to the case where the structural analysis of the model of the marine structure 1 is performed using all possible plate thicknesses. Therefore, the structural analysis step SA3 can be shortened.

The first manufacturing process SB1 also produces the components that are rate-limiting in the manufacturing process of the marine structure 1. In this way, by manufacturing the rate-limiting components in advance in the first manufacturing process SB1, the process of the construction project for the marine structure 1 can be shortened.

Here, the shear key requires a relatively large amount of welding, which can be a rate-limiting factor in the production of the marine structure 1. Therefore, in the first production process SB1, a component with a shear key is produced. In this way, by producing a component with a shear key in the first production process SB1, which is carried out before the structural analysis process SA3, the waiting period for the completion of the component with the shear key can be shortened (or eliminated), and the process of the construction project for the marine structure 1 can be shortened.

The marine structure 1 also has auxiliary equipment 30. If the auxiliary equipment 30 requires a large amount of welding, this can become a rate-limiting step in the manufacture of the marine structure 1. Therefore, the first manufacturing process SB1 manufactures the auxiliary equipment 30. This shortens (or eliminates) the waiting period for the completion of the auxiliary equipment 30, and shortens the process of the construction project for the marine structure 1.

The auxiliary facilities 30 are at least one of the mooring facilities 31, ladders 32, landings 33, work platforms 34, and passageways 35. This shortens (or eliminates) the waiting period for the completion of any of the mooring facilities 31, ladders 32, landings 33, work platforms 34, and passageways 35, thereby shortening the construction project process for the marine structure 1.

The marine structure 1 also has a transition piece 20. The transition piece 20 is arranged so as to overlap the upper part of the marine structure 1, which makes it relatively strong. For this reason, the transition piece 20 is relatively unlikely to have its shape changed due to the analysis results of the marine structure 1. Therefore, the first manufacturing process SB1 manufactures the transition piece 20. This makes it easier to shorten the manufacturing period of the marine structure 1. Alternatively, the waiting period for the completion of the transition piece 20 can be shortened (or eliminated), thereby shortening the process of the construction project of the marine structure 1.

The transition piece 20 also has an interface flange IF. The interface flange IF requires corrosion protection processing, which can be a rate-limiting factor in the production of the marine structure 1. Therefore, the first production process SB1 produces the interface flange IF. This shortens (or eliminates) the waiting period for the interface flange IF to be completed, and shortens the process of the construction project for the marine structure 1.

The marine structure 1 is a monopile foundation. The monopile foundation has a monopile body 10, and the first manufacturing process SB1 manufactures the monopile body 10. This shortens (or eliminates) the waiting period for the completion of the monopile body 10, and shortens the process of the construction project for the marine structure 1.

Here, a relatively large bending moment may act on the portion of the monopile body 10 that is installed underground, and on that portion, particularly that portion close to the surface (seabed surface) of the seabed OF. For this reason, it may be necessary to increase the plate thickness of the portion of the monopile body 10 that is installed underground. This may lengthen the time required to weld the material used in that portion, which may become a rate-limiting factor in the manufacture of the marine structure 1. Therefore, the first manufacturing process SB1 manufactures the portion of the monopile body 10 that is installed underground. This shortens (or eliminates) the waiting period for the completion of the portion of the monopile body 10 that is installed underground, and shortens the process of the construction project for the marine structure 1.

In addition, the components constituting the marine structure 1 that are not produced in the first production process SB1 are produced in the second production process SB2 after the structural analysis process SA3 is completed. This makes it easier to prevent, for example, changes to the shape of the components occurring during production, which may result in redoing the production. Also, for example, it makes it easier to prevent excess inventory from occurring, as materials procured in advance before the structural analysis process SA3 are not used in the production of the marine structure 1. This reduces the amount of material used and the production costs of the marine structure 1.

The first manufacturing process SB1 also manufactures all of the components that make up the marine structure 1. This makes it possible to more reliably shorten the process of the construction project for the marine structure 1. Also, for example, compared to a case in which only some of the components that make up the marine structure 1 are manufactured in the first manufacturing process SB1, it is easier to adjust the order in which each component is manufactured. This makes it easier to carry out the first manufacturing process SB1 efficiently.

Here, multiple marine structures 1 at the same installation location A may be installed one by one in sequence. Therefore, the first manufacturing process SB1 is performed for at least one of the multiple marine structures 1 at the same installation location A. This allows, for example, early manufacturing to begin for the marine structure 1 that is to be installed first among the multiple marine structures 1 by the first manufacturing process SB1. This makes it easier to shorten the period from the start of a construction project for the marine structure 1 to the start of installation of the marine structure 1.

The first manufacturing process SB1 includes a pre-first manufacturing process SB1a and a middle-first manufacturing process SB1b that are started before the start of the structural analysis process SA3, and a post-first manufacturing process SB1c that is started after the start of the structural analysis process SA3. As a result, for example, in the marine structure 1, for members whose shapes have been determined before the start of the structural analysis process SA3, manufacturing can be started by the pre-first manufacturing process SB1a and the middle-first manufacturing process SB1b, and manufacturing can be started for other members in the post-first manufacturing process SB1c. Therefore, it is possible to prevent the start of manufacturing of members that include uncertain elements before the structural analysis process SA3. Therefore, it is possible to easily prevent the need to redo the manufacturing of members due to changes in the shape of the marine structure 1. Therefore, it is possible to optimize the process plan. It is also possible to easily prevent increases in costs.

The marine structure 1 is a monopile foundation. The monopile foundation has a transition piece 20 and ancillary equipment 30, and the first post-fabrication process SB1c fabricates at least one of the transition piece 20 and the ancillary equipment 30. In this way, by fabricating at least one of the transition piece 20 and the ancillary equipment 30 in the first post-fabrication process SB1c, which is started after the start of the structural analysis process SA3, it is possible to more easily prevent the need to redo the fabrication of either the transition piece 20 or the ancillary equipment 30.

The marine structure 1 is a monopile foundation. The monopile foundation has a monopile body 10, and in the first manufacturing process SB1, at least one of the inner and outer surfaces of the monopile body 10 is coated and protected from corrosion. This shortens the waiting period for the completion of the work of coating and protecting the monopile body 10 from corrosion, and shortens the process of the construction project for the marine structure 1.

The process planning method according to the present disclosure is also applied to the marine structure 1. This makes it possible to shorten the process of the construction project for the marine structure 1. This allows the offshore wind turbine WM to start operation earlier.

Second Embodiment
Next, a process planning method according to a second embodiment of the present disclosure will be described.
In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and their description will be omitted, with only the differences being described.

In the second embodiment, in the first manufacturing process SB1, for example, no components are manufactured that are not rate-limiting in the process of manufacturing the marine structure 1. In this embodiment, not being rate-limiting means, for example, that there is little room to shorten the manufacturing process of the marine structure 1 because procuring materials and processing and assembling the materials do not require a long period of time, and that there is a relatively high possibility that changes to the shape will occur in the structural analysis process SA3, so it is more preferable to start manufacturing after the shape is determined.
In this way, for the members that are not rate-limiting, by not manufacturing them in the first manufacturing process SB1 that is performed before the completion of the structural analysis process SA3, manufacturing can be started after the shape is determined. This prevents changes to the shape during manufacturing, which contributes to reducing the need to redo manufacturing.
Below, we will explain several examples of members that are not rate-limiting in the process of manufacturing the marine structure 1. In this embodiment, it is preferable to appropriately select any of the members described below and not manufacture them in the first manufacturing process SB1.

In the second embodiment, for example, the transition piece 20 is not manufactured in the first manufacturing process SB1. The transition piece 20 is a component that accounts for a large proportion of the processing cost and the weight of the material (e.g., steel) used in the marine structure 1. For this reason, it is possible to not manufacture the transition piece 20 in the first manufacturing process SB1, but to manufacture it after the shape has been determined, thereby further reducing costs incurred by reworking the manufacturing process.

In the second embodiment, for example, the monopile body 10 may not be manufactured in the first manufacturing process SB1. The monopile body 10 is a component that accounts for a large proportion of the weight of the material (e.g., steel) used in the marine structure 1. For this reason, the monopile body 10 may not be manufactured in the first manufacturing process SB1, but may be manufactured after the shape has been determined, thereby further reducing costs incurred by reworking the manufacturing process.

In the second embodiment, for example, in the first manufacturing process SB1, at least one of both ends of the monopile body 10 may not be manufactured. As described above, the monopile body 10 is formed by connecting multiple unit cylindrical bodies 11 in the longitudinal direction. At this time, the unit cylindrical bodies 11 located at other than both ends of the monopile body 10 are welded at both ends, whereas the unit cylindrical bodies 11 located at both ends of the monopile body 10 are welded only at one end. Therefore, the amount of welding at both ends of the monopile body 10 is small, and it is unlikely to be a rate-limiting factor in the manufacturing process. For this reason, by not manufacturing at least one of both ends of the monopile body 10 in the first manufacturing process SB1, it may be possible to more flexibly respond to changes in shape in the structural analysis process SA3.

In the second embodiment, for example, the auxiliary equipment 30 may not be fabricated in the first fabrication process SB1. The auxiliary equipment 30 is at least one of the mooring equipment 31, ladder 32, landing 33, work platform 34, and passageway 35. These auxiliary equipment 30 are easily affected by the design results of the main components of the marine structure 1 (e.g., transition piece 20), and therefore their shapes are likely to change due to the structural analysis process SA3. For this reason, the auxiliary equipment 30 may not be fabricated in the first fabrication process SB1, but may be fabricated after the shape has been determined, thereby further reducing costs incurred by re-fabrication.

In the second embodiment, at least one of the above-mentioned components is not produced in the first manufacturing process SB1. Also, it is possible to avoid producing a plurality of the above-mentioned components in the first manufacturing process SB1. Alternatively, it is possible to avoid producing all of the above-mentioned various components in the first manufacturing process SB1.

As described above, according to the process planning method of the second embodiment, the first manufacturing process SB1 does not manufacture components that are not rate-limiting in the manufacturing process of the marine structure 1. This makes it easier to flexibly respond to changes in shape for components that are not manufactured.

The marine structure 1 also has a transition piece 20. The transition piece 20 requires a relatively large amount of material and processing effort. Therefore, the first manufacturing process SB1 does not manufacture the transition piece 20. This allows the manufacturing of the transition piece 20 to begin after the shape of the transition piece 20 has been optimized. This prevents the shape of the transition piece 20 from being changed during manufacturing, making it easier to reduce the manufacturing costs of the marine structure 1.

The marine structure 1 is a monopile foundation, which has a monopile body 10. The monopile body 10 uses a relatively large amount of material. Therefore, the first manufacturing process SB1 does not manufacture the monopile body 10. This allows the manufacturing of the monopile body 10 to begin after the shape of the monopile body 10 has been optimized. This prevents the shape of the monopile body 10 from being changed during manufacturing, making it easier to reduce the manufacturing costs of the marine structure 1.

The monopile body 10 is constructed by welding multiple unit tubular bodies 11 in the longitudinal direction. At this time, the unit tubular bodies 11 located at positions other than both ends of the monopile body 10 are welded at both ends, whereas the unit tubular bodies 11 located at both ends of the monopile body 10 are welded at only one end. Therefore, the amount of welding at both ends of the monopile body 10 is small, and it is relatively unlikely to be a rate-limiting step in the manufacture of the marine structure 1. Therefore, in the first manufacturing process SB1, at least one of the two ends of the monopile body 10 is not manufactured. This makes it easier to flexibly respond to changes in shape that occur in the member.

The marine structure 1 also has ancillary equipment 30. The ancillary equipment 30 is easily affected by the design results of the main components of the marine structure 1 (e.g., the transition piece 20), and is therefore prone to changes in shape. Therefore, the first manufacturing process SB1 does not manufacture the ancillary equipment 30. This allows the manufacturing of the ancillary equipment 30 to begin after the shape of the ancillary equipment 30 has been optimized. This prevents the ancillary equipment 30 from being subject to shape changes during manufacturing, making it easier to keep manufacturing costs of the marine structure 1 down.

The auxiliary equipment 30 is at least one of the mooring equipment 31, ladder 32, landing 33, work floor 34, and passageway 35. This prevents changes to the shape of the mooring equipment 31, ladder 32, landing 33, work floor 34, and passageway 35 during production, making it easier to reduce the production costs of the marine structure 1.

The technical scope of the present disclosure is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present disclosure.
For example, the process planning method according to this embodiment may be applied to structures other than the marine structure 1.
Furthermore, in the structural analysis step SA3, the structural analysis of the model of the marine structure 1 may be performed at any diameter or thickness instead of at a predetermined diameter or thickness increment.
Also, the first manufacturing process SB1 may be configured not to manufacture any members having shear keys.
Furthermore, the marine structure 1 does not need to be equipped with a transition piece 20.
Furthermore, the marine structure 1 does not have to be a monopile foundation.
In addition, in the first manufacturing process SB1, it is possible not to manufacture the portion of the monopile body 10 that is to be installed underground.
In addition, in the first manufacturing process SB1, one or both of the two end portions of the monopile body 10 may be manufactured.
In addition, in the first manufacturing process SB1, it is possible not to manufacture all of the components that make up the marine structure 1.
Furthermore, the first manufacturing process SB1 may be performed for two or more of the multiple marine structures 1 present at the same installation site A, or may be performed for all of them.
Furthermore, the first manufacturing process SB1 does not necessarily have to include the intermediate first manufacturing process SB1b and the subsequent first manufacturing process SB1c.
Furthermore, in the first manufacturing process SB1, at least one of the inner and outer surfaces of the monopile body 10 does not need to be coated with corrosion protection.

In addition, the components in the above embodiment may be replaced with well-known components as appropriate without departing from the spirit of this disclosure, and the above-mentioned modifications may be combined as appropriate.

(Additional Note)
The process planning method and the marine structure according to the embodiment can be understood, for example, as follows.

<1> A process planning method according to one aspect of the present disclosure is a process planning method for planning the process of a construction project of a monopile foundation that has a monopile body and a transition piece and supports the tower of an offshore wind turbine, the process including: a structural analysis process in which a computer performs structural analysis of a model of the monopile foundation multiple times; and a first manufacturing process that is started after completion of an earthquake response analysis included in the first structural analysis process and before completion of an earthquake response analysis included in the second structural analysis process, and that manufactures at least a part of the components that constitute the monopile foundation, the first manufacturing process manufacturing the transition piece, the first manufacturing process not manufacturing an interface flange of the transition piece, and manufacturing a part of the transition piece other than the interface flange, the first manufacturing process manufacturing the monopile body, the first manufacturing process manufacturing a connection part of the monopile body that is connected in a state where it overlaps with the transition piece in a horizontal view, and not manufacturing a part of the monopile body other than the connection part.

According to the above process planning method, a first fabrication process is started after completion of the earthquake response analysis included in the first structural analysis process and before completion of the earthquake response analysis included in the second structural analysis process, and includes a first fabrication process for fabricating at least some of the components that constitute the monopile foundation. This allows the fabrication of the components to be started in advance in the first fabrication process. Therefore, for example, the process of a construction project for an offshore structure can be shortened compared to a case in which fabrication of the offshore structure is started after completion of the structural analysis process. Therefore, the operation of the offshore wind turbine can be started earlier.
Moreover, the first manufacturing process manufactures the transition piece. In the first manufacturing process, the interface flange of the transition piece is not manufactured, but the portion of the transition piece other than the interface flange is manufactured. This shortens the waiting period for the completion of the portion of the transition piece other than the interface flange, and shortens the process of the offshore structure construction project. Furthermore, the interface flange of the transition piece can easily and flexibly respond to changes in shape that occur in the structural analysis process.
In addition, the first manufacturing process manufactures the monopile body. In the first manufacturing process, a connection portion of the monopile body that is connected to the transition piece in a state where it overlaps with the transition piece in a horizontal view is manufactured, and no portion of the monopile body other than the connection portion is manufactured. This shortens the waiting period for the completion of the connection portion of the monopile body, and shortens the process of the marine structure construction project. In addition, the portion of the monopile body other than the connection portion can be easily and flexibly adapted to changes in shape that occur in the structural analysis process.

<2> A process planning method according to one aspect of the present disclosure is a process planning method for planning the process of a construction project for an offshore structure that supports the tower of an offshore wind turbine, and is characterized by comprising a structural analysis process for performing a structural analysis of a model of the offshore structure, and a first manufacturing process for manufacturing at least a portion of the components that make up the offshore structure before completion of the structural analysis process.

According to the above process planning method, in the structural analysis process, a structural analysis is performed using a model of the marine structure. Then, in the first manufacturing process, at least some of the components that make up the marine structure are manufactured before the structural analysis process is completed. This makes it possible to shorten the process of a construction project for the marine structure, for example, compared to a case in which manufacturing of the marine structure begins after the structural analysis process is completed. This makes it possible to start operation of the offshore wind turbine earlier.

<3> In the process planning method according to <2> above, the first manufacturing process may be configured to manufacture a portion of a component that constitutes the marine structure.

The first manufacturing process also produces some of the components that make up the marine structure. In this way, by producing some of the components that make up the marine structure in the first manufacturing process before the structural analysis process is performed, the process of the marine structure construction project can be shortened.

<4> In the process planning method according to <2> or <3> above, the structural analysis process may be configured to perform structural analysis of the marine structure model only at predetermined diameter intervals.

In addition, the structural analysis step performs structural analysis of the marine structure model only at a predetermined diameter interval. In this way, by managing the diameter of the pipes used in the manufacture of the marine structure at a predetermined diameter interval in accordance with the diameter for which the structural analysis is performed, it is possible to easily manage the inventory of pipes. Specifically, for example, it is possible to prevent the occurrence of pipes of a diameter that are procured in advance and then not used in the manufacture of the marine structure due to the results of the structural analysis, and thus prevent the occurrence of surplus inventory.
In addition, for example, the number of times the structural analysis is performed can be reduced compared to when the structural analysis of the marine structure model is performed for all possible diameters, thereby shortening the structural analysis process.

<5> In the process planning method according to any one of the above <2> to <4>, the structural analysis process may be configured to perform structural analysis of the marine structure model only at a predetermined plate thickness increment.

In addition, the structural analysis step performs structural analysis of the marine structure model only in predetermined plate thickness increments. In this way, by managing the plate thickness of the plate used in the production of the marine structure in predetermined plate thickness increments according to the plate thickness for which the structural analysis is performed, it is possible to easily manage the plate inventory. Specifically, for example, it is possible to prevent the occurrence of plates of a plate thickness that are procured in advance and then not used in the production of the marine structure due to the results of the structural analysis, and thus prevent the occurrence of excess inventory.
In addition, for example, the number of times the structural analysis is performed can be reduced compared to when the structural analysis of the marine structure model is performed using all possible plate thicknesses, thereby shortening the structural analysis process.

<6> In the process planning method according to any one of the above <2> to <5>, the first manufacturing process may be configured to manufacture a component that is rate-limiting in the manufacturing process of the marine structure.

The first manufacturing process also produces the components that are rate-limiting in the manufacturing process of the marine structure. In this way, by manufacturing the rate-limiting components in advance in the first manufacturing process, the process of the marine structure construction project can be shortened.

<7> In the process planning method according to any one of the above <2> to <6>, the first manufacturing process may be configured to manufacture a component having a shear key.

Here, the shear key requires a relatively large amount of welding, which can be a rate-limiting factor in the production of marine structures. Therefore, in the first production process, components with shear keys are produced. In this way, by producing components with shear keys in the first production process, which is carried out before the structural analysis process, the waiting period for the completion of components with shear keys can be shortened, and the process of marine structure construction projects can be shortened.

<8> In the process planning method according to any one of the above <2> to <7>, the marine structure may have auxiliary equipment, and the first manufacturing process may be configured to manufacture the auxiliary equipment.

In addition, marine structures have auxiliary equipment. If the auxiliary equipment requires a large amount of welding, this can become a rate-limiting factor in the manufacture of the marine structure. Therefore, the first manufacturing process manufactures the auxiliary equipment. This shortens the waiting period for the completion of the auxiliary equipment, and shortens the process of the marine structure construction project.

<9> In the process planning method according to <8> above, the auxiliary equipment may be at least one of a mooring facility, a ladder, a landing, a work platform, and a passageway.

The auxiliary equipment is at least one of the following: mooring equipment, ladders, landings and work platforms, and gangways. This shortens the waiting period for the completion of the mooring equipment, ladders, landings and work platforms, and gangways, and shortens the process of the marine structure construction project.

<10> In the process planning method according to any one of the above <2> to <9>, the marine structure may have a transition piece, and the first manufacturing process may be configured to manufacture the transition piece.

The marine structure also has a transition piece. The transition piece is placed so as to overlap the upper part of the marine structure, which makes it relatively strong. For this reason, the transition piece is relatively unlikely to undergo changes in shape due to the analysis results of the marine structure. Therefore, the first manufacturing process is to manufacture the transition piece. This makes it easier to shorten the manufacturing period of the marine structure. Alternatively, it is possible to shorten the waiting period for the completion of the transition piece and shorten the process of the marine structure construction project.

<11> In the process planning method according to <10> above, the transition piece may have an interface flange, and the first manufacturing process may be configured to manufacture the interface flange.

The transition piece also has an interface flange. The interface flange requires corrosion protection processing, which can be a time-limiting step in the manufacture of marine structures. Therefore, the first manufacturing process is to manufacture the interface flange. This shortens the waiting period for the interface flange to be completed, and shortens the process of the marine structure construction project.

<12> In the process planning method according to any one of the above <2> to <11>, the marine structure may be a monopile foundation, the monopile foundation may have a monopile body, and the first manufacturing process may be configured to manufacture the monopile body.

The marine structure is a monopile foundation. The monopile foundation has a monopile body, and the first manufacturing process is to manufacture the monopile body. This shortens the waiting period for the completion of the monopile body, and shortens the process of the marine structure construction project.

<13> In the process planning method according to <12> above, the first manufacturing process may be configured to manufacture the portion of the monopile body that is to be installed underground.

Here, a relatively large bending moment may act on the portion of the monopile body that is installed underground, and on that portion, particularly that portion close to the seabed. For this reason, it may be necessary to increase the plate thickness of the portion of the monopile body that is installed underground. This may lengthen the time required to weld the material used in that portion, which may become a rate-limiting factor in the manufacture of marine structures. Therefore, the first manufacturing process manufactures the portion of the monopile body that is installed underground. This shortens the waiting period for the completion of the portion of the monopile body that is installed underground, and shortens the process of the marine structure construction project.

<14> The process planning method according to any one of the above <2> to <13> may be configured to include a second manufacturing process in which, after completion of the structural analysis process, components constituting the marine structure that are not manufactured by the first manufacturing process are manufactured.

In addition, the components constituting the marine structure that are not produced in the first production process are produced in the second production process after the structural analysis process is completed. This makes it easier to prevent, for example, changes to the shape of a component occurring during production, which would require redoing production. Also, for example, it makes it easier to prevent excess inventory from occurring, since materials procured in advance before the structural analysis process are not used in the production of the marine structure. This therefore reduces the amount of material used and the production costs of the marine structure.

<15> In the process planning method according to any one of the above <2> to <14>, the first manufacturing process may be configured to not manufacture any components that are not rate-limiting in the manufacturing process of the marine structure.

In addition, the first manufacturing process does not manufacture components that are not rate-limiting in the manufacturing process of the marine structure. This makes it easier to flexibly respond to changes in the shape of the components that are not manufactured.

<16> In the process planning method according to any one of the above <2> to <15>, the marine structure may have a transition piece, and the first manufacturing process may be configured not to manufacture the transition piece.

The marine structure also has a transition piece. The transition piece requires a relatively large amount of material and processing effort. Therefore, the first manufacturing process does not manufacture the transition piece. This allows the manufacturing of the transition piece to begin after the shape of the transition piece has been optimized. This prevents the transition piece from being subject to shape changes during manufacturing, making it easier to reduce the manufacturing costs of the marine structure.

<17> In the process planning method according to any one of the above <2> to <16>, the marine structure may be a monopile foundation, the monopile foundation may have a monopile body, and the first manufacturing process may be configured not to manufacture the monopile body.

The marine structure is a monopile foundation, which has a monopile body. A relatively large amount of material is used in the monopile body. Therefore, the first manufacturing process does not manufacture the monopile body. This allows the manufacture of the monopile body to begin after the shape of the monopile body has been optimized. This prevents the shape of the monopile body from being changed during manufacturing, making it easier to reduce the manufacturing costs of the marine structure.

<18> In the process planning method according to <17> above, the first manufacturing process may be configured such that at least one of the two ends of the monopile body is not manufactured.

The monopile body is constructed by welding multiple basic pipes (blank pipes) in the longitudinal direction. In this case, the blank pipes located at any other end of the monopile body are welded at both ends, whereas the blank pipes located at both ends of the monopile body are welded at only one end. Therefore, the amount of welding at both ends of the monopile body is small, and it is relatively unlikely to be a rate-limiting step in the manufacture of marine structures. Therefore, in the first manufacturing process, at least one of the ends of the monopile body is not manufactured. This makes it easier to flexibly respond to changes in shape that occur in the member.

<19> In the process planning method according to any one of the above <2> to <18>, the marine structure may have auxiliary equipment, and the first manufacturing process may be configured to not manufacture the auxiliary equipment.

The marine structure also has auxiliary equipment. The auxiliary equipment is easily affected by the design results of the main components of the marine structure (e.g., transition pieces), and so changes in shape are likely to occur. Therefore, the first manufacturing process does not manufacture the auxiliary equipment. This allows the manufacturing of the auxiliary equipment to begin after the shape of the auxiliary equipment has been optimized. This prevents the auxiliary equipment from changing its shape during manufacturing, making it easier to reduce the manufacturing costs of the marine structure.

<20> In the process planning method according to <19> above, the auxiliary equipment may be at least one of a mooring facility, a ladder, a landing, a work platform, and a passageway.

The auxiliary equipment is at least one of the mooring equipment, ladders, landings and work platforms, and walkways. This prevents changes to the shape of the mooring equipment, ladders, landings and work platforms, and walkways during construction, making it easier to reduce the manufacturing costs of marine structures.

<21> In the process planning method according to any one of the above <2> to <20>, the first manufacturing process may be configured to manufacture all of the components that constitute the marine structure.

The first manufacturing process also produces all of the components that make up the marine structure. This makes it possible to more reliably shorten the process of a marine structure construction project. Also, for example, compared to a case in which only some of the components that make up the marine structure are produced in the first manufacturing process, it is easier to adjust the order in which each component is manufactured. This makes it easier to carry out the first manufacturing process efficiently.

<22> In the process planning method according to any one of the above <2> to <21>, the first manufacturing process may be performed on at least one of the multiple marine structures present in the same wind farm or sea area.

Here, multiple marine structures that exist in the same wind farm or sea area may be installed one by one in sequence. Thus, the first manufacturing process is performed for at least one of the multiple marine structures that exist in the same wind farm or sea area. This allows, for example, early manufacturing to begin for an marine structure that is to be installed first among the multiple marine structures through the first manufacturing process. This makes it easier to shorten the period from the start of a marine structure construction project to the start of installation of the marine structure.

<23> In the process planning method according to any one of the above <2> to <22>, the first manufacturing process may be configured to include a pre-first manufacturing process and a middle-first manufacturing process that are started before the structural analysis process begins, and a post-first manufacturing process that is started after the structural analysis process begins.

The first manufacturing process includes a first pre-manufacturing process and a first intermediate manufacturing process that are started before the start of the structural analysis process, and a first post-manufacturing process that is started after the start of the structural analysis process. This allows, for example, in an offshore structure, the manufacturing of members whose shapes have been determined before the start of the structural analysis process to begin in the first pre-manufacturing process and the first intermediate manufacturing process, and the manufacturing of other members to begin in the first post-manufacturing process. This makes it possible to prevent the manufacturing of members that include uncertain elements from beginning before the structural analysis process. This makes it easier to prevent the need to redo the manufacturing of members due to changes in the shape of the offshore structure. This makes it easier to optimize the process plan. It also makes it easier to prevent increases in costs.

<24> In the process planning method according to <23> above, the marine structure may be a monopile foundation, the monopile foundation may have a transition piece and ancillary equipment, and the first fabrication process may be configured to fabricate at least one of the transition piece and the ancillary equipment.

The marine structure is a monopile foundation. The monopile foundation has a transition piece and ancillary equipment, and the first post-fabrication process fabricates at least one of the transition piece and the ancillary equipment. In this way, by fabricating at least one of the transition piece and the ancillary equipment in the first post-fabrication process that is started after the start of the structural analysis process, it is possible to more easily prevent the need to redo the fabrication of either the transition piece or the ancillary equipment.

<25> In the process planning method according to any one of the above <2> to <24>, the marine structure may be a monopile foundation, the monopile foundation may have a monopile body, and in the first manufacturing process, at least one of the inner and outer surfaces of the monopile body may be coated and protected from corrosion.

The marine structure is a monopile foundation. The monopile foundation has a monopile body, and in the first manufacturing process, at least one of the inner and outer surfaces of the monopile body is coated and protected from corrosion. This shortens the waiting period for the completion of the work of coating and protecting the monopile body from corrosion, and shortens the process of the marine structure construction project.

<26> The marine structure according to one embodiment of the present disclosure is applied to a process planning method according to any one of the above <1> to <25>.

The process planning method according to the present disclosure is also applied to the marine structure according to the present disclosure. This makes it possible to shorten the process of the marine structure construction project. As a result, it is possible to speed up the start of operation of offshore wind turbines.

1 Marine structure 10 Monopile body 11 Unit cylindrical body 11A Plate 20 Transition piece 30 Accessory equipment 31 Mooring equipment 32 Ladder 33 Landing 34 Work floor 35 Passage A Installation location B Bolt C Cable DC Davit crane G Grout H Hole IF Interface flange OF Seabed SA Design review flow SA1 Preliminary investigation process SA2 Shape review process SA3 Structural analysis process SA3a Analysis implementation step SA3b First confirmation step SA3c Second confirmation step SA3d Third confirmation step SA3e Review step SB Production flow SB1 First production process SB1a Front first production process SB1b Middle first production process SB1c Rear first production process SB2 Second production process SB3 Assembly process T Tower WM Offshore wind turbine

Claims (1)

A process planning method for planning a process for a construction project of a monopile foundation that supports a tower of an offshore wind turbine, the monopile foundation having a monopile body and a transition piece, comprising:
a structural analysis step in which a computer performs a structural analysis of the monopile foundation model multiple times;
a first fabrication process that is started after completion of an earthquake response analysis included in a first structural analysis process and before completion of an earthquake response analysis included in a second structural analysis process, the first fabrication process fabricating at least a part of the members that constitute the monopile foundation;
Equipped with
The first manufacturing step includes manufacturing the transition piece,
The first manufacturing step does not manufacture an interface flange of the transition piece, and manufactures a portion of the transition piece other than the interface flange,
The first manufacturing step includes manufacturing the monopile body,
The first manufacturing process is a process planning method in which a connection portion of the monopile body is manufactured so as to be connected to the transition piece in a state where it overlaps with the transition piece when viewed horizontally, and no portion of the monopile body other than the connection portion is manufactured.

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