Work scaffolding, removal method for work scaffolding, and attaching method for work scaffolding

Abstract

To provide a work scaffolding which can be suppressed from being large-sized and enables stabler work, and a removal method for the work scaffolding and an attaching method for the work scaffolding.SOLUTION: There is provided a work scaffolding 1 for a jacket structure J for an offshore wind turbine that includes a first leg L1 stood on the ground, a second leg L2 stood on the ground, and a brace B connecting the first leg L1 and second leg L2. The work scaffolding also comprises a work floor into which the first leg L1 or brace B is inserted.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a work scaffold, a method for removing the work scaffold, and a method for installing the work scaffold. [Background technology]

[0002] 2. Description of the Related Art Jacket structures for offshore wind turbines have been assembled in the past. US Patent No. 5,399,633 discloses a scaffolding provided for welding the upper and lower ends of a brace to a leg. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-46721 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the scaffolding in Patent Document 1 has a problem in that when two tiers of braces are installed on the jacket structure for an offshore wind turbine, if the distance between the upper end of the lower brace and the lower end of the upper brace, or the distance between the connection between the leg and transition piece and the upper end of the upper brace, becomes long, the scaffolding becomes large.

[0005] Therefore, an object of the present disclosure is to provide a work scaffolding that can prevent an increase in size and enables more stable work, a method for removing the work scaffolding, and a method for installing the work scaffolding. [Means for solving the problem]

[0006] <1> The work scaffolding according to aspect 1 of the present disclosure is a work scaffolding for a jacket structure for an offshore wind turbine including a first leg erected on the ground, a second leg erected on the ground, and a brace connecting the first leg and the second leg, and is characterized in that it comprises a work floor into which the first leg or the brace is inserted. Effect of the Invention

[0007] According to the present disclosure, it is possible to provide a work scaffolding that can be prevented from becoming large and that enables more stable work to be performed, a method for removing the work scaffolding, and a method for installing the work scaffolding. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of a jacket structure for an offshore wind turbine installed offshore. [Diagram 2] FIG. 13 is an enlarged view of a portion of the first leg where the first work platform is provided. [Diagram 3] FIG. 11 is a plan view of the jacket structure for an offshore wind turbine when a boat fender is provided on the first leg. [Figure 4] FIG. 13 is an enlarged view of a portion of the first leg where the second work scaffold is provided. [Diagram 5] 2 is a schematic diagram showing a connection structure between a mounting piece 22 and a bracket 23. FIG. [Figure 6] FIG. 13 is an enlarged view of a portion of the transition piece where a third work scaffold is provided. [Figure 7] FIG. 1 is a first diagram of the process of removing the first work platform from the first leg. [Figure 8] FIG. 2 is a second diagram of the process of removing the first work platform from the first leg. [Figure 9] FIG. 13 is a diagram showing the process of removing the second work scaffold from the first leg. [Figure 10] FIG. [Figure 11] 13 is a diagram showing a state in which the first leg and the second leg are stood on the ground by the mounting jig. FIG. [Figure 12]FIG. [Figure 13] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] A work scaffold according to an embodiment of the present disclosure will be described below with reference to the drawings. The work scaffold according to this embodiment is used when assembling an offshore wind turbine jacket structure. That is, the work scaffold according to this embodiment is attached to components of the offshore wind turbine jacket structure when assembling the offshore wind turbine jacket structure. Workers stand on the work scaffold thus attached and perform various tasks. Then, the work scaffold is removed after the assembly of the offshore wind turbine jacket structure is completed. In describing the work scaffolding, first, the jacket structure for an offshore wind turbine according to this embodiment will be described.

[0010] (Jacket structure for offshore wind turbines) FIG. 1 is a perspective view of a jacket structure J for an offshore wind turbine installed on the sea. The jacket structure J for an offshore wind turbine is placed on the ocean and supports an offshore wind turbine. As shown in Fig. 1, the jacket structure J for an offshore wind turbine includes a transition piece T, a leg L, and a brace B. Note that a first work scaffold 10, a second work scaffold 20, and a third work scaffold 30, which will be described later, are each provided in the areas shown in Fig. 1.

[0011] (Transition Piece) A lower end of the offshore wind turbine tower WT is connected to the transition piece T. The transition piece T is supported by a plurality of legs L including a first leg L1 and a second leg L2 described below. The transition piece T includes a center pipe T1, an upper flange T2, a lower flange T3, and a web T4. The center pipe T1 is a cylindrical member provided in the center of the transition piece T. The axis of the center pipe T1 is aligned in the vertical direction. The lower end of the offshore wind turbine tower WT is connected to the upper end of the center pipe T1.

[0012] The upper flange T2 is a plate-like member disposed on the upper part of the center pipe T1. The upper flange T2 is disposed so as to be perpendicular to the pipe axis of the center pipe T1. That is, the upper flange T2 has a through hole H in the center. The center pipe T1 is inserted into the through hole H provided in the upper flange T2. The center pipe T1 and the upper flange T2 are joined by, for example, welding.

[0013] The lower flange T3 is configured to be paired with the upper flange T2. That is, the lower flange T3 is a plate-shaped member disposed at the lower part of the center pipe T1. The lower flange T3 is disposed so as to be perpendicular to the pipe axis of the center pipe T1. The lower end of the center pipe T1 is disposed so as to be in contact with the upper surface of the lower flange T3. The center pipe T1 and the lower flange T3 are joined by, for example, welding.

[0014] The web T4 is a plate-like member that reinforces the transition piece T. That is, the web T4 connects the center pipe T1, the upper flange T2, and the lower flange T3 to one another. Specifically, the edges of the web T4 are joined to each of the center pipe T1, the upper flange T2, and the lower flange T3 by welding or the like. Furthermore, the legs L may be joined to the edges of the web T4 by welding or the like. In this way, the web T4 reinforces the structure of the transition piece T.

[0015] (Reg) The leg L supports the transition piece T. Specifically, the leg L is a rod-shaped member whose upper end is connected to the transition piece T and whose lower end is connected to a pile P driven into the seabed. A plurality of legs L are provided in the jacket structure J for an offshore wind turbine. In the jacket structure J for an offshore wind turbine according to this embodiment, four legs L are provided. In this embodiment, one of the four legs L is referred to as a first leg L1. The leg L located next to the first leg L1 in the circumferential direction of the jacket structure J for an offshore wind turbine is referred to as a second leg L2. The leg L located next to the second leg L2 and facing the first leg L1 is referred to as a third leg L3. The leg L located next to the third leg L3 and the first leg L1 and facing the second leg L2 is referred to as a fourth leg L4. Hereinafter, when there is no need to distinguish between the first leg L1, the second leg L2, the third leg L3, and the fourth leg L4, they will be referred to as legs L.

[0016] Each of the multiple legs L in the jacket structure J for an offshore wind turbine includes a tubular member Lp. The tubular member Lp is a tubular member that is joined to the leg L. One end of the tubular member Lp is connected to the leg L. The tubular member Lp extends from the one end connected to the leg L such that the other end faces diagonally upward or diagonally downward. Note that diagonally upward refers to a direction that is inclined with respect to upward in the vertical direction and that faces higher than the horizontal direction. Diagonally upward refers to a direction that is inclined with respect to downward in the vertical direction and that faces lower than the horizontal direction. The lower end of the brace B provided on the upper or lower side in the vertical direction is connected to the cylindrical member Lp extending diagonally upward. The upper end of the brace B provided on the upper or lower side in the vertical direction is connected to the cylindrical member Lp extending diagonally downward. Details of the brace B will be described later. Although not shown, in this embodiment, the outer diameter of the cylindrical member Lp is larger than the outer diameter of the brace B.

[0017] In the leg L, the tubular members Lp are provided in the same number as the number of connection parts with the brace B. For example, as described below, two X-shaped braces B are provided, one above the other, between the first leg L1 and the second leg L2. Thus, the first leg L1 includes four tubular members Lp for the brace B provided between the first leg L1 and the second leg L2. Similarly, the first leg L1 includes four tubular members Lp for the brace B provided between the first leg L1 and the fourth leg L4. Therefore, in this embodiment, the first leg L1 has eight tubular members Lp. In this embodiment, the second leg L2, the third leg L3, and the fourth leg L4 each similarly have eight tubular members Lp. The form of the tubular members Lp is common to the multiple legs L provided in the offshore wind turbine jacket structure J. In this embodiment, the tubular member Lp and the brace B are joined by, for example, welding.

[0018] (Brace) The brace B connects the multiple legs L together. Specifically, the brace B is provided between the first leg L1 and the second leg L2, between the second leg L2 and the third leg L3, between the third leg L3 and the fourth leg L4, and between the fourth leg L4 and the first leg L1, and connects these to each other. In this embodiment, the brace B is joined to the legs L by welding via the cylindrical member Lp. In this way, the brace B reinforces the jacket structure J for an offshore wind turbine. In this embodiment, the brace B is a steel pipe assembled in an X-shape. The brace B is provided in two stages in the vertical direction between the multiple legs L. Hereinafter, the upper end of the steel pipes in the brace B formed in the X-shape is referred to as the upper end of the brace B. The lower end of the steel pipes in the brace B formed in the X-shape is referred to as the lower end of the brace B. Alternatively, the brace B may be a steel pipe extending horizontally. The horizontally extending brace B is preferably provided, for example, near the lower end of the leg L of the jacket structure J for an offshore wind turbine.

[0019] (Work scaffolding) Next, the work scaffold 1 according to this embodiment will be described. The work scaffold 1 is provided during the assembly work of the jacket structure J for an offshore wind turbine having the above-mentioned configuration. This allows workers to stand on the work scaffold 1 and perform work such as welding and painting on the jacket structure J for an offshore wind turbine.

[0020] In this embodiment, an example will be described in which the work scaffold 1 is attached to the first leg L1 of the multiple legs L. Also, an example will be described in which a worker stands on the work scaffold 1 and performs work such as welding and painting the brace B provided between the first leg L1 and the second leg L2, and welding and painting the periphery of the connection part between the first leg L1 and the transition piece T. Note that the work scaffold 1 may also be similarly attached to the second leg L2, the third leg L3, and the fourth leg L4. That is, the work scaffold 1 may be provided on the second leg L2, the third leg L3, and the fourth leg L4, and work similar to each of the above-mentioned works may be performed on each of them.

[0021] FIG. 2 is an enlarged view of a portion of the first leg L1 where the first work scaffold 10 is provided. FIG. 3 is a plan view of the jacket structure J for an offshore wind turbine when a boat fender Lb is provided on the first leg L1. FIG. 4 is an enlarged view of a portion of the first leg L1 where the second work platform 20 is provided. FIG. 5 is a schematic diagram showing a connection structure between the mounting piece 22 and the bracket 23. As shown in FIG. FIG. 6 is an enlarged view of a portion of the transition piece T where the third work platform 30 is provided. In this embodiment, the work scaffolding 1 is classified into a first work scaffolding 10, a second work scaffolding 20, and a third work scaffolding 30 depending on the location of attachment to the offshore wind turbine jacket structure J. Hereinafter, when there is no need to distinguish between these, they will be referred to as the work scaffolding 1.

[0022] (First work scaffold) The first work scaffolding 10 is provided around a connection portion between the lower end of the upper brace B and the first leg L1, and a connection portion between the upper end of the lower brace B and the first leg L1, among the braces B provided in two stages in the vertical direction in the jacket structure J for an offshore wind turbine. In other words, the first work scaffolding 10 is a so-called middle stage scaffolding in the jacket structure J for an offshore wind turbine. On the first work scaffold 10, a worker performs work on, for example, the first leg L1 or the brace B, which is a portion where the first leg L1 and the brace B are connected. That is, on the first work scaffold 10, a worker performs work such as welding the first leg L1 and the brace B together.

[0023] As shown in FIG. 2, the first work scaffold 10 includes a rod-shaped member 11 and a first work floor 12 (work floor). The rod-shaped member 11 is a rod-shaped member extending along the horizontal direction. In the first working scaffold 10 provided on the first leg L1, the rod-shaped member 11 abuts against the first leg L1 (details will be described later). The rod-shaped member 11 is connected to the first working platform 12, which will be described next.

[0024] The first working floor 12 is a configuration including a portion of the first working scaffold 10 where a worker stands. The first working floor 12 is for a worker to perform work on the portion of the first leg L1 or the brace B where the first leg L1 and the brace B are connected. The first working floor 12 is connected to the rod-shaped member 11. As shown in FIG. 2, the first working floor 12 includes a scaffolding board 12a, a vertical frame 12b, an inclined frame 12c, and a support frame 12d.

[0025] The scaffold plank 12a is a portion on which a worker stands in the first work scaffold 10. The scaffold plank 12a is formed, for example, by arranging a plurality of long planks. Alternatively, the scaffold plank 12a may be formed from a single plank. The scaffolding board 12a is supported by a vertical frame 12b, a diagonal frame 12c, and a support frame 12d. In the first working floor 12, the vertical frame 12b, the diagonal frame 12c, and the support frame 12d are provided in pairs so as to be symmetrical on both ends of the rod-shaped member 11 extending along the horizontal direction. Hereinafter, one of the configurations provided in the pair will be described, and the description of the other will be omitted.

[0026] The vertical frame 12b is a member extending downward from an end of the rod-shaped member 11. One end of the vertical frame 12b is connected to the rod-shaped member 11. The other end of the vertical frame 12b is connected to the support frame 12d. The oblique frame 12c is a member extending obliquely downward from an end of the rod-shaped member 11. Specifically, the oblique frame 12c extends in a direction in which a plane including the downward direction in which the vertical frame 12b extends and the direction in which the oblique frame 12c extends is substantially perpendicular to the direction in which the rod-shaped member 11 extends. In this embodiment, substantially perpendicular means that the angle at which the two intersect is 85 degrees or more and 95 degrees or less. One end of the oblique frame 12c is connected to the rod-shaped member 11. The other end of the oblique frame 12c is connected to the support frame 12d.

[0027] The support frame 12d supports the scaffold plank 12a. That is, in the first work scaffold 10, the scaffold plank 12a is arranged so as to be spanned across a pair of support frames 12d. The support frame 12d is supported by the vertical frame 12b and the diagonal frame 12c, and functions as a girder on which the scaffold plank 12a is spanned. The support frame 12d is fixed to the scaffold plank 12a by wire or the like.

[0028] In this embodiment, as shown in Fig. 2, a first leg L1 is inserted into the first working floor 12 of the first working scaffold 10. Specifically, of the multiple tubular members Lp provided on the first leg L1, a tubular member Lp whose tip is welded to the lower end of the brace B and extends obliquely upward is inserted into the first working floor 12 of the first working scaffold 10. The first working floor 12 has an opening 12o for inserting the first leg L1. The opening 12o is an area surrounded by the scaffolding board 12a, the vertical frame 12b, the diagonal frame 12c, and the support frame 12d. In this embodiment, inserting the first leg L1 into the first working floor 12 means that the cylindrical member Lp of the first leg L1 is placed in the opening 12o thus formed. In other words, the first working platform 12 is provided so as to surround the cylindrical member Lp of the first leg L1. This makes it possible to easily arrange the first working platform 12 in the vicinity of the first leg L1.

[0029] In this embodiment, the first work scaffold 10 having the above-mentioned configurations is provided on the first leg L1 such that the first work floor 12 is suspended from the first leg L1. Here, as described above, the rod-shaped member 11 abuts against the first leg L1. More specifically, as shown in Fig. 2, the rod-shaped member 11 is positioned so as to be sandwiched between the first leg L1 and a cylindrical member Lp, of the multiple cylindrical members Lp provided on the first leg L1, whose tip is welded to the lower end of the brace B and which extends obliquely upward. That is, the first work scaffold 10 is provided on the first leg L1 with the first work floor 12 suspended from the first leg L1 by hooking the rod-shaped members 11 onto the tubular members Lp. By supporting the first work floor 12 by the first leg L1, which is part of the offshore wind turbine jacket structure J in this way, the structure of the first work scaffold 10 can be simplified. This makes it easier to make the first work scaffold 10 more compact.

[0030] Here, as shown in Fig. 3, the first leg L1 may include a boat fender Lb. The boat fender Lb allows a work boat to come into contact with the first leg L1. The boat fender Lb is located outside the area surrounded by the first leg L1, the second leg L2, and the third leg L3. That is, the boat fender Lb is provided outside the jacket structure J for an offshore wind turbine. In this case, the first work scaffold 10 is preferably located inside the area surrounded by the first leg L1, the second leg L2, and the third leg L3, as shown in Fig. 3. This makes it possible to prevent interference between the first work floor 12 and the boat fender Lb when the boat fender Lb is provided on the first leg L1. Also, when the first work scaffold 10 is provided on a leg L where no boat fender Lb is provided, the structure of the first work scaffold 10 can be reused. In this embodiment, when the first work scaffold 10 is located inside the area surrounded by the first leg L1, the second leg L2, and the third leg L3, this also includes a state in which only a portion of the first work scaffold 10 is located in the area. Moreover, it is preferable that the first work scaffold 10 is not located within a plane including the central axis of the center pipe T1 and the central axis of the first leg L1. Furthermore, the first work scaffolding 10 may be provided in a pair on the first leg L1 so as to be symmetrical with respect to a plane including the central axis of the center pipe T1 and the central axis of the first leg L1.

[0031] The first work scaffold 10 is formed by the above-mentioned components. In addition to the above configurations, a fence F may be provided around the first working floor 12 to ensure the safety of the worker. A ladder Ld may be provided outside the fence F so that the worker can move up and down. When the ladder Ld is provided in this way, the fence F may not be provided in the area in order to ensure an area in which the worker can move from the ladder Ld to the first working floor 12. A step 12s may be provided in the area in order for the worker to move from the ladder Ld to the first working floor 12. Alternatively, the ladder Ld may be provided inside the fence F. In addition, a step scaffold S may be provided by attaching it to the fence F provided around the first working floor 12 to make it easier for the worker to work around the tubular member Lp and the brace B.

[0032] (Second work scaffold) The second work scaffolding 20 is provided around a connection between the upper end of the upper brace B and the first leg L1, and a connection between the transition piece T and the first leg L1, of the braces B provided in two stages in the vertical direction in the jacket structure J for an offshore wind turbine. In other words, the second work scaffolding 20 is what is called an upper stage scaffolding in the jacket structure J for an offshore wind turbine. On the second work scaffold 20, a worker performs work on, for example, the first leg L1 or the brace B, which is a portion where the first leg L1 and the brace B are connected. Alternatively, on the second work scaffold 20, a worker may perform work on, for example, a portion where the transition piece T and the first leg L1 are connected.

[0033] As shown in FIG. 4, the second work scaffold 20 includes a second work floor 21 (work floor), an attachment piece 22, and a bracket 23. The second work floor 21 is a portion of the second work scaffolding 20 on which a worker stands. The second work floor 21 is for the worker to work on, for example, a portion of the first leg L1 or the brace B where the first leg L1 and the brace B are connected, or a portion where the transition piece T and the first leg L1 are connected. Alternatively, the second work floor 21 is for the worker to work on, for example, a portion where the transition piece T and the first leg L1 are connected.

[0034] In this embodiment, a brace B is inserted into the second working floor 21 of the second working scaffolding 20, as shown in Fig. 4. The second working floor 21 is a plate-like member having a notch 21C for inserting the brace B into. The notch 21C is a portion that corresponds to the opening 12o in the first working floor 12 described above. In this embodiment, inserting the brace B into the second working floor 21 means that the brace B is placed in the notch 21C formed in the second working floor 21. In other words, the second working floor 21 is provided so as to surround the brace B. This makes it possible to easily arrange the second working floor 21 in the vicinity of the brace B. The second work platform 21 is supported on the first leg L1 by a mounting piece 22 and a bracket 23, which will be described below.

[0035] The mounting piece 22 is a plate-like member attached to the outer circumferential surface of the first leg L1. The mounting piece 22 is attached to the outer circumferential surface of the first leg L1 by, for example, welding or the like. As shown in FIG. 5, the mounting piece 22 has a mounting through hole 22H to which the bracket 23 can be attached. The bracket 23 is a rod-shaped member provided between the mounting piece 22 and the second working floor 21. That is, one end of the bracket 23 is fixed to the mounting piece 22, and the other end is fixed to the lower surface of the second working floor 21. In this embodiment, the bracket 23 is an H-shaped steel, and is formed by cutting out the end of the H-shaped steel to match the shape of the mounting piece 22. The bracket 23 is fixed to the mounting piece 22 and the second working floor 21, for example, by bolt fastening. Note that, as shown in FIG. 5, the bracket 23 has a bracket through-hole 23H corresponding to the mounting through-hole 22H of the mounting piece 22. That is, the mounting piece 22 and the bracket 23 are fixed to each other by a bolt (not shown) after the mounting through-hole 22H and the bracket through-hole 23H are aligned with each other. Thus, in this embodiment, the second working floor 21 is supported by the first leg L1 by connecting the bracket 23 provided on the underside of the second working floor 21 to the mounting piece 22 provided on the first leg L1. By supporting the second working floor 21 by the first leg L1, which is part of the offshore wind turbine jacket structure J, the structure of the second working scaffolding 20 can be simplified. Therefore, the second working scaffolding 20 can be made more compact.

[0036] The second work scaffold 20 is formed by the above-mentioned components. It is preferable that the second work scaffold 20 is also located inside the area surrounded by the first leg L1, the second leg L2, and the third leg L3 for the same reasons as the first work scaffold 10. The second work scaffold 20 being located inside the area surrounded by the first leg L1, the second leg L2, and the third leg L3 also includes a state in which only a portion of the second work scaffold 20 is located in the area. In addition, it is preferable that the second work scaffold 20 is not located within a plane including the central axis of the center pipe T1 and the central axis of the first leg L1. Furthermore, the second work scaffolding 20 may be provided in a pair on the first leg L1 so as to be symmetrical with respect to a plane including the central axis of the center pipe T1 and the central axis of the first leg L1.

[0037] Also, in the second work scaffold 20, a fence F may be provided around the second work floor 21 to ensure the safety of the worker. Also, a ladder Ld may be provided on the outside of the fence F to enable the worker to move up and down. Depending on the ladder Ld provided on the second work scaffold 20, it may be possible to move between the second work scaffold 20 and the lower part of the third work scaffold 30 described next. In addition, in order to make it easier for workers to work around the tubular member Lp and the brace B, a step scaffold S may be provided so as to be attached to a fence F provided around the second work floor 21.

[0038] (Third work scaffold) The third work scaffold 30 is provided around the upper end of the first leg L1 in the transition piece T of the jacket structure J for an offshore wind turbine. In other words, the third work scaffold 30 is a so-called TP scaffold in the jacket structure J for an offshore wind turbine. At the third work scaffold 30, a worker performs, for example, work on the periphery of the first leg L1 connected to the transition piece T. That is, at the third work scaffold 30, a worker performs, for example, work of welding the first leg L1 to the upper flange T2 and the lower flange T3 of the transition piece T. Note that welding of the first leg L1 to the upper flange T2 is preferably performed inside a factory building, and is preferably not performed outside the factory building and with the first leg L1 standing on the ground.

[0039] As shown in FIG. 6, the third work scaffold 30 includes a plate-like member 31 and a third work floor 32 (work floor). The plate-shaped member 31 is a plate-shaped member disposed along the horizontal direction. The plate-shaped member 31 abuts against the upper surface of the upper flange T2 of the transition piece T (details will be described later). As shown in FIG. 6, the plate-shaped member 31 has an opening 31o for preventing the upper end of the first leg L1 from being covered. The plate-shaped member 31 is connected to a third work floor 32 described next. In the third work scaffold 30, a worker may perform work while standing on the plate-shaped member 31. In addition, when a worker enters the inside of the first leg L1 from the upper end of the first leg L1 to perform work, the worker may enter the inside of the first leg L1 from the opening 31o provided in the plate-shaped member 31.

[0040] The third work floor 32 is a portion of the third work scaffold 30 that includes a portion on which a worker stands. The third work floor 32 is for a worker to perform work in the area surrounding the first leg L1 connected to the transition piece T. The third work floor 32 is connected to the plate-like member 31. The third work floor 32 includes a scaffold frame 32a, a vertical frame 12b, and an inclined frame 12c. The scaffolding frame 32a is a portion on which a worker stands in the third work scaffolding 30. The scaffolding frame 32a is formed, for example, by arranging a plurality of planks on a rod-shaped framework. Alternatively, the scaffolding frame 32a may be formed by a single plank. The scaffolding frame 32a is supported by a vertical frame 12b and an inclined frame 12c. In the third working floor 32, the vertical frame 12b and the inclined frame 12c are provided in pairs so as to be symmetrical on both ends of the plate-like member 31 arranged along the horizontal direction. Hereinafter, one of the components provided in the pair will be described, and the description of the other will be omitted. The vertical frame 12b and the diagonal frame 12c have the same configuration as those provided on the first work floor 12 of the first work scaffolding 10, but differ from the first work floor 12 in the following points.

[0041] In the third working floor 32, one end of the vertical frame 12b is connected to the plate-like member 31, and the other end is connected to the scaffolding frame 32a. In addition, in the third working floor 32, a plurality of the vertical frames 12b are provided on each of one side and the other side. In the third working platform 32, the diagonal frame 12c has one end connected to the plate-like member 31 and the other end connected to the scaffolding frame 32a.

[0042] In this embodiment, the first leg L1 is inserted into the third working floor 32 of the third working scaffold 30, as shown in FIG. The third working floor 32 has an opening 32o for inserting the first leg L1. The opening 32o is an area surrounded by the scaffolding frame 32a, the vertical frame 12b, and the diagonal frame 12c. In this embodiment, inserting the first leg L1 into the third working floor 32 means that the first leg L1 is placed in the opening 32o thus formed. In other words, the third working platform 32 is provided so as to surround the first leg L1. This makes it possible to easily arrange the third working platform 32 in the vicinity of the first leg L1.

[0043] The third work scaffold 30 having the above-mentioned configuration is provided around the first leg L1 with the third work floor 32 suspended from the transition piece T. Here, as described above, the plate-like member 31 abuts against the upper flange T2 of the transition piece T. That is, the third work scaffold 30 is provided around the first leg L1 with the plate-like member 31 hooked onto the upper flange T2 of the transition piece T, so that the third work floor 32 is suspended from the transition piece T. In this way, by supporting the third work floor 32 by the transition piece T, which is part of the offshore wind turbine jacket structure J, the structure of the third work scaffold 30 can be simplified. Therefore, the third work scaffold 30 can be made easier to miniaturize. In order to protect the paint on the upper flange T2, it is preferable to place a stand (not shown) between the plate-shaped member 31 and the upper flange T2. For example, an H-shaped steel beam or the like is preferably used as the stand. In this embodiment, the plate-shaped member 31 abutting against the upper flange T2 includes a state in which a stand is provided between the plate-shaped member 31 and the upper flange T2.

[0044] The third work scaffold 30 is formed by the above-mentioned components. Also, in the third work scaffold 30, a fence F may be provided around the third work floor 32 to ensure the safety of workers. Also, a staircase St may be provided outside the fence F to enable workers to move up and down. Depending on the staircase St provided in the third work scaffold 30, it may be possible to move between the third work scaffold 30 and the upper part of the second work scaffold 20. In addition, the second work scaffold 20 may be connected to a third work scaffold 30 to reinforce the attachment of the second work scaffold 20 to the first leg L1.

[0045] (How to remove work scaffolding) Next, a method for removing the work scaffolding 1 in the offshore wind turbine jacket structure J according to this embodiment will be described. That is, a moving step in the process of removing the first work scaffolding 10 and the second work scaffolding 20 from the offshore wind turbine jacket structure J will be described. FIG. 7 is a first view of the process of removing the first work scaffold 10 from the first leg L1. FIG. 8 is a second view of the process of removing the first work scaffold 10 from the first leg L1. FIG. 9 is a diagram showing the process of removing the second work scaffold 20 from the first leg L1. Here, when removing the first work scaffolding 10 and the second work scaffolding 20 after the assembly of the offshore wind turbine jacket structure J is completed, for example, as shown in Figs. 7 and 8, the second work scaffolding 20 is located above the first work scaffolding 10. Furthermore, as shown in Fig. 9, the transition piece T and the third work scaffolding 30 are located above the second work scaffolding 20. For this reason, when removing the first work scaffolding 10 and the second work scaffolding 20, it is necessary to take into consideration each component located above. For this reason, when removing the first work scaffolding 10 and the second work scaffolding 20, it is preferable to remove them by moving them horizontally with respect to the offshore wind turbine jacket structure J.

[0046] The moving step is a process of moving the first work scaffold 10 or the second work scaffold 20 from inside the area surrounded by the first leg L1, the second leg L2, and the third leg L3 to outside the area. That is, for example, as shown in Figures 7 and 8, when removing the first work scaffolding 10, after removing the fence F, ladder Ld, etc., the first work scaffolding 10 is lifted up to an extent that the tubular member Lp can be removed from the opening 12o, and then it is moved horizontally and removed from the jacket structure J for the offshore wind turbine. 9, when removing the second work scaffolding 20, after removing the fence F, ladder Ld, etc., the second work floor 21 is removed from the brackets 23 and mounting pieces 22 while being supported by a hanging device CL described below. After that, the second work floor 21 is suspended from between the first leg L1 and the brace B to a height at which it can be removed, and then moved horizontally and removed from the jacket structure J for an offshore wind turbine.

[0047] In this way, by moving the first work scaffolding 10 and the second work scaffolding 20 horizontally outside the jacket structure J for the offshore wind turbine, the first work scaffolding 10 and the second work scaffolding 20 can be removed without interfering with the structures located above them.

[0048] In addition, when removing the first work scaffolding 10 and the second work scaffolding 20, it is difficult to lift the first work scaffolding 10 and the second work scaffolding 20 directly from above because they interfere with the various components located above. Therefore, the moving step includes a connecting step of connecting the suspending device CL to the work scaffold 1. That is, in the moving step, by suspending the first work scaffold 10 and the second work scaffold 20 using the suspending device CL, it is possible to move the first work scaffold 10 and the second work scaffold 20 without interfering with the structures located above the first work scaffold 10 and the second work scaffold 20, respectively.

[0049] FIG. 10 is an enlarged view of the suspension device CL. In this embodiment, the suspension device CL is a balance-like device as shown in Fig. 10. The suspension device CL includes a horizontal beam CL1 extending in the horizontal direction, a weight CL2 provided at one end of the horizontal beam CL1, a suspension wire CL3 for suspending the horizontal beam CL1, and a slide mechanism CL4 that can change the position of the suspension wire CL3 in the longitudinal direction of the horizontal beam CL1.

[0050] That is, in the connection step, with the weight CL2 attached to one end of the cross beam CL1, the first work scaffolding 10 or the second work scaffolding 20 is connected to the other end of the cross beam CL1. At this time, the other end of the cross beam CL1 and the first work scaffolding 10 or the second work scaffolding 20 are fixed by, for example, a wire or a bolt (not shown). Then, the first work scaffolding 10 or the second work scaffolding 20 and the weight CL2 are balanced. At this time, in addition to balancing the cross beam CL1 by adjusting the weight of the weight CL2, the position of the hanging wire CL3 relative to the cross beam CL1 may be adjusted by a slide mechanism. This makes it possible to lift the first work scaffolding 10 or the second work scaffolding 20 by the cross beam CL1, and enables the first work scaffolding 10 and the second work scaffolding 20 to be removed without affecting the various components located above.

[0051] (How to install a work scaffold) Next, a method for attaching the work scaffolding 1 in the offshore wind turbine jacket structure J according to this embodiment will be described. That is, a method for attaching the first work scaffolding 10 and the second work scaffolding 20 in the assembly process of the offshore wind turbine jacket structure J will be described. FIG. 11 is a diagram showing a state in which the first leg L1 and the second leg L2 are erected on the ground by the mounting jig BJ. FIG. 12 is a diagram showing the suspension step. FIG. 13 is a diagram showing a supporting step. The following describes an example of the next process for the offshore wind turbine jacket structure J in the middle of assembly. That is, the process of attaching the first work scaffold 10 and the second work scaffold 20 to the first leg L1 when connecting the first leg L1 and the second leg L2 with the brace B in a state in which the first leg L1 and the second leg L2 are standing on the ground leaning against the mounting jig BJ as shown in Fig. 11 will be described. That is, the method of attaching the first work scaffold 10 and the second work scaffold 20 includes a hanging step and a supporting step.

[0052] The hanging step is a step of attaching the first work scaffold 10 to the first leg L1 as shown in Fig. 12. As described above, the first work scaffold 10 is provided on the first leg L1 such that the first work floor 12 is suspended from the first leg L1 by hooking the rod-shaped member 11 onto the tubular member Lp. That is, the hanging step is a process of suspending the first work scaffold 10 from the tubular member Lp of the first leg L1, which is a tubular member Lp whose tip is welded to the lower end of the brace B and extends obliquely upward. When the hanging step is performed, the second work scaffold 20 and the like are not positioned above the first work scaffold 10, as shown in Fig. 12. Therefore, unlike the moving step for removing the first work scaffold 10, the hanging step may use a normal crane instead of using the hanging device CL.

[0053] When the first work scaffold 10 is suspended by the suspension step, the scaffold board 12a of the first work floor 12 is not provided. This allows the cylindrical member Lp to be inserted into the opening 12o of the first work floor 12. The scaffold board 12a is arranged so as to be hung between the pair of support frames 12d after the first work scaffold 10 is hooked onto the cylindrical member Lp by the suspension step.

[0054] The supporting step is a step of making the first leg L1 support the second work scaffold 20 after the hanging step, as shown in Fig. 12. As described above, the second work floor 21 is supported by the first leg L1 by joining the bracket 23 provided on the underside of the second work floor 21 to the mounting piece 22 provided on the first leg L1. That is, the supporting step is That is, the support step is a process in which the second work floor 21 of the second work scaffolding 20 is inserted into the upper end of the brace B temporarily placed near the first leg L1, i.e., the temporarily placed brace B is placed in the notch 21C formed in the second work floor 21, and then the second work floor 21 and the first leg L1 are connected by the mounting piece 22 and the bracket 23.

[0055] In addition, when performing the supporting step, in order to avoid interference with the cylindrical member Lp and the like provided on the first leg L1, the second working floor 21 is placed on the first leg L1 while being lifted by the above-mentioned hoisting device CL. At this time, it is preferable that the mounting piece 22 is attached to the first leg L1 in advance. Also, it is preferable that the bracket 23 is attached to the lower surface of the second working floor 21 in advance. Thus, in the supporting step, it is preferable that only the work of fixing the bracket 23 and the mounting piece 22 with bolts is performed.

[0056] After the first work scaffold 10 and the second work scaffold 20 are attached to the first leg L1 by the hanging step and supporting step described above, the first leg L1 and the second leg L2 are connected by a brace B. Similarly, the first leg L1, the second leg L2, the third leg L3, and the fourth leg L4 are each connected by a brace B. In this way, the structure in which multiple legs L are connected by the braces B becomes self-supporting without being leaned against the mounting jig BJ. After the above-mentioned state is reached, the transition piece T is attached to the upper ends of the multiple legs L. At this time, it is preferable that the third work scaffold 30 is attached to the transition piece T on the ground in advance before moving to the upper ends of the multiple legs L.

[0057] As described above, the working scaffold 1 according to this embodiment includes the first working floor 12, the second working floor 21, or the third working floor 32 into which the first leg L1 or the brace B is inserted. Hereinafter, these may be referred to as working floors without distinction. In other words, the working floor of the working scaffold 1 according to this embodiment has the opening 12o, 32o or the notch 21C, and is arranged on the jacket structure J for an offshore wind turbine so that the first leg L1 or the brace B is inserted into the opening 12o. This makes it easier to arrange the working floor in the vicinity of the first leg L1 or the brace B. Also, the configuration supporting the working floor and the like can be easily arranged in the vicinity of the first leg L1 or the brace B. Thus, the working scaffold 1 can be made smaller. Therefore, the cost of the working scaffold 1 can be reduced. Also, by suppressing the increase in size of the working scaffold 1, the increase in size of the configuration supporting the working floor can be suppressed, and the working floor can be more stably arranged. Furthermore, by being able to arrange the working floor in the vicinity of the first leg L1 or the brace B, the worker can stand closer to the connection between the first leg L1 and the brace B. Therefore, it is easier to perform work on the first leg L1 or the brace B in a stable manner.

[0058] Moreover, the first working floor 12 is suspended from the first leg L1. In this way, the structure of the working scaffold 1 can be simplified by supporting the working floor by the first leg L1, which is a part of the jacket structure J for an offshore wind turbine. Therefore, the working scaffold 1 can be easily made compact. Also, the work of attaching the working floor to the first leg L1 can be performed, for example, by suspending the working floor from above the first leg L1 using a crane or a hoisting device CL. Therefore, for example, the working scaffold 1 can be brought close to the installation location of the first leg L1 in a pre-assembled state. Therefore, the work of attaching the working scaffold 1 to the first leg L1 can be easily performed.

[0059] Moreover, the first working floor 12 is suspended from the first leg L1 by the rod-shaped member 11 connected to the working floor abutting against the first leg L1. In other words, the working floor is suspended from the first leg L1 by allowing the rod-shaped member 11 connected to the working floor to be hooked onto the first leg L1. This makes it possible to more easily and stably attach the working floor to the first leg L1. Therefore, it is possible to more easily and stably install the working scaffold 1 on the jacket structure J for an offshore wind turbine.

[0060] In addition, the first working floor 12 is suspended from the first leg L1 by hooking the rod-shaped member 11 connected to the working floor on the cylindrical member Lp provided on the first leg L1. This allows the working floor to be located near the cylindrical member Lp. Here, the tip of the cylindrical member Lp is welded to the end of the brace B. Therefore, the worker can perform the welding work between the cylindrical member Lp and the end of the brace B while standing near the cylindrical member Lp. This makes it easier for the worker to stably perform the welding work between the cylindrical member Lp and the end of the brace B.

[0061] In addition, the second working floor 21 is supported by the first leg L1. This makes it possible to improve the stability of the working floor attached to the offshore wind turbine jacket structure J.

[0062] Furthermore, the second working floor 21 is supported by the first leg L1 by joining a bracket 23 provided on the underside of the working floor to an attachment piece 22 provided on the first leg L1. As a result, for example, after attaching the working floor to the jacket structure J for an offshore wind turbine so as to suspend it from above, the bracket 23 provided on the underside of the working floor can be joined to the attachment piece 22, thereby making it possible to support the working floor on the first leg L1. This makes it easier to carry out work to improve the stability of the working floor.

[0063] Furthermore, in the offshore wind turbine jacket structure J, the boat fender Lb included in the first leg L1 is located outside the area surrounded by the first leg L1, the second leg L2, and the third leg L3, and the work floor is located inside the area surrounded by the first leg L1, the second leg L2, and the third leg L3. This makes it possible to prevent the work floor from interfering with the boat fender Lb when the work floor is attached to the offshore wind turbine jacket structure J. Furthermore, when the work scaffold 1 is provided on a leg L where no boat fender Lb is provided, the structure of the work scaffold 1 can be reused.

[0064] Moreover, the third working floor 32 is suspended from a transition piece T supported by the first leg L1 and the second leg L2. In this way, by supporting the working floor by the transition piece T, which is part of the offshore wind turbine jacket structure J, the structure of the working scaffold 1 can be simplified. Therefore, the working scaffold 1 can be easily made compact.

[0065] In addition, the third working floor 32 is suspended from the transition piece T by hooking the plate-like member 31 connected to the working floor onto the upper flange T2 of the transition piece T. This allows the working floor to be disposed in the vicinity of the transition piece T. This allows workers to stably perform work around the transition piece T.

[0066] Moreover, according to the method for removing the work scaffolding 1 according to this embodiment, in the moving step, the first work scaffolding 10 or the second work scaffolding 20 is moved from inside to outside the area surrounded by the first leg L1, the second leg L2, and the third leg L3 in the jacket structure J for an offshore wind turbine. That is, in the moving step, the first work scaffolding 10 or the second work scaffolding 20 to be removed is moved to the outside of the jacket structure without being moved upward. This makes it possible to prevent the work scaffolding 1 to be removed, the hoisting wire CL3 that suspends the work scaffolding 1, the crane, etc. from interfering with the components located above, for example, when components of the jacket structure J for an offshore wind turbine or another work scaffolding 1 are located above the first work scaffolding 10 or the second work scaffolding 20 to be removed.

[0067] The moving step also includes a connecting step of connecting the suspension device CL to the first work scaffold 10 or the second work scaffold 20. This allows the suspension device CL to perform the work of moving the first work scaffold 10 or the second work scaffold 20 from the inside to the outside of the area surrounded by the first leg L1, the second leg L2, and the third leg L3 of the offshore wind turbine jacket structure J. Therefore, the work of moving the first work scaffold 10 or the second work scaffold 20 can be performed stably without being affected by the configurations located above the first work scaffold 10 and the second work scaffold 20 during removal.

[0068] Furthermore, the installation method for the work scaffold 1 according to this embodiment includes a hanging step and a supporting step that is performed after the hanging step. In the hanging step, the first work scaffold 10 is hung from the tubular member Lp of the first leg L1. The tip of the tubular member Lp is welded to the lower end of the brace B. In the supporting step, after the hanging step, the work floor of the second work scaffold 20 is inserted into the upper end of the brace B, and the second work scaffold 20 is supported by the first leg L1. That is, the first work scaffolding 10 located below the brace B is provided on the offshore wind turbine jacket structure J prior to the second work scaffolding 20 located above the brace B. This allows the work of attaching the first work scaffolding 10 in the hanging step to be performed in a state where the second work scaffolding 20 is not attached to the offshore wind turbine jacket structure J. This makes it possible to prevent the second work scaffolding 20 from interfering with the work of attaching the first work scaffolding 10 to the offshore wind turbine jacket structure J. This makes it possible to improve the efficiency of the work of attaching the first work scaffolding 10.

[0069] 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, in the jacket structure J for an offshore wind turbine, four legs L are provided, but this is not limited thereto. That is, only three legs L may be provided in the jacket structure J for an offshore wind turbine, or five or more legs L may be provided.

[0070] In addition, within the scope of the present disclosure, the components in the above-described embodiments may be replaced with well-known components as appropriate, and the above-described modified examples may be combined as appropriate. [Explanation of symbols]

[0071] 1 Working scaffolding 10 First work platform 11 Rod-shaped member 12 First work platform 12a Scaffolding board 12b Vertical Frame 12c diagonal frame 12d Support frame 12o opening 20 Second work scaffold 21 Second work platform 22 Mounting piece 23 Bracket 30 Third Work Scaffold 31 Plate-shaped members 31o opening 32 Third Work Platform 32a Scaffolding Frame 32o opening B Brace BJ mounting fixture CL device CL1 crossbeam CL2 weight CL3 Wire CL4 Slide mechanism F fence J Jacket structure for offshore wind turbines L leg L1 First Leg L2 Second Leg L3 Third Leg L4 4th Leg Lb Boat Fender Ld ladder Lp Cylindrical member P pile S Step Scaffolding St stairs T Transition Piece T1 Center Pipe T2 Top flange T3 Bottom flange T4 Web WT Offshore Wind Turbine Tower

Claims

1. The first leg was erected on the ground, The second leg was erected on the ground, a brace connecting the first leg and the second leg; A work scaffold for an offshore wind turbine jacket structure comprising: A work floor into which the first leg or the brace is inserted; A work scaffold comprising:

2. The working platform is suspended from the first leg. A working scaffold as claimed in claim 1.

3. A rod-shaped member connected to the work floor; Further comprising: The work floor is suspended from the first leg by the rod-shaped member abutting against the first leg. A working scaffold as claimed in claim 2.

4. The first leg is a cylindrical member whose tip is welded to the lower end of the brace and extends obliquely upward; Equipped with The work floor is suspended from the first leg by hooking the rod-shaped member onto the cylindrical member. A working scaffold as claimed in claim 3.

5. The working platform is supported on the first leg. A working scaffold as claimed in claim 1.

6. The work floor is supported by the first leg by joining a bracket provided on a lower surface of the work floor to a mounting piece provided on the first leg. A working scaffold as claimed in claim 5.

7. The jacket structure for an offshore wind turbine further includes a third leg, the first leg includes a boat fender; the boat fender is located outside an area surrounded by the first leg, the second leg, and the third leg; The work platform is located inside the area. A working scaffold according to any one of claims 1 to 6.

8. The offshore wind turbine jacket structure includes a transition piece supported by the first leg and the second leg; Including, The working platform is suspended from the transition piece. A working scaffold as claimed in claim 1.

9. A plate-shaped member connected to the work floor; Further comprising: The working floor is suspended from the transition piece by hooking the plate-shaped member onto the upper flange of the transition piece. A working scaffold as claimed in claim 8.

10. A method for removing a work scaffold according to any one of claims 1 to 6, The jacket structure for an offshore wind turbine includes a third leg, a moving step of moving the work scaffold from inside an area surrounded by the first leg, the second leg, and the third leg to outside the area; A method for removing a work scaffolding comprising:

11. The moving step includes a connecting step of connecting a suspension device to the working platform. A method for removing a work scaffold according to claim 10.

12. The first leg was erected on the ground, The second leg was erected on the ground, a brace connecting the first leg and the second leg; A method for attaching a first work scaffold and a second work scaffold to an offshore wind turbine jacket structure comprising: a suspending step of suspending the first work scaffold from a tubular member of the first leg, the tubular member having a tip welded to the lower end of the brace and extending obliquely upward; After the hanging step, a supporting step of inserting a work floor of the second work scaffold into the upper end of the brace and supporting the second work scaffold on the first leg; A method for installing a work scaffold, comprising:

Images