Jacket structure

Abstract

To provide a jacket structure allowing smooth load transmission between a leg and a connection member for connecting the leg and a pile.SOLUTION: A jacket structure 100 has a plurality of legs 20 to support a marine structure, a plurality of piles 40 respectively connected to the plurality of legs 20, and a connection member 50 to connect one of the plurality of legs 20 and a sleeve 51 into which the pile 40 corresponding to one of the plurality of piles 40 is inserted. The connection member 50 includes an upper flange 52, a lower flange 53, and a web 54. A rib 60 for connecting one of the legs 20 and the upper flange 52 is disposed on the upper flange 52.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a jacket structure.

Background Art

[0002] In order to arrange a windmill or the like used for wind power generation on the sea (offshore windmill), a foundation structure may be connected to a foundation pile driven into the seabed or the like (jacket structure). Patent Document 1 discloses a technique for avoiding the occurrence of resonance in an underwater structure. Specifically, an underwater structure in which a support member is filled with a filler is disclosed in order to freely determine the natural period. Patent Document 2 discloses a joint structure in which the filling position of grout between a steel pipe pile and an externally inserted steel pipe is limited in order to facilitate the removal work of a pile-type structure.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] The skirt sleeve and its periphery have a complex structure and are likely to have stress concentration. In particular, stress is likely to concentrate between the leg of the jacket structure and the connecting member that connects the leg and the pile driven into the ground. Therefore, there is a problem in ensuring the load transmission path between the leg and the connecting member.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a jacket structure capable of smoothly transmitting a load between a leg and a connecting member that connects the leg and a pile. [Means for solving the problem]

[0006] To solve the aforementioned problems, the present invention proposes the following means. <1> A jacket structure according to Embodiment 1 of the present invention is a jacket structure comprising: a plurality of legs supporting an offshore structure; a plurality of piles connected to each of the plurality of legs; a connecting member connecting one of the plurality of legs and a pile corresponding to one of the plurality of piles into a sleeve, wherein the connecting member includes an upper flange, a lower flange, and a web, and the upper flange is provided with a rib connecting the one and the upper flange.

[0007] According to this invention, the upper flange is provided with a rib that connects one of the multiple legs to the upper flange. This reinforces the connection between one of the legs and the upper flange, and allows for smoother load transfer from one of the legs to the upper flange.

[0008] <2> A jacket structure according to embodiment 2 of the present invention is characterized in that, in the jacket structure according to embodiment 1, the upper flange connects the one and a sleeve into which a pile corresponding to the one is inserted, and the upper flange is inclined such that the end of the upper flange on the side of the one is located vertically lower than the end of the upper flange on the side of the pile corresponding to the one.

[0009] According to this invention, the upper flange is inclined such that the end of the upper flange on one side of the leg is located vertically lower than the end of the upper flange on the pile side corresponding to one of the legs. Here, the leg may have a bending point on the upper side of the connecting member, particularly near the upper flange. In this case, if the rib connecting the connecting member and one of the legs interferes with the bending point of one of the legs, the conditions for structural design become complicated. For this reason, it is preferable that the bending point and the rib are in separate positions. In contrast, the upper flange is inclined such that the position of the end of the upper flange on one side of the leg is lower. This makes it possible to increase the distance between the upper surface of the upper flange and one of the legs. Therefore, even if the bending point of the leg is near the connecting member, the rib can be made larger without interfering with the bending point of one of the legs. Thus, it is possible to avoid the conditions for structural design becoming complicated.

[0010] <3> A jacket structure according to aspect 3 of the present invention is characterized in that, in the jacket structure according to aspect 1 or aspect 2, the rib connects the one rib to the upper surface of the upper flange.

[0011] According to this invention, the rib connects one of the legs to the upper surface of the upper flange. Here, the lower end of the leg is connected to a connecting member. The leg extends upward from the connecting member. Therefore, stress concentration between the leg and the connecting member is likely to occur, particularly between the portion of the leg located above the connecting member and the upper flange of the connecting member. Thus, by connecting one of the legs to the upper surface of the upper flange with a rib, the reinforcing effect of the rib can be made more pronounced.

[0012] <4> A jacket structure according to aspect 4 of the present invention is a jacket structure according to any one of aspects 1 to 3, characterized in that the one is inserted through a through hole provided in the upper flange.

[0013] According to this invention, one of the legs is inserted through a through hole provided in the upper flange. This facilitates alignment between one of the legs and the upper flange. This configuration is particularly suitable, for example, when the bending point of the leg is located above the connecting member and the bending point and the connecting member do not interfere with each other.

[0014] <5> A jacket structure according to aspect 5 of the present invention is a jacket structure according to any one of aspects 1 to 3, characterized in that the one is divided by the upper flange.

[0015] According to this invention, one of the legs is divided by the upper flange. That is, the upper flange does not have a through hole for inserting one of the legs, and the divided legs are positioned on the upper and lower surfaces of the upper flange, respectively. This allows the portion of the leg divided by the upper flange to be a bending point of the leg. Thus, the bending point of the leg can be positioned below the rib. Consequently, the leg can be made larger. This configuration is particularly suitable, for example, when, due to the conditions of the installation location of the jacket structure, it is necessary to set the bending point of one of the legs as low as possible.

[0016] <6> A jacket structure according to aspect 6 of the present invention is characterized in that, in the jacket structure according to aspect 5, each of the one sections separated by the upper flange is welded to the upper flange.

[0017] According to this invention, each of the multiple legs separated by the upper flange is welded to the upper flange. In other words, in addition to connecting the upper flange and one of the legs by a rib, one of the legs and the upper flange are fixed together by direct welding (e.g., double-sided welding). This makes it possible to further improve the fatigue strength of the connection between one of the legs and the upper flange.

[0018] <7> The jacket structure according to aspect 7 of the present invention is characterized in that, in the jacket structure according to aspect 6, each of the one sections separated by the upper flange is welded to the upper flange on both sides.

[0019] According to this invention, each of the multiple legs separated by the upper flange is welded to the upper flange on both sides. This further improves the fatigue strength of the connection between one of the legs and the upper flange.

[0020] <8> A jacket structure according to embodiment 8 of the present invention is a jacket structure according to any one of embodiments 5 to 7, characterized in that the longitudinal direction of the one of the two sections separated by the upper flange, which is on the side of the offshore structure, intersects substantially perpendicular to the upper flange.

[0021] According to this invention, the longitudinal direction of one of the legs separated by the upper flange, specifically the leg on the offshore structure side, intersects the upper flange substantially perpendicularly. This prevents the load from acting in the shear direction at the connection between one of the legs and the upper flange when the load is transmitted from one end of the leg to the upper flange.

[0022] <9> A jacket structure according to aspect 9 of the present invention is a jacket structure according to any one of aspects 5 to 8, characterized in that, in one side view, the angle between the upper surface of the upper flange and the one pipe axis on the side of the offshore structure that is divided by the upper flange is equal to the angle between the lower surface of the upper flange and the one pipe axis on the side of the seabed ground that is divided by the upper flange.

[0023] According to the present invention, the angle formed by the upper surface of the upper flange and the pipe axis of one of the legs on the side of the marine structure is equal to the angle formed by the lower surface of the upper flange and the pipe axis of one of the legs on the side of the seabed ground. As a result, for the cross-sectional shape of one of the legs divided by the upper flange, the cross-section of one of the legs on the side of the marine structure can be congruent with the cross-sectional shape of one of the legs on the side of the seabed ground. Therefore, the positions of the pipe walls of the legs on both sides of the upper flange can be made to coincide. Thus, the load transfer from one of the legs on the side of the marine structure to one of the legs on the side of the seabed ground can be made smooth.

[0024] <10>The jacket structure according to aspect 10 of the present invention is the jacket structure according to any one of aspects 5 to 9, wherein the longitudinal direction of the one on the side of the seabed ground among the ones divided by the upper flange is parallel to the vertical direction.

[0025] Here, the pile is driven into the seabed ground and extends parallel to the vertical direction. In contrast, the longitudinal direction of one of the legs on the side of the seabed ground among the ones divided by the upper flange is parallel to the vertical direction. That is, the portion of one of the legs located inside the connecting member in the vertical direction is parallel to the vertical direction. Therefore, when connecting one of the legs and the pile by the connecting member, interference between one of the legs and the pile can be prevented.

[0026] <11>The jacket structure according to aspect 11 of the present invention is the jacket structure according to any one of aspects 1 to 10, wherein the pile corresponding to the one is inserted into sleeves provided on each of the upper flange and the lower flange.

[0027] According to this invention, the pile corresponding to one of the legs is inserted through sleeves provided on the upper flange and the lower flange, respectively. This makes it easy to align the pile when connecting it to the connecting member. Therefore, compared to the case where the pile driven into the seabed is directly connected to the upper and lower flanges by welding or the like, work at sea can be made easier.

[0028] <12> A jacket structure according to aspect 12 of the present invention is characterized in that, in a jacket structure according to any one of aspects 1 to 11, the lower flange is horizontal.

[0029] According to this invention, the lower flange is horizontal. This allows, for example, after the construction of the jacket structure, to visually confirm that the lower flange is parallel to the sea surface, thereby confirming that the connecting members are positioned at the correct angle. Thus, post-construction management can be facilitated.

[0030] <13> A jacket structure according to aspect 13 of the present invention is a jacket structure according to any one of aspects 1 to 12, characterized in that the upper side of the web is inclined and the lower side of the web is horizontal.

[0031] According to this invention, the upper edge of the web is inclined, and the lower edge of the web is horizontal. The inclined upper edge of the web allows for a gap-free connection between the web and the upper flange when the upper flange is inclined. The horizontal lower edge of the web allows for a gap-free connection between the web and the lower flange when the lower flange is horizontal.

[0032] <14> A jacket structure according to aspect 14 of the present invention is characterized in that, in a jacket structure according to any one of aspects 1 to 13, the lower flange is inclined.

[0033] According to this invention, the lower flange is inclined. This prevents seawater from simultaneously impacting the entire lower surface of the lower flange when waves are generated on the sea surface and seawater collides with the lower surface of the lower flange. Therefore, the impact on the connecting member due to seawater collision can be minimized.

[0034] <15> A jacket structure according to embodiment 15 of the present invention is a jacket structure according to any one of embodiments 1 to 14, characterized in that the lower flange is inclined such that the end of the lower flange on the side of one of the piles is located vertically above the end of the lower flange on the side of one of the piles.

[0035] In this case, when the lower flange is inclined, the other end located above the other end is closer to the upper flange. Therefore, when connecting one leg or pile to the upper and lower flanges, the distance between the parts supported by the upper and lower flanges becomes smaller. In this case, in order to provide sufficient strength against inputs such as overturning moments applied to the jacket structure, it is preferable to increase the distance between the parts supported by the upper and lower flanges, especially on the pile side.

[0036] In contrast, the lower flange is inclined such that the end of the lower flange on one leg is positioned vertically above the end of the lower flange on the pile side corresponding to one of the legs. This structure allows for a larger distance between the upper and lower flanges on the pile side. Therefore, sufficient strength against input can be achieved on the pile side.

[0037] <16> A jacket structure according to aspect 16 of the present invention is characterized in that, in a jacket structure according to any one of aspects 1 to 15, the piles corresponding to that one are a plurality of piles.

[0038] According to this invention, the piles corresponding to one of the legs are multiple piles. In other words, multiple piles are connected to one of the legs via connecting members. This makes it possible to strengthen the connection between one of the legs and the seabed ground via the piles. Therefore, sufficient strength can be provided against inputs such as overturning moments on the leg. [Effects of the Invention]

[0039] According to the present invention, it is possible to provide a jacket structure that can smoothly transmit load between a leg and a connecting member that connects the leg and the pile. [Brief explanation of the drawing]

[0040] [Figure 1] This is a jacket structure according to the present invention. [Figure 2] Figure 1 is a perspective view of the jacket structure. [Figure 3] Figure 2 is an enlarged view of part III. [Figure 4] This is a side view of the first example of the connection between the connecting member and the leg. [Figure 5] This is a side view of a second example of the connection between the connecting member and the leg. [Modes for carrying out the invention]

[0041] The following describes a jacket structure 100 according to one embodiment of the present invention, with reference to the drawings. The jacket structure 100 is, for example, placed on the sea or other offshore areas. The jacket structure 100 is used, for example, to support a wind turbine (offshore wind turbine 200) on the sea, as shown in Figure 1. As shown in Figure 1, the jacket structure 100 comprises a transition piece 10, a leg 20, a brace 30, a pile 40, a connecting member 50, and a rib 60.

[0042] The transition piece 10 supports the offshore wind turbine 200, as shown in Figure 1. Specifically, the transition piece 10 is located at the upper end of the jacket structure 100 and is the part to which the lower end of the offshore wind turbine 200 is connected. As shown in Figure 2, the transition piece 10 is cross-shaped. Legs 20 are positioned at each outer end of the cross shape of the transition piece 10.

[0043] Legs 20 support the transition piece 10. Multiple legs 20 are provided along the vertical direction of the jacket structure 100. In this embodiment, the vertical direction refers to the direction perpendicular to the sea surface on which the offshore wind turbine 200 is installed. For example, steel pipes are used for the legs 20. In this embodiment, four legs 20 are provided. The transition piece 10 is connected to the upper end of each leg 20. A connecting member 50 is connected to the lower end of each leg 20. The detailed shape of each leg 20 will be described later, along with the structure of the connecting member 50.

[0044] The brace 30 is a member that connects the multiple legs 20 provided in the transition piece 10 and reinforces the jacket structure 100. For example, a steel pipe is used for the brace 30. In this embodiment, the brace 30 is configured in an X shape between the legs 20. As shown in Figures 1 and 2, the X shape is provided in two stages in the vertical direction of the jacket structure 100. However, depending on conditions such as water depth, the X shape may be provided in only one stage or in three or more stages.

[0045] The piles 40 are driven into the seabed. Multiple piles 40 are provided in the jacket structure 100. Steel pipes are preferably used for the piles 40. The piles 40 are connected to each of the multiple legs 20 via connecting members 50. Multiple piles 40 are connected to one of the legs 20 via connecting members 50. In other words, in this embodiment, the piles 40 corresponding to one of the legs 20 are multiple piles 40. For example, two piles 40 are provided for one of the legs 20. Alternatively, three or more piles 40 may be provided for one of the legs 20.

[0046] The connecting member 50 connects one of the multiple legs 20 to the multiple piles 40 corresponding to one of the legs 20. In this embodiment, one connecting member 50 is provided for each of the four legs 20 provided as described above. In other words, in this embodiment, four connecting members 50 are provided. As shown in Figure 3, the connecting member 50 includes a sleeve 51, an upper flange 52, a lower flange 53, and a web 54.

[0047] The sleeve 51 is a cylindrical member. The upper end of the sleeve 51 is supported by the upper flange 52. The lower end of the sleeve 51 is supported by the lower flange 53. The piles 40 are inserted into the sleeves 51 provided on the upper flange 52 and the lower flange 53, respectively. In other words, the piles 40 corresponding to one of the legs 20 are inserted through the sleeves 51. For example, as shown in Figure 3, two sleeves 51 are provided for one of the legs 20. Alternatively, three or more sleeves 51 may be provided for one of the legs 20.

[0048] The upper flange 52 is provided on the upper part of the connecting member 50. The upper flange 52 is a plate-shaped member. The upper end of the sleeve 51 is connected to the upper flange 52. The connection between the upper flange 52 and the sleeve 51 is preferably fixed by welding, for example. The upper flange 52 and the sleeve 51 may be fixed with the sleeve 51 positioned inside a hole provided in the upper flange 52. The upper flange 52 and the sleeve 51 may be fixed with the upper end of the sleeve 51 abutting against the lower surface of the upper flange 52.

[0049] One of the legs 20 is connected to the upper flange 52. The upper flange 52 connects one of the legs 20 to the sleeve 51. The upper flange 52 is inclined with respect to the horizontal. As shown in Figure 4, the upper flange 52 is inclined such that the upper second end 52d is located vertically lower than the upper first end 52u. The upper first end 52u is the end on the pile 40 side. The upper second end 52d is the end on the leg 20 side.

[0050] Here, the leg 20 is provided with a bending point 20B, as shown in Figures 4 and 5. In the jacket structure 100, two adjacent legs 20 in the circumferential direction have different distances between their upper ends and between their lower ends. The distance between the upper ends of the legs 20 is determined by the size of the transition piece 10. The distance between the lower ends of the legs 20 is determined appropriately so that the jacket structure 100 can adequately withstand the input. The input is, for example, an overturning moment input from the offshore wind turbine 200 to the jacket structure 100 via the transition piece 10. In the leg 20, the difference in size between the distance between the upper ends and the distance between the lower ends is adjusted by adjusting the bending angle of the bending point 20B.

[0051] In this embodiment, the method of connecting the upper flange 52 to one of the legs 20 can be used as follows, depending on the positional relationship between the upper flange 52 and the aforementioned bending point 20B. That is, as shown in Figure 4, in the first example of the connection method, for example, one of the legs 20 is inserted through a through hole 52h provided in the upper flange 52. This method is particularly suitable when, for example, the bending point 20B of the leg 20 is located above the connecting member 50 and the bending point 20B and the connecting member 50 do not interfere with each other.

[0052] Alternatively, as shown in Figure 5, in the second example of the connection method, one of the legs 20 is divided by the upper flange 52. That is, the upper flange 52 does not have a through hole 52h, and the divided legs 20 are placed on the upper and lower surfaces of the upper flange 52, respectively. In this case, the part where the leg 20 is divided by the upper flange 52 is defined as the bending point 20B of the leg 20. This method allows the position of the bending point 20B to be lower compared to the first example. Therefore, it is particularly suitable for use when, for example, the conditions of the installation location of the jacket structure 100 necessitate setting one of the bending points 20B of the leg 20 as low as possible.

[0053] In the second example, where one of the legs 20 is separated by the upper flange 52, each of the legs 20 separated by the upper flange 52 is welded to the upper flange 52. In this case, it is more preferable that the legs 20 and the upper flange 52 are welded on both sides.

[0054] In the second example, where one of the legs 20 is divided by the upper flange 52, the longitudinal direction of the leg 20 located on the transition piece 10 side of the leg 20 divided by the upper flange 52 is positioned to intersect the upper flange 52 approximately perpendicularly. Here, the butter angle of the leg 20, that is, the bending angle of the leg 20 with respect to the vertical direction, is generally set to 15° or less. From this viewpoint, in this embodiment, approximately perpendicular means in the range of 90° ± 8°. This ensures the butter angle described above even when both legs 20 divided by the upper flange 52 are at the maximum or minimum value of the above range. By adopting this positional relationship, when a load is transmitted from one end of the leg 20 to the upper flange 52, the load is prevented from acting in the shear direction at the connection between one of the legs 20 and the upper flange 52.

[0055] Here, in one side view of leg 20 shown in Figure 5, the angle between the upper surface of the upper flange 52 and the pipe axis of the leg 20 located on the transition piece 10 side of the leg 20 separated by the upper flange 52 is referred to as the first angle A1. The angle between the lower surface of the upper flange 52 and the pipe axis of the leg 20 located on the seabed side of the leg 20 separated by the upper flange 52 is referred to as the second angle A2.

[0056] At this time, the first angle A1 and the second angle A2 are equal. This ensures that, for one cross-sectional shape of the leg 20 divided by the upper flange 52, the cross-sectional shape of the leg 20 on the transition piece 10 side and the cross-sectional shape of the leg 20 on the seabed side are congruent. Furthermore, the longitudinal direction of the leg 20 located on the seabed side of the leg 20 that is divided by the upper flange 52 is arranged to be parallel to the vertical direction.

[0057] The lower flange 53 is provided at the lower part of the connecting member 50. The lower flange 53 is a plate-shaped member. The lower end of the sleeve 51 is connected to the lower flange 53. The connection between the lower flange 53 and the sleeve 51 is preferably fixed by welding, for example. The lower end of the sleeve 51 is positioned inside a hole provided in the lower flange 53. This allows the pile 40 to be inserted through the opening at the lower end of the sleeve 51.

[0058] One of the legs 20 is connected to the lower flange 53. Specifically, the lower end of the leg 20 is connected to the upper surface of the lower flange 53. The lower flange 53 connects one of the legs 20 to the sleeve 51. One of the legs 20 and the sleeve 51 are supported at two points each by the upper flange 52 and the lower flange 53. In this way, the connecting member 50 connects one of the legs 20 to the sleeve 51 into which a pile 40 corresponding to one of the multiple piles 40 is inserted.

[0059] As shown in Figures 4 and 5, the lower flange 53 is horizontal. The lower flange 53 is parallel to the water surface. Alternatively, the lower flange 53 may be inclined with respect to the water surface. If the lower flange 53 is positioned at an inclination, it is inclined such that, for example, the lower second end 53d is positioned vertically above the lower first end 53u. Alternatively, it may be inclined such that the lower second end 53d is positioned vertically below the lower first end 53u. The lower first end 53u is the end on the pile 40 side. The lower second end 53d is the end on the leg 20 side.

[0060] The web 54 is a plate-shaped member provided between the upper flange 52 and the lower flange 53. The web 54 is positioned vertically. As shown in Figures 4 and 5, the web 54 is, for example, rectangular in shape. The upper edge of the web 54 is in contact with the lower surface of the upper flange 52. The lower edge of the web 54 is in contact with the upper surface of the lower flange 53. One horizontal side of the web 54 is in contact with the outer circumferential surface of the leg 20. The other horizontal side of the web 54 is in contact with the outer circumferential surface of the sleeve 51. Alternatively, as shown in Figure 3, both horizontal sides of the web 54 may be in contact with the outer circumferential surface of the sleeve 51.

[0061] As shown in Figures 4 and 5, the upper edge of the web 54 is inclined to match the slope of the upper flange 52. The lower edge of the web 54 is horizontal to match the lower flange 53. Alternatively, for example, if the lower flange 53 is inclined, the lower edge of the web 54 may be inclined to match the slope of the lower flange 53.

[0062] Preferably, the upper edge of the web 54 and the lower surface of the upper flange 52, the lower edge of the web 54 and the upper surface of the lower flange 53, and the edges located on both horizontal sides of the web 54 and one of the legs 20 and the outer circumferential surface of the sleeve 51 are fixed together by welding (e.g., welding on both sides).

[0063] The rib 60 is a plate-shaped member that connects one of the legs 20 to the upper flange 52. The rib 60 reinforces the connection between one of the legs 20 and the upper flange 52 and facilitates smooth load transfer from one of the legs 20 to the upper flange 52. The rib 60 is, for example, triangular in shape. One side of the triangular shape is positioned on the outer circumferential surface of the leg 20, which is located on the side of the transition piece 10 that is closer to the upper flange 52. The other side of the triangular shape is positioned on the upper surface of the upper flange 52. It is preferable that the rib 60, one of the legs 20, and the upper flange 52 are fixed by welding. The rib 60 connects one of the legs 20 to the upper surface of the upper flange 52.

[0064] As described above, the leg 20 may have a bending point 20B near the upper flange 52. In this case, if the rib 60 connecting the connecting member 50 and one of the legs 20 interferes with one of the bending points 20B of the leg 20, the conditions for structural design become complicated. For this reason, it is preferable that the side of the rib 60 that contacts the outer surface of the leg 20 be of a length that does not interfere with the bending point. In this case, as described above, the upper flange 52 is inclined, so it is preferable to increase the distance between the upper flange 52 and the bending point, thereby lengthening the side of the rib 60 that contacts the outer surface.

[0065] As described above, according to the jacket structure 100 of this embodiment, the upper flange 52 is provided with a rib 60 that connects one of the multiple legs 20 to the upper flange 52. This reinforces the connection between one of the legs 20 and the upper flange 52, and allows for smoother load transmission from one of the legs 20 to the upper flange 52.

[0066] Furthermore, the rib 60 connects one of the legs 20 to the upper surface of the upper flange 52. Here, the lower end of the leg 20 is connected to the connecting member 50. The leg 20 extends upward from the connecting member 50. Therefore, stress concentration between the leg 20 and the connecting member 50 is particularly likely to occur between the portion of the leg 20 located above the connecting member 50 and the upper flange 52 of the connecting member 50. Thus, by connecting one of the legs 20 to the upper surface of the upper flange 52 with the rib 60, the reinforcing effect of the rib 60 can be made more pronounced.

[0067] Furthermore, the upper flange 52 is inclined such that the end of the upper flange 52 on one side of the leg 20 is located vertically lower than the end of the upper flange 52 on the pile 40 side corresponding to one of the legs 20. Here, the leg 20 may have a bending point 20B above the connecting member 50, particularly near the upper flange 52. In this case, if the rib 60 connecting the connecting member 50 and one of the legs 20 interferes with the bending point 20B of the leg 20, the conditions for structural design become complicated. For this reason, it is preferable that the bending point 20B and the rib 60 are in separate positions. In contrast, the upper flange 52 is inclined such that the position of the end of the upper flange 52 on one side of the leg 20 is lower. This makes it possible to increase the distance between the upper surface of the upper flange 52 and one of the legs 20. Therefore, even if the bending point 20B of the leg 20 is near the connecting member 50, the rib 60 can be made larger without interfering with one of the bending points 20B of the leg 20. Thus, the connection between the leg 20 and the upper flange 52 can be reinforced more strongly.

[0068] Furthermore, one of the legs 20 is inserted through a through hole 52h provided in the upper flange 52. This makes it easy to align one of the legs 20 with the upper flange 52. This configuration is particularly suitable, for example, when the bending point 20B of the leg 20 is located above the connecting member 50 and the bending point 20B and the connecting member 50 do not interfere with each other.

[0069] Furthermore, one of the legs 20 is divided by the upper flange 52. In other words, the upper flange 52 does not have a through hole 52h through which one of the legs 20 is inserted, and the divided legs 20 are positioned on the upper and lower surfaces of the upper flange 52, respectively. This allows the portion of the leg 20 divided by the upper flange 52 to become the bending point 20B of the leg 20. Thus, the bending point of the leg 20 can be positioned below the rib 60. Consequently, the leg 20 can be made larger. This configuration is particularly suitable, for example, when, due to the conditions of the installation location of the jacket structure 100, it is necessary to set one of the bending points 20B of the leg 20 as low as possible.

[0070] Furthermore, each of the multiple legs 20 separated by the upper flange 52 is welded to the upper flange 52. In other words, in addition to connecting the upper flange 52 and one of the legs 20 by the rib 60, one of the legs 20 and the upper flange 52 are fixed together by direct welding (e.g., double-sided welding). This further improves the fatigue strength of the connection between one of the legs 20 and the upper flange 52.

[0071] Furthermore, each of the multiple legs 20 separated by the upper flange 52 is welded to the upper flange 52 on both sides. This further improves the fatigue strength of the connection between one of the legs 20 and the upper flange 52.

[0072] Furthermore, the longitudinal direction of one of the legs 20 separated by the upper flange 52, specifically the leg 20 on the transition piece 10 side, intersects the upper flange 52 approximately perpendicularly. This prevents the load from acting in the shear direction at the connection between one of the legs 20 and the upper flange 52 when the load is transmitted from one end of the leg 20 to the upper flange 52.

[0073] Furthermore, the angle between the upper surface of the upper flange 52 and the pipe axis of one of the legs 20 on the transition piece 10 side is equal to the angle between the lower surface of the upper flange 52 and the pipe axis of one of the legs 20 on the seabed side. This makes it possible to make the cross-sectional shape of one of the legs 20 separated by the upper flange 52 congruent to the cross-sectional shape of one of the legs 20 on the transition piece 10 side and one of the cross-sectional shapes of one of the legs 20 on the seabed side. Therefore, the positions of the pipe walls of the legs 20 on both sides of the upper flange 52 can be aligned. Thus, load transfer from one of the legs 20 on the transition piece 10 side to one of the legs 20 on the seabed side can be made smooth.

[0074] Here, the pile 40 is driven into the seabed and extends parallel to the vertical direction. In contrast, the longitudinal direction of one of the legs 20 that is separated by the upper flange 52 and is on the seabed side is parallel to the vertical direction. In other words, the portion of one of the legs 20 that is located inside the connecting member 50 in the vertical direction is parallel to the vertical direction. Therefore, when connecting one of the legs 20 and the pile 40 with the connecting member 50, interference between one of the legs 20 and the pile 40 can be prevented.

[0075] Furthermore, the pile 40 corresponding to one of the legs 20 is inserted through a sleeve 51 provided on the upper flange 52 and the lower flange 53, respectively. This makes it easy to align the pile 40 and the connecting member 50 when connecting them. Therefore, compared to the case where the pile 40 driven into the seabed is directly connected to the upper flange 52 and the lower flange 53 by welding or the like, work at sea can be made easier.

[0076] Furthermore, the lower flange 53 is horizontal. This allows, for example, after the construction of the jacket structure 100, to visually confirm that the lower flange 53 is parallel to the sea surface, thereby confirming that the connecting member 50 is positioned at the correct angle. Thus, post-construction management can be easily managed.

[0077] Furthermore, the upper edge of the web 54 is inclined, while the lower edge of the web 54 is horizontal. The inclined upper edge of the web 54 allows for a gap-free connection between the web 54 and the upper flange 52 when the upper flange 52 is inclined. The horizontal lower edge of the web 54 allows for a gap-free connection between the web 54 and the lower flange 53 when the lower flange 53 is horizontal.

[0078] Furthermore, the lower flange 53 is inclined. This prevents seawater from simultaneously impacting the entire lower surface of the lower flange 53 when waves are generated on the sea surface and seawater collides with the lower surface of the lower flange 53. Thus, the impact on the connecting member 50 due to seawater collision can be minimized.

[0079] In this case, when the lower flange 53 is inclined, the other end located above one end is closer to the upper flange 52. Therefore, when connecting one of the legs 20 or the pile 40 to the upper flange 52 and the lower flange 53, the distance between the parts supported by the upper flange 52 and the lower flange 53 becomes smaller. In this case, in order to provide sufficient strength against inputs such as overturning moments applied to the jacket structure 100, it is preferable to increase the distance between the parts supported by the upper flange 52 and the lower flange 53, especially on the pile 40 side.

[0080] In contrast, the lower flange 53 is inclined such that the end of the lower flange 53 on the side of one leg 20 is positioned vertically above the end of the lower flange 53 on the pile 40 side that corresponds to one of the legs 20. This structure allows for a larger distance between the upper flange 52 and the lower flange 53 on the pile 40 side. Therefore, sufficient strength against input can be achieved on the pile 40 side.

[0081] Furthermore, one of the legs 20 corresponds to multiple piles 40. In other words, multiple piles 40 are connected to one of the legs 20 via connecting members 50. This strengthens the connection between one of the legs 20 and the seabed ground via the piles 40. Therefore, the legs 20 can be given sufficient strength against inputs such as overturning moments.

[0082] It should be noted that the technical scope of the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the invention. For example, when the lower flange 53 is positioned at an angle, the lower flange 53 may be inclined such that one end of the lower flange 53 is located vertically below the end of the lower flange 53 that corresponds to the pile 40.

[0083] Furthermore, without departing from the spirit of the present invention, the components in the above embodiments may be replaced with well-known components as appropriate, and the above-described modifications may be combined as appropriate. [Explanation of Symbols]

[0084] 10 Transition Pieces 20 Legs 40 stakes 50 Connecting Members 51 sleeves 52 Upper flange 52h through hole 53 Lower flange 54 Web 60 Ribs 100 Jacket Structure 200 offshore wind turbines

Claims

1. Multiple legs, Multiple piles connected to each of the aforementioned multiple legs, A connecting member that connects one of the plurality of legs and a sleeve into which a pile corresponding to one of the plurality of piles is inserted, A jacket structure comprising, The connecting member includes an upper flange, a lower flange, and a web. The upper flange is provided with a rib that connects the one and the upper flange. A jacket structure characterized by the following features.

2. The upper flange connects the one and the sleeve into which the pile corresponding to the one is inserted. The upper flange is inclined such that the end of the upper flange on the side corresponding to one of the piles is located vertically lower than the end of the upper flange on the side corresponding to one of the piles. The jacket structure according to feature 1.

3. The rib connects the one and the upper surface of the upper flange. The jacket structure according to feature 2.

4. The aforementioned one is inserted through a through hole provided in the upper flange, The jacket structure according to feature 3.

5. The aforementioned one is separated by the upper flange. The jacket structure according to feature 3.

6. Each of the two pieces separated by the upper flange is welded to the upper flange. The jacket structure according to feature 5.

7. Each of the two pieces separated by the upper flange is welded to the upper flange on both sides. The jacket structure according to feature 6.

8. The pile corresponding to the aforementioned one is multiple piles. The jacket structure according to any one of claims 1 to 7.

Images