Offshore wind turbine foundation with negative pressure bucket and underwater monopile combined with transition section and installation method

Abstract

The application relates to a sea wind turbine foundation combined with a negative pressure barrel and an underwater single pile, which comprises an upper structure and a lower structure connected with the upper structure; the upper structure comprises a transition section, two or more inclined support members and negative pressure barrel members, one end of the two or more inclined support members is respectively connected with the transition section, and the other end of the two or more inclined support members is respectively connected with the negative pressure barrel members; the lower part of the transition section is provided with a transition section connecting part; the lower structure is an underwater single pile connected with the seabed, and the upper part of the underwater single pile is provided with a single pile connecting part connected with the transition section connecting part; the application discards the underwater grouting connection mode between the pile and the barrel, adopts the connection scheme of the inclined support combined with the grouting transition section above the seabed surface, can more effectively transfer the load, has high connection reliability and is convenient for construction; the upper and lower structures are adopted, the structural design is optimized, the connection strength is improved, and the sea construction process is reduced.

Description

Technical Field

[0001] This invention belongs to the category of marine engineering structures, and in the technical field of offshore wind power foundation design, it particularly relates to an offshore wind turbine foundation and installation method that combines a negative pressure tank with a transition section and an underwater monopile. Background Technology

[0002] As a new type of foundation combining large-diameter monopiles and negative pressure buckets, the pile-bucket composite foundation can effectively reduce the penetration depth of the pipe piles, improve the foundation's resistance to horizontal deformation, and obtain a foundation type with higher bearing capacity and stronger adaptability to marine environments; this foundation type has been successfully applied in the Fujian sea area.

[0003] The pile-bucket composite foundation currently used in the market generally adopts a construction process of driving piles first and then sinking the bucket or sinking the bucket first and then driving piles. Then, grouting is performed between the piles and the bucket. The piles and the bucket are relatively independent, and the load transfer relies entirely on the grouting under the mud between the piles and the bucket. Auxiliary components need to be installed separately, and the construction process is complicated. Summary of the Invention

[0004] (a) Technical problems to be solved

[0005] To address the aforementioned problems in the prior art, this invention provides an offshore wind turbine foundation and installation method that combines a negative pressure tank with a transition section and an underwater monopile. It abandons the underwater grouting connection method between the piles and tanks, and adopts a connection scheme that combines inclined supports with a grouting transition section above the seabed surface. This can more effectively transfer loads, has high connection reliability, and is easy to construct.

[0006] (II) Technical Solution

[0007] To achieve the above objectives, the main technical solutions adopted by the present invention include:

[0008] A combination of a negative pressure tank with a transition section and an underwater monopile for offshore wind turbine foundations, comprising: a superstructure and a substructure connected to the superstructure;

[0009] The upper structure includes a transition section, two or more inclined support members, and a negative pressure tank member. One end of each of the two or more inclined support members is connected to the transition section, and the other end of each of the two or more inclined support members is connected to the negative pressure tank member. The lower part of the transition section is provided with a transition section connection part.

[0010] The lower structure is an underwater monopile connected to the seabed, and the upper part of the underwater monopile is provided with a monopile connection part that connects to the transition section connection part.

[0011] Furthermore, a grouting connection section is provided between the transition section and the underwater monopile. The grouting connection section includes a grouting gap formed between the outer wall of the transition section and the inner wall of the underwater monopile. A grouting partition plate is provided in the upper part of the underwater monopile. The bottom of the transition section is a closed inverted cone structure. A grouting zone is formed between the bottom of the transition section and the grouting partition plate. The grouting gap is connected to the grouting zone.

[0012] Furthermore, the upper part of the underwater monopile is provided with a bracket plate for connecting the grouting partition plate, and the bracket plate is provided with a partition plate fixing hook for fixing the grouting partition plate; there is a space between the grouting partition plate and the partition plate fixing hook.

[0013] Furthermore, several L-shaped shear keys are provided at intervals on the outer wall of the transition section located between the grouting gaps and on the inner wall of the underwater monopile.

[0014] Furthermore, a number of grouting connection pipes are provided at intervals within the transition section, and the grout outlet of the grouting connection pipe is connected to the grouting gap.

[0015] Furthermore, the transition section is provided with a submarine cable hole, which is located above the connection part of the transition section.

[0016] Furthermore, the inclined support is a variable diameter steel pipe structure, with the diameter on the side near the transition section being larger than the diameter on the side near the negative pressure tank; the inclined support and the negative pressure tank are connected by a wing plate.

[0017] Furthermore, the negative pressure tank is an inverted annular barrel structure; the negative pressure tank consists of a top cover plate, an inner barrel, an outer barrel, and several barrel partition plates, with the inner barrel and outer barrel respectively connected to the inner and outer sides of the top cover plate; the barrel partition plates are connected between the inner barrel and the outer barrel.

[0018] Furthermore, the negative pressure tank is connected to a connecting pipe for connecting submarine cables.

[0019] On the other hand, an installation method for an offshore wind turbine foundation combining a negative pressure tank with a transition section and an underwater monopile is proposed, with the specific steps as follows:

[0020] S1. First, connect the underwater monopile to the replacement steel pipe fitting through the monopile connector, and then sink the underwater monopile to the design elevation; then remove the replacement steel pipe fitting to complete the installation of the underwater monopile.

[0021] S2. After the transition section, inclined support and negative pressure tank are assembled on land, they are hoisted and installed as a whole. The inverted conical structure of the transition section is inserted into the underwater monopile for positioning. The negative pressure tank begins to sink slowly under its own weight. After it stabilizes under its own weight, water and air are pumped out through the pipelines embedded in the negative pressure tank to complete the negative pressure sinking.

[0022] S3. After the leveling and settlement are completed, high-pressure grouting material is injected into the grouting connection section, and then the single pile connection part and the transition section connection part are connected by fasteners.

[0023] During installation, the angle between the submarine cable hole and the connecting pipe should be consistent. The submarine cable passes through the connecting pipe and the submarine cable hole, enters the transition section, and is pulled to the upper tower. After the submarine cable exits the submarine cable hole, it is buried below the mud surface through the connecting pipe.

[0024] (III) Beneficial Effects

[0025] The beneficial effects of this invention are: 1. It abandons the underwater grouting connection method between piles and adopts a connection scheme of inclined support combined with grouting transition section above the seabed, which can more effectively transfer loads, has high connection reliability and is easy to construct.

[0026] 2. The use of an upper and lower structure, with auxiliary components prefabricated on land as a whole with the upper structure, can optimize structural design, improve connection strength, and reduce offshore construction procedures.

[0027] 3. Based on the structural characteristics of the pile foundation, a cable threading scheme combining J-shaped connecting pipe fittings and opening holes in the pipe piles is proposed, which can effectively reduce the risk of scouring around the foundation to the submarine cable. Attached Figure Description

[0028] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0029] Figure 1 This is a front view of the upper structure according to an embodiment of the present invention;

[0030] Figure 2 This is a top view of the upper structure of an embodiment of the present invention;

[0031] Figure 3 This is a front view of the lower structure according to an embodiment of the present invention;

[0032] Figure 4 This is a top view of the lower structure according to an embodiment of the present invention;

[0033] Figure 5 This is a schematic diagram of a structure according to an embodiment of the present invention;

[0034] Figure 6 This is a schematic diagram of the first state of an installation method according to an embodiment of the present invention;

[0035] Figure 7 This is a schematic diagram of the second state of the installation method according to an embodiment of the present invention;

[0036] Figure 8 This is a schematic diagram of the third state of the installation method according to an embodiment of the present invention;

[0037] Figure 9 This is a schematic diagram of the fourth state of the installation method according to an embodiment of the present invention. Detailed Implementation

[0038] To better explain and facilitate understanding of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0039] An embodiment of the present invention provides an offshore wind turbine foundation combining a negative pressure tank with a transition section and an underwater monopile, such as... Figures 1-5 As shown, it includes: an upper structure and a lower structure connected to the upper structure;

[0040] The upper structure includes a transition section 1, two or more inclined support members 2, and a negative pressure tank member 3. It should be noted that the transition section 1 is a cylindrical tube, which is existing technology and will not be described in detail. In this embodiment, the number of inclined support members 2 is six. One end of two or more inclined support members 2 is connected to the transition section 1, and the other end of two or more inclined support members 2 is connected to the negative pressure tank member 3. The lower part of the transition section 1 is provided with a transition section connecting part 7.

[0041] The lower structure is an underwater monopile 4 connected to the seabed. The upper part of the underwater monopile 4 is provided with a monopile connection part 6 that is connected to the transition section connection part 7. As an example, the transition section connection part 7 is an upper flange, and the monopile connection part 6 is a lower flange that mates with the upper flange. The upper flange and the lower flange are connected by fasteners, so that the upper structure and the lower structure are connected.

[0042] As further explained, in this embodiment, such as Figure 5 As shown, a grouting connection section 8 is provided between the transition section 1 and the underwater monopile 4. The grouting connection section 8 includes a grouting gap 101 formed between the outer wall of the transition section 1 and the inner wall of the underwater monopile 4. A grouting partition plate 17 is provided in the upper part of the underwater monopile 4. The bottom of the transition section 1 is a closed inverted cone structure, which serves as an installation guide and can improve the installation accuracy. A grouting area 102 is formed between the bottom of the transition section 1 and the grouting partition plate 17. The grouting gap 101 is connected to the grouting area 102, which further strengthens the connection and fixation between the upper structure and the lower structure.

[0043] Furthermore, in this embodiment, as Figures 3-4As shown, the upper part of the underwater monopile 4 is provided with a bracket plate 19 for connecting the grouting partition plate 17. The bracket plate 19 is provided with a partition plate fixing hook 18 for further fixing the grouting partition plate 17, so that the grouting partition plate 17 is reliably connected and has good stability.

[0044] The grouting partition plate 17 is fixed to the annular corbel plate 19 inside the pile using eight partition plate fixing hooks 18; there is a certain space between the grouting partition plate 17 and the partition plate fixing hooks 18, so that water can freely enter the pile space above the grouting partition plate 17 during the pile driving process; and it can play a good role in grouting and sealing during grouting.

[0045] To further explain, in this embodiment, as Figure 1 and Figure 3 As shown, in order to make the grouting connection more reliable, several L-shaped shear keys 12 are provided at intervals on the outer wall of the transition section 1 located between the grouting gaps 101 and the inner wall of the underwater monopile 4, respectively, to strengthen the grouting connection between the transition section 1 and the underwater monopile 4.

[0046] To further explain, in this embodiment, as Figure 1 As shown, in order to facilitate grouting, a number of grouting connection pipes 14 are provided at intervals in the transition section 1. For example, there are 6-8 grouting connection pipes 14. The grout outlet of the grouting connection pipe 14 is connected to the grouting gap 101. The transition section 1 is provided with a mooring ladder 9 and / or an outer platform 10 for easy use.

[0047] To further explain, in this embodiment, the transition section 1 is provided with a submarine cable hole 13, which is located above the transition section connecting part 7.

[0048] To further explain, in this embodiment, as Figure 1 As shown, the inclined support 2 is a variable diameter steel pipe structure, with the diameter on the side closer to the transition section 1 being larger than the diameter on the side closer to the negative pressure tank 3; the connection between the inclined support 2 and the negative pressure tank 3 is reinforced by an arc-shaped wing plate 151; the inclined support 2 can effectively transfer horizontal force and bending moment to the lower negative pressure tank 3, thereby reducing the load level on the grouting connection section 8.

[0049] Specifically, in this embodiment, as follows: Figure 1 and Figure 2As shown, the negative pressure tank 3 is an inverted annular barrel-shaped structure; the negative pressure tank 3 is composed of a top cover plate 16, an inner barrel 13, an outer barrel 12, and several barrel partition plates 14. The inner barrel 13 and the outer barrel 12 are respectively connected to the inner and outer sides of the top cover plate 16; the barrel partition plates 14 are connected between the inner barrel 13 and the outer barrel 12, and the barrel partition plates 14 divide the negative pressure tank 3 into six compartments evenly. The barrel partition plates 14 play the role of compartment division and improve the overall rigidity of the negative pressure tank 3.

[0050] Furthermore, the top cover plate 16 of the negative pressure tank 3 is connected to a J-shaped connecting pipe 11 for connecting the submarine cable 15. The connecting pipe 11 cooperates with the submarine cable hole 13 for threading the submarine cable 15.

[0051] In this embodiment, the substructure is an underwater monopile 4, with its top located below the water surface and protruding 5 to 8 meters above the mud surface. The elevation of the foundation top depends on the horizontal and vertical bearing requirements of the transition section.

[0052] The underwater monopile 4 has a monopile connector 6 at the top. During construction, the monopile connector 6 connects the steel pipe fittings 5. During operation, it connects with the transition section connector 7 as a permanent force transmission structure.

[0053] On the other hand, an installation method for an offshore wind turbine foundation combining a negative pressure tank with a transition section and an underwater monopile is proposed, with the specific steps as follows:

[0054] S1. First, connect the underwater monopile 4 to the replacement steel pipe fitting 5 via the monopile connector 6, then sink the underwater monopile 4 to the design elevation; then remove the replacement steel pipe fitting 5 to complete the installation of the underwater monopile 4. Figure 6 and Figure 7 As shown;

[0055] S2. After the transition section 1, inclined support 2, negative pressure tank 3, and foundation auxiliary components including the mooring ladder 9, outer platform 10, and connecting pipes 11 are assembled on land, they are hoisted and installed as a whole. This eliminates the need for secondary hoisting and installation of auxiliary components, effectively improving construction efficiency. The inverted conical structure of the transition section 1 is inserted into the underwater monopile 4 for positioning. The negative pressure tank 3 begins to slowly sink under its own weight. Once it stabilizes under its own weight, water and air are pumped out through pipes pre-embedded in the negative pressure tank 3 to complete the negative pressure penetration. Figure 8 and Figure 9 As shown;

[0056] S3. After the settlement and leveling are completed, high-pressure grouting material is injected into the grouting connection section 8. Then, the single pile connection part 6 and the transition section connection part 7 are connected with fasteners, such as... Figure 9 As shown;

[0057] During installation, the angle between the cable hole 13 and the connecting pipe 11 should be consistent. The cable 15 passes through the connecting pipe 11 and the cable hole 13, enters the transition section 1, and is pulled to the upper tower. After the cable 15 passes through the cable hole 13, it is buried below the mud surface through the connecting pipe 11. Since it is far from the single pile foundation, the flow is relatively stable, which can greatly reduce the damage caused by pile scouring to the cable 15.

[0058] From the above description, it can be seen that the embodiments of this application achieve the following technical effects: 1. More reasonable structural stress: Compared with traditional pile-bucket composite foundations, which are mainly connected by grouting under mud between pipe piles and negative pressure tanks, in this application, part of the load transferred to the transition section is transferred to the lower negative pressure tank component through the inclined support, and part is transferred to the underwater pile body through the external flange and grouting connection section, making load transfer more effective and reasonable; the external flange form, with bolt holes located outside the pile, facilitates installation; at the same time, transferring part of the load through the bolt flange connection can shorten the length of the grouting connection section and reduce the amount of high-strength grout used.

[0059] 2. The connection method facilitates construction and offers high reliability: Traditional pile-bucket composite foundations require grouting under mud within the annular space between the single pile foundation and the inner wall of the negative pressure bucket, which is difficult to construct and results in limited grouting connection strength. In contrast, in this application, the grouting connection section between the transition section and the underwater pile is located above the mud surface. The grouting pipe can be pre-embedded in the transition section, and grouting can be performed using platforms pre-installed inside and outside the transition section, making construction convenient and resulting in higher grouting connection strength.

[0060] 3. The improved grouting and sealing method reduces the risk of grout leakage and saves on project costs. Traditional marine grouting connection structures generally use grouting packers, which are expensive and prone to damage. This invention uses a novel grouting partition plate, which is fixed to the annular bracket plate inside the pile using eight fixing hooks. The fixing hooks have a certain amount of space, allowing water to freely enter the pile space above the partition plate during pile driving; while providing excellent grouting and sealing during grouting.

[0061] 4. Convenient installation of auxiliary components and robust structure: Due to the negative pressure tank structure with a transition section on the upper part, construction is carried out through negative pressure sinking, eliminating the need for piling. Auxiliary components such as the outer platform, ladders, and J-shaped pipes can be pre-welded to the transition section and negative pressure tank structure and installed simultaneously with the upper structure. This avoids the need for offshore installation of auxiliary components, effectively improving construction efficiency. Furthermore, welding of auxiliary components on land ensures stronger connections and higher structural safety.

[0062] 5. It can effectively reduce the risk of scouring around the foundation to the submarine cable: After the submarine cable passes through the submarine cable hole in the transition section, it is buried below the mud surface through the J-shaped pipe installed on the negative pressure tank. Since it is far away from the single pile foundation, the flow is relatively stable, which can greatly reduce the damage to the submarine cable caused by scouring around the pile.

[0063] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0064] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0065] In the description of this application, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this application; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0066] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0067] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be construed as limiting the scope of protection of this application.

[0068] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0069] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made within the scope of the claims of the present invention should be included in the scope of the present invention.

Claims

1. An installation method for an offshore wind turbine foundation consisting of a negative pressure tank with a transition section and an underwater monopile, characterized in that, The offshore wind turbine foundation includes a superstructure and a substructure connected to the superstructure; the superstructure includes a transition section (1), two or more inclined support members (2) and a negative pressure tank member (3), one end of the two or more inclined support members (2) is connected to the transition section (1) respectively, and the other end of the two or more inclined support members (2) is connected to the negative pressure tank member (3) respectively; the lower part of the transition section (1) is provided with a transition section connection part (7); the substructure is an underwater monopile (4) connected to the seabed, and the upper part of the underwater monopile (4) is provided with a monopile connection part (6) connected to the transition section connection part (7); A grouting connection section (8) is provided between the transition section (1) and the underwater monopile (4). The grouting connection section (8) includes a grouting gap (101) formed between the outer wall of the transition section (1) and the inner wall of the underwater monopile (4). A grouting partition plate (17) is provided in the upper part of the underwater monopile (4). The bottom of the transition section (1) is a closed inverted cone structure. A grouting area (102) is formed between the bottom of the transition section (1) and the grouting partition plate (17). The grouting gap (101) is connected to the grouting area (102). The transition section (1) is provided with a submarine cable hole (13), which is located above the transition section connection part (7); The negative pressure tank (3) is connected to a connecting pipe (11) for connecting the submarine cable (15). The specific steps are as follows: S1. First, connect the underwater monopile (4) to the replacement steel pipe fitting (5) through the monopile connection part (6), and then sink the underwater monopile (4) to the design elevation; then remove the replacement steel pipe fitting (5) to complete the installation of the underwater monopile (4); S2. After the transition section (1), inclined support (2), and negative pressure tank (3) are assembled on land, they are hoisted and installed as a whole. The inverted cone structure of the transition section (1) is inserted into the underwater monopile (4) for positioning. The negative pressure tank (3) begins to sink slowly under its own weight. After the self-weight has penetrated and stabilized, water and air are pumped out through the pipes embedded in the negative pressure tank (3) to complete the negative pressure penetration. S3. After the sinking and leveling are completed, high-pressure grouting material is injected into the grouting connection section (8), and then the single pile connection part (6) and the transition section connection part (7) are connected by fasteners. During installation, the angle between the cable hole (13) and the connecting pipe (11) should be consistent. The cable (15) passes through the connecting pipe (11) and the cable hole (13) and enters the transition section (1) and is pulled to the upper tower. After the cable (15) passes through the cable hole (13), it is buried below the mud surface through the connecting pipe (11).

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