Large cylindrical foundation and installation method for offshore wind power conductor frame suitable for deep water

Abstract

The present invention discloses a large cylindrical foundation of an offshore wind power conductor frame suitable for deep water, and relates to an offshore wind power foundation structure. It comprises a circular cylinder and a conductor frame, the circular cylinder comprises a central cabin and a plurality of outer cabins, the top of the circular cylinder has a tube skirt top plate and a bottom opening; the conductor frame is wide at the bottom and narrow at the top, the conductor frame comprises a plurality of main leg columns and diagonal braces, and the bottom of the main leg columns is connected to the top of the central cabin through a connecting transition section. The present invention has a simple force transmission path, no underwater grouting operation, shortens the offshore construction period of the cylindrical foundation, saves offshore piling and barge costs, and has good application prospects in my country's 30-50m sea area. The present invention also relates to an installation method of the large cylindrical foundation of an offshore wind power conductor frame suitable for deep water.

Description

Technical Field

[0001] The present invention relates to an offshore wind power foundation structure, more specifically, it is a large cylindrical foundation of an offshore wind power conductor frame suitable for deep waters. The present invention also relates to an installation method of the large cylindrical foundation of an offshore wind power conductor frame suitable for deep waters. Background Art

[0002] Due to the fact that most of my country's offshore areas are soft geological conditions such as silt, silty soil, and silty clay, traditional pile foundations such as single pile foundations and multi-pile jacket foundations are usually used. Both of these foundation types require the pile foundation to penetrate the soft soil layer through hammering or static pressure to reach the sand layer or bedrock and other bearing layers with good bearing capacity, which requires a large workload and a long offshore operation time.

[0003] With the increase of the unit capacity of the unit, the use of traditional single pile and jacket foundation needs to increase the size of the foundation and the amount of materials used. In addition, with the increase of water depth, the offshore operation window period decreases, and the difficulty of offshore pile construction increases. Under this background, the barrel foundation came into being in the field of offshore wind power. The barrel foundation sinks by its own weight and negative pressure, which avoids the cumbersome piling process and greatly shortens the offshore operation time. For example, the composite barrel foundation with patent number: 201711241209.7 and patent name "A composite barrel foundation for offshore wind power" has been applied to several offshore wind farms and has good applicability in offshore waters. However, for water depths above 30m, considering that the foundation flange needs to be at a certain elevation above the still water surface, the height of the concrete transition section generally needs to reach 50-60m or more. The existing transition section height cannot meet the requirements, and the water surface line of the arc-shaped transition section is large, which generates a large wave force, which is not conducive to the safety of the foundation structure.

[0004] Since the surface of my country's offshore waters is covered with soft soils such as thick silt, muddy soil and silt, in order to overcome the difficulties of piling operations at a water depth of 30-50m, it is necessary to develop a large cylindrical foundation for offshore wind turbine conductor racks suitable for deep water. Summary of the invention

[0005] The first purpose of the present invention is to overcome the shortcomings of the above-mentioned background technology and provide a large cylindrical foundation for an offshore wind power conductor frame suitable for deep water.

[0006] The second purpose of the present invention is to provide an installation method for the large cylindrical foundation of an offshore wind power conductor frame suitable for deep water.

[0007] In order to achieve the above first purpose, the technical solution of the present invention is: a large cylindrical foundation for offshore wind power conductor racks suitable for deep water, characterized in that: it includes a circular cylinder and a conductor rack, the circular cylinder includes a central cabin and a plurality of outer cabins on the outer surface of the central cabin, the top of the circular cylinder has a tube skirt top plate and a bottom opening;

[0008] The conductor frame is wide at the bottom and narrow at the top, and comprises a plurality of main leg columns and diagonal braces located between two main leg columns. The bottom of the main leg column is connected to the top vertex of the center cabin through a connecting transition section.

[0009] In the above technical solution, the central cabin is a cube with an opening at the bottom, and the central cabin includes four core-filled columns and four central cabin steel plates located between the four core-filled columns.

[0010] In the above technical solution, there are four main leg columns and four connecting transition sections. The bottom diameter of the connecting transition section is equal to the diameter of the core filling column, and the top diameter of the connecting transition section is equal to the diameter of the main leg column.

[0011] In the above technical solution, there are multiple stiffening plates between the connecting transition section and the top plate of the tube skirt.

[0012] In the above technical solution, there are eight outer cabins, which include a basic outer cylinder wall and two partition plates connected to the basic outer cylinder wall, one partition plate is connected to the core filling column, and the other partition plate is connected to the middle part of the central cabin steel plate. Two adjacent outer cabins share one partition plate, and the eight outer cabins share one basic outer cylinder wall.

[0013] In the above technical solution, the thickness of the outer wall of the foundation is 15-40mm, the thickness of the compartment plate is 10mm-30mm, the thickness of the central cabin steel plate is 10-30mm, the diameter of the core column is 500-2500mm, the thickness of the tube skirt top plate is 10-20mm, and the length of the connecting transition section is 1-3m.

[0014] In the above technical solution, the core-filled column and the connecting transition section are filled with C30-C60 fine aggregate concrete.

[0015] In the above technical solution, a steel cage is placed in the core-filled column.

[0016] In order to achieve the above second purpose, the technical solution of the present invention is: a method for installing a large cylindrical foundation of an offshore wind power conductor frame suitable for deep water, characterized in that it includes the following steps:

[0017] Step 1: First erect four core-filling columns, then splice the central cabin steel plates to form a cube-shaped central cabin;

[0018] Step 2: First, weld four compartment plates on four core-filled columns to form the internal frame of the tube skirt, then assemble the foundation outer tube wall, and finally weld the remaining four compartment plates between the foundation outer tube wall and the middle of the center cabin steel plate; install the tube skirt top plate on the top of the center cabin and the outer cabin; complete the installation of the circular cylinder;

[0019] Step 3: Weld four connecting transition sections on the four core-filling columns. The bottom diameter of the connecting transition section is the same as the diameter of the core-filling column, and the top diameter of the connecting transition section is the same as the diameter of the main leg column;

[0020] Step 4: Lift the entire catheter rack to the upper part of the circular cylinder, weld the four main legs to the four connecting transition sections respectively, and then connect the stiffening plates to complete the overall installation.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] 1) The invention has a simple force transmission path and no underwater grouting operation, which shortens the offshore construction period of the barrel foundation and saves the cost of offshore piling and barge transportation. It has good application prospects in my country's 30-50m sea area.

[0023] 2) The present invention transmits the upper load to the core-filled column through the catheter frame. The force transmission path is simple, and the compressive and tensile capabilities of the core-filled column are fully utilized, while the structure has self-bearing capacity.

[0024] 3) The four main legs of the upper conductor frame of the present invention are directly connected to the four core-filling columns of the circular cylinder. When the circular cylinder is on the ground, it can directly bear the weight of the upper conductor frame structure, eliminating the risk of the top plate of the tube skirt being bent due to the upper weight.

[0025] 4) The present invention can be transported from the construction base to the installation position by complete towing and floating. The circular cylinder provides the buoyancy and stability required for towing. The central cabin and the outer cabin can adjust the air pressure inside the cylinder to maintain stability, and no barge is required for transportation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the structure of the present invention.

[0027] Figure 2 It is a cross-sectional view of the present invention.

[0028] Figure 3 This is a schematic diagram of the structure of the central cabin and the outer cabin.

[0029] Among them, 1-circular cylinder, 11-center cabin, 111-core column, 112-center cabin steel plate, 12-outer cabin, 121-foundation outer cylinder wall, 122-division plate, 13-cylinder skirt top plate, 2-duct frame, 21-main leg column, 22-diagonal brace, 3-connecting transition section, 31-stiffening plate. DETAILED DESCRIPTION

[0030] The following detailed description of the implementation of the present invention is made in conjunction with the accompanying drawings, but they do not constitute a limitation of the present invention and are only given as examples. At the same time, the advantages of the present invention will become clearer and easier to understand through the description.

[0031] Referring to the attached drawings, it can be seen that the large cylindrical foundation of offshore wind power conductor frame suitable for deep water is characterized by comprising a circular cylinder 1 and a conductor frame 2, wherein the circular cylinder 1 comprises a central cabin 11 and a plurality of outer cabins 12 on the outer surface of the central cabin 11, and the circular cylinder 1 has a skirt top plate 13 on the top and an opening at the bottom;

[0032] The conductor frame 2 is wide at the bottom and narrow at the top. The conductor frame 2 includes a plurality of main leg columns 21 and a diagonal brace 22 located between two main leg columns 21. The bottom of the main leg column 21 is connected to the top vertex of the center cabin 11 through a connecting transition section 3. When the circular cylinder 1 is on the ground, it can directly bear the weight of the upper conductor frame 2 structure, eliminating the risk of the upper weight causing the cylinder skirt top plate 13 to buckle. The diagonal brace 22 is a plurality of X-shaped brackets.

[0033] The central cabin 11 is a cube with an opening at the bottom, and includes four core-filled columns 111 and four central cabin steel plates 112 located between the four core-filled columns 111 .

[0034] There are four main leg columns 21 and four connecting transition sections 3 . The bottom diameter of the connecting transition section 3 is equal to the diameter of the core filling column 111 , and the top diameter of the connecting transition section 3 is equal to the diameter of the main leg column 21 .

[0035] There are multiple stiffening plates 31 between the connecting transition section 3 and the tube skirt top plate 13.

[0036] There are eight outer cabins 12, and the outer cabins 12 include a basic outer cylinder wall 121 and two partition plates 122 connected to the basic outer cylinder wall 121, one partition plate 122 is connected to the core filling column 111, and the other partition plate 122 is connected to the middle of the central cabin steel plate 112. Two adjacent outer cabins 12 share one partition plate 122, and the eight outer cabins 12 share one basic outer cylinder wall 121.

[0037] The thickness of the basic outer cylinder wall 121 is 15-40 mm, the thickness of the compartment plate 122 is 10 mm-30 mm, the thickness of the central cabin steel plate 112 is 10-30 mm, the diameter of the core column 111 is 500-2500 mm, the thickness of the cylinder skirt top plate 13 is 10-20 mm, and the length of the connecting transition section 3 is 1-3 m.

[0038] The core-filled column 111 and the connecting transition section 3 are filled with C30-C60 fine aggregate concrete.

[0039] A steel cage is placed in the core-filled column 111 .

[0040] The installation method of a large cylindrical foundation of an offshore wind power conductor frame applicable to deep water is characterized by comprising the following steps:

[0041] Step 1: First erect four core-filling columns 111, and then splice the central cabin steel plate 112 to form a cubic central cabin 11;

[0042] Step 2: First, weld four compartment plates 122 on the four core-filled columns 111 to form the internal frame of the tube skirt, then assemble the basic outer tube wall 121, and finally weld the remaining four compartment plates 122 between the basic outer tube wall 121 and the middle of the central cabin steel plate 112; install the tube skirt top plate 13 on the top of the central cabin 11 and the outer cabin 12; and complete the installation of the circular cylinder 1;

[0043] Step 3: Weld four connecting transition sections 3 on the four core filling columns 111, the bottom diameter of the connecting transition section 3 is the same as the diameter of the core filling column 111, and the top diameter of the connecting transition section 3 is the same as the diameter of the main leg column 21;

[0044] Step 4: hoist the jacket 2 as a whole to the upper part of the circular cylinder 1, weld the four main legs 21 to the four connecting transition sections 3 respectively, and then connect the stiffening plate 31 to complete the overall installation.

[0045] Example

[0046] like Figure 1 As shown, the circular cylinder 1 includes a basic outer cylinder wall 121, a cylinder skirt top plate 13, a compartment plate 122, a central cabin steel plate 112, and a core-filling column 111. The diameter of the basic outer cylinder wall 121 is 40m, the side length of the cube-shaped central cabin 11 is 18m, and four core-filling columns 111 are located at the four corners of the central cabin 11. The inside of the core-filling column 111 is filled with C60 concrete. Each core-filling column 111 is connected to a compartment plate 122 and connected to the basic outer cylinder wall 121. In addition, a compartment plate 122 is set at the midpoint of each central cabin steel plate 112 and connected to the basic outer cylinder wall 121;

[0047] The foundation construction process is as follows: Step 1: first erect four core-filled columns 111, and then splice the central cabin steel plate 112 to form a cubic central cabin 11;

[0048] Step 2: First, weld four compartment plates 122 on the four core-filled columns 111 to form the internal frame of the tube skirt, then assemble the basic outer tube wall 121, and finally weld the remaining four compartment plates 122 between the basic outer tube wall 121 and the middle of the central cabin steel plate 112; install the tube skirt top plate 13 on the top of the central cabin 11 and the outer cabin 12; and complete the installation of the circular cylinder 1;

[0049] Step 3: Weld four connecting transition sections 3 on the four core filling columns 111, the bottom diameter of the connecting transition section 3 is the same as the diameter of the core filling column 111, and the top diameter of the connecting transition section 3 is the same as the diameter of the main leg column 21;

[0050] Step 4: hoist the jacket 2 as a whole to the upper part of the circular cylinder 1, weld the four main legs 21 to the four connecting transition sections 3 respectively, and then connect the stiffening plate 31 to complete the overall installation.

[0051] like Figure 2 As shown, when the diameter of the main leg column 21 is the same as that of the core filling column 111, the connecting transition section 3 adopts a steel pipe of equal diameter; when the diameter of the main leg column 21 is different from that of the core filling column 111, the connecting transition section 3 is in the form of a gradual circular cross-section cone tube. In this embodiment, the length of the connecting transition section 3 is 3m.

[0052] like Figure 3 As shown, in the present embodiment, there are 9 cabins in the circular cylinder 1, including a cubic central cabin 11 and 8 fan-shaped outer cabins 12. The foundation is transported by overall self-floating towing transportation. The draft of the foundation as a whole is controlled by adjusting the air pressure in the central cabin 11, thereby adjusting the buoyancy center height of the foundation. The stability and anti-overturning of the foundation floating are achieved by adjusting the air pressure in the 8 outer cabins 12. These 8 outer cabins 12 can control the swing amplitude of the foundation in 8 directions. When the center of gravity of the foundation shifts from the center of the central cabin 11 to one of the outer cabins 12, the air pressure in the two outer cabins 12 opposite to the outer cabin 12 can be reduced equally at the same time to restore the foundation. When the center of gravity of the foundation shifts toward the core filling column 111, the air pressure in the two outer cabins 12 adjacent to the core filling column 111 can be increased, while the air pressure in the two adjacent outer cabins 12 on the opposite side of the core filling column 111 can be reduced.

[0053] Other parts not described belong to the prior art.

Claims

1. Suitable for deep-water offshore wind power pipe frame large cylinder foundation, characterized by: The invention comprises a circular cylinder (1) and a pipe frame (2), wherein the circular cylinder (1) comprises a central chamber (11) and a plurality of outer chambers (12) connected to the outer surface of the central chamber (11), and the circular cylinder (1) has a cylinder skirt top plate (13) at the top and an opening at the bottom; The catheter frame (2) is wide at the bottom and narrow at the top, and comprises a plurality of main leg columns (21) and a diagonal brace (22) located between two main leg columns (21), and the bottom of the main leg column (21) is connected to the top vertex of the central cabin (11) through a connecting transition section (3); The central cabin (11) is a cube with an opening at the bottom, and the central cabin (11) comprises four core-filled columns (111) and four central cabin steel plates (112) located between the four core-filled columns (111); There are four main leg columns (21), and there are four connecting transition sections (3). The bottom diameter of the connecting transition section (3) is equal to the diameter of the core filling column (111), and the top diameter of the connecting transition section (3) is equal to the diameter of the main leg column (21); Welding four connecting transition sections (3) onto the four core filling columns (111); The four main leg columns (21) of the upper conductor frame (2) are directly connected to the four core filling columns (111) of the circular cylinder (1). When the circular cylinder (1) is on the ground, it directly bears the weight of the upper conductor frame (2) structure and transmits the upper load to the core filling columns (111) through the conductor frame (2), thereby eliminating the risk of the cylinder skirt top plate (13) being bent due to the upper weight.

2. The large cylindrical foundation of offshore wind power pipe frame suitable for deep water according to claim 1 is characterized in that: A plurality of stiffening plates (31) are provided between the connecting transition section (3) and the tube skirt top plate (13).

3. The large cylindrical foundation of offshore wind power pipe frame suitable for deep water according to claim 2 is characterized by: There are eight outer cabins (12), each of which comprises a basic outer cylinder wall (121) and two partition plates (122) connected to the basic outer cylinder wall (121), one partition plate (122) being connected to the core filling column (111), and the other partition plate (122) being connected to the middle of the central cabin steel plate (112), two adjacent outer cabins (12) sharing one partition plate (122), and the eight outer cabins (12) sharing one basic outer cylinder wall (121).

4. The large cylindrical foundation of offshore wind power pipe frame suitable for deep water according to claim 3 is characterized in that: The thickness of the base outer cylinder wall (121) is 15-40 mm, the thickness of the compartment plate (122) is 10 mm-30 mm, the thickness of the central cabin steel plate (112) is 10-30 mm, the diameter of the core column (111) is 500-2500 mm, the thickness of the cylinder skirt top plate (13) is 10-20 mm, and the length of the connecting transition section (3) is 1-3 m.

5. The large cylindrical foundation of offshore wind power pipe frame suitable for deep water according to claim 4 is characterized in that: The core-filled column (111) and the connecting transition section (3) are filled with C30-C60 fine aggregate concrete.

6. The large cylindrical foundation of offshore wind power pipe frame suitable for deep water according to claim 5 is characterized in that: A steel cage is placed inside the core-filled column (111).

7. The method for installing a large cylindrical foundation of an offshore wind power conductor frame suitable for deep water according to any one of claims 1 to 6, characterized in that: The following steps are involved: Step 1: First erect four core-filling columns (111), then splice the central cabin steel plate (112) to form a cubic central cabin (11); Step 2: First, four compartment plates (122) are welded on four core-filled columns (111) to form an internal frame of the tube skirt, and then the base outer tube wall (121) is assembled around it. Finally, the remaining four compartment plates (122) are welded between the base outer tube wall (121) and the middle of the central cabin steel plate (112); the tube skirt top plate (13) is installed on the top of the central cabin (11) and the outer cabin (12); and the installation of the circular cylinder (1) is completed; Step 3: Weld four connecting transition sections (3) onto the four core filling columns (111), wherein the bottom diameter of the connecting transition section (3) is the same as the diameter of the core filling column (111), and the top diameter of the connecting transition section (3) is the same as the diameter of the main leg column (21); Step 4: hoist the catheter frame (2) as a whole to the upper part of the circular cylinder (1), weld the four main legs (21) to the four connecting transition sections (3) respectively, and then connect the stiffening plate (31) to complete the overall installation.

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