Offshore wind turbine jacket foundation structure and installation method thereof

Abstract

The invention discloses an offshore wind turbine jacket foundation structure and a mounting method thereof. The offshore wind turbine jacket foundation structure comprises a jacket assembly and a plurality of pile leg assemblies connected to the jacket assembly. According to the offshore wind turbine jacket foundation structure, the barrel assembly is arranged to serve as a reinforcing part of the pile leg body, the pile diameter and the pile length of a single-pile type pile leg are reduced, the foundation manufacturing cost is reduced, and the barrel assembly and the part, located below the datum plane, of the pile leg body are installed in seabed foundation soil; enough anti-overturning capacity is provided for the whole offshore wind turbine jacket foundation structure, and the horizontal bearing capacity of the offshore wind turbine jacket foundation structure is improved. According to the offshore wind turbine jacket foundation structure, the overall rigidity of a wind turbine system can be effectively improved through the combination of the cylinder assembly and the pile leg body, the foundation manufacturing cost and the construction cost are greatly reduced while the bearing capacity of the offshore wind turbine jacket foundation structure is guaranteed, and the bearing capacity of the offshore wind turbine jacket foundation structure can be effectively improved when the soil texture of a foundation is poor.

Description

Technical Field

[0001] The invention relates to an offshore wind turbine foundation, and in particular to an offshore wind turbine conductor frame foundation structure and an installation method thereof. Background Art

[0002] The offshore wind turbine foundation is a key component of wind farm design. Offshore wind turbines are huge in size, and their foundations need to withstand long-term cyclic loads such as wind and waves 107 to 108 times in their lifetime. At the same time, they also need to resist extreme loads such as storm surges that occur with a certain probability. Complex load conditions impose strict requirements on the horizontal bearing capacity and deformation characteristics of the wind turbine pile foundation. For example, DNVGL stipulates that the cumulative rotation angle of the offshore wind turbine foundation at the seabed mud surface shall not exceed 0.25°. Design practice shows that the horizontal ultimate bearing capacity of the wind turbine pile foundation is no longer the dominant design variable, and its horizontal and rotational deformation are the design points. At present, common offshore wind turbine pile foundation types at home and abroad include super-large diameter single pile foundations, tripod foundations, conductor frame foundations and pile group foundations.

[0003] The jacket foundation was originally used to support offshore oil and gas platforms. In recent years, the offshore wind power industry has gradually used this foundation form for wind farms with medium water depths. When the foundation soil is poor, such as soft muddy soil on the seabed, the jacket often tilts or settles due to large deformation of the surface soil. At this time, in order to meet the bearing capacity of the wind turbine, the jacket foundation needs to increase the pile leg length, pile diameter and penetration depth. This will greatly increase the cost of the jacket foundation, and the bearing advantage is no longer worth mentioning compared to its construction cost. Therefore, seeking more reasonable foundation forms and structural reinforcement measures is an engineering problem that needs to be solved urgently. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide an offshore wind turbine duct foundation structure and an installation method thereof.

[0005] The technical solution adopted by the present invention to solve the technical problem is: constructing an offshore wind turbine jacket foundation structure, which includes a jacket assembly and a plurality of pile leg assemblies connected to the jacket assembly;

[0006] The catheter frame assembly includes a plurality of positioning members and a plurality of connecting members, wherein the plurality of connecting members are cross-connected to each other between adjacent positioning members;

[0007] Each of the pile leg assemblies includes a pile leg body connected to the positioning member and a cylinder assembly, the pile leg body and the cylinder assembly are connected by grouting, and the cylinder assembly is sleeved on the outside of the pile leg body, with the upper end surface of the cylinder assembly as the reference plane, and the cylinder assembly and the part of the pile leg body located below the reference plane are installed in the seabed foundation soil.

[0008] In some embodiments, the cylinder assembly includes an outer cylinder, an inner cylinder, and a connecting cover plate;

[0009] A grouting annular space is provided between the inner cylinder and the pile leg body, the connecting cover plate is connected to the outer side surface of the inner cylinder, and the outer cylinder is connected to a side of the connecting cover plate away from the inner cylinder.

[0010] In some embodiments, the connection cover plate is provided with grouting holes;

[0011] The inner cylinder is provided with an introduction hole.

[0012] In some embodiments, the barrel assembly further comprises a plurality of ribs, wherein the plurality of ribs are spaced apart and arranged along the circumferential direction of the leg body;

[0013] Each of the ribs comprises a fixing portion and a partition formed integrally with the fixing portion, wherein the fixing portion is respectively connected to the outer side surface of the inner cylinder and the upper surface of the connecting cover plate;

[0014] The partitions are respectively connected to the outer side surface of the inner cylinder and the inner side surface of the outer cylinder. The plurality of partitions divide the interior of the outer cylinder into a plurality of partition chambers. The grouting holes are communicated with the partition chambers.

[0015] In some embodiments, the number of the ribs is 6 to 12.

[0016] In some embodiments, the height of the fixing portion is 0.3m to 0.7m, the height of the partition portion is 2m to 4m, and the thickness of the rib plate is 1cm to 3cm;

[0017] The wall thickness of the outer cylinder is 1 cm to 6 cm.

[0018] In some embodiments, the diameter of the pile leg body is 3m to 12m, the height of the pile leg body is 30m to 150m, and the ratio of the wall thickness of the pile leg body to the diameter of the pile leg body is 0.6% to 2.4%.

[0019] In this embodiment, a method for installing an offshore wind turbine jacket foundation structure is also constructed. The method is based on the offshore wind turbine jacket foundation structure and comprises the following steps:

[0020] S1. Transport the pile leg body and the cylinder assembly to the construction site;

[0021] S2, opening the grouting hole as an exhaust channel, hoisting the cylinder assembly as a whole to a designated position and sinking it to the seabed, so that the cylinder assembly as a whole sinks under the action of its own weight until the cylinder assembly can no longer penetrate into the seabed foundation soil due to its own weight;

[0022] S3, connecting the grouting holes corresponding to each separated chamber to a pump, and starting the pump to work, so that negative pressure is gradually formed inside the cylinder assembly and reaches a preset negative pressure value, so that the cylinder assembly continues to penetrate into the seabed foundation soil to a preset depth by relying on the pressure difference between the inside and the outside;

[0023] S4, when the cylinder assembly reaches a preset depth, disconnecting the water pump from the grouting hole, connecting the grouting pipe to the grouting hole, and injecting slurry into the cylinder assembly;

[0024] S5. After the cylinder assembly is positioned and fixed on the seabed, the pile leg body is positioned at a relative position of the cylinder assembly, and the pile leg body is driven into a predetermined depth;

[0025] S6. After the pile leg body is driven into a predetermined depth, a grouting pipe is used to connect the introduction hole and slurry is injected to connect the barrel assembly and the pile leg body.

[0026] In some embodiments, the method for installing the offshore wind turbine jacket foundation structure further includes:

[0027] S7, connecting the jacket assembly with the pile leg assembly to complete the overall installation of the offshore wind turbine jacket foundation structure.

[0028] In some embodiments, during the process of the cylinder assembly penetrating into the seabed foundation soil, the cylinder assembly is leveled by obtaining the pressure difference between the separate chambers.

[0029] The implementation of the present invention has the following beneficial effects: the offshore wind turbine jacket foundation structure reduces the pile diameter and pile length of the single pile leg by setting the cylinder assembly as the reinforcement part of the leg body, and reduces the foundation cost, and the cylinder assembly and the part of the leg body located below the reference plane are installed in the seabed foundation soil, which provides sufficient anti-overturning ability for the offshore wind turbine jacket foundation structure as a whole, and improves the horizontal bearing capacity of the offshore wind turbine jacket foundation structure. Compared with the single pile leg, the combination of the cylinder assembly and the leg body can effectively improve the overall rigidity of the wind turbine system, while ensuring the bearing capacity of the offshore wind turbine jacket foundation structure, greatly reducing the foundation cost and construction cost, and can effectively improve the bearing capacity of the offshore wind turbine jacket foundation structure when the foundation soil is poor. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solution of the present invention, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. It should be understood that the following drawings only show certain embodiments of the present invention and should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work. In the drawings:

[0031] Figure 1 is a schematic diagram of the overall structure of an offshore wind turbine jacket foundation structure in some embodiments of the present invention;

[0032] Figure 2 is a schematic diagram of the three-dimensional structure of a pile leg assembly in some embodiments of the present invention;

[0033] Figure 3 is a top view of the structure of the pile leg assembly in some embodiments of the present invention;

[0034] Figure 4 It is a structural front view of the pile leg assembly in some embodiments of the present invention. DETAILED DESCRIPTION

[0035] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific embodiments of the present invention are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the directions or positional relationships indicated by "front", "back", "up", "down", "left", "right", "longitudinal", "horizontal", "vertical", "horizontal", "top", "bottom", "inside", "outside", "head", "tail", etc. are based on the directions or positional relationships shown in the accompanying drawings, are constructed and operated in a specific direction, and are only for the convenience of describing the present technical solution, rather than indicating that the device or element referred to must have a specific direction, and therefore cannot be understood as a limitation to the present invention.

[0036] It should also be noted that, unless otherwise clearly specified and limited, the terms such as "installed", "connected", "connected", "fixed", "set" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. When an element is referred to as being "on" or "under" another element, the element can be "directly" or "indirectly" located on the other element, or there may be one or more intermediate elements. The terms "first", "second", "third", etc. are only for the convenience of describing the present technical solution, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", "third", etc. can explicitly or implicitly include one or more of the features. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0037] See also Figures 1 to 4 The present invention discloses an offshore wind turbine jacket foundation structure, which is installed on the seabed foundation soil, and includes a jacket assembly 1 and a plurality of leg assemblies 2 connected to the jacket assembly 1. The jacket assembly 1 includes a plurality of positioning members 11 and a plurality of connecting members 12, and the plurality of connecting members 12 are cross-connected between adjacent positioning members 11. Each leg assembly 2 includes a leg body 21 connected to the positioning member 11 and a cylinder assembly 22. The leg body 21 and the cylinder assembly 22 are connected by grouting, and the cylinder assembly 22 is sleeved on the outside of the leg, with the upper end surface of the cylinder assembly 22 as the reference surface 23, and the cylinder assembly 22 and the portion of the leg body 21 located below the reference surface 23 are installed in the seabed foundation soil.

[0038] Specifically, the seabed foundation soil is of the nature of seabed silt soft soil, the positioning member 11 is a round steel pipe, the connecting member 12 is an oblique tie bar, the jacket assembly 1 is composed of a plurality of round steel pipes and a plurality of oblique tie bars to form a lattice structure, the round steel pipes are three or more, and adjacent round steel pipes are connected by a plurality of groups of double-limb oblique tie bars. The leg body 21 and the cylinder assembly 22 are connected by grouting to form a pile-cylinder composite foundation, and the jacket assembly 1 and the leg assembly 2 are both made of steel. In addition, the leg body 21 is a hollow cylinder with a closed top, and the top of the leg body 21 is the connection end between the leg body 21 and the jacket assembly 1. The cylinder assembly 22 and the part of the leg body 21 located below the reference plane 23 are installed in the seabed foundation soil, that is, the part of the leg body 21 located above the reference plane 23 does not penetrate into the seabed foundation soil. During the installation process, the upper end surface of the cylinder assembly 22 is kept flush with the mud surface of the seabed foundation soil, and the installation is considered complete. The unreinforced part of the leg body 21 has sufficient anti-overturning ability through the following aspects: providing sufficient burial depth, providing greater side friction resistance and passive earth pressure, and resisting horizontal loads; optimizing load transfer, effectively transferring upper loads to deep soil, and reducing local stress concentration; improving overall stiffness, and cooperating with the cylinder assembly 22 part to improve the overall stiffness of the offshore wind turbine duct frame foundation structure; providing sufficient bending resistance and reducing bending deformation.

[0039] It can be understood that the offshore wind turbine jacket foundation structure reduces the pile diameter and pile length of the single pile leg by setting the cylinder assembly 22 as the reinforcement part of the leg body 21, and reduces the foundation cost. The cylinder assembly 22 and the part of the leg body 21 located below the reference plane 23 are installed in the seabed foundation soil, which provides sufficient anti-overturning ability for the offshore wind turbine jacket foundation structure as a whole, and improves the horizontal bearing capacity of the offshore wind turbine jacket foundation structure. Compared with the single pile leg, the combination of the cylinder assembly 22 and the leg body 21 can effectively improve the overall stiffness of the wind turbine system, so that the overall natural frequency of the wind turbine system is between 1P and 3P. While ensuring the bearing capacity of the offshore wind turbine jacket foundation structure, it greatly reduces the foundation cost and construction cost, and can effectively improve the bearing capacity of the offshore wind turbine jacket foundation structure when the foundation soil is poor.

[0040] like Figure 2As shown, the cylinder assembly 22 includes an outer cylinder 221, an inner cylinder 222 and a connecting cover plate 223. A grouting annular space is provided between the inner cylinder 222 and the pile leg body 21, the connecting cover plate 223 is connected to the outer side of the inner cylinder 222, and the outer cylinder 221 is connected to the side of the connecting cover plate 223 away from the inner cylinder 222. Specifically, the outer cylinder 221 and the inner cylinder 222 are both cylindrical structures with upper and lower parts open, and the connecting cover plate 223 can be welded to the outer cylinder 221 and the inner cylinder 222, and the inner cylinder 222 is used to connect with the outer side of the pile leg body 21. Further, a grouting hole 2231 is provided on the connecting cover plate 223, and an introduction hole 2221 is provided on the inner cylinder 222. The grouting hole 2231 or the introduction hole 2221 can be connected by a grouting pipe to inject slurry.

[0041] like Figures 2 to 4 As shown, the cylinder assembly 22 further includes a plurality of ribs 224, which are arranged in a spaced relationship along the circumferential direction of the leg body 21. Each rib 224 includes a fixing portion 2241 and a partition 2242 integrally formed with the fixing portion 2241, the fixing portion 2241 is respectively connected to the outer side surface of the inner cylinder 222 and the upper surface of the connecting cover plate 223, the partition 2242 is respectively connected to the outer side surface of the inner cylinder 222 and the inner side surface of the outer cylinder 221, and the plurality of partitions 2242 divide the interior of the outer cylinder 221 into a plurality of partition chambers 225, and the grouting holes 2231 are connected to the partition chambers 225. It can be understood that the ribs 224 can enhance the connection strength between the inner cylinder 222 and the outer cylinder 221. The multiple ribs 224 are evenly spaced and arranged along the circumferential direction of the leg body 21. The ribs 224 are generally in the shape of a right-angled trapezoid, while the fixing portions 2241 are in the shape of a right-angled triangle and are spaced and arranged along the circumferential direction of the leg body 21. The spacers 2242 are in the shape of a rectangle and are also spaced and arranged along the circumferential direction of the leg body 21. In addition, the multiple partitions 2242 divide the interior of the outer cylinder 221 into multiple separated chambers 225, and slurry can be poured into each independent separated chamber 225 through the grouting holes 2231. Pouring slurry into each independent separated chamber 225 can facilitate the leveling of the overall horizontality of the cylinder assembly 22 during the negative pressure sinking process of the cylinder assembly 22. If the catheter frame assembly 1 tilts in a certain direction during the installation process, the foundation level can be adjusted by pumping negative pressure into one of the separated chambers 225 or pouring more grout into one of the separated chambers 225.

[0042] The number of the ribs 224 is 6 to 12, and the number of the ribs 224 is preferably 8. The 8 ribs 224 divide the interior of the barrel assembly 22 into 8 partition chambers 225 .

[0043] In this embodiment, the height of the fixing portion 2241 is 0.3m to 0.7m, the height of the partition 2242 is 2m to 4m, the thickness of the rib 224 is 1cm to 3cm, and the wall thickness of the outer cylinder 221 is 1cm to 6cm. Preferably, the height of the fixing portion 2241 is 0.5m, the height of the partition 2242 is 3m, the thickness of the rib 224 is 2cm, and the wall thickness of the outer cylinder 221 is 2cm.

[0044] The diameter of the leg body 21 is 3m to 12m, the height of the leg body 21 is 30m to 150m, and the ratio of the wall thickness of the leg body 21 to the diameter of the leg body 21 is 0.6% to 2.4%. Preferably, the diameter of the leg body 21 is 6m, the height of the leg body 21 is 80m, and the ratio of the wall thickness of the leg body 21 to the diameter of the leg body 21 is 1%. Since the barrel assembly 22 is a reinforcement structure of the leg body 21, in order to save materials, the wall thickness of the leg body 21 is 2cm.

[0045] In this embodiment, a method for installing an offshore wind turbine jacket foundation structure is also constructed. The method is based on the above offshore wind turbine jacket foundation structure and comprises the following steps:

[0046] S1, transporting the pile leg body 21 and the cylinder assembly 22 to the construction location, and transporting the pile leg body 21 and the cylinder assembly 22 to the designated construction location by floating during construction;

[0047] S2, opening the grouting hole 2231 as an exhaust channel, hoisting the cylinder assembly 22 as a whole to the designated position and sinking it to the seabed, so that the cylinder assembly 22 as a whole sinks under the action of its own weight until the cylinder assembly 22 can no longer penetrate into the seabed foundation soil due to its own weight;

[0048] S3, connecting the grouting holes 2231 corresponding to each partition chamber 225 to a water pump, and starting the water pump to work, so that negative pressure is gradually formed inside the cylinder assembly 22 and reaches a preset negative pressure value, so that the cylinder assembly 22 continues to penetrate into the seabed foundation soil to a preset depth by relying on the pressure difference between the inside and the outside;

[0049] S4, when the cylinder assembly 22 reaches the preset depth, disconnect the water pump from the grouting hole 2231, connect the grouting pipe to the grouting hole 2231, and inject slurry into the cylinder assembly 22;

[0050] S5. After the cylinder assembly 22 is positioned and fixed on the seabed, the pile leg body 21 is positioned relative to the cylinder assembly 22, and the pile leg body 21 is driven into a predetermined depth;

[0051] S6. When the pile leg body 21 is driven into a predetermined depth, a grouting pipe is used to connect the introduction hole 2221 and slurry is injected to connect the barrel assembly 22 and the pile leg body 21.

[0052] S7, connecting the jacket assembly 1 and the pile leg assembly 2 to complete the overall installation of the jacket foundation structure of the offshore wind turbine.

[0053] While the cylinder assembly 22 is penetrating the seabed foundation soil, the pressure difference of each separated chamber 225 is obtained to level the cylinder assembly 22. The pressure value of each separated chamber 225 can be obtained through a pressure sensor, thereby obtaining the pressure difference of each separated chamber 225.

[0054] It is understandable that in the old technology, the cylinder assembly 22 is set at a position close to the mud surface. On the seabed with poor foundation soil, it is first subjected to vacuum preloading treatment to make the soft soil have a certain strength before the next step of construction. The pile leg body 21 and the cylinder assembly 22 of the present invention can effectively utilize the horizontal resistance of the soil within the depth range of 3d to 5d (d is the diameter of the pile leg body 21), omitting the foundation treatment step, which can not only improve the horizontal bearing capacity of the foundation but also simplify the construction steps. That is, by adding the cylinder assembly 22 to increase the contact surface between the foundation and the soft soil, it can mobilize more soil reaction force, and reduce the pile diameter and pile length on the original single pile foundation, so as to reduce the construction difficulty while saving steel loss.

[0055] The offshore wind turbine jacket foundation structure first installs the cylinder assembly 22 and then installs the pile leg body 21, which has the following advantages:

[0056] 1. It is beneficial to reduce the impact on the environment. Since the cylinder assembly 22 is first settled in place, the noise and vibration generated in the subsequent piling process are relatively small, which is beneficial to protecting the marine ecological environment;

[0057] 2. It is conducive to improving construction efficiency. The cylinder assembly 22 is used as a temporary support, and piling operations can be carried out inside it, reducing the dependence on large piling ships, especially in deep water areas, which can significantly reduce construction costs;

[0058] 3. It has better adaptability. This method is more suitable for soft soil or loose sediments, because the cylinder assembly 22 can sink steadily to the designed depth by its own weight and the negative pressure formed by internal pumping, without the need for strong external force. The combination of the cylinder assembly 22 and the pile leg body 21 is designed to cope with soft strata.

[0059] 4. It is conducive to improving construction safety. After the cylinder assembly 22 is lowered, it has stabilized on the seabed, providing a relatively safe and stable platform, and the piling process can be carried out on the water surface. Since most of the work is completed above the water surface, such as the sinking of the cylinder assembly 22 and the installation of the pile leg body 21, this method has lower safety risks than piling directly on the seabed.

[0060] It can be understood that the above embodiments only express the preferred implementation modes of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the patent scope of the present invention. It should be pointed out that, for ordinary technicians in this field, without departing from the concept of the present invention, the above technical features can be freely combined, and several deformations and improvements can be made, which all belong to the protection scope of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should belong to the scope covered by the claims of the present invention.

Claims

1. An offshore wind turbine jacket foundation structure, characterized in that: It comprises a conductor frame assembly (1) and a plurality of pile leg assemblies (2) connected to the conductor frame assembly (1); The catheter frame assembly (1) comprises a plurality of positioning members (11) and a plurality of connecting members (12), wherein the plurality of connecting members (12) are cross-connected to each other between adjacent positioning members (11); Each of the pile leg assemblies (2) comprises a pile leg body (21) connected to the positioning member (11) and a cylinder assembly (22); the pile leg body (21) and the cylinder assembly (22) are connected by grouting, and the cylinder assembly (22) is sleeved on the outside of the pile leg body (21); the upper end surface of the cylinder assembly (22) is used as a reference surface (23); the cylinder assembly (22) and the portion of the pile leg body (21) located below the reference surface (23) are installed in the seabed foundation soil.

2. The offshore wind turbine jacket foundation structure according to claim 1, characterized in that: The cylinder assembly (22) comprises an outer cylinder (221), an inner cylinder (222) and a connecting cover plate (223); A grouting annular space is provided between the inner cylinder (222) and the pile leg body (21); the connecting cover plate (223) is connected to the outer side surface of the inner cylinder (222); and the outer cylinder (221) is connected to a side of the connecting cover plate (223) away from the inner cylinder (222).

3. The offshore wind turbine jacket foundation structure according to claim 2, characterized in that: The connecting cover plate (223) is provided with a grouting hole (2231); The inner cylinder (222) is provided with an introduction hole (2221).

4. The offshore wind turbine jacket foundation structure according to claim 3, characterized in that: The cylinder assembly (22) further comprises a plurality of ribs (224), wherein the plurality of ribs (224) are arranged in a spaced relationship along the circumferential direction of the leg body (21); Each of the ribs (224) comprises a fixing portion (2241) and a partition portion (2242) formed integrally with the fixing portion (2241), wherein the fixing portion (2241) is respectively connected to the outer side surface of the inner cylinder (222) and the upper surface of the connecting cover plate (223); The partitions (2242) are respectively connected to the outer side surface of the inner cylinder (222) and the inner side surface of the outer cylinder (221); the plurality of partitions (2242) divide the interior of the outer cylinder (221) into a plurality of partition chambers (225); and the grouting holes (2231) are connected to the partition chambers (225).

5. The offshore wind turbine jacket foundation structure according to claim 4, characterized in that: The number of the ribs (224) is 6 to 12.

6. The offshore wind turbine jacket foundation structure according to claim 4, characterized in that: The height of the fixing portion (2241) is 0.3m to 0.7m, the height of the partition portion (2242) is 2m to 4m, and the thickness of the rib plate (224) is 1cm to 3cm; The wall thickness of the outer cylinder (221) is 1 cm to 6 cm.

7. The offshore wind turbine jacket foundation structure according to claim 1, characterized in that: The diameter of the pile leg body (21) is 3m to 12m, the height of the pile leg body (21) is 30m to 150m, and the ratio of the wall thickness of the pile leg body (21) to the diameter of the pile leg body (21) is 0.6% to 2.4%.

8. A method for installing an offshore wind turbine jacket foundation structure, based on the offshore wind turbine jacket foundation structure according to any one of claims 1 to 7, characterized in that: Includes steps: S1, transporting the pile leg body (21) and the cylinder assembly (22) to the construction site; S2, opening the grouting hole (2231) as an exhaust passage, hoisting the cylinder assembly (22) as a whole to a designated position and sinking it to the seabed, so that the cylinder assembly (22) as a whole sinks under the action of its own weight until the cylinder assembly (22) can no longer penetrate into the seabed foundation soil due to its own weight; S3, connecting the grouting hole (2231) corresponding to each partition chamber (225) to a water pump, and starting the water pump to work, so that a negative pressure is gradually formed inside the cylinder assembly (22) and reaches a preset negative pressure value, and the cylinder assembly (22) continues to penetrate into the seabed foundation soil to a preset depth by relying on the pressure difference between the inside and the outside; S4. When the barrel assembly (22) reaches a preset depth, disconnect the water pump from the grouting hole (2231), connect the grouting pipe to the grouting hole (2231), and inject slurry into the barrel assembly (22); S5. After the cylinder assembly (22) is positioned and fixed on the seabed, the pile leg body (21) is positioned at a relative position of the cylinder assembly (22), and the pile leg body (21) is driven into a predetermined depth; S6. After the pile leg body (21) is driven into a predetermined depth, a grouting pipe is used to connect the introduction hole (2221) and slurry is injected to connect the barrel assembly (22) and the pile leg body (21).

9. The method for installing an offshore wind turbine jacket foundation structure according to claim 8, characterized in that: The installation method of the offshore wind turbine jacket foundation structure also includes: S7, connecting the jacket assembly (1) and the leg assembly (2) to complete the overall installation of the offshore wind turbine jacket foundation structure.

10. The method for installing an offshore wind turbine jacket foundation structure according to claim 8, characterized in that: When the cylinder assembly (22) is penetrating into the seabed foundation soil, the cylinder assembly (22) is leveled by obtaining the pressure difference of each of the separated chambers (225).

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