Flexible reinforcing device for offshore wind turbine foundation and construction method

Abstract

The invention relates to the technical field of offshore wind power, and discloses a flexible reinforcing device for an offshore wind turbine foundation and a construction method. According to the flexible reinforcing device for the offshore wind turbine foundation, the annular hoop is installed on the outer wall of the main bearing pile to form a rigid restraint ring, then the annular hoop is rigidly connected with the auxiliary bearing pile through the first traction piece, a space cooperative stress system is formed, and when the main pile has the lateral bending tendency under the storm cyclic load, the main pile can be bent in the radial direction, and the main pile can be bent in the radial direction. The hoop directly transmits part of load to the auxiliary bearing pile through the traction piece. Namely, under the condition of bearing the same external load, the reinforcing device can enable the auxiliary bearing pile to share the load, so that the bending stress and local deformation of the pile body of the main bearing pile are reduced, the bending rigidity of the main bearing pile is effectively improved, foundation supporting force loss caused by weakening of soil around the main bearing pile is compensated, and displacement accumulation of the main bearing pile is greatly restrained.

Description

Technical Field

[0001] The present invention relates to the technical field of offshore wind power, and in particular to a flexible reinforcement device for an offshore wind turbine foundation and a construction method. Background Art

[0002] As the global energy transition accelerates, offshore wind power, a crucial component of clean energy, has become a core focus of energy strategies worldwide due to its abundant wind resources, high power generation efficiency, and minimal land occupation. Compared to onshore wind power, offshore wind power is less restricted by topography, boasts more stable wind speeds, and is located near economically developed coastal areas, facilitating power transmission and consumption. However, offshore wind farms must withstand the long-term challenges of a complex marine environment (such as typhoons, waves, tides, and corrosion), placing higher demands on the safety, durability, and economic efficiency of their infrastructure.

[0003] Offshore wind turbine monopile foundations are one of the most widely used support structures, typically consisting of a main pile, flange connectors, and an anchoring system. The main pile is a large-diameter steel pipe pile sunk into the seabed by hydraulic piling equipment, directly bearing the load of the wind turbine. Flange connectors connect the main pile to the wind turbine tower, ensuring efficient load transfer. Furthermore, the construction process requires equipment such as a piling vessel, floating crane, and vibratory hammer, and strict control of the pile foundation's inclination, displacement, and natural frequency is essential to ensure safe operation in complex marine environments.

[0004] However, in actual application, it was found that under the action of cyclic loads (such as wind, waves, and tides), the initial foundation reaction modulus and ultimate soil resistance of the soil around the pile will gradually decay, resulting in the accumulation of pile displacement. At the same time, due to the high salt spray, high humidity and microbial corrosion in the marine environment, the corrosion rate of steel will be accelerated, resulting in a decrease in the lateral stiffness of the single pile foundation and even causing structural instability. Summary of the Invention

[0005] In view of this, the present invention provides a flexible reinforcement device and construction method for an offshore wind turbine foundation to solve the problem of reduced bearing capacity of a single pile foundation.

[0006] In a first aspect, the present invention provides a flexible offshore wind turbine foundation reinforcement device comprising a primary bearing pile, an auxiliary bearing pile, and a reinforcement structure. The auxiliary bearing pile is spaced apart from the primary bearing pile; the reinforcement structure comprises an annular clamp assembly and a first tension member. The annular clamp assembly includes at least one annular clamp mounted on the outer wall of the primary bearing pile, and the at least one annular clamp is connected to the auxiliary bearing pile via the first tension member.

[0007] Beneficial effect: By installing the annular clamp on the outer wall of the main bearing pile to form a rigid constraint ring, and then by using the first pulling member to rigidly connect the annular clamp to the auxiliary bearing pile, a spatial coordinated force system is formed, so that when the main pile has a tendency to bend laterally under the cyclic load of wind and waves, the clamp transfers part of the load directly to the auxiliary bearing pile through the pulling member. That is, under the same external load conditions, this reinforcement device can enable the auxiliary bearing pile to share the load, thereby reducing the bending stress and local deformation of the main bearing pile body, effectively increasing the bending stiffness of the main bearing pile, and compensating for the loss of foundation support force caused by the weakening of the soil around the main bearing pile, thereby greatly suppressing the displacement accumulation of the main bearing pile. At the same time, the auxiliary bearing pile transfers part of the load to the deep seabed, reducing the corrosion rate of the surface steel of the main bearing pile, thereby delaying the degradation of the lateral stiffness of the main bearing pile.

[0008] In an optional embodiment, the annular hoop group includes at least a first annular hoop and a second annular hoop arranged at intervals along the axial direction of the main bearing pile. In the first annular hoop and the second annular hoop, the high-position annular hoop is connected to the auxiliary bearing pile through a first pull member, and the low-position annular hoop is connected to the first pull member through a second pull member.

[0009] Beneficial effect: By arranging the first annular hoop and the second annular hoop in the axial direction of the main bearing pile, and using the first pulling member to complete the connection between the high-position hoop and the auxiliary bearing pile and the second pulling member to complete the connection between the low-position hoop and the first pulling member through a layered pulling design, a three-level mechanical coordination system is formed. That is, the high-position hoop directly transfers the lateral load on the upper part of the main bearing pile to the auxiliary bearing pile through the first pulling member, reducing the peak bending moment at the top of the main bearing pile, while the low-position hoop further transfers the load on the middle and lower part of the main bearing pile to the auxiliary bearing pile through the series connection of the second pulling member and the first pulling member, realizing longitudinal graded unloading of the load, thereby reducing the overall displacement accumulation of the main pile. Compared with the stress distribution of the traditional single pile foundation under cyclic loads (wind, waves), the flexible reinforcement device of the offshore wind turbine foundation of this structure can delay the attenuation of the soil foundation reaction modulus around the main bearing pile, so that the main bearing pile can maintain the expected stiffness for a long time.

[0010] In an optional embodiment, along the radial direction of the main bearing pile, the inner wall of each annular hoop is spaced apart from the outer wall of the main bearing pile. The flexible offshore wind turbine foundation reinforcement device further includes two annular shear key assemblies, one mounted on the inner wall of the first annular hoop and the other mounted on the inner wall of the second annular hoop. The annular shear key assemblies in each annular hoop and the outer wall of the main bearing pile form a grouting chamber for filling with a reinforcement medium.

[0011] Beneficial effects: Through the arrangement of the annular shear key group and the inherent characteristics of its protrusion or groove structure, a mechanical interlocking structure can be formed after the reinforcing medium is filled between it and the outer wall of the main bearing pile. Under the action of cyclic loads such as waves and tides, the lateral shear force is directly transmitted through geometric interlocking, reducing fatigue damage to the main bearing pile and improving the lateral restraint ability of the clamp on the main pile. At the same time, after the reinforcing medium (such as high-strength grouting material) is filled in the grouting chamber, the protrusion or groove structure of the annular shear key can directly provide shear stiffness, and after the grouting material fills the gap, it absorbs local stress concentration through bonding and micro-deformation, preventing the annular shear key from breaking due to overload, forming a coupling system of rigid constraint and flexible buffering, and significantly improving the shear bearing capacity and durability of the main bearing pile.

[0012] In an optional embodiment, an annular elastic member is further provided between the inner wall of any of the annular clamps and the outer wall of the main bearing pile.

[0013] Beneficial effect: By adding an annular elastic part, during installation, the inner wall of the annular hoop will squeeze the annular elastic part, and use its flexible characteristics to ensure full-circumference contact between the annular hoop and the main bearing pile. When the main bearing pile is subjected to cyclic loads (wind, waves), the annular elastic part can absorb part of the vibration and dissipate energy.

[0014] In an optional embodiment, the flexible reinforcement device for an offshore wind turbine foundation further includes a bearing assembly. There is at least one bearing assembly, each of which includes a plurality of bearing members mounted in a circular array on the outer wall of the main bearing pile, the bearing assembly being used to support the annular clamp.

[0015] Beneficial Effects: By using multiple bearing elements installed in a circular array on the outer wall of the main pile, a rigid and stable bearing surface is provided for the hoop, effectively transmitting the entire load of the hoop and its load to the main pile. Furthermore, the hoop effectively resists bending and shear forces, reducing vibration and fatigue risks of the structure.

[0016] In an optional embodiment, any of the annular clamps is of split structure.

[0017] Benefits: By designing the ring clamp as a split structure, it can be disassembled into multiple independent components, significantly reducing the size and weight of each unit and simplifying transportation to the construction site. Furthermore, the split structure allows for rapid assembly through standardized interfaces, enabling quick installation and significantly reducing downtime required for maintenance or replacement. Furthermore, if a part needs to be replaced due to corrosion, wear, or damage, only the damaged part can be replaced, eliminating the need to scrap the entire unit, thus reducing maintenance costs.

[0018] In an optional embodiment, the annular hoop and the auxiliary bearing pile are both provided with hanging ears.

[0019] Beneficial Effects: The mounting lugs, as standardized interfaces, can be directly connected to the first pull member through plugging, snapping, or bolting, eliminating the need for complex on-site alignment, enabling rapid fixation and shortening construction time. Furthermore, there's no need for complex operations on the platform, reducing the risk of falls.

[0020] In the second aspect, the present invention also provides a construction method for a flexible reinforcement device for an offshore wind turbine foundation, which is applied to the flexible reinforcement device for an offshore wind turbine foundation of the first aspect. The construction method includes: prefabricating auxiliary bearing piles, annular hoops and a first pulling member; and installing the auxiliary bearing piles, annular hoops and a first pulling member in sequence outside the main bearing piles.

[0021] In an optional embodiment, the steps of installing the annular clamp include: transporting the annular clamp to an area near the main bearing pile by ship, and building a construction platform on the ship; installing the bearing component group on the outer wall of the main bearing pile; using a crane to lift the annular clamp and the annular elastic component to the required height, and completing the installation of the annular elastic component and the annular clamp in sequence; injecting a reinforcing medium into the gap between the annular clamp and the outer wall of the main bearing pile.

[0022] In an optional embodiment, the step of installing the first pulling member includes: using the first pulling member to connect the annular hoop and the auxiliary bearing pile; and completing tensioning of the first pulling member in stages. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the specific embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the specific embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 A three-dimensional view of a flexible reinforcement device for an offshore wind turbine foundation provided by an embodiment of the present invention;

[0025] Figure 2 A partial three-dimensional view of a flexible reinforcement device for an offshore wind turbine foundation provided by an embodiment of the present invention;

[0026] Figure 3 A partial cross-sectional view of a flexible reinforcement device for an offshore wind turbine foundation provided by an embodiment of the present invention;

[0027] Figure 4 A top view of a flexible reinforcement device for an offshore wind turbine foundation provided by an embodiment of the present invention;

[0028] Figure 5A partial exploded view of the annular clamp in the flexible reinforcement device for the offshore wind turbine foundation provided by an embodiment of the present invention when the annular clamp is a split structure.

[0029] Description of reference numerals:

[0030] 1. Main bearing piles;

[0031] 2. Auxiliary bearing piles;

[0032] 3. Reinforcement structure; 301. First pulling member; 302. First annular clamp; 303. Second annular clamp; 304. Second pulling member; 305. Annular shear key; 306. Grouting chamber; 307. Annular elastic member; 308. Bearing member; 309. Hanging ear; 310. Clamp body; 311. Ear plate; 312. Bolt. DETAILED DESCRIPTION

[0033] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0034] In the description of this application, it should be understood that the terms "upper", "lower", "horizontal", "top", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on this application.

[0035] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. Throughout this application, unless otherwise specified, "plurality" means two or more.

[0036] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0037] As the global energy transition accelerates, offshore wind power, a crucial component of clean energy, has become a core focus of energy strategies worldwide due to its abundant wind resources, high power generation efficiency, and minimal land occupation. Compared to onshore wind power, offshore wind power is less restricted by topography, boasts more stable wind speeds, and is located near economically developed coastal areas, facilitating power transmission and consumption. However, offshore wind farms must withstand the long-term challenges of a complex marine environment (such as typhoons, waves, tides, and corrosion), placing higher demands on the safety, durability, and economic efficiency of their infrastructure.

[0038] Offshore wind turbine monopile foundations are one of the most widely used support structures, typically consisting of a main pile, auxiliary piles, diagonal braces, flange connectors, and an anchoring system. The main pile is a large-diameter steel pipe pile sunk into the seabed by hydraulic piling equipment, directly bearing the load of the wind turbine. The auxiliary piles are connected to the main pile via diagonal braces, creating a mechanical synergy and enhancing overall stability. Flange connectors connect the main pile to the wind turbine tower, ensuring efficient load transfer. Furthermore, the construction process requires the use of equipment such as piling vessels, floating cranes, and vibratory hammers, and strict control of the pile foundation's inclination, displacement, and natural frequency to meet the requirements for safe operation in complex marine environments.

[0039] However, in actual application, it was found that under the action of cyclic loads (such as wind, waves, and tides), the initial foundation reaction modulus and ultimate soil resistance of the soil around the pile will gradually decay, resulting in the accumulation of pile displacement. At the same time, due to the high salt spray, high humidity and microbial corrosion in the marine environment, the corrosion rate of steel will be accelerated, resulting in a decrease in the lateral stiffness of the single pile foundation and even causing structural instability.

[0040] To this end, the flexible reinforcement device and construction method for offshore wind turbine foundations provided by the present invention can improve the horizontal and moment bearing capacity of existing single pile foundations (main bearing piles) by adding reinforcement structures.

[0041] The following combination Figures 1 to 5 , describing embodiments of the present invention.

[0042] According to an embodiment of the present invention, on the one hand, a flexible reinforcement device for an offshore wind turbine foundation is provided, such as Figure 1 As shown, it includes main bearing piles 1, auxiliary bearing piles 2 and reinforcement structure 3.

[0043] The auxiliary bearing piles 2 and the main bearing piles 1 are arranged at intervals.

[0044] like Figures 1 to 5 As shown, the reinforcement structure 3 includes an annular hoop group and a first pulling member 301 . The annular hoop group includes at least one annular hoop installed on the outer wall of the main bearing pile 1 , and at least one annular hoop is connected to the auxiliary bearing pile 2 through the first pulling member 301 .

[0045] In this arrangement, a rigid constraint ring is formed by installing the annular clamp on the outer wall of the main bearing pile 1, and then the annular clamp is rigidly connected to the auxiliary bearing pile 2 by using the first pulling member 301 to form a spatial cooperative force system. When the main pile tends to bend laterally under the cyclic load of wind and waves, the clamp transfers part of the load directly to the auxiliary bearing pile 2 through the pulling member.

[0046] That is, under the same external load conditions, this reinforcement device can enable the auxiliary bearing pile 2 to share the load, thereby reducing the bending stress and local deformation of the main bearing pile 1, effectively increasing the bending stiffness of the main bearing pile 1, and compensating for the loss of foundation support force caused by the weakening of the soil around the main bearing pile 1, thereby greatly suppressing the displacement accumulation of the main bearing pile 1.

[0047] At the same time, the auxiliary bearing piles 2 transfer part of the load to the deep seabed, reducing the corrosion rate of the surface steel of the main bearing piles 1, thereby delaying the degradation of the lateral stiffness of the main bearing piles 1.

[0048] It can be explained that the auxiliary bearing pile 2 is selected from one of hollow steel pipe piles, PHC pipe piles or negative pressure barrels. Its pile length and diameter are reduced compared to the existing main bearing pile 1, and the specific size is determined according to actual needs.

[0049] During installation, the auxiliary bearing piles 2 are located below the mud surface around the main bearing piles 1 .

[0050] In one embodiment, Figures 1 to 5 As shown, the annular hoop group includes at least a first annular hoop 302 and a second annular hoop 303 arranged at intervals along the axial direction of the main bearing pile 1. In the first annular hoop 302 and the second annular hoop 303, the high-position annular hoop is connected to the auxiliary bearing pile 2 through the first pulling member 301, and the low-position annular hoop is connected to the first pulling member 301 through the second pulling member 304.

[0051] In this way, by setting the first annular hoop 302 and the second annular hoop 303 in the axial direction of the main bearing pile 1, and using the first pulling member 301 to complete the connection between the high-position hoop and the auxiliary bearing pile 2 and the second pulling member 304 to complete the connection between the low-position hoop and the first pulling member 301, a layered pulling design is formed to form a three-level mechanical coordination system.

[0052] That is, the high-position hoop directly transfers the lateral load on the upper part of the main bearing pile 1 to the auxiliary bearing pile 2 through the first pulling member 301, thereby reducing the peak bending moment at the top of the main bearing pile 1, while the low-position hoop further transfers the load on the middle and lower part of the main bearing pile 1 to the auxiliary bearing pile 2 through the series connection of the second pulling member 304 and the first pulling member 301, thereby realizing longitudinal graded unloading of the load, thereby reducing the overall displacement accumulation of the main pile.

[0053] Compared with the stress distribution of traditional single pile foundations under cyclic loads (wind, waves), the flexible reinforcement device of the offshore wind turbine foundation of this structure can delay the attenuation of the soil foundation reaction modulus around the main bearing pile 1, so that the main bearing pile 1 can maintain the expected stiffness for a long time.

[0054] In one embodiment, Figures 1 to 5 As shown, along the radial direction of the main bearing pile 1, the inner wall of each annular hoop is spaced from the outer wall of the main bearing pile 1. The flexible reinforcement device for offshore wind turbine foundations also includes two annular shear key assemblies, one mounted on the inner wall of the first annular hoop 302 and the other mounted on the inner wall of the second annular hoop 303. The annular shear key assemblies in each annular hoop and the outer wall of the main bearing pile 1 form a grouting chamber 306, which is filled with a reinforcement medium.

[0055] With such a setting, through the arrangement of the annular shear key group and the inherent characteristics of its protrusion or groove structure, a mechanical bite structure can be formed after filling the reinforcing medium between it and the outer wall of the main bearing pile 1. Under the action of cyclic loads such as waves and tides, the lateral shear force is directly transmitted through geometric interlocking, thereby reducing the fatigue damage of the main bearing pile 1 and improving the lateral restraint ability of the clamp on the main pile.

[0056] At the same time, after the grouting chamber 306 is filled with a reinforcing medium (such as high-strength grouting material), the protrusion or groove structure of the annular shear key 305 can directly provide shear stiffness. After the grouting material fills the gap, it absorbs local stress concentration through bonding and micro-deformation, preventing the annular shear key 305 from breaking due to overload, forming a coupling system of rigid constraint and flexible buffering, and significantly improving the shear bearing capacity and durability of the main bearing pile 1.

[0057] It can be explained that the material of the annular shear key 305 is steel.

[0058] In one embodiment, Figures 1 to 5 As shown, the flexible reinforcement device for offshore wind turbine foundations also includes a bearing assembly. There is at least one bearing assembly, and each bearing assembly includes multiple bearing members 308 , which are mounted in a circular array on the outer wall of the main bearing pile 1 . Each bearing assembly is used to support the annular clamp.

[0059] Such an arrangement, by using multiple bearing members 308 to be installed in a circular array on the outer wall of the main bearing pile 1, can provide a rigid and stable supporting surface for the annular clamp, effectively transfer the annular clamp and all the loads it carries, and safely transfer them to the main bearing pile 1.

[0060] At the same time, it can effectively resist the bending and shear forces transmitted by the annular hoop, reducing the vibration and fatigue risks of the structure.

[0061] Wherein, a bearing component group is used to support an annular clamp.

[0062] It can be explained that the bearing member 308 is welded to the outer wall of the main bearing pile 1 .

[0063] During installation, the welding work of the bearing member 308 is completed first, and then the annular hoop is installed to support the annular hoop.

[0064] In one embodiment, Figures 1 to 5 As shown, any annular clamp is a split structure.

[0065] In this way, by setting the annular clamp as a split structure, it can be split into multiple independent parts, significantly reducing the volume and weight of a single piece and reducing the difficulty of transportation to the construction site.

[0066] The split structure also allows for quick assembly through standardized interfaces, enabling rapid installation and significantly reducing downtime for maintenance or replacement. Furthermore, if a component requires replacement due to corrosion, wear, or damage, only the damaged section can be replaced, eliminating the need to scrap the entire unit, thus reducing maintenance costs.

[0067] It can be explained that any annular clamp is composed of at least two clamp bodies 310. At the same time, two adjacent clamp bodies 310 are spliced together by setting up a set of ear plates 311. Each ear plate 311 in the set has a mounting hole, and after the mounting holes are aligned one by one, they are fixed using fasteners such as bolts 312 and nuts.

[0068] Preferably, any annular clamp is composed of three clamp bodies 310 spliced together.

[0069] Preferably, any annular hoop is 3m high and 40mm thick.

[0070] In one embodiment, Figures 1 to 5 As shown, an annular elastic member 307 is further provided between the inner wall of any annular hoop and the outer wall of the main bearing pile 1 .

[0071] With such a configuration, by adding an annular elastic member 307, during installation, the inner wall of the annular hoop will squeeze the annular elastic member 307, and utilize its flexible characteristics to ensure full circumference contact between the annular hoop and the main bearing pile 1. When the main bearing pile 1 is subjected to cyclic loads (wind, waves), the annular elastic member 307 can absorb part of the vibration and dissipate energy.

[0072] It can be explained that the annular elastic member 307 is selected as a hard rubber ring to ensure that when the three clamp bodies 310 are initially connected by bolts 312 to form a complete annular clamp, the hard rubber can be fully squeezed so that the clamp node can be effectively connected to the existing main bearing pile 1.

[0073] In one embodiment, Figures 1 to 5 As shown, the surfaces of the annular hoop and the auxiliary bearing pile 2 are both provided with hanging ears 309 .

[0074] With such a configuration, the hanging ear 309 serves as a standardized interface and can be directly connected to the first pulling member 301 by plugging, snapping or bolts 312, without the need for complex alignment on site, thereby achieving rapid fixation and shortening construction time.

[0075] At the same time, there is no need to perform complex operations on the platform, reducing the risk of people falling.

[0076] Furthermore, at least one steel hanging ear 309 is provided on the outer wall of each clamp body 310 .

[0077] Furthermore, when the number of the steel hanging ears 309 is two or more, they are arranged in a circumferentially uniform manner.

[0078] Such an arrangement can support multiple groups of first pulling members 301 and second pulling members 304 to apply force synchronously, thereby eliminating the pile body deflection caused by single-point traction.

[0079] Furthermore, a sensor interface (such as a strain gauge slot) is reserved at the lug 309 to cooperate with the intelligent traction system to achieve closed-loop control.

[0080] It can be explained that the first pulling member 301 and the second pulling member 304 are selected to be steel cables, chains and other components.

[0081] During installation, after all the annular hoops on the outer wall of the main bearing pile 1 are installed, the auxiliary bearing pile 2 is installed to a certain depth, and the two ends of the first pulling member 301 in the length direction are respectively connected to the high-position annular hoops and the hanging ears 309 on the surface of the auxiliary bearing pile 2. Then, the installation depth of the auxiliary bearing pile 2 is further increased, and it is gradually installed to the required depth, so that the auxiliary bearing pile 2 applies tensile stress to the first pulling member 301.

[0082] During this process, the second pulling member 304 is used to complete the connection between the low-position annular clamp and the first pulling member 301 .

[0083] The flexible reinforcement device for offshore wind turbine foundations provided in the above embodiment can ensure that damage to the in-service wind turbine monopile structure (main bearing pile 1) is reduced during installation.

[0084] In the second aspect, the present invention also provides a construction method for a flexible reinforcement device for an offshore wind turbine foundation, which is applied to the flexible reinforcement device for an offshore wind turbine foundation of the first aspect. The construction method includes: prefabricating auxiliary bearing piles 2, annular hoops and a first pulling member 301; and sequentially installing the auxiliary bearing piles 2, annular hoops and a first pulling member 301 outside the main bearing piles 1.

[0085] It can be explained that the auxiliary bearing pile 2, the first annular hoop 302, the second annular hoop 303, the first pulling member 301, and the second pulling member 304 are prefabricated in the factory, and annular shear keys 305 and annular elastic members 307 are installed on the inner walls of the first annular hoop 302 and the second annular hoop 303.

[0086] Then, the auxiliary bearing pile 2 is moved to the installation position.

[0087] For example, after selecting the installation location of the auxiliary load-bearing pile 2, a deck transport vessel (e.g., with a draft of 5.4 m and a load capacity of 12,630 t) is used to transport the auxiliary load-bearing pile 2 to the installation location. The auxiliary load-bearing pile 2 is hoisted to a certain height using the crane of the pile-driving vessel, and pile driving is carried out using a hydraulic hammer (e.g., IHC S-800) according to the design depth of penetration into the soil.

[0088] In one embodiment, the steps of installing the annular hoop include: transporting the annular hoop to an area near the main bearing pile 1 by ship, and building a construction platform on the ship; installing a bearing component group on the outer wall of the main bearing pile 1; using a crane to lift the annular hoop and the annular elastic component 307 to the required height, and completing the installation of the annular elastic component 307 and the annular hoop in sequence; injecting a reinforcing medium into the gap between the annular hoop and the outer wall of the main bearing pile 1.

[0089] It can be explained that the annular elastic member 307 is closely fitted to the main bearing pile 1 , and the annular clamp is arranged outside the annular elastic member 307 .

[0090] Subsequently, a reinforcing medium (such as concrete) is injected into the gap between the complete annular hoop and the main bearing pile 1 . After the reinforcing medium reaches the curing strength, the first pulling member 301 and the second pulling member 304 are connected.

[0091] In one embodiment, the step of installing the first pulling member 301 includes: using the first pulling member 301 to connect the annular hoop and the auxiliary bearing pile 2; and completing tensioning of the first pulling member 301 in stages.

[0092] Specifically, the first pulling member 301 passes through the annular clamp and the preset lug 309 on the surface of the auxiliary bearing pile 2, and anchors (such as OVM anchors) are installed at both ends of the pulling member in the length direction, and the tensioning length is reserved. A tensioner (DYWIDAG DY-300) is installed at one end, and the other end is fixed with a temporary anchor plate. The hydraulic pump station and the pressure sensor are connected, and the system is calibrated, and then the anchor is locked in stages.

[0093] Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention. Such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A flexible reinforcement device for offshore wind turbine foundation, characterized in that: include: Main bearing pile (1); Auxiliary bearing piles (2) are arranged at intervals from the main bearing piles (1); The reinforcement structure (3) comprises an annular hoop group and a first pulling member (301), wherein the annular hoop group comprises at least one annular hoop mounted on the outer wall of the main bearing pile (1), and at least one annular hoop is connected to the auxiliary bearing pile (2) via the first pulling member (301).

2. The flexible reinforcement device for offshore wind turbine foundation according to claim 1, characterized in that: The annular hoop group comprises at least a first annular hoop (302) and a second annular hoop (303) which are arranged at intervals along the axial direction of the main bearing pile (1); in the first annular hoop (302) and the second annular hoop (303), the high-position annular hoop is connected to the auxiliary bearing pile (2) through a first pulling member (301), and the low-position annular hoop is connected to the first pulling member (301) through a second pulling member (304).

3. The flexible reinforcement device for offshore wind turbine foundation according to claim 2, characterized in that: Along the radial direction of the main bearing pile (1), the inner wall of any of the annular hoop is spaced apart from the outer wall of the main bearing pile (1); The flexible reinforcement device for offshore wind turbine foundations also includes: There are two annular shear key groups, and the two annular shear key groups are respectively installed on the inner wall of the first annular hoop (302) and the inner wall of the second annular hoop (303); The annular shear key group in any annular hoop is enclosed with the outer wall of the main bearing pile (1) to form a grouting chamber (306), and the grouting chamber (306) is used to fill the reinforcement medium.

4. The flexible reinforcement device for offshore wind turbine foundation according to claim 2 or 3, characterized in that: An annular elastic member (307) is further provided between the inner wall of any annular hoop and the outer wall of the main bearing pile (1).

5. The flexible reinforcement device for offshore wind turbine foundation according to any one of claims 1 to 3, characterized in that: The flexible reinforcement device for offshore wind turbine foundations also includes: A bearing member group is provided, wherein at least one bearing member group comprises a plurality of bearing members (308), wherein the plurality of bearing members (308) are installed in a circumferential array on the outer wall of the main bearing pile (1), and wherein the bearing member group is used for supporting an annular hoop.

6. The flexible reinforcement device for offshore wind turbine foundation according to any one of claims 1 to 3, characterized in that: Any of the annular hoop is of split structure.

7. The flexible reinforcement device for offshore wind turbine foundation according to any one of claims 1 to 3, characterized in that: The surfaces of the annular hoop and the auxiliary bearing pile (2) are both provided with hanging ears (309).

8. A construction method for a flexible reinforcement device for an offshore wind turbine foundation, applied to the flexible reinforcement device for an offshore wind turbine foundation according to any one of claims 1 to 7, characterized in that: Construction methods include: Prefabricated auxiliary bearing pile (2), an annular hoop and a first pulling member (301); An auxiliary bearing pile (2), an annular hoop and a first pulling member (301) are sequentially installed outside the main bearing pile (1).

9. The construction method of the flexible reinforcement device for offshore wind turbine foundation according to claim 8, characterized in that: The steps for installing a ring clamp include: The annular clamp is transported to an area near the main bearing pile (1) by ship, and a construction platform is constructed on the ship; Installing a bearing component group on the outer wall of the main bearing pile (1); Using a crane to lift the annular hoop and the annular elastic member (307) to a required height, and completing the installation of the annular elastic member (307) and the annular hoop in sequence; A reinforcing medium is injected into the gap between the annular hoop and the outer wall of the main bearing pile (1).

10. The construction method of the flexible reinforcement device for offshore wind turbine foundation according to claim 8, characterized in that: The steps of installing the first pulling member (301) include: Using a first pulling member (301) to connect the annular hoop and the auxiliary bearing pile (2); The first pulling member (301) is tensioned in stages.

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