Offshore wind power single pile foundation scour prevention structure

Abstract

The present application relates to offshore wind power engineering technical field, especially to a kind of offshore wind power single pile foundation scour prevention structure, including pile foundation, rigid support frame, wave reduction and flow control structure and silt barrier structure, wherein, rigid support frame includes circumferential support frame and axial support pole;Circumferential support frame is set around the four of pile foundation, and circumferential support frame is provided with two layers of upper and lower;Axial support pole is fixedly arranged on circumferential support frame, and two layers of circumferential support frame are fixedly connected by axial support pole;Wave reduction and flow control structure includes flexible cavity, top composite film and horizontal strip, and flexible cavity is fixedly arranged in rigid support frame;Top composite film is fixedly arranged on the top side of circumferential support frame, and the present application significantly reduces the hydrodynamic load suffered by foundation structure by absorbing wave energy, inhibiting horseshoe vortex and kármán vortex and other adverse flow patterns;Meanwhile, it reduces the occurrence of scour accident fundamentally by weakening bottom flow and blocking silt movement.

Description

Technical Field

[0001] This invention relates to the field of offshore wind power engineering technology, and in particular to an anti-scour structure for offshore wind power monopile foundations. Background Technology

[0002] Offshore wind power, as an important component of clean energy, relies on monopile foundations that operate in the complex and ever-changing marine environment, continuously subjected to the scouring effects of waves, currents, and other hydrodynamic loads. Especially on the upstream side of the pile, horseshoe vortices and Kármán vortex streets easily form, causing strong entrainment and removal of seabed sediment around the pile, leading to the development of deep scour pits. As scouring intensifies, the effective embedment depth of the pile decreases, and its free length increases, severely weakening its bending capacity and overall stability. In severe cases, this can even lead to major safety accidents such as turbine tilting, tower fracture, or even collapse.

[0003] To mitigate the aforementioned scouring problems, traditional anti-scouring measures such as riprap and sandbags are commonly used in engineering projects. However, these methods are difficult to precisely place in designated areas around the piles, and there are significant gaps between the sandbags and the pile foundation. Under the long-term action of water flow, these gaps are easily eroded and hollowed out, which in turn exacerbates local scouring, causing the scour pit to expand further and threatening the stability of the pile foundation. In addition, traditional measures lack the ability to effectively control the flow field around the piles, making it difficult to suppress the formation of horseshoe vortices and Karman vortex streets, and unable to fundamentally prevent the continuous loss of sediment, thus offering limited protective effects. Summary of the Invention

[0004] In view of this, the present invention proposes an anti-scour structure for offshore wind power monopile foundations. It is constructed by setting up a rigid support frame consisting of upper and lower circumferential support frames and axial struts, and integrating a flexible cavity, a top composite membrane, and horizontal strips connecting the pile foundation and the frame to form a wave reduction and flow control structure. A sediment barrier structure is configured at the bottom, thereby synergistically achieving wave energy dissipation, suppression of unfavorable eddies around the pile, sealing of the top gap, and sealing of the bottom sediment. This effectively solves the technical problems of existing anti-scour measures, such as poor fit, easy hollowing of gaps leading to local scour aggravation, and lack of overall flow field control and stable protection capabilities.

[0005] The technical solution of this invention is implemented as follows: This invention provides an anti-scour structure for a monopile foundation of offshore wind power, comprising a pile foundation, a rigid support frame, a wave reduction and flow control structure, and a sediment barrier structure, wherein... The rigid support frame includes a circumferential support frame and an axial support rod. The circumferential support frame is arranged around the perimeter of the pile foundation and has two layers, upper and lower. The axial support rod is fixedly arranged on the circumferential support frame, and the two layers of the circumferential support frame are fixedly connected by the axial support rod. The wave reduction and flow control structure includes a flexible cavity, a top composite membrane, and a horizontal strip. The flexible cavity is fixedly installed within the rigid support frame. The top composite membrane is fixedly installed on the top side of the circumferential support frame, and the top side of the flexible cavity is spaced apart from the top composite membrane. One end of the horizontal strip is fixedly installed on the top side of the circumferential support frame, and the other end of the horizontal strip is fixedly installed on the pile foundation. The silt barrier structure is fixedly installed on the bottom side of the circumferential support frame.

[0006] Based on the above technical solutions, preferably, the circumferential support frame is located in two places, symmetrically arranged on both sides of the pile foundation, wherein... The two circumferential support frames together form a ring frame structure.

[0007] Based on the above technical solutions, preferably, the circumferential support frame includes circumferential frame rods and radial support rods, wherein, The circumferential frame has multiple layers in the radial direction, and the multiple layers of circumferential frame are arranged coaxially. The radial support rods are provided in multiple forms, and the multiple circumferential frame rods are connected and combined to form a semi-circular frame structure.

[0008] Based on the above technical solutions, preferably, the flexible cavity is disposed within a plurality of gaps between the circumferential frame rod and the radial support rod, and the flexible cavity includes an axial flexible membrane and a circumferential flexible membrane, wherein, Both the axial flexible membrane and the circumferential flexible membrane are fixedly mounted on the axial support rod, and the axial flexible membrane and the circumferential flexible membrane are connected end to end to form a cavity structure that is open at the top and bottom.

[0009] Based on the above technical solutions, preferably, the sediment barrier structure includes a bottom composite membrane and a bottom membrane cover blanket, wherein, The bottom composite membrane is fixedly disposed on the bottom side of the circumferential support frame, and the bottom composite membrane is spaced apart from the flexible cavity; The bottom membrane cover blanket is laid on the bottom composite membrane.

[0010] Based on the above technical solutions, preferably, the bottom composite film is annular in shape and has multiple layers, wherein... The multiple layers of the bottom composite film are arranged coaxially, and the joints of adjacent layers of the bottom composite film are fixedly connected.

[0011] Based on the above technical solutions, preferably, a stabilizing structure is also included, wherein the stabilizing structure comprises a bottom support frame, a side composite membrane, and a side membrane cover blanket, wherein, The bottom support frame is fixedly installed on the outside of the circumferential support frame; The side composite membrane is fixedly installed on the top side of the bottom support frame; The side membrane cover blanket is laid on the side composite membrane.

[0012] Based on the above technical solutions, preferably, the bottom support frame includes radial outer support rods and circumferential support rods, wherein, One end of the radial outer support rod is fixedly mounted on the circumferential support frame; The circumferential support rod is fixedly installed at the other end of the radial outer support rod, and the radial span of the circumferential support rod is greater than that of the circumferential support frame, and the height of the circumferential support rod is lower than that of the circumferential support frame.

[0013] Based on the above technical solutions, preferably, multiple horizontal strips are provided on the circumferential support frame, and the multiple horizontal strips are spaced apart along the surface of the pile foundation, and the sides of adjacent horizontal strips are in contact with each other.

[0014] Based on the above technical solutions, preferably, the horizontal strip has multiple cutting slits on its surface.

[0015] The anti-scour structure for offshore wind turbine monopile foundations of the present invention has the following advantages over the prior art: (1) By setting up a rigid support frame consisting of upper and lower circumferential support frames and axial struts, and integrating a flexible cavity, a top composite membrane, and horizontal strips connecting the pile foundation and the frame to form a wave reduction and flow control structure, and configuring a sediment barrier structure at the bottom, a multi-dimensional synergistic protection is achieved, including wave energy dissipation, suppression of unfavorable eddies around the pile, sealing of the top annular gap, and sealing of the bottom sediment. This not only improves the structural stability of the device in complex marine environments, but also blocks the scouring mechanism from the source, effectively preventing the seabed sediment around the pile foundation from being carried away by the water flow, thereby achieving efficient and systematic control of the scouring problem of offshore wind power monopile foundations.

[0016] (2) By setting multiple cuts on the surface of the horizontal strip, a flexible interface with microporous characteristics is formed. While maintaining the mud and sand blocking effect, a small amount of water flow is allowed to slowly infiltrate, balancing the water pressure inside and outside the device, thereby reducing the risk of the flexible membrane structure bulging, tearing or fatigue damage due to sudden pressure changes, and improving the durability and long service life of the device.

[0017] (3) By setting up a flexible cavity, which is formed by an axial flexible membrane and a circumferential flexible membrane enclosing the gaps in the frame to form a cavity structure that is open at the top and bottom, the wave energy can be dissipated by the resonance of the water column in the cavity and the vibration of the membrane, and the intensity of the incident wave can be weakened by multi-layer reflection. At the same time, the open design allows water to enter the cavity in an orderly manner to form multi-directional vortices, which disrupts the high-speed low-pressure zone and periodic vortex shedding of the external flow, effectively reducing the pressure gradient of the flow field pulsation, reducing the stress on the device itself and suppressing the external scouring.

[0018] (4) The top side of the flexible cavity is spaced apart from the top composite membrane, and the bottom side is spaced apart from the bottom composite membrane, forming a vertically connected water flow channel. Water can enter the device through these gaps and flow in the flexible cavity, breaking the traditional unidirectional flow around the pile. This allows the high-speed, low-pressure zone and the pulsating region of the karman vortex street, which were originally concentrated on the outer edge of the structure, to dissipate, and the pressure distribution of the flow field becomes more uniform and stable, thereby effectively inhibiting the entrainment and scouring of sediment from the external seabed. At the same time, the downward pressure difference generated by the water flow in the cavity, combined with the hydrostatic pressure and the negative pressure suction of the seabed, acts on the entire device, significantly improving its anti-buoyancy, anti-slip, and anti-overturning capabilities, ensuring the long-term stable bottom-hugging state of the structure in complex marine environments.

[0019] (5) By setting the circumferential support rod of the bottom support frame to be lower than the main frame and embedded in the seabed sediment, and with the side composite membrane covering it and the side membrane cover blanket after immersion and solidification, the water inlet channel at the bottom edge of the device is effectively blocked. Under the combined action of deep water static pressure, gravity and seabed negative pressure suction, multiple anti-overturning and anti-slipping mechanisms are formed to ensure that the device is stable and fits the seabed for a long time. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a perspective view of an anti-scour structure for a monopile foundation for offshore wind power according to the present invention. Figure 2 This is a perspective view of the wave reduction and flow control structure in an anti-scour structure for a monopile foundation of offshore wind power according to the present invention. Figure 3 This is an exploded view of the flexible cavity in an anti-scour structure for a monopile foundation of offshore wind power according to the present invention. Figure 4 This is a schematic diagram of the rigid support frame in an anti-scour structure for a monopile foundation of offshore wind power according to the present invention. Figure 5 This is a perspective view of the circumferential support frame in an anti-scour structure for a monopile foundation of offshore wind power according to the present invention. Figure 6 This is a perspective view of the mud and sand barrier structure in an anti-scour structure for a monopile foundation of offshore wind power according to the present invention. Figure 7 This is a perspective view of the bottom support frame in an anti-scour structure for a monopile foundation of offshore wind power according to the present invention. In the diagram: 1. Pile foundation; 2. Rigid support frame; 3. Wave reduction and flow control structure; 4. Sediment barrier structure; 5. Stabilizing structure; 21. Circumferential support frame; 22. Axial support rod; 31. Flexible cavity; 32. Top composite membrane; 33. Horizontal strip; 41. Bottom composite membrane; 42. Bottom membrane cover; 51. Bottom support frame; 52. Side composite membrane; 53. Side membrane cover; 211. Circumferential frame rod; 212. Radial support rod; 311. Axial flexible membrane; 312. Circumferential flexible membrane; 511. Radial outer support rod; 512. Circumferential support rod. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0023] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0024] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention.

[0025] Furthermore, 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 technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0026] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0027] The following disclosure provides numerous different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. Additionally, examples of various specific processes and materials are provided in this invention; however, those skilled in the art will recognize the applicability of other processes and / or the use of other materials.

[0028] like Figures 1 to 7 As shown, the present invention provides an anti-scour structure for a single pile foundation for offshore wind power, comprising a pile foundation 1, a rigid support frame 2, a wave reduction and flow control structure 3, a sediment barrier structure 4, and a stabilizing structure 5.

[0029] Among them, the pile foundation 1 is a monopile foundation for offshore wind power facilities, which is driven vertically into the seabed to withstand the scouring effect of waves and ocean currents.

[0030] The rigid support frame 2, serving as the supporting skeleton of the overall device, is made of high-density polyethylene (HDPE) pipe, possessing high strength, corrosion resistance, and lightweight characteristics. The frame is divided into two symmetrically arranged semi-circular sections, which can be prefabricated on shore, transported separately, and then assembled underwater around the pile foundation 1. The frame includes a circumferential support frame 21 and axial support rods 22.

[0031] Two circumferential support frames 21 are symmetrically arranged on both sides of the pile foundation 1, forming a ring-shaped frame structure. The circumferential support frames 21 have two layers, which are distributed parallel to each other and are fixedly connected by perpendicular axial support rods 22, providing stable support for the overall structure.

[0032] Furthermore, the circumferential support frame 21 includes circumferential frame members 211 and radial support members 212. The circumferential frame members 211 are arranged in multiple layers radially from the inside out, and these multiple layers of circumferential frame members 211 are arranged coaxially. Radial support members 212 are provided between adjacent layers of circumferential frame members 211 for connection. The number of radial support members 212 is determined according to the arc length of the circumferential frame members 211, and the radial support members 212 are evenly distributed. The multiple layers of circumferential frame members 211 are connected and combined by multiple radial support members 212 to form a semi-circular frame structure, enhancing the overall structural rigidity and stability.

[0033] The wave reduction and flow control structure 3 is set inside the rigid support frame 2 to weaken wave energy, regulate the flow field around the pile and suppress unfavorable vortices. It includes a flexible cavity 31, a top composite membrane 32 and a horizontal strip 33.

[0034] The flexible cavity 31 is fixedly installed within the rigid support frame 2, specifically located in multiple gaps between the circumferential frame rod 211 and the radial support rod 212. The flexible cavity 31 includes an axial flexible membrane 311 and a circumferential flexible membrane 312, both of which are HDPE composite membranes. The edges of both the axial flexible membrane 311 and the circumferential flexible membrane 312 are fixed to the axial support rod 22 and are joined end-to-end within each gap, forming a cavity structure that is open at both ends. The top composite membrane 32 is fixedly installed on the top side of the circumferential support frame 21, and its material is also HDPE composite membrane.

[0035] This structure utilizes the resonance of the water column within the cavity and the synergistic vibration of the membrane to dissipate wave energy, and weakens the intensity of incident waves through multi-layer reflection. Simultaneously, the permeable design allows water flow to enter the cavity in an orderly manner, forming multi-directional vortices, disrupting the high-speed, low-pressure zone of the external flow and the periodic vortex shedding of the Karman vortex street, effectively reducing the pulsating pressure gradient of the flow field. Furthermore, the top composite membrane 32 also blocks the upward flow path of seabed sediment, ensuring sufficient sediment protection at the bottom of pile foundation 1.

[0036] The horizontal strips 33 are fan-shaped sheet structures arranged circumferentially around the top annular gap between the pile foundation 1 and the circumferential support frame 21. One end is fixed to the top side of the circumferential support frame 21, and the other end is anchored to the surface of the pile foundation 1, with the sides of adjacent horizontal strips 33 adhering to each other. These horizontal strips 33 effectively impede high-speed jets flowing downwards along the pile wall, eliminating the conditions for horseshoe vortex formation and actively suppressing the source of pile foot scour. At the same time, the horizontal strips 33 also block the path for seabed sediment to flow upwards along the surface of the pile foundation 1, ensuring sufficient sediment protection at the bottom of the pile foundation 1.

[0037] Furthermore, each horizontal strip 33 has multiple parallel cuts on its surface, forming a microporous flexible interface. While effectively blocking the upward migration of large particles of sediment, it allows a small amount of water to slowly infiltrate, thereby balancing the water pressure inside and outside the device. This prevents the accumulation of abnormal positive or negative pressure inside due to sealing, reduces the risk of the flexible membrane bulging, tearing, or fatigue damage, and extends its service life.

[0038] The sediment barrier structure 4 is located at the bottom of the rigid support frame 2 and is used to physically cut off the direct contact between the water flow and the seabed sediment. It includes a bottom composite membrane 41 and a bottom membrane cover 42.

[0039] The bottom composite membrane 41 is made of HDPE composite membrane, is ring-shaped, and is fixed to the bottom side of the circumferential support frame 21. It has multiple coaxial ring-shaped membranes in the radial direction, and the joints of adjacent membranes are sealed and fixed by thermoplastic welding. After installation, the bottom composite membrane 41 is laid tightly on the seabed, ensuring sufficient coverage and no leakage channels, thereby completely sealing the silt around the pile foundation 1 under the device.

[0040] The bottom membrane cover blanket 42 is laid on the bottom composite membrane 41 and is made of cement blanket material. When dry, it is lightweight and easy to transport and install. After being immersed in water for 24 hours, it cures and increases in weight. Its own weight tightly presses the bottom composite membrane 41 to the seabed, effectively suppressing membrane swaying and edge lifting, and significantly improving long-term service reliability.

[0041] In the above structure, the top side of the flexible cavity 31 is spaced apart from the top composite membrane 32, and the bottom side of the flexible cavity 31 is also spaced apart from the bottom composite membrane 41, leaving gaps between the flexible cavity 31 and the top and bottom composite membranes 32 and 41 to form a water flow channel. Water flows through this gap into the device and into the flexible cavity 31, breaking the traditional unidirectional flow around the pile. This dissipates the high-speed, low-pressure zone and the Karman vortex street pulsation region that were originally concentrated on the outer edge of the structure, making the pressure distribution of the flow field more uniform and stable, thereby effectively inhibiting the entrainment and scouring of sediment from the external seabed. At the same time, the downward pressure difference generated by the water flow in the cavity, combined with the deep-water static pressure and the negative pressure suction of the seabed, acts on the entire device, significantly improving its anti-buoyancy, anti-slip, and anti-overturning capabilities.

[0042] The stabilizing structure 5 is disposed on the outside of the rigid support frame 2 to further enhance the stability of the bottom of the device. It includes a bottom support frame 51, a side composite membrane 52, and a side membrane cover 53.

[0043] The bottom support frame 51 is fixedly installed on the outside of the circumferential support frame 21, and includes a radial outer support rod 511 and a circumferential support rod 512. One end of the radial outer support rod 511 is fixedly installed on the circumferential support frame 21, and the other end of the circumferential support rod 512 is fixedly installed on the radial outer support rod 511. The radial span of the circumferential support rod 512 is greater than that of the circumferential support frame 21, and the height of the circumferential support rod 512 is lower than that of the circumferential support frame 21. This allows it to embed into the seabed sediment, effectively sealing the water inlet channel at the bottom edge of the device and preventing water from seeping into the bottom of the device and causing erosion or suction instability.

[0044] The side composite membrane 52 is fixedly mounted on the top side of the bottom support frame 51, and its material is HDPE composite membrane. The side membrane cover blanket 53 is laid on the side composite membrane 52, and the side membrane cover blanket 53 is made of the same material as the bottom membrane cover blanket 42. Under the combined action of deep-water hydrostatic pressure, gravity, and seabed negative pressure suction, the two form a multiple anti-overturning and anti-slip mechanism to ensure that the device is stably attached to the seabed for a long time.

[0045] It should be noted that the HDPE composite membrane can be selected from different types of composite membrane materials according to the functional requirements of its location in the erosion protection structure, so as to achieve the optimal match between performance and durability.

[0046] The flexible cavity 31 can be made of HDPE / LLDPE co-extruded film (thickness 0.8-1.2mm). Because it needs to vibrate repeatedly under the action of waves to dissipate energy, the material is required to have excellent flexibility, fatigue resistance and dynamic deformation ability.

[0047] The top composite membrane 32, bottom composite membrane 41 and side composite membrane 52 can be two-layer geotextile and one-layer membrane type HDPE composite geomembrane (HDPE membrane thickness ≥1.0mm, non-woven geotextile on both sides with a unit area mass ≥200g / m²). This structure combines the high impermeability of HDPE membrane with the puncture resistance, slip resistance and interfacial friction performance of geotextile, which is convenient for underwater laying and can achieve reliable sealing through hot melt welding.

[0048] The horizontal strip 33 can be made of a single layer of HDPE membrane or a composite strip of HDPE and geotextile. While ensuring a certain rigidity to maintain the sealing shape of the annular gap, the microporous structure allows water to slowly permeate, effectively balancing the internal and external water pressure and preventing bulging and damage.

[0049] Based on the aforementioned scour protection structure for offshore wind turbine monopile foundations, this invention provides a method for using the scour protection structure for offshore wind turbine monopile foundations, as detailed below: The first step involves prefabricating the support frame and auxiliary structures on shore: First, high-density polyethylene (HDPE) pipes are cut on shore to fabricate circumferential frame rods 211, radial support rods 212, axial support rods 22, and radial outer support rods 511 and circumferential support rods 512 in the stabilizing structure 5. Using thermoplastic welding, the circumferential frame rods 211 and radial support rods 212 are assembled into a two-layer semi-circular circumferential support frame 21. The two layers are then fixedly connected by the axial support rods 22 to form a semi-circular main frame with three-dimensional rigidity. Simultaneously, one end of the radial outer support rod 511 is welded to the outside of the circumferential support frame 21, and the other end is connected to the circumferential support rod 512, completing the assembly of the bottom support frame 51. The installation height of the circumferential support rod 512 is lower than that of the circumferential support frame 21 to ensure it can be embedded into the seabed later.

[0050] The second step is to install the flexible membrane assembly and cover blanket: Cut the HDPE composite membrane into axial flexible membrane 311 and circumferential flexible membrane 312 of the designed size, and fix them to the axial support rod 22 by thermoplastic welding, forming a flexible cavity 31 with open top and bottom in the gap between the circumferential frame rod 211 and the radial support rod 212; lay the top composite membrane 32 flat and fix it to the top side of the circumferential support frame 21, and pay attention to maintaining a set interval between it and the top side of the flexible cavity 31; lay the bottom composite membrane 41 and fix it to the bottom side of the circumferential support frame 21, and seal the splicing of the multi-layer annular membrane sheets by thermoplastic welding; cover the top side of the bottom support frame 51 with the side composite membrane 52; then, lay the bottom membrane cover blanket 42 on the bottom composite membrane 41 and lay the side membrane cover blanket 53 on the side composite membrane 52; the membrane cover blanket is preferably a cement blanket, which is lightweight in the dry state and easy to transport and lay.

[0051] The third step is to install the strip: The horizontal strip 33 with parallel cuts is arranged circumferentially in the top annular gap area between the pile foundation 1 and the circumferential support frame 21. One end of the strip is fixed to the top side of the circumferential support frame 21 by thermoplastic welding or mechanical clamps, and the other end is temporarily free to extend.

[0052] The fourth step is offshore hoisting and assembly: using an offshore crane vessel, the two semi-circular rigid support frames 2, which have been covered with film and have their accessories installed, are simultaneously hoisted from both sides of the pile foundation 1 and slowly lowered to the predetermined seabed position; after the circumferential support rods 512 of the bottom support frame 51 are embedded in the seabed sediment, the two semi-rings are firmly connected at the joint with special connectors (such as bolts, flanges, clamps or locking buckles) with the assistance of an underwater ROV, forming a complete annular anti-scouring device; then, the horizontal strip 33 is fastened to the surface of the pile foundation 1 with clamps or jigs, and after installation, it is ensured that the end closest to the pile foundation 1 is slightly higher than the outside to guide the water flow direction and enhance the sealing effect of the annular gap.

[0053] Step 5: System placement and functional activation: After the device is in place, the bottom membrane blanket 42 and the side membrane blanket 53 gradually solidify and increase in weight under seawater immersion, tightly pressing the bottom composite membrane 41 and the side composite membrane 52 onto the seabed; water flows through the top and bottom gaps into the flexible cavity 31, forming a multi-directional vortex to achieve wave reduction and flow control; the horizontal strip 33 and the sediment barrier structure 4 work together to effectively block the sediment migration path, and the entire system enters a long-term stable protection state.

[0054] It should be noted that this invention is not only applicable to offshore wind power monopile foundations, but can also be extended to the scour protection of various seabed driven pile structures such as bridge piers, wharf pile foundations, trestle supports, or fixed offshore platforms.

[0055] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A scour-resistant structure for a monopile foundation in offshore wind power, characterized in that: It includes pile foundation (1), rigid support frame (2), wave reduction and flow control structure (3), and sediment barrier structure (4), among which, The rigid support frame (2) includes a circumferential support frame (21) and an axial support rod (22). The circumferential support frame (21) is arranged around the pile foundation (1) and has two layers. The axial support rod (22) is fixedly arranged on the circumferential support frame (21) and the two layers of the circumferential support frame (21) are fixedly connected by the axial support rod (22). The wave reduction and flow control structure (3) includes a flexible cavity (31), a top composite membrane (32), and a horizontal strip (33). The flexible cavity (31) is fixedly installed inside the rigid support frame (2). The top composite membrane (32) is fixedly installed on the top side of the circumferential support frame (21), and the top side of the flexible cavity (31) is spaced apart from the top composite membrane (32). One end of the horizontal strip (33) is fixedly installed on the top side of the circumferential support frame (21), and the other end of the horizontal strip (33) is fixedly installed on the pile foundation (1). The sediment barrier structure (4) is fixedly installed on the bottom side of the circumferential support frame (21). The sediment barrier structure (4) includes a bottom composite membrane (41) and a bottom membrane cover (42). The bottom composite membrane (41) is fixedly disposed on the bottom side of the circumferential support frame (21), and the bottom composite membrane (41) is spaced apart from the flexible cavity (31); the bottom membrane cover blanket (42) is laid on the bottom composite membrane (41).

2. The anti-scour structure for a single pile foundation for offshore wind power as described in claim 1, characterized in that: The circumferential support frame (21) is located in two places, symmetrically arranged on both sides of the pile foundation (1), wherein, The two circumferential support frames (21) together form a ring frame structure.

3. The anti-scour structure for a single pile foundation for offshore wind power as described in claim 1, characterized in that: The circumferential support frame (21) includes circumferential frame rods (211) and radial support rods (212), wherein, The circumferential frame rod (211) is provided with multiple layers in the radial direction, and the multiple layers of the circumferential frame rod (211) are arranged coaxially; Multiple radial support rods (212) are provided, and the multiple circumferential frame rods (211) are connected and combined to form a semi-circular frame structure through multiple radial support rods (212).

4. The anti-scour structure for a single pile foundation for offshore wind power as described in claim 3, characterized in that: The flexible cavity (31) is disposed within a plurality of gaps between the circumferential frame rod (211) and the radial support rod (212). The flexible cavity (31) includes an axial flexible membrane (311) and a circumferential flexible membrane (312). The axial flexible membrane (311) and the circumferential flexible membrane (312) are both fixedly mounted on the axial support rod (22), and the axial flexible membrane (311) and the circumferential flexible membrane (312) are connected end to end to form a cavity structure that is open at the top and bottom.

5. The anti-scour structure for a single pile foundation for offshore wind power as described in claim 1, characterized in that: The bottom composite film (41) is generally annular, and the bottom composite film (41) is provided with multiple layers, wherein, The multiple layers of the bottom composite film (41) are arranged coaxially, and the joints of adjacent layers of the bottom composite film (41) are fixedly connected.

6. The anti-scour structure for a single pile foundation for offshore wind power as described in claim 1, characterized in that: It also includes a stabilizing structure (5), which comprises a bottom support frame (51), a side composite membrane (52), and a side membrane cover blanket (53), wherein, The bottom support frame (51) is fixedly installed on the outside of the circumferential support frame (21); The side composite membrane (52) is fixedly disposed on the top side of the bottom support frame (51); The side membrane cover blanket (53) is laid on the side composite membrane (52).

7. The anti-scour structure for a single pile foundation for offshore wind power as described in claim 6, characterized in that: The bottom support frame (51) includes radial outer support rods (511) and circumferential support rods (512), wherein, One end of the radial outer support rod (511) is fixedly mounted on the circumferential support frame (21); The circumferential support rod (512) is fixedly installed at the other end of the radial outer support rod (511), and the radial span of the circumferential support rod (512) is greater than that of the circumferential support frame (21), and the height of the circumferential support rod (512) is lower than that of the circumferential support frame (21).

8. The anti-scour structure for a single pile foundation for offshore wind power as described in claim 1, characterized in that: Multiple horizontal strips (33) are provided on the circumferential support frame (21), and the multiple horizontal strips (33) are spaced apart along the surface of the pile foundation (1), and the sides of adjacent horizontal strips (33) are in contact with each other.

9. The anti-scour structure for a single pile foundation for offshore wind power as described in claim 1, characterized in that: The horizontal strip (33) has multiple cutting slits on its surface.

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