An assembled ductility enhanced offshore photovoltaic single pile foundation and construction method

Abstract

This invention belongs to the technical field of fixed monopile foundations for near-shore photovoltaic systems. It discloses a prefabricated, toughened, reinforced near-shore photovoltaic monopile foundation and its construction method. The foundation includes a monopile and a concrete wing plate around its periphery. Each wing plate comprises at least two fan-shaped ring plates, with at least one flange plate fixedly connected to the outer periphery of each ring plate. Interlocking toothed groove structures are pre-reserved at both ends of the ring plates, with shear keys embedded within these grooves. The inner diameter of the ring plates is larger than the diameter of the monopile, and a circumferential gap is reserved between the ring plates and the monopile, filled with a coupling body. The monopile has multiple layers of wing plates from top to bottom, including the original wing plates during installation and reinforcing wing plates installed above the original wing plates during service. This invention uses a coupling body between the ring plates and the monopile to form a flexible, coordinated, and reinforced structure of "monopile + coupling body + wing plate + surrounding soil," which enhances the horizontal bearing capacity of the monopile foundation. Furthermore, this invention facilitates the reinforcement of the monopile foundation.

Description

Technical Field

[0001] This invention belongs to the technical field of fixed monopile foundations for offshore photovoltaic systems, specifically relating to a prefabricated, toughened offshore photovoltaic monopile foundation and its construction method. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] Currently, with the rapid development of green energy such as wind power and photovoltaics along the coast, existing nearshore photovoltaic fixed monopile foundations face a significant problem of insufficient horizontal bearing capacity under soft seabed conditions. The main reasons are as follows: First, the seabed strata in nearshore areas are generally silty clay with low shear strength, making it difficult to provide effective horizontal resistance for monopile foundations; second, the diameter of nearshore photovoltaic fixed monopile foundations is relatively small, limiting their horizontal bearing capacity; third, the long-term high-frequency cyclic loading of wind and waves causes degradation of the clay's strength and stiffness; and fourth, the spatial variability of soft silty clay seabeds is significant, and the dispersion of survey data is large, leading to uncertainties in foundation design parameters.

[0004] To address the insufficient horizontal bearing capacity of fixed monopile foundations for nearshore photovoltaic systems in soft seabed conditions, existing technologies often employ monopile wing-enhancing techniques. For example, a composite foundation for offshore wind power using a monopile-wing-rockfill structure is disclosed, which improves the horizontal bearing capacity of the monopile foundation through the combined action of the monopile, welded conical steel wing, and rockfill. However, the steel wing in this composite foundation is highly susceptible to corrosion in marine environments, leading to increased corrosion protection and maintenance costs. Furthermore, this solution utilizes welding, which prevents flexible connections between the wing and the monopile foundation, and it cannot be expanded or reinforced during service.

[0005] To address the issue of high corrosion costs associated with steel wing plates, existing technologies also disclose a monopile-type offshore photovoltaic support structure. This structure incorporates an integral precast concrete ring fitted onto the mud surface outside the support pile to achieve horizontal constraint on the pile body.

[0006] However, the above scheme still has the following drawbacks: the effective contact area between the concrete ring and the surrounding soil is small, and the range of action is concentrated near the mud surface. In addition, the inner ring of the concrete ring is fixedly connected with a convex arc-shaped constraint key, which constrains the support pile horizontally. This means that when the support pile is subjected to wave erosion or wind load during the service stage, it cannot buffer and unload the force, which may lead to stress concentration and cannot effectively enhance the horizontal bearing capacity of the single pile foundation. Furthermore, the constraint key also affects the installation of the concrete ring and makes it difficult to expand and reinforce the support pile. Summary of the Invention

[0007] In view of this, the purpose of this invention is to provide a prefabricated, toughened nearshore photovoltaic monopile foundation and its construction method, which can solve the technical problems in the prior art that the concrete ring cannot effectively enhance the horizontal bearing capacity of the monopile foundation and that it is not easy to reinforce and modify the monopile foundation.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: Firstly, a prefabricated, toughened, near-shore photovoltaic monopile foundation includes a monopile and a concrete wing plate around the monopile. The wing plate includes at least two fan-shaped ring plates. At least one flange plate is fixedly connected to the outer periphery of each fan-shaped ring plate. The two ends of the fan-shaped ring plates are reserved with interlocking toothed groove structures, and shear keys are provided in the toothed groove structures. The inner diameter of the ring plate is larger than the diameter of the single pile. A circumferential gap is reserved between the ring plate and the single pile, and the circumferential gap is filled with a coupling body. The single pile is equipped with multiple layers of wing plates from top to bottom, including the original wing plates during the installation stage and the reinforcing wing plates that are installed on top of the original wing plates according to the load-bearing requirements during the service stage. Alternatively, the inner diameter of the ring plate is equal to the diameter of the single pile, and the ring plate is rigidly connected to the single pile.

[0009] Preferably, a first lifting point is pre-embedded on the top surface of the flange plate, and multiple second lifting points are fixedly connected to the upper end of the single pile. A tensioning member is set between the first and second lifting points of the top flange plate.

[0010] Preferably, the flanges of the multi-layer reinforcing flanges are arranged to overlap in the circumferential direction with the central axis of the single pile as the reference, and the flanges of the multi-layer original flanges are also arranged to overlap in the circumferential direction. The flanges are provided with lifting holes, and the tensioning member of the first lifting point of the lower flange passes through the lifting hole and is connected to the first lifting point of the upper flange. The first lifting point and the second lifting point of the top flange are connected by the tensioning member.

[0011] Preferably, the flange plates of the reinforcing flange and the flange plates of the original flange are staggered in the circumferential direction with the central axis of the single pile as the reference, and the first lifting point of each flange plate is connected to the second lifting point through a tensioning member.

[0012] Preferably, corresponding grouting holes are opened on the toothed structure, and grout is injected into the grouting holes to form shear-resistant keys.

[0013] Preferably, a grouting pipe is installed inside the grouting hole, the diameter of the grouting pipe being smaller than the diameter of the grouting hole, and the grouting pipe is wrapped in the grout of the shear key.

[0014] Preferably, a protective layer is reserved at the bottom of the grouting hole, and the length of the grouting pipe is less than the length of the grouting hole.

[0015] Secondly, a construction method for the aforementioned prefabricated, toughened, near-shore photovoltaic monopile foundation is provided, the specific steps of which include: Based on the geological conditions of the seabed, the connection method between the ring plate and the monopile was selected, and the wing plates were prefabricated. The single pile is hoisted to the designated position and driven to the design depth, and multiple second hoisting points are fixed at the top of the single pile; Multiple fan-shaped ring plates are assembled into a wing plate along the outer perimeter of the single pile, and then the wing plate is pressed into the soil. After the previous wing plate is pressed to the specified elevation, the tensioning member of the previous layer is pulled out, and then the next wing plate is reassembled, and the tensioning member of the previous layer is passed through the lifting hole of the next wing plate. After the next layer of wing plates is pressed to the designated elevation, the tensioning member of the previous layer is tensioned and fixed to the first lifting point of the next layer; after all wing plates are pressed to the designated elevation, the tensioning member of the top layer wing plate is tensioned and fixed to the second lifting point.

[0016] Preferably, if the geological conditions are stable, a ring plate with an inner diameter equal to the diameter of a single pile is prefabricated; if the geological conditions are unstable, a ring plate with an inner diameter greater than the diameter of a single pile is prefabricated. If the inner diameter of the ring plate is larger than the diameter of the single pile, a coupling body should be filled between the ring plate and the single pile before the tensioning of the top wing plate tensioning member is completed.

[0017] Preferably, if the inner diameter of the ring plate is larger than the diameter of the single pile, and the environment changes during the service phase of the single pile foundation, the single pile needs to be reinforced. The specific steps are as follows: Loosen the tensioning components of the original top wing plate; assemble a layer of reinforcing wing plate, and make the flange plates of the reinforcing wing plate and the flange plates of the original top wing plate distributed in a quincunx pattern; Then, the reinforcing wing plate is pressed into the soil along the axis of the single pile. Next, the tensioner of the previous reinforcing wing plate is pulled out. Then, the next reinforcing wing plate is assembled, and the tensioner of the previous reinforcing wing plate is passed through the lifting hole of the next reinforcing wing plate. After pressing the rear reinforcing wing plate to the designated elevation, tensioning and fixing the tensioning member of the front reinforcing wing plate to the first lifting point of the rear reinforcing wing plate; Once all reinforcing wing plates are pressed to the designated elevation below the seabed, the first lifting point of the top reinforcing wing plate and the first lifting point of the original top wing plate are connected to the second lifting point via tensioning components.

[0018] Compared with the prior art, the advantages and positive effects of this invention are: This invention relates to a prefabricated, toughened, near-shore photovoltaic fixed monopile foundation. It employs prefabricated, modularly assembled concrete flanges, which avoids flange corrosion during service and facilitates transportation and on-site assembly, improving work efficiency. A coupling body is installed between the ring plate and the monopile, forming a flexible, coordinated, and reinforced structure of "monopile + coupling body + flange + surrounding soil." This allows the monopile foundation to maintain a flexible connection during normal service. Under extreme loads, the monopile compresses the coupling body, causing it to compact. Through gap compaction and coupled force transmission, a flexible-rigid transition is achieved, enhancing the toughness of the monopile foundation and improving its overall bearing capacity and stability. Furthermore, if environmental changes necessitate reinforcement of the monopile during service, this invention allows the existing flanges from the installation phase to be pressed into the seabed, and additional reinforcing flanges to be added on top of the existing flanges. Compared to existing technologies, this invention offers the advantages of on-demand enhancement of the horizontal bearing capacity of the monopile foundation and facilitates reinforcement and modification of the monopile foundation. Attached Figure Description

[0019] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0020] Figure 1 This is a cross-sectional schematic diagram of a flexible connection between a single pile and a wing plate in Embodiment 1 or Embodiment 2 of the present invention; Figure 2 This is a cross-sectional schematic diagram of a rigid connection between a single pile and a wing plate in Embodiment 1 or Embodiment 2 of the present invention; Figure 3 This is a top view of the wing plate of Embodiment 1 or Embodiment 2 of the present invention; Figure 4 This is a schematic diagram of the splicing of adjacent sector-shaped ring plates in Embodiment 1 or Embodiment 2 of the present invention; Figure 5 This is a schematic diagram of grouting reinforcement after splicing adjacent sector-shaped ring plates in Embodiment 1 or Embodiment 2 of the present invention; Figure 6 This is a cross-sectional schematic diagram of a single pile with multiple wing plates installed on it, as shown in Embodiment 1 or Embodiment 2 of the present invention; Figure 7 This is a schematic diagram showing the distribution of the reinforcing wing plate and the original wing plate in the circumferential direction with the central axis of the single pile as the reference in Embodiment 1 or Embodiment 2 of the present invention. In the picture: 1. Monopile; 2. Ring plate; 3. Flange plate; 4. First lifting point; 5. Second lifting point; 6. Tensioning member; 7. Seabed surface; 8. Grouting hole; 9. Toothed structure; 10. First sector ring plate; 11. Second sector ring plate; 12. Grouting pipe; 13. Protective layer; 14. Grout; 15. Coupler; 16. Reinforcing flange plate; 17. Original flange plate. Detailed Implementation

[0021] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0022] The present invention will now be described in detail with reference to the accompanying drawings.

[0023] Example 1 This embodiment discloses a prefabricated, toughened, near-shore photovoltaic monopile foundation, such as... Figure 1 , Figure 2 As shown, the structure includes a monopile 1 and a flange surrounding the monopile 1, with the flange embedded at a predetermined distance below the seabed surface 7. It should be noted that the monopile, as the main load-bearing component of the near-shore photovoltaic foundation, is sunk into the seabed to bear the vertical and horizontal loads transmitted from the superstructure; the flange is used to increase the contact area between the monopile 1 and the surrounding soil, further improving the foundation's horizontal bearing capacity and lateral stiffness.

[0024] In this embodiment, the wing plate is a precast concrete wing plate, such as... Figures 1 to 3 As shown, the flange includes a ring plate 2 fitted around the periphery of the single pile 1, and multiple flange plates 3 are fixedly connected to the periphery of the ring plate 2. It can be understood that using concrete flange plates can effectively solve the problem of easy corrosion of steel flange plates; and the prefabricated concrete flange plates have standardized dimensions and strength, which facilitates transportation and rapid on-site installation.

[0025] like Figure 3As shown, the flange includes at least two sector-shaped ring plates. At least one flange plate 3 is fixedly connected to the outer periphery of each sector-shaped ring plate. Interlocking toothed structures 9 are pre-installed at both ends of the sector-shaped ring plates. Shear keys are provided in the toothed structures 9 to achieve the interlocking and fixing of the toothed structures 9. It is understood that these sector-shaped ring plates are prefabricated in the factory. The number of sector-shaped ring plates is flexibly designed based on factors such as the diameter of the single pile 1, transportation conditions, and on-site hoisting capabilities. For example, they can be divided into two, three, four, or more pieces. This design aims to reduce the size and weight of individual components, thereby simplifying the transportation process and improving the convenience and safety of on-site hoisting, reducing the offshore construction window period, reducing the difficulty of offshore construction, and improving installation accuracy, assembly efficiency, and structural integrity. In this embodiment, the ring plates and flange plates are integrally cast, and the concrete grade is not lower than C50 to ensure that the components have sufficient load-bearing capacity and durability.

[0026] In this embodiment, a mechanical connection structure with mutual meshing is designed at both ends of adjacent sector ring plates, which provides a fast and accurate alignment function during on-site assembly, and provides limiting and shear force transmission capabilities for subsequent connections, effectively preventing relative displacement of the sector ring plates during assembly.

[0027] like Figure 1 As shown, the inner diameter of the ring plate 2 is larger than the diameter of the single pile 1. A circumferential gap is reserved between the ring plate 2 and the single pile 1, and a coupling body 15 is installed within the circumferential gap. In this case, a flexible connection and coordination reinforcement structure of "single pile 1 + coupling body 15 + wing plate + surrounding soil" is formed. In this embodiment, the coupling body 15 is used to transfer loads and coordinate deformation between the single pile 1 and the wing plate, so that the structure exhibits a flexible connection state during normal service. Under extreme loads, such as large wave erosion or large wind loads, the single pile 1 compresses the coupling body 15, and the coupling body 15 is compressed and compacted. Through gap compaction and coupling force transmission, a flexible-rigid switching is achieved, enhancing the overall bearing capacity and stability of the structure and strengthening the toughness of the single pile foundation.

[0028] In this embodiment, the coupling body 15 is either pile-intercalation soil or coarse-graded crushed stone. Pile-intercalation soil refers to the soil naturally formed around the piles or between pile groups during pile foundation construction, offering advantages such as low cost and easy availability. Coarse-graded crushed stone refers to crushed stone materials with larger particle sizes and better gradation, possessing good permeability, shear strength, and compaction. The friction and embedding between crushed stone particles effectively transfer loads, and under compression, stiffness is increased through particle rearrangement and compaction.

[0029] Understandably, during normal service, the compressibility and deformability of the inter-pile soil or coarse-graded crushed stone allow for a relatively flexible connection between the monopile foundation and the flange, effectively absorbing and buffering external loads and preventing excessive stress concentration under small loads. When subjected to extreme loads, such as strong winds or high waves, the relative displacement between the monopile foundation and the flange increases, causing the inter-pile soil or coarse-graded crushed stone within the circumferential gap to be compacted, thus switching from a flexible to a rigid connection. Using the inter-pile soil or coarse-graded crushed stone as the coupling body 15 not only enables effective load transfer and deformation coordination but also allows for the full utilization of readily available materials, reducing engineering costs and simplifying the construction process.

[0030] It should be noted that during the service phase, as environmental loads change, local scour develops, and structural bearing capacity requirements increase, when it is necessary to further enhance the horizontal bearing capacity of the monopile foundation, the position of the original wing plate 17 is adjusted and a reinforcing wing plate 16 is added above it, so that a multi-layered reinforcing structure is formed on the outside of the monopile foundation along the vertical arrangement of the pile body. This allows the foundation to continuously expand the contact area between the foundation and the soil around the pile without removing the existing foundation body, thereby improving the horizontal bearing capacity of the foundation and realizing the extension from the initial adaptive design to the later continuous reinforcement design.

[0031] In this embodiment, the existing wingplate installed during the installation phase can be pressed into the seabed, and a reinforcing wingplate can be added to the top surface of the existing wingplate. For example... Figure 6 As shown, in this embodiment, the single pile 1 is provided with multiple layers of wing plates from top to bottom, including the original wing plate 17 and the reinforcing wing plate 16 above the original wing plate 17.

[0032] It is understandable that the original flange 17 is installed during the initial installation phase. After the monopile foundation enters service, and environmental changes necessitate reinforcement, a reinforcing flange 16 is installed above the original flange 17. It is also understandable that the original flange 17 consists of at least one layer. Depending on the soil quality at the actual construction site and the bearing capacity of the monopile 1, the original flange 17 can have multiple layers to expand the contact area between the monopile and the surrounding soil, enhancing the synergistic force-bearing effect between the pile, flange, and soil, and reducing the risk of insufficient horizontal bearing capacity due to uncertainties in the initial survey and design. Similarly, the reinforcing flange 16 also consists of at least one layer, and during service, depending on the reinforcement requirements of the monopile foundation, the number of reinforcing flanges 16 can also be multiple layers. This phased installation method allows for the reinforcement and performance improvement of the monopile foundation to be carried out without interruption or with minimal interruption of service. It allows for the continuous expansion of the contact area between the foundation and the surrounding soil without dismantling the existing foundation structure, improving the horizontal bearing capacity of the foundation, and extending from initial adaptive design to subsequent continuous reinforcement design.

[0033] It is also understandable that using an installation method where the inner diameter of ring plate 2 is larger than the diameter of single pile 1 not only creates a flexible connection between single pile 1 and the flange plate, achieving effective load transfer and coordinated deformation; it also enables... During service, the installation of reinforcing wing plates effectively expands and strengthens the monopile foundation. Furthermore, the modular structure of ring plate 2 facilitates on-site assembly and transportation, reducing construction difficulty and improving efficiency. This effectively solves the problems in existing technologies where constraint keys on the inner side of the concrete ring prevent stress buffering when the support pile is subjected to wave erosion or wind loads during service, potentially leading to stress concentration and hindering the enhancement of the monopile foundation's horizontal bearing capacity. Additionally, the constraint keys also affect the installation of the concrete ring, making it difficult to expand and strengthen the support pile.

[0034] It should be noted that, as Figure 1 The connection method shown is suitable for nearshore seabed soil, especially for seabeds with soft geological conditions. In seabed locations with favorable geological conditions, minimal wave erosion, and low wind loads, this embodiment also offers another connection method, such as... Figure 2 As shown, the inner diameter of the ring plate 2 is equal to the diameter of the monopile 1. After assembly and installation, the ring plate 2 is fitted against the outer wall of the monopile 1, forming an integral force transmission relationship with the monopile, thus constituting a rigid connection and coordination reinforcement component of "monopile 1 + wing plate + surrounding soil". In this configuration, the wing plate directly participates in the pile's load-bearing capacity, significantly increasing the contact area between the monopile foundation and the surrounding soil, thereby improving the horizontal bearing capacity, lateral stiffness, and overall stability of the near-shore photovoltaic monopile foundation. It is understandable that this connection method allows for the pre-installation of multiple wing plates based on geological conditions to enhance bearing capacity.

[0035] To further strengthen the connection between the wing plate and the monopile, this embodiment includes a tensioning member 6 between the monopile and the wing plate. Tensioning force is applied through the tensioning member 6 to enhance the overall bearing capacity of the monopile foundation and prevent wing plate slippage. Figures 1 to 3 As shown, a first lifting point 4 is pre-embedded on the top surface of the flange plate 3, and multiple second lifting points 5 are fixedly connected to the upper end of the monopile 1. A tensioning member 6 is installed between the first lifting point 4 and the second lifting points 5 of the top flange plate 3. Before installing the reinforcing flange plate 16, the tensioning member 6 of the original flange plate 17 is loosened, and the original flange plate 17 is further pressed downward into the soil to provide space for the installation of the reinforcing flange plate 16. It should be noted that after the flange plate is installed, tensioning force is applied by tensioning the tensioning member 6 to enhance the connection strength and integrity between the flange plate and the monopile 1, ensuring effective load transfer.

[0036] In some embodiments, the first lifting point 4 is a steel ring or plate pre-embedded inside the flange, with the top of the steel ring or plate protruding from the top surface of the flange for easy connection. The second lifting point 5 is a steel lug or clamp welded or bolted to the upper part of the monopile 1. The tensioning member 6 is a steel strand, one end connected to the first lifting point 4 of the top flange 3, and the other end connected to the second lifting point 5 on the upper part of the monopile 1. In this embodiment, the first lifting point 4 facilitates transportation, hoisting, and on-site installation after factory prefabrication.

[0037] Tensioning steel strands refers to applying tension force to put the steel strands under tension, thereby generating a continuous compressive force between the single pile 1 and the flange. This tension force can significantly improve the tightness and integrity of the connection interface, effectively resisting relative displacement caused by external loads. The tensioning process can be carried out using specialized equipment such as hydraulic jacks. After reaching the design tension value, the steel strands are fixed by anchorages.

[0038] It should be noted that during the service phase, seabed erosion may reduce the foundation depth of the monopile foundation, necessitating reinforcement to ensure its long-term stability. In this case, it is not necessary to remove the entire foundation or undertake large-scale modifications. Simply loosen the tensioning member 6 of the original flange 17, press the original flange 17 into the soil, and install a reinforcing flange 16 on top of the original flange 17. Once all reinforcing flanges 16 are in place, a new tensioning member 6 is connected between the first lifting point 4 of the top reinforcing flange 16 and the second lifting point 5 on the upper part of the monopile 1, and tension is applied again. This forms a new integrated structure between the reinforcing flange 16 and the monopile 1, further increasing the effective bearing area of ​​the monopile foundation and improving its horizontal bearing capacity and lateral stiffness.

[0039] In this embodiment, the flange plates 3 of the multi-layer reinforcing wing plate 16 are spaced apart, or as shown in the figure. Figure 6 The flanges 3 of the multi-layer original wing plate 17 shown are arranged to overlap in the circumferential direction. The flanges 3 have lifting holes. The tensioning member 6 of the first lifting point 4 of the lower flange 3 passes through the lifting hole and is connected to the first lifting point 4 of the upper flange. The first lifting point 4 and the second lifting point 5 of the top flange are connected by the tensioning member 6.

[0040] It should be noted that this arrangement ensures that the stress center of the reinforcing flange 16 or the original flange 17 remains consistent, which is beneficial for the vertical transfer of loads and the overall stability of the structure. The lifting holes in the flange plate 3 refer to pre-reserved or machined through holes in the flange plate 3 to provide a passage for the tensioning member 6 of the lower flange, allowing it to extend upwards and connect to the upper flange or monopile 1. The lifting holes can be circular, elliptical, or rectangular, and their size should be sufficient to accommodate the tensioning member 6 and its necessary connecting accessories.

[0041] The connection method in this embodiment allows the tensioning member 6 to continuously penetrate multiple layers of wing plates, forming an integral tensioning system, ensuring the directness and efficiency of load transfer. Then, the first lifting point 4 and the second lifting point 5 of the top wing plate are connected by the tensioning member 6 to ensure that all wing plates are fixed to the single pile 1 by tension force.

[0042] like Figure 7 As shown, the reinforcing flange 16 and the flange plates 3 of the original flange 17 are staggered in the circumferential direction with the central axis of the single pile as the reference, and the first lifting point 4 of the flange plate 3 is connected to the second lifting point 5 through the tensioning member 6. It should be noted that the staggered arrangement can adopt a quincunx pattern. This staggered arrangement aims to optimize the load transfer path, avoid stress concentration, and improve the torsional stiffness and stability of the overall structure.

[0043] Understandably, after the installation of the reinforcing flange 16 is completed, the first lifting points 4 on all flange plates 3 of the reinforcing flange 16 and the original flange 17 are connected to the second lifting points 5 on the monopile 1 through the tensioning member 6. This ensures that all flanges can effectively participate in load transfer, and the tensioning member 6 applies tension force to enhance the connection strength and overall stiffness between the flange and the monopile 1. This avoids excessive structural superposition at the same circumferential position based on the central axis of the monopile, thereby dispersing stress concentration and improving the torsional performance and overall stability of the structure.

[0044] like Figure 4 ,like Figure 5 As shown, corresponding grouting holes 8 are opened on the toothed structure 9. Grout 14 is injected into the connection gap between the toothed structures 9 through the grouting holes 8 to form shear keys, ensuring the connection strength between the fan-shaped ring plates and ensuring the integrity of the wing plates.

[0045] In this embodiment, the grout 14 can be a high-strength, non-shrink grout, epoxy resin mortar, or other structural grouting materials suitable for marine environments. The grouting process typically employs a pumping method to ensure that the grout 14 can completely fill the connection area. The grooves and protrusions of the toothed structure 9 can be rectangular, trapezoidal, or dovetail-shaped.

[0046] The wingplate is composed of multiple fan-shaped ring plates, such as Figure 3 , Figure 4 As shown, when adjacent first sector-shaped ring plates 10 and second sector-shaped ring plates 11 are connected, after the adjacent end toothed groove structures 9 are aligned, the grouting holes 8 of the toothed groove structures 9 are aligned. Directly injecting grout 14 into the grouting holes 8 may result in the grout 14 failing to fill the connection gap, causing it to solidify and potentially fail to withstand the shear force between adjacent sector-shaped ring plates, thus affecting the connection between them. To address this, in this embodiment, a grouting pipe 12 is installed inside the grouting hole 8. The diameter of the grouting pipe 12 is smaller than the diameter of the grouting hole 8, used to enhance the shear resistance at the connection point of adjacent sector-shaped ring plates.

[0047] Specifically, the top of the grouting pipe 12 is connected to a grouting pump via a pipe, and the end of the grouting pipe 12 is open. The grouting pipe 12 directly delivers the grout 14 to the bottom of the grouting hole 8 or deep into the joint. Because the diameter of the grouting pipe 12 is smaller than the diameter of the grouting hole 8, an annular channel is formed between the grouting pipe 12 and the inner wall of the grouting hole 8. When the grout 14 is injected through the grouting pipe 12, it flows out from the end of the grouting pipe 12 and fills the entire grouting hole 8 and joint area from bottom to top along the annular channel. This bottom-up filling method can effectively expel air from the grouting hole 8 and the joint upwards, avoiding the formation of cavities and ensuring the dense filling of the grout 14. At the same time, the annular channel also provides space for the uniform diffusion of the grout 14, allowing the grout 14 to fully penetrate into every corner of the joint, thereby forming a uniform and high-strength connection.

[0048] In addition, the grouting pipe 12 in this embodiment is a steel grouting pipe (preferably Q355 seamless steel pipe). After grouting is completed, it is retained in the grouting hole 8 as the skeleton of the grout. The grouting pipe is wrapped in the grout of the shear key and participates in the shear resistance force.

[0049] Understandably, grouting pipe 12 is inserted into grouting hole 8 from bottom to top, requiring the bottom of grouting hole 8 to be sealed. The steel grouting pipe ultimately remains inside grouting hole 8 to bear the load. Regarding this, as... Figure 5 As shown, in this embodiment, a protective layer 13 is reserved at the bottom of the grouting hole 8, and the length of the grouting pipe 12 is less than the length of the grouting hole 8.

[0050] It is not difficult to understand that, such as Figure 5 As shown, the protective layer 13 at the bottom of the grouting hole 8 seals the bottom of the grouting hole 8, ensuring that when the grouting pipe 12 is grouting, the grout 14 can fill the grouting hole 8 from bottom to top from the bottom of the grouting hole 8. The length of the grouting pipe 12 is less than the length of the grouting hole 8. After the grouting is completed, the grouting hole 8 at the top of the grouting pipe 12 is filled. After the grout solidifies, it ensures that the top and bottom of the grouting pipe 12 are wrapped in the grout, preventing the grouting pipe 12 from rusting and corroding during service and ensuring its strength stability.

[0051] In this embodiment, the strength of grout 14 should not be lower than C60 to ensure the connection strength of adjacent ring plates. A 30mm layer of concrete is reserved at the bottom of the grouting hole, and the length of the grouting pipe should be at least 60mm shorter than the length of the grouting hole, so that the upper and lower ends of the grouting pipe have a 30mm protective layer to prevent corrosion of the grouting pipe and to prevent local cracking at the end of the flange.

[0052] Example 2 This embodiment discloses a construction method for a prefabricated, toughened, near-shore photovoltaic monopile foundation, using methods such as... Figures 1 to 7The prefabricated, toughened nearshore photovoltaic monopile foundation disclosed in Embodiment 1 includes the following specific steps: Based on the geological conditions of the seabed surface to be installed, the connection method between the ring plate 2 and the single pile 1 is selected; With the seabed surface flat, the monopile is hoisted to the designated location and driven to the design depth, ensuring its stable placement within the soft, silty seabed. It's understood that a flat seabed refers to the necessary clearing and preparation of the seabed in the construction area before monopile foundation installation to ensure smooth installation and foundation stability. Driving to the design depth can be achieved using methods such as hydraulic hammers or suction pile driving to ensure the monopile foundation reaches sufficient bearing capacity.

[0053] Multiple second lifting points 5 are fixedly installed at predetermined positions on the outside of the single pile 1. The second lifting points 5 can also be pre-embedded at a predetermined height of the single pile 1 to provide a fixed point for connection to the tensioning member 6 of the first lifting point 4 of the wing plate.

[0054] Multiple fan-shaped ring plates are hoisted to the design position and then assembled sequentially along the outer perimeter of the single pile 1, so that the toothed groove structure 9 of adjacent fan-shaped ring plates 2 interlock to form a closed circumferential structure. After the fan-shaped ring plates are assembled, the grouting pipe 12 is inserted into the corresponding grouting hole 8, and grout 14 is injected into the grouting hole 8 and the splicing joint area. After the grout 14 reaches the design strength, the wing plate is pressed to the designated elevation below the seabed surface, and then the multiple first lifting points 4 and second lifting points 5 of the wing plate are connected by the tensioning member 6.

[0055] When setting up multi-layer wing plates, after the previous layer of wing plates is pressed or assembled to the specified elevation, the tensioning member 6 of the first lifting point 4 of the previous layer of wing plates should be pulled out. Then, the next layer of wing plates should be re-lifted and assembled, and the tensioning member 6 of the previous layer of wing plates should be passed through the lifting hole of the next layer of wing plates.

[0056] After pressing or assembling the next layer of wing panels to the designated elevation, tensioner 6 of the first lifting point 4 of the previous layer of wing panels is tensioned and fixed to the first lifting point 4 of the next layer of wing panels. After all wing panels are pressed or assembled to the designated elevation, tensioner 6 of the top layer of wing panels is tensioned and fixed to the second lifting point 5.

[0057] In this embodiment, if the geological conditions are stable, a ring plate 2 with an inner diameter equal to that of a single pile 1 is prefabricated; if the geological conditions are unstable, a ring plate 2 with an inner diameter greater than that of a single pile 1 is prefabricated. If the inner diameter of the ring plate 2 is larger than the diameter of the single pile 1, before the tensioning of the top wing plate tensioning member is completed, a coupling body is filled between the ring plate 2 and the single pile 1.

[0058] It should be noted that when the inner diameter of the ring plate 2 is larger than the diameter of the single pile 1, if the environment changes or the bearing capacity of the single pile needs to be increased during the service stage of the single pile foundation, the single pile 1 needs to be reinforced.

[0059] The specific steps are as follows: Release the tensioning member 6 of the original top wing plate, hoist multiple fan-shaped ring plates of the reinforcing wing plate 16 to the outer periphery of the single pile 1, assemble the reinforcing wing plate 16, so that the flange plates of the reinforcing wing plate 16 and the flange plates of the original top wing plate are distributed in a plum blossom pattern. The reinforcing wing plate 16 is then pressed into the soil along the axis of the single pile 1. When the reinforcing wing plate 16 is designed to be multi-layered, the tensioning member 6 of the previous layer of reinforcing wing plate 16 is pulled out, and then the next layer of reinforcing wing plate is re-hoisted and assembled, and the tensioning member 6 of the previous layer of reinforcing wing plate is passed through the lifting hole of the next layer of reinforcing wing plate. After pressing the rear reinforcing wing plate to the designated elevation, tensioner 6 of the first lifting point 4 of the front reinforcing wing plate is tensioned and fixed to the first lifting point 4 of the rear reinforcing wing plate. Once all reinforcing wing plates are pressed to the designated elevation below the seabed, the first lifting point 4 of the top reinforcing wing plate 16 and the first lifting point 4 of the original top wing plate are connected to the second lifting point 5 via the tensioning member 6.

[0060] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A prefabricated, toughened, near-shore photovoltaic monopile foundation, comprising a monopile and a concrete flange surrounding the monopile, characterized in that, The wing plate includes at least two sector-shaped ring plates, and at least one flange plate is fixedly connected to the outer periphery of each sector-shaped ring plate. The two ends of the sector-shaped ring plates are reserved with interlocking toothed groove structures, and shear keys are provided in the toothed groove structures. The inner diameter of the ring plate is larger than the diameter of the single pile. A circumferential gap is reserved between the ring plate and the single pile, and the circumferential gap is filled with a coupling body. The single pile is provided with multiple layers of wing plates from top to bottom, including the original wing plate during the installation stage and the reinforcing wing plate installed above the original wing plate during the service stage. Alternatively, the inner diameter of the ring plate is equal to the diameter of the single pile, and the ring plate is rigidly connected to the single pile.

2. The prefabricated, toughened, near-shore photovoltaic monopile foundation as described in claim 1, characterized in that, The first lifting point is pre-embedded on the top surface of the flange plate, and multiple second lifting points are fixedly connected to the upper end of the single pile. A tensioning member is set between the first and second lifting points of the top flange plate.

3. The prefabricated, toughened, nearshore photovoltaic monopile foundation as described in claim 1, characterized in that, The flanges of the multi-layered reinforcing flanges are arranged to coincide in the circumferential direction with the central axis of the single pile as the reference. The flanges of the multi-layered original flanges are also arranged to coincide in the circumferential direction with the central axis of the single pile as the reference. The flanges are provided with lifting holes. The tensioning member of the first lifting point of the lower flange passes through the lifting hole and is connected to the first lifting point of the upper flange. The first lifting point and the second lifting point of the top flange are connected by the tensioning member.

4. The prefabricated, toughened, near-shore photovoltaic monopile foundation as described in claim 1, characterized in that, The flange plates of the reinforcing flange and the flange plates of the original flange are staggered in the circumferential direction with the central axis of the single pile as the reference, and the first lifting point of each flange plate is connected to the second lifting point through a tensioning member.

5. A prefabricated, toughened, near-shore photovoltaic monopile foundation as described in claim 1, characterized in that, The toothed structure has corresponding grouting holes, and grout is injected into the grouting holes to form shear keys.

6. A prefabricated, toughened, near-shore photovoltaic monopile foundation as described in claim 5, characterized in that, A grouting pipe is installed inside the grouting hole. The diameter of the grouting pipe is smaller than the diameter of the grouting hole, and the grouting pipe is wrapped in the grout of the shear key.

7. A prefabricated, toughened, near-shore photovoltaic monopile foundation as described in claim 5, characterized in that, A protective layer is reserved at the bottom of the grouting hole, and the length of the grouting pipe is less than the length of the grouting hole.

8. A construction method for a prefabricated, toughened, near-shore photovoltaic monopile foundation as described in any one of claims 1-7, characterized in that, The specific steps include: Based on the geological conditions of the seabed, the connection method between the ring plate and the monopile is selected, and the wing plate is prefabricated; The single pile is hoisted to the designated position and sunk to the designed depth, and multiple second hoisting points are fixed at the upper end of the single pile; Multiple fan-shaped ring plates are assembled into a wing plate along the outer perimeter of the single pile, and then the wing plate is pressed into the soil. After the previous wing plate is pressed to the specified elevation, the tensioning member of the previous layer is pulled out, and then the next wing plate is reassembled, and the tensioning member of the previous layer is passed through the lifting hole of the next wing plate. After the next layer of wing plates is pressed to the designated elevation, the tensioning member of the previous layer is tensioned and fixed to the first lifting point of the next layer; after all wing plates are pressed to the designated elevation, the tensioning member of the top layer wing plate is tensioned and fixed to the second lifting point.

9. The construction method of a prefabricated, toughened, near-shore photovoltaic monopile foundation as described in claim 8, characterized in that, If the geological conditions are stable, the ring plate with an inner diameter equal to that of a single pile is prefabricated; if the geological conditions are unstable, the ring plate with an inner diameter greater than that of a single pile is prefabricated. If the inner diameter of the ring plate is larger than the diameter of the single pile, a coupling body should be filled between the ring plate and the single pile before the tensioning of the top wing plate tensioning member is completed.

10. The construction method of a prefabricated, toughened, near-shore photovoltaic monopile foundation as described in claim 8, characterized in that, If the inner diameter of the ring plate is larger than the diameter of the single pile, and the single pile needs reinforcement due to environmental changes during the service phase, the specific steps are as follows: Loosen the tensioning member of the original top wing plate; assemble a layer of reinforcing wing plate, and make the flange plates of the reinforcing wing plate and the flange plates of the original top wing plate be distributed in a quincunx pattern; Then, the reinforcing wing plate is pressed into the soil along the axis of the single pile. Next, the tensioner of the previous reinforcing wing plate is pulled out. Then, the next reinforcing wing plate is assembled, and the tensioner of the previous reinforcing wing plate is passed through the lifting hole of the next reinforcing wing plate. After pressing the rear reinforcing wing plate to the designated elevation, tensioning and fixing the tensioning member of the front reinforcing wing plate to the first lifting point of the rear reinforcing wing plate; Once all reinforcing wing plates are pressed to the designated elevation below the seabed, the first lifting point of the top reinforcing wing plate and the first lifting point of the original top wing plate are connected to the second lifting point via tensioning components.

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