Self-adapting portable assembled anti-scouring device for offshore single-pile foundation

Abstract

This invention proposes an adaptive, portable, prefabricated anti-scour device for offshore monopile foundations, comprising: a directional anti-vibration sleeve, movably connected to the monopile foundation; an anti-scour cover plate; multiple sets of rotating frames, circumferentially hinged to the outer side of the anti-scour cover plate; telescopic frame crossbars, connecting the ends of adjacent rotating frames; frame outer end wedges, fixed to the bottom of the rotating frame ends; a double-layer elastic membrane with flexible deformation and airtight inflation capability; carbon fiber strips, spaced and pasted on the upper and lower layers of the double-layer membrane; a spring connecting the rotating frames and the anti-scour cover plate; and an automatic pressurization unit that monitors the pile perimeter pore pressure in real time, automatically activating when the pile perimeter pore pressure exceeds a preset critical pore pressure to pressurize and inflate the double-layer elastic membrane; after the rotating frames and double-layer elastic membrane are deployed, they cover the seabed around the monopile foundation, blocking direct erosion of the seabed soil around the pile by ocean currents; the inflation of the double-layer elastic membrane further reduces the pile perimeter scour effect; and the directional anti-vibration sleeve can buffer damage to the monopile foundation during installation and operation.

Description

Technical Field

[0001] This invention relates to the field of offshore wind power and offshore photovoltaic engineering technology, and in particular to an adaptive portable prefabricated offshore monopile foundation anti-scour device. Background Technology

[0002] In the fields of offshore wind power and offshore photovoltaics, with the continuous growth of global demand for clean energy, offshore wind power and offshore photovoltaics have been widely used as important methods for obtaining renewable energy. As a key structure supporting wind turbine generators, the stability and safety of the monopile foundation for offshore wind power and offshore photovoltaics directly affect the normal operation of the entire wind power generation system. Offshore wind power and offshore photovoltaic monopile foundations are located in a complex marine environment, subjected to dynamic factors such as waves and ocean currents, making the seabed soil around the piles highly susceptible to erosion. Erosion around the piles leads to the erosion of the seabed soil around the piles, reducing the penetration depth of the monopile foundation and decreasing the relative stiffness of the pile and soil. This, in turn, affects the bearing capacity and stability of the monopile foundation, increases the risk of engineering accidents, and seriously threatens the safe operation of the facilities.

[0003] Currently, there are various types of scour protection measures for offshore monopile foundations. The most common is rockfill protection, but this has problems such as rocks being easily washed away by water currents and the protective effect diminishing over time. Another option is to install concrete protective structures, but this is costly, difficult to construct, and time-consuming. In addition, some geotextile protection measures are also used, but in actual use, geotextiles are prone to tearing and other damage under the action of water currents, affecting the protective effect. Patent CN110761313B proposes a pile foundation scour protection umbrella-shaped device and installation method, which extends the structure by releasing weight blocks. However, releasing the weight blocks still requires manual control, which is very difficult to implement on the seabed. Furthermore, the weight blocks are scattered around the scour protection device, and after deployment on the seabed, they may not reach the intended position. The lack of an overall rigid frame around the scour protection device significantly reduces its scour protection effect. Patent CN16677020B proposes a sand-fixing cover anti-erosion device. Due to the large impact of seabed waves and currents, the bottom of the sand-fixing cover will be eroded by ocean currents after a period of use, and the anti-erosion effect is not ideal.

[0004] To address this, an adaptive, portable, prefabricated anti-scour device for offshore monopile foundations was developed. This device protects the monopile foundation from the effects of the installation equipment while significantly improving the anti-scour effect of the offshore monopile foundation. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention proposes an adaptive, portable, prefabricated anti-scour device for offshore monopile foundations. This device can effectively protect the seabed soil around the monopile foundations of offshore wind power and offshore photovoltaic projects from scour, and is quick, convenient, simple, and economical to install.

[0006] The technical solution is as follows: This invention provides an adaptive portable prefabricated marine monopile foundation scour protection device, which is sleeved on a monopile foundation and includes: Directional anti-seismic sleeve, with internal ball bearings, is movably connected to the outer wall of the monopile foundation through the ball bearings; Anti-erosion cover plate, fixed on the outside of directional shockproof sleeve; Multiple sets of rotating frames are circumferentially hinged to the outside of the anti-erosion cover. The device can be unfolded and retracted by changing the rotation angle between the rotating frames and the anti-erosion cover. The telescopic frame crossbar is laterally connected to the end of the adjacent rotating frame; The outer end wedge is fixed to the bottom of the end of the rotating frame and is used to embed the device into the seabed soil after it is deployed. A double-layer elastic membrane is set at the bottom of the rotating frame, which has the ability to deform flexibly and inflate in a sealed manner; Carbon fiber tapes are bonded at intervals to the upper and lower surfaces of the double-layer membrane; The extension spring connects the rotating frame and the anti-erosion cover. With the assistance of the extension spring, the rotating frame rotates around the hinge point of the anti-erosion cover, which drives the telescopic crossbar to extend and retract, realizing the circumferential expansion and contraction of the double-layer elastic membrane. The automatic pressurization unit is connected to the double-layer elastic membrane, which monitors the pile periphery pressure in real time and automatically starts when the pile periphery pressure exceeds the preset critical pressure, pressurizing the double-layer elastic membrane to inflate it. The rotating frame and double-layer elastic membrane, once unfolded, cover the seabed around the pile foundation, blocking the direct erosion of the seabed soil around the pile by ocean currents. At the same time, the double-layer elastic membrane is inflated to further reduce the scouring effect around the pile, and the directional anti-vibration sleeve can buffer the damage to the single pile foundation during the installation and operation of the device.

[0007] Furthermore, the shock-absorbing sleeve has a groove in the middle, and the ball bearings are assembled in the groove and contact the outer wall of the pile foundation. The groove depth is greater than the diameter of the ball bearings, and ball bearing displacement limiting side guards are provided on both sides of the ball bearings. The ball bearings can roll freely in the groove of the directional shock-absorbing sleeve, and with the ball bearing displacement limiting side guards, the ball bearings are limited and prevented from falling off, so that the directional shock-absorbing sleeve and the pile foundation form a rolling fit structure.

[0008] Furthermore, the extension spring is a tension spring, and spring end plates are fixed to the rotating frame and the anti-erosion cover respectively, with the spring end plates connected to the tension spring. In this way, a stable assembly is achieved by connecting the spring end plates at both ends of the extension spring. The extension spring drives multiple sets of rotating frames to extend outward synchronously by its own elastic thrust, ensuring the stability and smoothness of the device's deployment.

[0009] Furthermore, a frame limiting support is circumferentially fixed to the anti-erosion cover. The frame limiting support corresponds to the rotating frame, supports the rotating frame in the deployed state, and limits the displacement of the rotating frame after the device is deployed.

[0010] Furthermore, the telescopic frame crossbars are configured as multi-section telescopic rods, with the unfolded length of the crossbars matching the width of the double-layer elastic membrane; the anti-erosion cover is configured as a polygonal structure, with a set of rotating frames hinged to each side. The telescopic frame crossbars adapt to the unfolding and retracting movements of the rotating frames, automatically extending and retracting according to the changing spacing between adjacent rotating frames, achieving synchronous linkage of multiple sets of rotating frames.

[0011] Furthermore, the rotating frame is configured as a two-segment, approximately inverted V-shaped zigzag structure, including a first sub-frame and a second sub-frame. A spring is connected to the first sub-frame, and the angle between the end of the first sub-frame near the scour protection cover and the seabed soil plane is set to 6°~10°. This two-segment rotating frame with a specific angle can raise the flow direction of the ocean currents near the seabed and prevent the seabed soil within a certain range around the pile from being directly exposed to the currents, significantly reducing the scouring effect of the currents on the seabed soil around the pile.

[0012] Furthermore, a flexible hose is installed between the double-layer elastic membranes of two adjacent rotating frames near the anti-erosion cover plate, and the double-layer elastic membranes between each two rotating frames form a sealed airbag, which is connected to the automatic pressurization unit by a flexible hose. The double-layer elastic membrane is made of corrosion-resistant rubber. The carbon fiber strips attached to the surface of the double-layer elastic membrane are evenly spaced in the transverse direction to form tensile reinforcement and prevent the rubber membrane from being stretched and torn during the unfolding of the rotating frame. The size of the double-layer elastic membrane is determined according to the coverage area after the rotating frame is unfolded.

[0013] Furthermore, the automatic pressurization unit includes a pore pressure monitoring module, a control module, and a pressurization pump body. The pore pressure monitoring module collects pore pressure data around the pile in real time and transmits it to the control module. The control module presets a critical pore pressure threshold and can automatically start and stop the pressurization pump body according to the monitoring data. The pressurization pump body is connected to a double-layer elastic membrane. The pore pressure monitoring module includes a fiber optic pore pressure sensor installed in the device and a fiber optic pore pressure sensor acquisition unit connected to the fiber optic pore pressure sensor. The fiber optic pore pressure sensor acquisition unit is also electrically connected to the control module.

[0014] Furthermore, an optical fiber optic pore pressure sensor is embedded in the end of the rotating frame. The transmission line of the optical fiber optic pore pressure sensor is pre-embedded in the upper slot of the anti-scouring cover through a slot in the top of the rotating frame. The top slot of the rotating frame and the upper slot of the anti-scouring cover are connected by a T-shaped flexible compressible sleeve. There is a branch in the middle of the T-shaped flexible compressible sleeve facing the double-layer elastic membrane. The double-layer elastic membrane pressurization hose is built into the branch and protected.

[0015] Furthermore, the outer end wedge of the frame has a conical wedge structure. After the frame is fully extended, the outer end wedge adaptively embeds into the seabed soil, achieving bottom positioning and fixation of the device and improving overall stability against ocean current impacts.

[0016] Compared with the prior art, the advantages of the present invention are as follows: 1. This invention combines a marine monopile foundation with a scour protection device. The grooves and balls inside the device allow for a certain degree of flexibility in the connection between the pile foundation and the protection device, while protecting the connection device from water flow impact and vibration damage. It can also absorb the vibration energy generated in the marine environment, reduce the impact of vibration on the entire pile foundation, and improve the stability and safety of the structure.

[0017] 2. In this invention, the rotating frame is in the form of a broken line. After being connected with the double-layer elastic membrane, it can play a role in guiding the flow. The rotating frame is composed of two sections with a certain angle, which can raise the flow direction of the ocean current near the seabed and prevent the seabed soil within a certain range around the pile from being directly exposed to the ocean current. This can significantly reduce the scouring of the seabed soil around the pile by the ocean current.

[0018] 3. This invention utilizes an adaptive linkage mechanism formed by a built-in fiber optic pore pressure sensor and an airbag consisting of a double-layer elastic membrane, enabling adaptive adjustment based on ocean current intensity. The system uses a critical pore pressure value as a trigger threshold to control the start and stop of the automatic pressurization unit, thereby achieving precise real-time control of the airbag's operation. After inflation, the airbag adheres tightly to the seabed surface under the constraint of the rotating support, with the bottom surface of the airbag in direct contact with the seabed soil, applying additional vertical stress to the seabed soil and effectively preventing erosion and loss of the seabed soil. The top surface of the airbag extends above the plane of the rotating frame, forming an arc-shaped interface at the top of the anti-erosion device, which can lift the ocean current and play a role in diverting and guiding the flow.

[0019] 4. The invention features a unique telescopic structure that facilitates assembly and installation while allowing for rapid deployment to form a stable support. The telescopic frame crossbars work in synergy with the rotating frame. The lightweight and convenient design ensures structural strength while reducing overall weight, making the device both portable and erosion resistant, perfectly adapting to the protection needs under complex sea conditions. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the adaptive portable prefabricated marine monopile foundation anti-scour device of the present invention. Figure 2 for Figure 1 Top view of the unfolded state; Figure 3 for Figure 1 A schematic diagram of the longitudinal section of the middle section in its unfolded state; Figure 4 for Figure 1 Side view of the unfolded state; Figure 5 for Figure 1 A top view of the closed state; Figure 6 for Figure 1 A schematic diagram of the middle longitudinal section in the closed state; Figure 7 for Figure 1 A side view of the closed state; Figure 8 This is a schematic diagram of the directional shockproof sleeve and ball bearing structure of the present invention; Figure 9 This is a schematic diagram of the unfolding of the double-layer elastic membrane and the arrangement of the carbon fiber strips according to the present invention; Figure 10 This is a schematic diagram showing the connection between the double-layer elastic membrane and the anti-erosion cover plate of the present invention; Figure 11 This is a planar schematic diagram of the air bladder and fiber optic pore pressure sensor of the double-layer elastic membrane of the present invention. Figure 12 This is a schematic diagram of the fiber optic pore pressure sensor and pressurized hose setup of the present invention (data acquisition and linkage pressurization). Figure 13 This is a flowchart of the adaptive linkage control of the fiber optic hole pressure and the double-layer elastic membrane airbag of the present invention. Figure 14 This is a schematic diagram illustrating the anti-erosion effect of the airbag of the double-layer elastic membrane of the present invention after inflation.

[0021] In the above figures: 1. Monopile foundation; 2. Directional anti-seismic sleeve; 3. Anti-scour cover plate; 31. Cover plate groove; 4. Rotating frame; 41. Frame groove; 5. Ball bearing; 6. Ball bearing displacement limiting side guard plate; 7. Carbon fiber strip; 8. Double-layer elastic membrane; 9. Rotating frame support; 10. Expansion spring; 11. Frame limiting support; 12. Telescopic frame crossbar; 13. Frame outer end wedge; 14. First spring end plate; 15. Second spring end plate; 16. Fiber optic pore pressure sensor; 18. Embedded bolt; 19. Telescopic multi-section rigid support rod; 20. Hoses; 21. Automatic pressurization unit; 22. T-shaped flexible compressible sheath; 23. Fiber optic pore pressure sensor data acquisition unit. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing 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, and therefore should not be construed as a limitation of the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0024] It should be noted that when a component is said to be "attached" to another component, it can be directly on the other component or it can be in the middle of another component. When a component is said to be "set" to another component, it can be directly set to the other component or it may also be in the middle of another component. When a component is said to be "fixed" to another component, it can be directly fixed to the other component or it may also be in the middle of another component.

[0025] It should also be noted that, unless otherwise explicitly specified and limited, the terms "setup" and "connection" 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0026] Unless otherwise defined, 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. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "or / and" as used herein includes any and all combinations of one or more of the associated listed items.

[0027] like Figures 1-14 As shown, the present invention provides an adaptive portable prefabricated marine monopile foundation anti-scour device, which is sleeved on the monopile foundation 1 and includes a directional anti-vibration sleeve 2, an anti-scour cover plate 3, multiple sets of rotating frames 4, telescopic frame crossbars 12, frame outer end wedges 13, double-layer elastic membranes 8, carbon fiber belts 7, extension springs 10 and automatic pressurization parts 21.

[0028] The main components are described below.

[0029] 1. Directional shockproof sleeve 2 The directional anti-seismic sleeve 2 is equipped with ball bearings 5, which are movably connected to the outer wall of the monopile foundation 1. Specifically, the directional anti-seismic sleeve 2 has a groove inside, and the ball bearings 5 ​​are installed inside the groove. The ball bearings 5 ​​are assembled in the groove and contact the outer wall of the pile foundation. There are ball bearing displacement limiting side guards 6 on both sides of the ball bearings 5. The ball bearing displacement limiting side guards 6 are used to restrain the lateral movement of the ball bearings 5, and the depth of the groove is greater than the length of the ball bearings 5. The movable connection between the ball bearings 5 ​​and the outer wall of the monopile foundation 1 allows the scour protection device to slide along the monopile foundation 1.

[0030] Specifically, the ball-bearing displacement limiting side guard plate 6 is connected to the shock-absorbing sleeve by welding.

[0031] Specifically, the ball bearings 5 ​​are arranged in three parallel rows along the height direction of the anti-vibration sleeve, with 6 ball bearings 5 ​​installed in each row, for a total of 18 ball bearings 5, to prevent damage to the anti-corrosion coating around the pile when the anti-vibration sleeve moves downward.

[0032] Through the above technical solution, the ball bearing 5 can roll freely in the groove of the directional anti-vibration sleeve 2. With the help of the ball bearing displacement limiting side guard steel plate 6, the ball bearing 5 is limited and prevented from falling off, so that the directional anti-vibration sleeve 2 and the pile foundation form a rolling fit structure. In this way, the directional anti-vibration sleeve 2 can buffer the damage to the single pile foundation 1 during the installation and operation of the device.

[0033] 2. Anti-erosion cover plate 3 The anti-erosion cover 3 is fixedly sleeved on the outside of the directional shockproof sleeve 2. The anti-erosion cover 3 is a polygonal anti-erosion cover, which is made of steel material resistant to high salt corrosion. Each side of the polygonal anti-erosion cover is fixedly installed with a frame limiting support 11 for supporting the rotating frame 4. Multiple sets of polygonal rotating frames 4 are hinged to the outside of the polygonal anti-erosion cover through the frame limiting support 11.

[0034] In this embodiment, the anti-erosion cover 3 is selected as a hexagonal structure.

[0035] Furthermore, multiple skeleton limiting supports 11 and spring end plates are welded to the circumferential side of the anti-erosion cover 3. The skeleton limiting supports 11 correspond to the rotating skeleton 4, supporting the rotating skeleton 4 in the deployed state and limiting the offset of the rotating skeleton 4 after deployment. The spring end plates are used to connect one end of the extension spring 10, and the other end of the spring is connected to the spring end plate welded to the rotating skeleton 4. For easy distinction, the spring end plates fixed to the rotating skeleton 4 and the anti-erosion cover 3 are named the first spring end plate 14 and the second spring end plate 15, respectively.

[0036] The extension spring 10 connects the rotating frame 4 to the anti-erosion cover 3. With the assistance of the extension spring 10, the rotating frame 4 rotates around the hinge point of the anti-erosion cover 3, driving the telescopic frame crossbar 12 to extend and retract, realizing the circumferential expansion and contraction of the double-layer elastic membrane 8. In this way, a stable assembly is achieved by connecting the spring end plates at both ends of the extension spring 10. The extension spring 10 drives multiple sets of rotating frames 4 to expand outward synchronously by its own elastic thrust, ensuring the stability and smoothness of the device's expansion.

[0037] The extension spring 10 is a tension spring.

[0038] 3. Rotate the frame 4 Multiple sets of rotating frames 4 are configured, circumferentially positioned on the outer side of the anti-erosion cover 3. The rotating frames 4 are hinged to the polygonal anti-erosion cover 3 via rotating frame supports 9, and can move vertically relative to the polygonal anti-erosion cover 3. The device can be deployed and retracted by changing the rotation angle between the rotating frames 4 and the anti-erosion cover 3. The number of rotating frames 4 corresponds to the number of sides of the polygonal anti-erosion cover 3.

[0039] Specifically, the rotating frame 4 is configured as a two-segment, approximately inverted V-shaped zigzag structure, including a first sub-frame and a second sub-frame. The extension spring 10 is connected to the first sub-frame, and the angle between the end of the first sub-frame near the anti-scour cover plate 3 and the seabed soil plane is set to 6°~10°. This two-segment rotating frame 4, with a certain angle, can raise the flow direction of the ocean currents near the seabed and prevent the seabed soil within a certain range around the pile from being directly exposed to the ocean currents, thus significantly reducing the scouring of the seabed soil around the pile by the ocean currents.

[0040] The connection between the two sub-frames is set at a certain angle, which can be adjusted according to the flatness of the seabed in the target sea area. The sub-frames are rigidly connected, such as by welding.

[0041] The end of the adjacent second sub-frame is laterally connected to a telescopic frame crossbar 12. When the device is in the unfolded state, the telescopic frame crossbar 12 extends; when the device is in the closed state, the telescopic frame crossbar 12 retracts. The length of the telescopic frame crossbar 12 after unfolding is adapted to the width of the double-layer elastic membrane 8.

[0042] Specifically, the telescopic frame crossbar 12 is configured as a multi-section telescopic rod. Existing structures with axial telescopic functionality can be used for the multi-section telescopic rod; no structural limitations are imposed here.

[0043] The bottom end of the second sub-frame is fixed with an outer end wedge 13, which is used to embed the device into the seabed soil after it is deployed.

[0044] Specifically, the outer end wedge 13 of the frame is initially selected as a conical wedge structure. After the frame 4 is fully extended by rotation, the outer end wedge 13 of the frame adaptively embeds into the seabed soil, realizing the bottom positioning and fixation of the device and improving the overall stability against ocean current impact.

[0045] To monitor the pore pressure around the pile in real time, a fiber optic pore pressure sensor 16 is embedded in the end of the rotating frame 4. The transmission line of the fiber optic pore pressure sensor 16 is pre-embedded in the upper slot of the anti-scour cover plate 3 through a slot cut in the top of the rotating frame 4. The top slot of the rotating frame 4 and the upper slot of the anti-scour cover plate 3 are connected by a T-shaped flexible compressible sleeve 22. There is a branch in the middle of the T-shaped flexible compressible sleeve 22 facing the double-layer elastic membrane 8, and the pressure hose 20 of the double-layer elastic membrane 8 is built into the branch and protected.

[0046] Specifically, the top of the anti-erosion cover plate 3 has a pre-drilled annular groove with a width of 5cm and a depth of 5cm, which facilitates the convergence of the fiber optic pore pressure sensors 16 in the 6 rotating skeletons 4 to the extension point. The groove is encapsulated with corrosion-resistant epoxy resin / polyurea material to make its surface flat and to test whether the fiber optic pore pressure sensors 16 are viable.

[0047] 4. Double-layer elastic membrane 8 A double-layer elastic membrane 8 is located at the bottom of the rotating frame 4, possessing both flexible deformation and airtight inflation capabilities. (See also...) Figure 10 The double-layer elastic membrane 8 can be fixed to the anti-erosion cover plate 3 by means of embedded bolts 18 and fixedly connected to the rotating frame 4 (e.g., by adhesive).

[0048] Carbon fiber strips 7 are provided on both the upper and lower surfaces of the double-layer rubber elastic membrane, forming multiple independent controllable airbags. In this embodiment, the number of airbags is six, corresponding to the number of sides of the hexagonal anti-erosion cover.

[0049] The double-layer elastic membrane 8 is made of corrosion-resistant rubber.

[0050] Carbon fiber strips 7, evenly spaced laterally, are attached to the upper and lower surfaces of the double-layer elastic membrane 8 to provide tensile reinforcement. This helps prevent the rubber membrane from stretching and tearing during the deployment of the rotating frame 4, and from fatigue damage caused by periodic ocean currents / scouring during scouring. Figure 9 As shown, the carbon fiber strips are arranged in a staggered mesh pattern in 7 rows.

[0051] The size of the double-layer elastic membrane 8 is determined based on the coverage area after the rotating frame 4 is unfolded.

[0052] A flexible hose 20 is installed between the double-layer elastic membrane 8 between two adjacent rotating frames 4 near the anti-scour cover plate 3. The double-layer elastic membrane 8 between each two rotating frames 4 forms a sealed airbag, which is extended from the flexible hose 20 to the automatic pressurization unit 21 above the sea surface via a telescopic multi-section rigid support rod.

[0053] The double-layer elastic membrane 8 has two working states. One is the unfolded state, in which the rotating frame 4 and the double-layer elastic membrane 8 unfold to cover the seabed around the pile foundation, blocking the direct erosion of the seabed soil around the pile by the ocean current. The other is the inflated state after unfolding. When the pore pressure around the pile is greater than the preset critical pore pressure, it is automatically activated. The automatic pressurization unit 21 pressurizes the double-layer elastic membrane 8 to make it inflated, which further reduces the scouring effect around the pile. The inflation of the double-layer elastic membrane 8 is automatically adjusted according to the intensity of the sea / ocean current in different directions.

[0054] This invention utilizes an independently controllable airbag, comprised of a built-in fiber optic pore pressure sensor 16 and a double-layer elastic membrane 8, to form an adaptive linkage mechanism that can adaptively adjust according to the intensity of ocean currents. The system uses a critical pore pressure value as a trigger threshold to control the start and stop of the automatic pressurization unit 21, thereby achieving precise real-time control of the airbag's operation. After inflation, the airbag, constrained by the rotating support, adheres tightly to the seabed surface, with the bottom surface of the airbag directly contacting the seabed soil, applying additional vertical stress to the seabed soil and effectively preventing erosion. The top surface of the airbag extends above the plane of the rotating frame 4, forming an arc-shaped interface at the top of the anti-erosion device, which can lift the ocean current and play a role in diverting and guiding flow. (See [reference]). Figure 13 .

[0055] 5. Automatic pressurization unit 21 The automatic pressurization unit 21 is connected to the double-layer elastic membrane 8, which can monitor the pile periphery pressure in real time and automatically start when the pile periphery pressure is greater than the preset critical pressure, pressurizing the double-layer elastic membrane 8 to inflate it.

[0056] Specifically, the automatic pressurization unit 21 includes a pore pressure monitoring module, a control module, and a pressurization pump. The pore pressure monitoring module collects pore pressure data around the pile in real time and transmits it to the control module. The control module presets a critical pore pressure threshold and can automatically start and stop the pressurization pump based on the monitoring data. The pressurization pump is connected to the double-layer elastic membrane 8.

[0057] The pore pressure monitoring module includes a fiber optic pore pressure sensor 16 installed in the device and a fiber optic pore pressure sensor 16 acquisition instrument connected to the fiber optic pore pressure sensor 16. The fiber optic pore pressure sensor 16 acquisition instrument is also electrically connected to the control module.

[0058] like Figure 11As shown, assuming six independent airbags are numbered Q1~Q6, and fiber optic pore pressure sensors 16, numbered u1~u6, are installed at the ends of the rotating frame 4, when ocean currents from different directions meet the monopile foundation 1, if the reading ui (i=1~6) of the fiber optic pore pressure sensor 16 is greater than ucritical (ucritical is the average pore water pressure value during periods of significant scour of marine structures in the surrounding sea area), two adjacent airbags Qi and Qi-1 will simultaneously restart, causing the airbags to inflate. After restarting, the two airbags press down on the seabed soil below the airbags and are higher than the top elevation of the surrounding airbags (uninflated airbags). This ensures that the seabed soil is not washed away while raising the ocean current, thus playing a role in diverting the current. When the reading ui (i=1~6) of the fiber optic pore pressure sensor 16 is less than or equal to ucritical, the airbags deflate to a deflated state. See the flowchart. Figure 14 . The construction process is as follows:

[0059] After the construction vessel arrives at the construction site of the offshore wind power monopile foundation 1, the position and verticality of the monopile foundation 1 are measured again with positioning instruments to ensure that it meets the installation requirements.

[0060] The anti-vibration sleeve was hoisted to the top of the monopile foundation 1 using a crane vessel. A positioning instrument was then used to slowly lower the sleeve, ensuring it was accurately fitted onto the foundation. During the lowering process, the verticality of the sleeve was monitored in real time, and adjustments were made promptly if any deviation was found. Once the sleeve was in its designed position, it was secured using a temporary support device. This device consisted of an adjustable-height steel frame with anti-slip pads at the bottom to enhance stability.

[0061] Apply a suitable amount of lubricant to the cleaned grooves, and then place the balls 5 one by one into the grooves according to the designed spacing and arrangement. During installation, use a special tool to ensure that the balls 5 are placed accurately and to avoid collisions between them. After installation, check the rolling flexibility of the balls 5 to ensure that they can roll freely within the grooves.

[0062] The rotating frame 4 is first merged into the vertical direction of the anti-erosion cover 3, which facilitates installation and reduces resistance during the fall.

[0063] The erosion protection cover 3 is fixedly equipped with a frame limiting support 11 that forms an angle with the horizontal plane to support the rotating frame 4. The polygonal erosion protection cover 3 has an mounting surface. After positioning and marking, it is fixedly installed using a welding connection to ensure a secure fit.

[0064] Connect the middle end of the rotating frame 4 to the anti-erosion cover 3, and connect one end of the extension spring 10 to the preset connection point of the rotating frame 4. Finally, connect the other end, according to the design angle and position, to the corresponding part of the cover plate, ensuring a stable connection and normal elasticity.

[0065] The pre-assembled polygonal scour protection cover plate 3, consisting of a rotating frame 4, is hoisted to the construction site. Its position is adjusted using a positioning instrument so that its center is aligned vertically with the center of the monopile foundation 1. Then, the scour protection cover plate 3 is slowly lifted close to the bottom of the anti-vibration sleeve. Through the sliding action of the ball bearings 5, the scour protection cover plate 3 is accurately installed at the predetermined position below the anti-vibration sleeve. The angle of the rotating frame 4 is adjusted to ensure it is evenly distributed around the scour protection cover plate 3. Finally, the rotating frame support 9 connecting the rotating frame 4 and the scour protection cover plate 3 is tightened using a torque wrench at the specified torque value to ensure a secure connection.

[0066] The device is initially in a closed state, with all rotating frames 4 retracted inwards and temporarily secured by high-strength biodegradable ropes. At this time, the expansion springs 10 are in a compressed, energy-storing state. During installation, the entire device is hoisted to the bottom of the pile foundation and positioned. Once the device is confirmed to be in contact with the seabed, the restraint straps are cut, and the expansion springs 10 immediately release their elasticity, pushing the rotating frames 4 outwards. Simultaneously, the double-layer elastic membrane 8 also unfolds. The outer wedges at the ends of the frames insert into the seabed during the unfolding process, while the telescopic frame crossbars 12 automatically extend and lock, forming a stable support structure. The entire process requires no underwater operation, completing the unfolding quickly and automatically, meeting the needs of efficient offshore construction.

[0067] The embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. An adaptive portable prefabricated marine monopile foundation scour protection device, fitted onto a monopile foundation (1), characterized in that, include: The directional shock-absorbing sleeve (2) is equipped with ball bearings (5) and is movably connected to the outer wall of the single pile foundation (1) through the ball bearings (5); Anti-erosion cover plate (3) is fixed on the outside of directional shockproof sleeve (2); Multiple sets of rotating frames (4) are circumferentially hinged to the outside of the anti-scouring cover (3). The device can be unfolded and retracted by changing the rotation angle between the rotating frames (4) and the anti-scouring cover (3). The telescopic frame crossbar (12) is laterally connected to the end of the adjacent rotating frame (4); The outer end wedge (13) of the skeleton is fixed at the bottom of the end of the rotating skeleton (4) and is used to embed into the seabed soil after the device is unfolded; A double-layer elastic membrane (8) is set at the bottom of the rotating frame (4) and has flexible deformation and air-filling capacity; Carbon fiber tape (7) is bonded at intervals to the upper and lower surfaces of the double-layer film; The extension spring (10) connects the rotating frame (4) and the anti-scouring cover (3). With the assistance of the extension spring (10), the rotating frame (4) rotates around the hinge point of the anti-scouring cover (3), which drives the telescopic frame crossbar (12) to extend and retract, thereby realizing the circumferential expansion and contraction of the double-layer elastic membrane (8). The automatic pressurization unit (21) is connected to the double-layer elastic membrane (8), monitors the pile periphery pressure in real time, and automatically starts when the pile periphery pressure is greater than the preset critical pressure, pressurizing the double-layer elastic membrane (8) to inflate it; After the rotating frame (4) and the double-layer elastic membrane (8) are unfolded, they cover the seabed around the single pile foundation (1), blocking the direct erosion of the seabed soil around the pile by the ocean current. At the same time, the double-layer elastic membrane (8) is inflated to further reduce the scouring effect around the pile. The directional anti-vibration sleeve (2) can buffer the damage to the single pile foundation (1) during the installation and operation of the device.

2. The adaptive portable prefabricated marine monopile foundation scour protection device according to claim 1, characterized in that, The anti-vibration sleeve has a groove in the middle, the ball (5) is assembled in the groove and contacts the outer wall of the pile foundation, and the groove depth is greater than the diameter of the ball (5). The ball (5) has ball displacement limiting side guard steel plates (6) on both sides.

3. The adaptive portable prefabricated marine monopile foundation scour prevention device according to claim 1, characterized in that, The extension spring (10) is a tension spring. Spring end plates are fixed on the rotating frame (4) and the anti-erosion cover plate (3), and the spring end plates are connected to the tension spring.

4. The adaptive portable prefabricated marine monopile foundation scour protection device according to claim 1, characterized in that, The anti-erosion cover (3) is circumferentially fixed with a frame limiting support (11).

5. The adaptive portable prefabricated marine monopile foundation scour protection device according to claim 1, characterized in that, The telescopic frame crossbar (12) is set as a multi-section telescopic bar, and the length of the telescopic frame crossbar (12) after unfolding is adapted to the width of the double-layer elastic membrane (8); the anti-erosion cover plate (3) is set as a polygonal structure, with a set of rotating frames (4) hinged on each side.

6. The adaptive portable prefabricated marine monopile foundation scour protection device according to claim 1, characterized in that, The rotating frame (4) is configured as a two-segment, approximately inverted V-shaped zigzag structure, including a first sub-frame and a second sub-frame. The extension spring (10) is located on the first sub-frame. The angle between the end of the first sub-frame near the anti-scour cover plate (3) and the seabed soil plane is set to 6°~10°.

7. The adaptive portable prefabricated marine monopile foundation scour protection device according to claim 1, characterized in that, A flexible hose (20) is installed near the anti-scouring cover plate (3) between two adjacent rotating frames (4) to connect the double-layer elastic membrane (8). The double-layer elastic membrane (8) between each two rotating frames (4) forms a sealed airbag, which is connected to the automatic pressurization unit (21) by the flexible hose (20). The double-layer elastic membrane (8) is made of corrosion-resistant rubber. The carbon fiber strips (7) attached to the surface of the double-layer elastic membrane (8) are evenly spaced in the transverse direction so that the double-layer elastic membrane (8) forms tensile reinforcement and prevents the rubber membrane from being stretched and torn during the unfolding of the rotating frame (4). The size of the double-layer elastic membrane (8) is determined according to the coverage area after the rotating frame (4) is unfolded.

8. The adaptive portable prefabricated marine monopile foundation scour protection device according to claim 1, characterized in that, The automatic pressurization unit (21) includes a pore pressure monitoring module, a control module and a pressurization pump body. The pore pressure monitoring module collects pore pressure data around the pile in real time and transmits it to the control module. The control module presets a critical pore pressure threshold and can automatically start and stop the pressurization pump body according to the monitoring data. The pressurization pump body is connected to the double-layer elastic membrane (8). The pore pressure monitoring module includes a fiber optic pore pressure sensor (16) installed in the device and a fiber optic pore pressure sensor acquisition unit (23) connected to the fiber optic pore pressure sensor (16). The fiber optic pore pressure sensor acquisition unit (23) is also electrically connected to the control module.

9. The adaptive portable prefabricated marine monopile foundation scour protection device according to claim 8, characterized in that, The rotating frame (4) has an embedded fiber optic pore pressure sensor (16) at its end. The transmission line of the fiber optic pore pressure sensor (16) is pre-embedded in the groove at the top of the rotating frame (4) and connected to the upper slot of the anti-scouring cover plate (3). The groove at the top of the rotating frame (4) and the groove at the upper slot of the anti-scouring cover plate (3) are connected by a T-shaped flexible compressible sleeve (22). There is a branch in the middle of the T-shaped flexible compressible sleeve (22) facing the double-layer elastic membrane (8). The pressure hose (20) of the double-layer elastic membrane (8) is built into the branch and protected.

10. The adaptive portable prefabricated marine monopile foundation scour protection device according to claim 1, characterized in that, The outer end wedge (13) of the skeleton is a conical wedge structure.

Images