Offshore wind power pile foundation scouring prevention device and construction method thereof

Abstract

The present application relates to a kind of offshore wind pile foundation scouring device and its construction method.The device includes the support platform around pile foundation, protective layer, embedded structure, constraint torus and pick-up flow platform;The material of protective layer is quick-setting cement blanket;The bottom of support platform is in contact with ground surface, constraint torus is located above support platform, pick-up flow platform is located above constraint torus;Distance is left between embedded structure and support platform;Protective layer is fixedly connected with support platform to form inverted umbrella structure, inner edge of protective layer is fixedly connected with outer edge of pick-up flow platform and forms pick-up flow structure.The present application utilizes the characteristics of quick-setting cement blanket, such as high mechanical properties and impermeability strength, and convenient and rapid hardening of laying forming, builds protective layer of specific structure to make impact water flow pick up and shoot back along the surface of protective layer, avoid water flow scouring pile foundation surrounding ground soil, reduce the adverse effects of water flow on pile stability, and the scope of application covers intertidal muddy seabed.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of offshore wind power pile foundation scouring prevention device, and corresponding construction method, belong to wind power auxiliary equipment technical field. BACKGROUND

[0002] With the deterioration of energy shortage problem, the world is actively seeking energy alternatives, as technology matures, high reliability wind power has become an indispensable part of the energy system of each country. According to incomplete statistics, by the end of 2022, the global wind power installed capacity has reached 923GW, of which the offshore wind power installed capacity has exceeded 60GW. Due to the simple structure of single pile foundation, convenient transportation, suitable for large-scale manufacturing, 80% of offshore wind power projects use single pile foundation (referred to as pile foundation). However, the ocean environment is complex, the coupling effect of tidal current and wave will form a horseshoe vortex and vortex shedding around the pile foundation, causing local scour around the pile foundation, reducing the ultimate bearing capacity of the wind power pile, and in severe cases, it will cause the instability and destruction of the wind power structure. Therefore, it is necessary to develop a scour prevention device for wind power pile foundation to weaken the scouring effect of water flow as much as possible.

[0003] The current traditional scour prevention measures can be divided into active protection and passive protection according to the protection principle. Active protection is to change the structure of the pile itself to weaken the intensity of water flow; this method can reduce the intensity of water flow to a certain extent, but it is complex in structure design and construction, and sacrifices the ultimate bearing strength of the pile foundation, which brings certain safety hazards to the structure itself.

[0004] Passive protection is to lay a protective layer on the seabed around the pile to improve the anti-scouring capacity of the surrounding foundation; the main measures are: throwing filling method, soil fabric compaction, solidified soil protection, bionic water grass treatment and reserved scouring length. The throwing filling method refers to throwing sand bags, stones, precast concrete structures to the seabed around the pile foundation according to the designed range and thickness; the soil fabric compaction refers to installing and laying the soil fabric stitched sand bag or chain row to the seabed around the pile foundation by hanger or laying ship; the solidified soil protection refers to pumping the prepared solidified soil into the root of the pile foundation, and it can be hardened and formed; these methods all have the problems of uncontrollable quality, insufficient durability, poor construction precision, etc. Planting bionic water grass refers to anchoring bionic water grass at the protection position to reduce the flow velocity and deposit sediment, but it cannot form an effective sedimentation coverage area due to the large seabed flow velocity and small sand particle size; the reserved scouring length refers to appropriately lengthening the pile length considering the scouring allowance to ensure sufficient soil penetration depth after scouring, but this method will form a large scouring pit at the pile foundation, and the design anchoring and detailed construction are complex and difficult, with high construction cost. Therefore, the current wind power foundation anti-scouring measures all have certain deficiencies.

[0005] Through retrieval, it is found that in the existing patents: from the laying form of the foundation protection, the invention patent application with application number CN201910907321.2 and publication number CN110593325A uses an anti-scouring curtain to directly cover the possible scouring range of the foundation, and a stable structure is formed by a tensioning rope and a counterweight; although this technical solution can protect the seabed silt in the short term, under the long-term reciprocating action of seawater, once the rope is damaged or the soil near the counterweight is loosened to cause sliding, the entire structure will be destroyed, which will significantly increase the repair frequency and is not conducive to the long-term protection of the wind power pile. The invention patent application with application number CN202111195575.X and publication number CN114032841A uses a concrete interlocking row and cement soil combination to reinforce the foundation, and a geotextile is laid thereon to reduce the scouring effect; this technical solution is relatively complex in construction, needs to manufacture and connect multiple concrete blocks, is complex to operate, and cannot guarantee the protection quality, and is not conducive to popularization and application. The above-mentioned patent represents a type of existing technical solution that has not broken through the laying form of the protection material, but focuses on the innovation of the material fixing structure.

[0006] From the structural form of the foundation protection, the invention patent application with application number CN202210001923.3 and publication number CN114250803A uses an umbrella-shaped support structure and a slidable bottom plate to form a protection structure that can automatically adapt to the deformation of the foundation, but the actual water flow scouring influence range far exceeds the protection capability of this technical solution, and long-term scouring will cause the loss of surrounding silt and the loosening of silt under the bottom plate, and then cause the pile foundation to sink, which is far from the ideal protection effect. The invention patent application with application number CN202011508832.6 and publication number CN112523266A uses an assembled energy-dissipation anti-scouring device, which is convenient to construct, but its weight is relatively large and is prone to large subsidence when laid in the loose silt tidal zone, and is not applicable in this working condition. The invention patent application with application number CN201310465331.8 and publication number CN103469829A uses a structure combining a conical cap and a skirt plate to directly cover the scouring range and depth; this technical solution can avoid the generation of a horseshoe-shaped vortex to a certain extent, but the scouring range of the silt tidal seabed is about 30m at present, and the conical cap needs to cover a too large area, and even if it is realized, it is easy to cause large foundation subsidence near the pile, which will greatly affect the overall structure and the surrounding environment. The above-mentioned patent represents a type of existing technical solution that uses high-strength materials to strengthen the foundation anti-scouring capability, but is not applicable to the soft silt tidal seabed.

[0007] It can be seen that the existing technology cannot well solve the problem of silt seabed wind power foundation protection, and breakthroughs are needed in the laying form of the protection material. SUMMARY

[0008] The main purpose of the present application is to overcome the problems existing in the prior art, provide an offshore wind power pile foundation anti-scouring device, make full use of the characteristics of the rapid-setting cement blanket, such as high mechanical properties and impermeability, and convenient laying and rapid hardening, build a protective layer with a specific structure, make the water flow rushing to the pile foundation shoot back along the surface of the protective layer, not only can avoid the scouring of the water flow to the surrounding soil of the pile foundation, but also can maximize the adverse effects of the water flow on the stability of the pile body, and the application range covers the intertidal muddy seabed. The application also provides a corresponding construction method.

[0009] The technical scheme for solving the technical problems of the present application is as follows:

[0010] An offshore wind power pile foundation anti-scouring device, comprising a support table and a protective layer, characterized in that it further comprises an embedded structure, a constraint ring and a flow-picking table; the material of the protective layer is a rapid-setting cement blanket; the support table, the constraint ring and the flow-picking table are respectively arranged around the pile foundation and adjacent to the pile foundation; the bottom of the support table is in contact with the ground surface around the pile foundation, the constraint ring is located above the support table, and the flow-picking table is located above the constraint ring; the embedded structure is arranged around the pile foundation and has a distance from the support table; the protective layer is annular and arranged around the pile foundation, the outer edge of the protective layer is embedded in the embedded structure and fixedly connected with the embedded structure, the protective layer successively covers the flat ground surface between the embedded structure and the support table, covers the outer side of the support table and is fixedly connected with the support table to form an inverted umbrella structure, is laid and fixed between the constraint ring and the pile foundation, and covers the lower side of the flow-picking table, and the inner edge of the protective layer is fixedly connected with the outer edge of the flow-picking table and forms a flow-picking structure.

[0011] In the structure, the material of the protective layer is a rapid-setting cement blanket, which can prevent the water flow from scouring the pile foundation of the wind power pile; the embedded structure plays a fixing role on the outer edge of the protective layer; the support table is an important supporting structure of the protective layer, and at the same time, the protective layer can be laid into an inverted umbrella structure along the surface of the support table, which is more conducive to the stability of the whole; the constraint ring fixes the protective layer on the surface of the pile foundation, so that the starting point of the flow-picking structure is better matched with the surface of the pile foundation; the flow-picking table can make the protective layer laid upward to form a flow-picking structure with a flow-picking angle, which can better adapt to the change of wave flow pressure caused by complex environmental factors.

[0012] The cement blanket has simple process, good flexibility and adaptability during construction, and the above structure can resist the scour of the wave flow on the wind power pile by using the excellent mechanical properties and impermeability of the cement blanket itself through laying the protective layer around the pile foundation. Moreover, the quick-setting cement blanket used in the above structure has the characteristics of rapid hydration and hardening, and can be rapidly hardened to form a stable structure with certain strength and bearing capacity within 24 hours, so that the rapid laying construction can be realized, a large amount of construction time is saved, and the above structure is suitable for intertidal zone, especially for the scene with tight construction period. Meanwhile, in the above structure, the overall laying structure of the protective layer is designed as a smooth curve, the lower part is laid as an inverted umbrella structure on the support platform, and the upper part is laid as an energy-dissipating flip structure on the flip platform, so that the incoming flow can be shot back along the structure surface, thereby the adverse effects of the water flow on the stability of the pile foundation are reduced to the maximum. In addition, the cement blanket itself has high strength, and the bending strength of the 1cm-thick cement blanket can reach more than 20MPa, so that the cement blanket can be directly used as a bearing structure, and therefore the above structure does not need other reinforcing materials, is low-carbon and environmentally friendly, and has great significance for protecting the ecological environment of the intertidal zone.

[0013] The further improved technical solutions of the present application are as follows:

[0014] Preferably, the support platform hoop is arranged in the circumferential direction of the pile foundation; the support platform comprises a support body in the shape of a cylinder, the support body has a cylinder wall, and the cylinder wall is fixedly connected with the pile foundation; a group of annular rings with different inner diameters are arranged on the outer side of the cylinder wall, the annular rings are coaxially arranged and have different heights, and each annular ring is fixedly connected with the outer side of the cylinder wall through a corresponding spoke, wherein the annular ring with the smallest inner diameter has the highest height, the annular ring with the largest inner diameter has the lowest height, and the remaining annular rings are arranged between the two annular rings in the order of the inner diameter size, so that the inner diameter of each annular ring gradually shrinks from bottom to top; and the protective layer is fixedly connected with each annular ring and forms an inverted umbrella structure. In this way, the specific composition of the inverted umbrella structure can be further optimized.

[0015] More preferably, each annular ring has an upward inclined surface on the outer side, and each inclined surface is provided with an annular support gasket, and the protective layer is fixedly connected with each support gasket and each annular ring in sequence through U-shaped nails. In this way, the support reliability of the support platform to the protective layer can be further improved.

[0016] More preferably, each annular ring is vertically arranged into several layers, and a distance is left between adjacent two layers, and a distance is left between the topmost layer and the top of the cylinder wall. In this way, the connection between the inverted umbrella structure and the flip structure is smoother.

[0017] The above preferred solutions can further optimize the specific details of the support platform.

[0018] Preferably, the constraint circular hoop is arranged in the circumferential direction of the pile foundation, and the constraint circular hoop clamps and fixes the protective layer beyond the top of the support platform on the pile foundation. In this way, the protective layer can better fit the outer wall of the pile foundation at the constraint circular hoop, and form the starting point of the pick-up flow structure.

[0019] With the above preferred scheme, the specific details of the constraint circular hoop can be further optimized.

[0020] Preferably, the pick-up platform is arranged in the circumferential direction of the pile foundation; the pick-up platform comprises a hub-shaped component, a set of spoke-shaped components, and a rim-shaped component; the hub-shaped component is fixedly connected with the pile foundation, the hub-shaped component is located on the inner side of the rim-shaped component and coaxial with the rim-shaped component, and the hub-shaped component is fixedly connected with the rim-shaped component through the spoke-shaped components; the inner edge of the protective layer is fixedly connected with the rim-shaped component and forms the pick-up flow structure.

[0021] With this preferred scheme, the specific composition of the pick-up flow structure can be further optimized, which starts at the constraint circular hoop and ends at the rim-shaped component, forming a complete pick-up flow surface and playing a role in energy dissipation and scour prevention.

[0022] Preferably, the embedded structure comprises a circular trench dug downward from the ground surface; the circular trench takes the intersection point of the pile foundation axis and the ground surface as the center; the outer edge of the protective layer is embedded in the circular trench and fixedly connected with the circular trench through grouting sealing.

[0023] With this preferred scheme, the specific composition of the embedded structure can be further optimized.

[0024] Preferably, the protective layer is a continuous and uninterrupted whole, and the protective layer is spliced by a plurality of cement carpet components.

[0025] With this preferred scheme, the specific structure of the protective layer can be further optimized, which is beneficial to rapid construction.

[0026] More preferably, in the support platform, the inner diameter of the circular ring with the largest inner diameter is 2 times the diameter of the pile foundation; the material of the support platform is steel reinforcement; the inner side of the cylinder wall of the support body is attached to the pile foundation; the cylinder wall of the support body is hollow, and the support body is provided with a grouting hole communicating with the inside of the cylinder wall at the top; in the pick-up platform, the difference between the diameter of the rim-shaped component and the diameter of the hub-shaped component is the diameter of the pile foundation; in the embedded structure, the radius of the circular trench is 6 times the diameter of the pile foundation, and the depth of the circular trench is 1.5 m; the cement carpet components are spliced by U-shaped nails, and the strip width of the cement carpet components is 1.5-2.0 m.

[0027] With this preferred scheme, the remaining technical details of the scour prevention device can be further optimized. When necessary, grouting treatment can be performed on the inside of the cylinder wall of the support body through the grouting hole, the self-weight of the support platform can be increased, the self-bearing pressure can be reduced, and the compression resistance grade can be improved.

[0028] This invention also provides:

[0029] A construction method for the aforementioned offshore wind turbine pile foundation scour prevention device includes the following steps:

[0030] The first step is to level the ground surface within the predetermined range around the target wind turbine foundation; and to build a support platform of predetermined height around the foundation.

[0031] The second step is to dig a circular trench of a predetermined depth at the predetermined location, with the intersection of the pile foundation axis and the ground surface as the center; lay the outer edge of the protective layer into the circular trench and seal it with concrete grout to fix the protective layer in place; then, lay the protective layer along the ground surface towards the bottom of the support platform.

[0032] The third step is to lay the protective layer from bottom to top along the outer surface of the support platform. After reaching the top of the support platform, leave a sufficient length of the protective layer and fix it to each ring of the support platform. The protective layer laid here forms an inverted umbrella-shaped structure.

[0033] Step 4: Use restraining rings to fix the protective layer extending beyond the top of the support platform to the pile foundation;

[0034] Step 5: At a preset height above the constraint ring, weld and fix the hub-shaped component of the jet platform to the outer wall of the pile foundation. Then, continue to lay the protective layer that extends beyond the top of the constraint ring to the rim-shaped component of the jet platform. Fix the protective layer to the rim-shaped component. Then, cut off the excess part of the protective layer that extends beyond the rim-shaped component. The protective layer laid here forms the jet structure.

[0035] Step 6: Hydrate the laid protective layer until it has fully hardened, at which point the construction is complete.

[0036] Compared with existing technologies, this invention makes full use of the characteristics of quick-setting cement blankets. By constructing a specific structural surface, the incoming flow is directed back along the structural surface, thereby minimizing the adverse effects of water flow on the stability of the pile body. The applicable scope covers intertidal silty seabeds. Attached Figure Description

[0037] Figure 1 This is a top view of Embodiment 1 of the present invention.

[0038] Figure 2 for Figure 1 AA cross-section view.

[0039] Figure 3 for Figure 2 Enlarged view of the area surrounding the pile foundation.

[0040] Figure 4 for Figure 2Enlarged view of the embedded structure area.

[0041] Figure 5 for Figure 1 Enlarged view of region B.

[0042] Figure 6 This is a cross-sectional schematic diagram of the protective layer splicing method in Embodiment 1 of the present invention.

[0043] Figure 7 This is a top view of the support platform in Embodiment 1 of the present invention.

[0044] Figure 8 This is a side cross-sectional view of the support platform in Embodiment 1 of the present invention.

[0045] Figure 9 This is a top view of the flow-lifting platform in Embodiment 1 of the present invention.

[0046] Figure 10 This is a side cross-sectional view of the flow platform in Embodiment 1 of the present invention. Detailed Implementation

[0047] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. However, the present invention is not limited to the examples given.

[0048] Example 1

[0049] like Figures 1 to 10 As shown, the offshore wind turbine pile foundation scour protection device of this embodiment includes a support platform 02, a constraint ring 03, a flow-lifting platform 04, a protective layer 01, and an embedded structure 05. The protective layer 01 is made of quick-setting cement blanket, which serves as the protective material to prevent water flow from scouring the wind turbine pile foundation.

[0050] like Figure 2 As shown, the support platform 02, the constraint ring 03, and the flow platform 04 are arranged around the pile foundation 06 and are adjacent to the pile foundation 06. The flow platform 04 is located above the constraint ring 03, the constraint ring 03 is located above the support platform 02, and the bottom of the support platform 02 is in contact with the ground surface around the pile foundation 06. The embedded structure 05 is located around the pile foundation 06 and is separated from the support platform 02 by a distance.

[0051] The protective layer 01 is annular and surrounds the pile foundation 06. The outer edge of the protective layer 01 is embedded in the embedded structure 05 and fixedly connected to the embedded structure 05. From its outer edge to its inner edge, the protective layer 01 covers the flat ground surface 07 between the embedded structure 05 and the support platform 02, covers the outer side of the support platform 02 and is fixedly connected to the support platform 02 to form an inverted umbrella structure, is laid and fixed between the constraint ring 03 and the pile foundation 06, and covers the lower side of the flow platform 04. The inner edge of the protective layer 01 is fixedly connected to the outer edge of the flow platform 04 to form a flow structure.

[0052] As shown in Figure 5 , Figure 6 , the protective layer 01 is a continuous and uninterrupted whole composed of several cement blanket components 11. When splicing, the ends of two adjacent cement blanket components 11 are overlapped, and then the two are fixedly connected by U-shaped nails 12. For each cement blanket component 11, when one end is located below the end of one cement blanket component 11 at the overlapping splicing position, the other end is preferably placed above the end of another cement blanket component 11 at the overlapping splicing position. In order to ensure the integrity of the circular arc laying structure, the strip width of the cement blanket component 11 used in this embodiment is 1.5-2.0 m.

[0053] Specifically, as shown in Figure 3 , Figure 7 , Figure 8 , the support table 02 is wrapped around the circumference of the pile foundation 06 and can be made of steel. The support table 02 includes a cylindrical support body having a cylinder wall 21, the top of which is fixedly connected to the pile foundation 06. The inner side of the cylinder wall 21 is in contact with the pile foundation 06, and the outer side of the cylinder wall 21 is provided with a group of annular rings 22 with different inner diameters. The annular rings 22 are coaxially arranged and have different heights, and each annular ring 22 is fixedly connected to the outer side of the cylinder wall 21 through a corresponding spoke 26. The annular ring 22 with the smallest inner diameter has the highest height, and the annular ring 22 with the largest inner diameter has the lowest height. The remaining annular rings 22 are arranged between the two according to the size of the inner diameter, so that the inner diameter of each annular ring 22 gradually shrinks from bottom to top. The annular rings 22 are distributed into several layers arranged vertically, and there is a distance between adjacent layers. The top layer has a distance from the top of the cylinder wall 21. The outer side of each annular ring 22 has an upward inclined surface, and an annular support gasket 23 is arranged on the inclined surface. The protective layer 01 is fixedly connected to each support gasket 23 and each annular ring 22 through U-shaped nails, thereby forming an inverted umbrella structure. The inner diameter of the annular ring 22 with the largest inner diameter is 2 times the diameter of the pile foundation. In addition, the cylinder wall 21 of the support body is hollow, and the top of the support body is provided with a grouting hole 24 communicating with the inside of the cylinder wall 21. In the actual construction, the above support table 02 can be divided into four equal parts and prefabricated. After the prefabrication is completed, they are sequentially welded and spliced into a whole around the circumference of the pile foundation 06, and then the splicing position between the support table 02 and the outer wall of the pile foundation 06 is welded and fixed, and then the protective layer 01 is laid and fixed.

[0054] Specifically, as shown in Figure 3As shown, the constraint circular ring 03 is arranged in the circumferential direction of the pile foundation 06, the overhanging layer 01 beyond the top of the support platform 02 is arranged between the constraint circular ring 03 and the pile foundation 06, and the constraint circular ring 03 tightly fixes the overhanging layer 01 on the pile foundation 06, so that the overhanging layer 01 and the overhanging structure formed after the overhanging platform 04 is fixed can better adhere to the outer wall of the pile foundation 06. In the specific construction, the overhanging layer 01 is laid on the outer wall surface of the pile foundation 06, and then the constraint circular ring 03 is welded by two semicircular parts and the overhanging layer 01 is fixed.

[0055] As shown in Figure 3 , Figure 9 , Figure 10 , the overhanging platform 04 is arranged in the circumferential direction of the pile foundation 06 and is fixedly connected with the pile foundation 06. The overhanging platform 04 adopts a hub structure, including a hub-shaped component 41, a set of spoke-shaped components 42, and a rim-shaped component 43, wherein the hub-shaped component 41 is fixedly connected with the pile foundation 06, the hub-shaped component 41 is located on the inner side of the rim-shaped component 43 and coaxial with the rim-shaped component 43, and the hub-shaped component 41 is fixedly connected with the rim-shaped component 43 through the spoke-shaped components 42; the overhanging layer 01 is fixedly connected with the rim-shaped component 43 through the U-shaped nails 12; the difference between the caliber of the rim-shaped component 43 and the caliber of the hub-shaped component 41 is the caliber of the pile foundation 06. In the specific construction, the hub-shaped component 41 is welded and fixed on the outer wall surface of the pile foundation 06 at a distance of 0.3m from the top of the constraint circular ring 03, the spoke-shaped components 42 are welded and fixed with the hub-shaped component 41, then the rim-shaped component 43 is welded and fixed around the spoke-shaped components 42, and finally the overhanging layer 01 is laid and fixed, so that the overhanging structure is formed, and the overhanging platform 04 with the hub structure provides support for the overhanging structure. When the overhanging layer 01 is laid to form the overhanging structure, the overhanging layer 01 beyond the constraint circular ring 03 is reserved with sufficient length, then the overhanging layer 01 is laid upward to the corresponding position of the rim-shaped component 43 for connection and fixation, the overhanging layer 01 with the excess length is cut to complete the laying, and the overhanging structure starts from the constraint circular ring 03 and ends at the rim-shaped component 43, forming a complete overhanging curved surface and playing a role of preventing scouring.

[0056] As shown in Figure 2 , Figure 4 , the embedded structure 05 includes a circular trench 51 dug downward from the ground surface; the circular trench 51 takes the intersection of the pile foundation 06 axis and the ground surface as the center and takes 6 times the caliber of the pile foundation as the radius, and the depth is 1.5m; the outer edge of the overhanging layer 01 is laid into the circular trench 51 and is sealed by concrete grouting to embed and fix the overhanging layer 01, which is beneficial to increase the stability of the overall structure.

[0057] In view of the actual situation in the laying process of the bottom protection layer 01, in the specific implementation, the ground surface around the pile foundation 06 is first leveled, then the support table 02 and the flow diversion table 04 are built around the pile foundation 06, and the embedded structure 05 is arranged. When laying the protection layer 01, the protection layer 01 is first fixed by the embedded structure 05, and after the grouting is solidified, the protection layer 01 is sequentially laid on the leveled ground surface 07, the support table 02, the constraint ring 03, and the flow diversion table 04, thereby completing the construction of the entire device.

[0058] In the device of the embodiment, the embedded structure 05 plays a fixing role on the outer edge of the protection layer 01; the support table 02, which is contracted from bottom to top around the wind power pile foundation 06, is an important support structure of the protection layer 01, and the protection layer 01 can be laid into an inverted umbrella-shaped structure along the surface thereof, which is more conducive to the stability of the whole; the constraint ring 03 fixes the protection layer 01 exceeding the top of the support table 02 on the surface of the pile foundation 06, so that the starting point of the flow diversion structure better fits the surface of the pile foundation 06; the flow diversion table 04 in the form of a hub can form a flow diversion structure with a flow diversion angle for the protection layer 01 laid upward, which can better adapt to the change of wave pressure caused by complex environmental factors.

[0059] The device of the embodiment is applied to the protection of the wind power pile foundation 06, and the main protection material is a rapid-setting cement blanket; compared with the reinforced concrete reinforcement in the prior art, the cement blanket has a simple construction process, good flexibility and adaptability, and by laying the protection layer 01 around the pile foundation 06, the excellent mechanical properties and impermeability of the cement blanket are used to resist the erosion of seawater on the wind power pile.

[0060] Embodiment 2

[0061] The embodiment is a specific construction method of the offshore wind power pile foundation anti-erosion device of embodiment 1, and specifically includes the following steps:

[0062] First step, around the target wind power pile foundation 06, the ground surface in a predetermined range is leveled; according to the shape of the ground surface after leveling around the pile foundation 06, a support table 02 with a suitable height is built around the pile foundation 06; for the convenience of construction splicing, four arc-shaped parts can be prefabricated respectively, and then welded and fixed around the pile foundation 06 (the specific welding positions are the welding gaps 25 in Figure 7 ).

[0063] Second step, taking the intersection of the pile foundation 06 axis and the ground surface as the center and taking 6 times the pile foundation caliber as the radius, a circular trench 51 with a depth of 1.5 m is dug downward on the ground surface; the outer edge of the protection layer 01 is laid into the circular trench 51, and the protection layer 01 is fixed by sealing with concrete grouting; then, the protection layer 01 is laid from the ground surface to the bottom of the support table 02. During the laying process, the overlapping parts of the cement blanket components 11 are fixed by U-shaped nails 12.

[0064] The third step is to lay the protection layer 01 along the outer surface of the support platform 02 from bottom to top. After reaching the top of the support platform 02, a sufficient length of the protection layer 01 is left, and the protection layer 01 is fixed to the support platform 02 by U-shaped nails. The protection layer 01 laid here forms an inverted umbrella structure.

[0065] The fourth step is to fix the protection layer 01 exceeding the top of the support platform 02 to the outer wall of the pile foundation 06 by the constraint ring 03.

[0066] The fifth step is to reduce the adverse effects of waves on the stress of the wind power pile. The protection layer 01 is continued to be laid on the inverted umbrella structure to build a pick-up flow structure that can dissipate energy. The specific process is as follows: the hub-shaped member 41 of the pick-up flow platform 04 is welded and fixed to the outer wall of the pile foundation 06 at a distance of 0.3 m above the constraint ring 03, then the protection layer 01 exceeding the top of the constraint ring 03 is continued to be laid upward to the rim-shaped member 43 of the pick-up flow platform 04, the protection layer 01 is fixed and connected to the rim-shaped member 43 by U-shaped nails 12, then the excess part of the protection layer 01 exceeding the rim-shaped member 43 is cut off. The pick-up flow structure has a bottom starting from the constraint ring 03 and an end at the rim-shaped member 43, forming a pick-up flow surface with a pick-up flow angle.

[0067] The sixth step is to perform hydration treatment on the laid protection layer 01, and after it is fully hardened, it can be normally put into use.

[0068] In addition, in order to adapt to the needs in different environments, if it is necessary to reinforce the device later, the grouting hole 24 of the support body can be grouted into the inner wall 21 of the cylinder 48 hours after the protection layer 01 is hydrated and hardened, the self-weight of the support platform 02 is increased, the self-bearing pressure is reduced, and the compression resistance grade is improved, so as to meet the application needs.

[0069] In addition to the above-mentioned embodiments, the present application can also have other implementation manners. Any technical solution formed by equivalent substitution or equivalent transformation falls within the protection scope required by the present application.

Claims

1. A device for preventing scour of offshore wind turbine foundation piles, comprising a support platform and a protective layer, characterized in that, It also includes an embedded structure, a constraint ring, and a flow platform; the protective layer is made of quick-setting cement blanket; the support platform, constraint ring, and flow platform are arranged around the pile foundation and adjacent to the pile foundation; the bottom of the support platform is in contact with the ground surface around the pile foundation, the constraint ring is located above the support platform, and the flow platform is located above the constraint ring; the embedded structure is located around the pile foundation and is spaced apart from the support platform; the protective layer is annular and arranged around the pile foundation, the outer edge of the protective layer is embedded in the embedded structure and fixedly connected to the embedded structure, the protective layer from the outer edge to the inner edge successively covers the flat ground surface between the embedded structure and the support platform, covers the outside of the support platform and is fixedly connected to the support platform to form an inverted umbrella structure, is laid and fixed between the constraint ring and the pile foundation, and covers the lower side of the flow platform; the inner edge of the protective layer is fixedly connected to the outer edge of the flow platform to form a flow structure; The support platform is installed around the circumference of the pile foundation; the support platform includes a cylindrical support body with a cylindrical wall, which is fixedly connected to the pile foundation; a set of rings with different inner diameters are provided on the outer side of the cylindrical wall, the rings are coaxially arranged and at different heights, and each ring is fixedly connected to the outer side of the cylindrical wall via corresponding spokes, wherein the ring with the smallest inner diameter is at the highest height, the ring with the largest inner diameter is at the lowest height, and the remaining rings are arranged in order of their inner diameter between the two, so that the inner diameter of each ring gradually decreases from bottom to top; the protective layer is fixedly connected to each ring and forms an inverted umbrella-shaped structure; The constraint ring is installed around the circumference of the pile foundation, and the constraint ring clamps and fixes the protective layer extending beyond the top of the support platform to the pile foundation; the flow-lifting platform is installed around the circumference of the pile foundation; the flow-lifting platform includes a hub-shaped component, a set of spoke-shaped components, and a rim-shaped component; the hub-shaped component is fixedly connected to the pile foundation, the hub-shaped component is located inside the rim-shaped component and the two are coaxial, and the hub-shaped component is fixedly connected to the rim-shaped component via the spoke-shaped component; the inner edge of the protective layer is fixedly connected to the rim-shaped component, forming a flow-lifting structure.

2. The anti-scour device for offshore wind turbine pile foundations according to claim 1, characterized in that, Each ring has an upward-facing bevel on its outer side, and each bevel is provided with an annular support pad. The protective layer is fixedly connected to each support pad and each ring in sequence by U-shaped nails.

3. The anti-scour device for offshore wind turbine foundation piles according to claim 1, characterized in that, The rings are arranged vertically in several layers, with a distance between each adjacent layer, and a distance between the top layer and the top of the cylinder wall.

4. The anti-scouring device for offshore wind turbine pile foundations according to claim 1, characterized in that, The embedded structure includes a circular trench dug downwards from the ground surface; the center of the circular trench is the intersection of the pile foundation axis and the ground surface; the outer edge of the protective layer is buried in the circular trench and fixedly connected to the circular trench by grouting and sealing.

5. The anti-scour device for offshore wind turbine pile foundations according to claim 4, characterized in that, The protective layer is a continuous and uninterrupted whole, and is composed of several cement blanket components spliced ​​together.

6. The anti-scour device for offshore wind turbine pile foundations according to claim 5, characterized in that, In the support platform, the inner diameter of the largest inner ring is twice the diameter of the pile foundation; the support platform is made of steel reinforcement; the inner side of the cylindrical wall of the support body is in contact with the pile foundation; the cylindrical wall of the support body is hollow, and the top of the support body is provided with a grouting hole communicating with the inside of the cylindrical wall; in the flow platform, the difference between the diameter of the rim-shaped component and the diameter of the hub-shaped component is the diameter of the pile foundation; in the embedded structure, the radius of the circular groove is 6 times the diameter of the pile foundation, and the depth of the circular groove is 1.5m; the cement blanket components are spliced ​​using U-shaped nails, and the width of the cement blanket components is 1.5~2.0m.

7. A construction method for an anti-scour device for offshore wind turbine pile foundations as described in any one of claims 1 to 6, comprising the following steps: The first step is to level the ground surface within the predetermined range around the target wind turbine foundation; and to build a support platform of predetermined height around the foundation. The second step is to dig a circular trench of a predetermined depth at the predetermined location, with the intersection of the pile foundation axis and the ground surface as the center; lay the outer edge of the protective layer into the circular trench and seal it with concrete grout to fix the protective layer in place; then, lay the protective layer along the ground surface towards the bottom of the support platform. The third step is to lay the protective layer from bottom to top along the outer surface of the support platform. After reaching the top of the support platform, leave a sufficient length of the protective layer and fix it to each ring of the support platform. The protective layer laid here forms an inverted umbrella-shaped structure. Step 4: Use restraining rings to fix the protective layer extending beyond the top of the support platform to the pile foundation; Step 5: At a preset height above the constraint ring, weld and fix the hub-shaped component of the jet platform to the outer wall of the pile foundation. Then, continue to lay the protective layer that extends beyond the top of the constraint ring to the rim-shaped component of the jet platform. Fix the protective layer to the rim-shaped component. Then, cut off the excess part of the protective layer that extends beyond the rim-shaped component. The protective layer laid here forms the jet structure. Step 6: Hydrate the laid protective layer until it has fully hardened, at which point the construction is complete.

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