Offshore wind power pile foundation scouring protection device for human-shaped submerged dike under reciprocating flow

Abstract

The invention belongs to the technical field of ocean engineering, and particularly relates to an offshore wind power pile foundation scouring protection device for a human-shaped submerged dike under reciprocating flow. The device comprises an embankment foundation, the dyke core is arranged on the dyke foundation, and the section is trapezoidal; the sea-facing slope is laid on the side, close to the ocean, of the dike core and comprises a deposition area, a sediment collection platform and an erosion prevention area from top to bottom. The back sea slope is laid on the side, away from the ocean, of the dike core, and the gradient ranges from 1: 1.5 to 1: 3; and the levee top is arranged at the top of the levee core, the section is triangular, the width is gradually increased from top to bottom, and the bottom abuts against the top of the sedimentary area, the top of the levee core and the top of the back-sea slope. Wherein the deposition area is located at the top of the sea-facing slope, and the gradient is 1: 1.5-1: 3; the anti-erosion area is located at the bottom of the sea facing slope, the bottom of the anti-erosion area abuts against the embankment foundation, and the gradient is 1: 1-1: 1.5. The sediment collecting platform is located between the deposition area and the anti-erosion area, the width of the sediment collecting platform is 1.5-3 times that of the upper portion of the dike core, and the sediment collecting platform is connected with the deposition area and the anti-erosion area.

Description

Technical Field

[0001] The present invention belongs to the field of marine engineering technology, and in particular relates to a scour protection device for offshore wind power pile foundations used for reciprocating flow. Background Art

[0002] With the rapid development of offshore wind power, the safety and stability of wind turbine pile foundations have become critical issues. Offshore wind turbine pile foundations are located underwater and are susceptible to erosion by currents and waves. This can lead to the loss of sediment around the piles, forming scour pits that can affect their stability and even damage them. Summary of the Invention

[0003] The present invention overcomes the deficiencies of the prior art and provides a scour protection device for offshore wind power pile foundations under a reciprocating flow and a human-shaped submerged dike.

[0004] To achieve the above-mentioned purpose, the present invention adopts the following technical solution: a scour protection device for offshore wind power pile foundations under reciprocating flow, comprising:

[0005] embankment foundation;

[0006] The core of the embankment is set on the embankment base and has a trapezoidal cross section;

[0007] The seaward slope is laid on the side of the embankment core close to the ocean and includes, from top to bottom, a sedimentation area, a sediment collection platform, and an anti-erosion area. The sedimentation area is located at the top of the seaward slope, with a slope of 1:1.5 to 1:3. The anti-erosion area is located at the bottom of the seaward slope, abutting the embankment base, with a slope of 1:1 to 1:1.5. The sediment collection platform is located between the sedimentation area and the anti-erosion area, connecting them.

[0008] The seaward slope is laid on the side of the embankment away from the ocean, with a slope of 1:1.5 to 1:3;

[0009] The top of the dike is set at the top of the dike core, with a triangular cross-section. The width gradually increases from the top to the bottom, and the bottom is respectively connected to the top of the sedimentation area, the top of the dike core and the top of the back sea slope.

[0010] In a preferred embodiment of the present invention, the width of the sediment collection platform is 1.5 to 3 times the width of the embankment core.

[0011] In a preferred embodiment of the present invention, diversion grooves are arranged at intervals on the surface of the sedimentation area; each diversion groove is arranged at intervals along the slope direction of the sedimentation area, and includes a main groove and branch grooves extending from the center of the main groove to both sides.

[0012] In a preferred embodiment of the present invention, a grid guide plate is provided at the connection between the sedimentation area and the sediment collection platform; the grid guide plate is composed of mutually intersecting strip structures, and cells with an aperture of 20 to 40 cm are formed between the strip structures.

[0013] In a preferred embodiment of the present invention, a retention layer is laid on the surface of the sediment collection platform; the retention layer includes one or more of a basalt gravel layer and a high-density polyethylene grid mat; wherein the particle size of the basalt gravel layer is 5 to 20 cm and the thickness is 10 to 30 cm; the pore size of the high-density polyethylene grid mat is 10 to 20 cm and the thickness is 5 to 15 cm.

[0014] In a preferred embodiment of the present invention, recessed areas are provided at intervals on the surface of the sediment collection platform; the recessed areas are shallow dish-shaped, with a depth of 0 to 10 cm, a diameter of 20 to 30 cm, and a spacing of 50 to 80 cm.

[0015] In a preferred embodiment of the present invention, bionic grass is laid on the surface of the slope facing away from the sea.

[0016] In a preferred embodiment of the present invention, a stone cushion layer is provided between the embankment core and the seaward slope, and between the embankment core and the seaward slope.

[0017] In a preferred embodiment of the present invention, the embankment core also includes a set of bottom protection; the bottom protection has a parallelogram cross-section and a thickness of 0.6 to 1.2 meters, which are respectively arranged on the embankment base on both sides of the embankment core, and abut against the outer edges of the seaward slope and the seaward slope; among them, the bottom protection abutting the seaward slope is the seaside bottom protection, with a width of 6 to 10 meters; the bottom protection abutting the seaward slope is the shoreside bottom protection, with a width of 4 to 6 meters.

[0018] In a preferred embodiment of the present invention, the embankment core further comprises a group of prisms; the prisms are prismatic structures with parallelogram cross-sections, with long sides parallel to the embankment core direction and fixed on the upper surface of the bottom protection (22), respectively abutting the seaward slope and the seaward slope; the top surface width of the prisms is 2 to 4 m, and the thickness is 2 to 4 m.

[0019] The present invention solves the defects existing in the background technology and has the following beneficial effects:

[0020] The present invention effectively improves the sediment retention rate and significantly reduces the scour pit range and maximum scour depth by optimizing the submerged dike structure, thereby better protecting the offshore wind power pile foundation from the impact of scour and improving the stability and safety of the pile foundation.

[0021] The present invention provides a scour protection device for offshore wind turbine pile foundations under reciprocating flow, comprising a dyke foundation, a trapezoidal dyke core arranged on the dyke foundation, a seaward slope arranged on the sea side of the dyke core, a seaward slope arranged on the shore side of the dyke core, and a dyke crest arranged on the top of the dyke core. The seaward slope is divided from top to bottom into a sedimentation area, a sediment collection platform, and an anti-erosion area. The sedimentation area promotes sedimentation by slowing down the water flow; the sediment collection platform, which is 1.5 to 3 times the width of the dyke core, provides space for sediment accumulation; and the anti-erosion area protects the bottom of the submerged dyke from direct scouring. Compared with simple riprap or slope protection, the present invention can more effectively intercept and retain sediments, thereby more effectively preventing scouring, reducing the amount of sediment reaching the wind turbine foundation, and reducing the depth and range of scouring.

[0022] The present invention provides a scour protection device for offshore wind turbine pile foundations under reciprocating flow, comprising a main trough and branch troughs extending from the center of the main trough to both sides, spaced apart on the surface of the sedimentation area. A grid guide plate is provided at the junction of the sedimentation area and the sedimentation area collection platform. A retention layer and a recessed area are laid on the surface of the sediment collection platform, and bionic grass is laid on the surface of the back-to-sea slope. The diversion trough guides the water flow, changes the water flow path and flow rate, and reduces the scouring force on the sediment. The grid guide plate intercepts some larger sediment particles, reducing the amount of sediment reaching downstream. The retention layer increases the surface roughness and porosity, increasing the friction of the sediment. The recessed area creates an additional sediment accumulation area. The bionic grass increases the surface roughness of the back-to-sea slope and reduces the flow rate of the back-to-sea slope. Compared with traditional scour prevention measures, the present invention can more effectively slow down the water flow speed, intercept and retain sediment, significantly improve the sediment retention rate, and effectively reduce the scope of the scour pit and the maximum scour depth.

[0023] The present invention forms a system for actively intercepting and retaining sediments by setting up a sedimentation area, a sediment collection platform and an anti-erosion area. On this basis, a diversion trough, a grid guide plate, a retention layer, a recessed area and bionic grass are arranged to increase the roughness and porosity of the sediment collection platform, improve the friction of the sediment, increase the sediment accumulation area, increase the roughness of the back-sea slope surface and reduce the flow velocity of the back-sea slope, further improving the sediment retention rate, significantly reducing the amount of sediment reaching the wind turbine foundation, and reducing the scouring depth and range. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments described in the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive efforts.

[0025] Figure 1 This is a schematic structural diagram of a scour protection device for offshore wind power pile foundations in a reciprocating flow, provided by the present invention;

[0026] Figure 2 This is a schematic diagram of the structure of the seaward slope;

[0027] In the figure: 1. Dike foundation; 2. Dike core; 3. Seaward slope; 4. Seaward slope; 5. Dike top; 21. Cushion layer; 22. Bottom protection; 23. Prism; 31. Sedimentation area; 32. Sediment collection platform; 33. Anti-erosion area; 34. Diversion channel; 35. Grid guide plate; 36. Retention layer; 37. Depression area; 44. Bionic grass; 341. Main trough; 342. Branch trough. DETAILED DESCRIPTION

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0029] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0030] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the scope of protection of the present application. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0031] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0032] Exemplary devices:

[0033] like Figure 1 、 Figure 2 As shown, a scour protection device for offshore wind power pile foundations under reciprocating flow, comprising:

[0034] Embankment 1.

[0035] The embankment core 2 is arranged on the embankment base 1 and has a trapezoidal cross section.

[0036] The seaward slope 3, located on the ocean side of the embankment core 2, comprises, from top to bottom, a sedimentation area 31, a sediment collection platform 32, and an anti-erosion area 33. Sedimentation area 31 is located at the top of the seaward slope 3, with a slope of 1:1.5 to 1:3. The anti-erosion area 33 is located at the bottom of the seaward slope 3, abutting the embankment foundation 1, with a slope of 1:1 to 1:1.5. Sediment collection platform 32 is located between sedimentation area 31 and anti-erosion area 33, connecting them.

[0037] The seaward slope 4 is laid on the side of the embankment core 2 away from the ocean, and has a slope of 1:1.5 to 1:3.

[0038] The dike top 5 is arranged at the top of the dike core 2, has a triangular cross section, and its width gradually increases from the top to the bottom. Its bottom is respectively in contact with the top of the sedimentation area 31, the top of the dike core 2 and the top of the back sea slope 4.

[0039] In a specific embodiment, the embankment base 1 is cast by concrete with a compressive strength greater than or equal to C40 and an average thickness of 2m. The embankment core 2 is formed by layered laying and compacting of natural blocks with a maximum block size of 1.2m, and a cross-section approximately in the shape of an isosceles trapezoid with an upper width of 3m, a lower width of 12m, and a height of 3m. The seaward slope 3 is cast by high-strength concrete with a compressive strength greater than or equal to C50 and an average thickness of 1.2m. The seaward slope 4 is cast by high-strength concrete with a compressive strength greater than or equal to C40 and an average thickness of 1.0m. The embankment top 5 is formed by layered laying and compacting of natural blocks with a maximum block size of 1.5m and grouting with cement mortar, and a cross-section approximately in the shape of a triangle.

[0040] like Figure 1As shown, a stone cushion layer 21 is provided between the embankment core 2 and the seaward slope 3 , and between the embankment core 2 and the seaward slope 4 .

[0041] In a specific embodiment, the stone cushion layer 21 is formed by layering and compacting natural stones with a maximum stone particle size of 0.6 m and grouting with cement mortar, with an average thickness of 1 m.

[0042] It should be noted that the width of the sediment collection platform 32 is 1.5 to 3 times the width of the embankment core 2.

[0043] In a specific embodiment, the cross-section of the embankment core 2 is 3m wide at the top, 12m wide at the bottom, and 3m high. The average thickness of the sedimentation area 31 and the anti-erosion area 33 is 1.2m, and the width of the sediment collection platform 32 is twice the width of the upper part of the embankment core 2.

[0044] like Figure 2 As shown, diversion grooves 34 are arranged at intervals on the surface of the deposition area 31. Each diversion groove 34 is arranged at intervals along the slope direction of the deposition area 31, including a main groove 341 and branch grooves 342 extending from the center of the main groove 341 to both sides. The cross-sections of the main groove 341 and the branch groove 342 are both arc-shaped.

[0045] like Figure 2 As shown, a gridded deflector 35 is installed at the junction of the sedimentation area 31 and the sediment collection platform 32. The gridded deflector 35 is composed of intersecting strips, forming cells with a pore size of 20 to 40 cm between the strips. The strips can be made of an alloy material such as steel plate or section steel that has sufficient strength, corrosion resistance, and erosion resistance.

[0046] like Figure 2 As shown, a retention layer 36 is laid on the surface of the sediment collection platform 32. Retention layer 36 comprises one or more of a basalt crushed stone layer and a high-density polyethylene mesh mat. The basalt crushed stone layer has a particle size of 5 to 20 cm and a thickness of 10 to 30 cm. The high-density polyethylene mesh mat has a pore size of 10 to 20 cm and a thickness of 5 to 15 cm.

[0047] In a specific embodiment, a 20 cm thick basalt gravel layer is laid on the surface of the sediment collection platform 32 , and a 10 cm thick high-density polyethylene mesh mat with a 15 cm pore size is laid on top of the basalt gravel layer.

[0048] like Figure 2 As shown, recessed areas 37 are provided at intervals on the surface of the sediment collection platform 32. The recessed areas 37 are shallow dish-shaped, with a depth of 0 to 10 cm, a diameter of 20 to 30 cm, and a spacing of 50 to 80 cm.

[0049] like Figure 1 As shown, bionic grass 44 is laid on the surface of the slope 4 facing away from the sea.

[0050] In a specific embodiment, the bionic grass 44 is made of high-strength, corrosion-resistant polyester fiber, with a grass height of 10 to 20 cm, a plant spacing of 5 to 10 cm, and a coverage rate greater than 80%. Through its flexible structure and high-density vegetation coverage, wave energy and water flow speed are reduced.

[0051] like Figure 1 As shown, the embankment core 2 also includes a set of bottom protections 22. These are parallelogram-shaped in cross-section and 0.6 to 1.2 meters thick. They are installed on the embankment base 1 on either side of the embankment core 2, abutting the outer edges of the seaward slope 3 and the seaward slope 4. The seaward bottom protection 221 abuts the seaward slope 3, with a width of 6 to 10 meters; the shoreward bottom protection 222 abuts the seaward slope 4, with a width of 4 to 6 meters.

[0052] like Figure 1 As shown, the dike core 2 also includes a set of prisms 23. These prisms 23 are prismatic structures with a parallelogram cross-section. Their long sides are parallel to the dike core and fixed to the upper surface of the retaining wall 22, abutting the seaward slope 3 and the seaward slope 4. The top surface width of the prisms 23 is 2 to 4 meters, and the thickness is 2 to 4 meters.

[0053] In one specific embodiment, the bottom protection 22 is cast from high-strength concrete and securely connected to the embankment foundation 1 and the seaward and coastal slopes 3 and 4 by grouting. It has a compressive strength of C40 or greater and an average thickness of 1.0 m. The seaward side protection 221 is 8 m wide, while the shoreside side is 5 m wide. The prisms 23 are constructed from natural stone blocks with a maximum particle size of 2.8 m, laid and compacted in layers. They have a parallelogram cross-section, a top width of 3 m, and a thickness of 4 m.

[0054] Example 1:

[0055] A scour protection device for offshore wind turbine pile foundations under reciprocating currents comprises a dike base 1 and a dike core 2 disposed on the dike base 1. The dike core 2 has an isosceles trapezoidal cross-section, with a top width of 3m, a bottom width of 12m, and a height of 3m. The slopes on the seaward side and the backside are 1:1.5, respectively.

[0056] Example 2:

[0057] A device for protecting offshore wind power pile foundations from scour under reciprocating flow and a submerged dike, comprising:

[0058] Embankment 1.

[0059] The embankment core 2 is set on the embankment base 1, with an isosceles trapezoidal cross-section, 3m wide at the top, 12m wide at the bottom, and 3m high. The slope on the sea side is 1:1.5, and the slope on the sea side is 1:1.5.

[0060] The seaward slope 3 is laid on the side of the embankment core 2 close to the ocean, with a slope of 1:1.5 and a thickness of 1.2m.

[0061] The seaward slope 4 is laid on the side of the embankment core 2 away from the ocean, with a slope of 1:1.5 and a thickness of 1.0 m.

[0062] The dike top 5 is set at the top of the dike core 2, with a triangular cross-section and a width gradually increasing from the top to the bottom. The slope on the side close to the seaward slope 3 is 1:1.5, and the slope on the side close to the away from the sea slope 4 is 1:3. The bottom is respectively in contact with the top of the seaward slope 3, the top of the dike core 2 and the top of the away from the sea slope 4.

[0063] Example 3:

[0064] A device for protecting offshore wind power pile foundations from scour under a reciprocating flow, characterized by comprising:

[0065] Embankment 1.

[0066] The embankment core 2 is set on the embankment base 1, with an isosceles trapezoidal cross-section, a top width of 3m, a slope of 1:1.5 on the seaward side, and a slope of 1:1.5 on the leeward side.

[0067] The seaward slope 3, located on the ocean side of the embankment core 2, comprises, from top to bottom, a sedimentation area 31, a sediment collection platform 32, and an anti-erosion area 33. Sedimentation area 31, located at the top of the seaward slope 3, has a slope of 1:1.5 and a thickness of 1.2 m. The anti-erosion area 33, located at the bottom of the seaward slope 3, abuts the embankment foundation 1 and has a slope of 1:1.5. Sediment collection platform 32, with a horizontal width of 2.0 m, is located between sedimentation area 31 and anti-erosion area 33, connecting them.

[0068] The seaward slope 4 is laid on the side of the embankment core 2 away from the ocean, with a slope of 1:1.5 and a thickness of 1.0 m.

[0069] The dike top 5 is set at the top of the dike core 2, with a triangular cross-section and a width gradually increasing from the top to the bottom. The slope on the side close to the seaward slope 3 is 1:1.5, and the slope on the side close to the away from the sea slope 4 is 1:3. The bottom is respectively in contact with the top of the sedimentation area 31, the top of the dike core 2 and the top of the away from the sea slope 4.

[0070] Example 4:

[0071] A device for protecting offshore wind power pile foundations from scour under a reciprocating flow, characterized by comprising:

[0072] Embankment 1.

[0073] The embankment core 2 is set on the embankment base 1, with an isosceles trapezoidal cross-section, a top width of 3m, a slope of 1:1.5 on the seaward side, and a slope of 1:1.5 on the leeward side.

[0074] The seaward slope 3, located on the ocean side of the embankment core 2, comprises, from top to bottom, a sedimentation area 31, a sediment collection platform 32, and an anti-erosion area 33. Sedimentation area 31, located at the top of the seaward slope 3, has a slope of 1:1.5 and a thickness of 1.2 m. The anti-erosion area 33, located at the bottom of the seaward slope 3, abuts the embankment foundation 1 and has a slope of 1:1.5. Sediment collection platform 32, with a horizontal width of 6.0 m, is located between sedimentation area 31 and anti-erosion area 33, connecting them.

[0075] The seaward slope 4 is laid on the side of the embankment core 2 away from the ocean, with a slope of 1:1.5 and a thickness of 1.0 m.

[0076] The dike top 5 is set at the top of the dike core 2, with a triangular cross-section and a width gradually increasing from the top to the bottom. The slope on the side close to the seaward slope 3 is 1:1.5, and the slope on the side close to the away from the sea slope 4 is 1:3. The bottom is respectively in contact with the top of the sedimentation area 31, the top of the dike core 2 and the top of the away from the sea slope 4.

[0077] Example 5:

[0078] A device for protecting offshore wind power pile foundations from scour under a reciprocating flow, characterized by comprising:

[0079] Embankment 1.

[0080] The embankment core 2 is set on the embankment base 1, with an isosceles trapezoidal cross-section, a top width of 3m, a slope of 1:1.5 on the seaward side, and a slope of 1:1.5 on the leeward side.

[0081] The seaward slope 3, located on the ocean side of the embankment core 2, comprises, from top to bottom, a sedimentation area 31, a sediment collection platform 32, and an anti-erosion area 33. Sedimentation area 31, located at the top of the seaward slope 3, has a slope of 1:1.5 and a thickness of 1.2 m. The anti-erosion area 33, located at the bottom of the seaward slope 3, abuts the embankment foundation 1 and has a slope of 1:1.5. Sediment collection platform 32, with a horizontal width of 10.0 m, is located between sedimentation area 31 and anti-erosion area 33, connecting them.

[0082] The seaward slope 4 is laid on the side of the embankment core 2 away from the ocean, with a slope of 1:1.5 and a thickness of 1.0 m.

[0083] The dike top 5 is set at the top of the dike core 2, with a triangular cross-section and a width gradually increasing from the top to the bottom. The slope on the side close to the seaward slope 3 is 1:1.5, and the slope on the side close to the away from the sea slope 4 is 1:3. The bottom is respectively in contact with the top of the sedimentation area 31, the top of the dike core 2 and the top of the away from the sea slope 4.

[0084] Example 6:

[0085] A device for protecting offshore wind power pile foundations from scour under a reciprocating flow, characterized by comprising:

[0086] Embankment 1.

[0087] The embankment core 2 is set on the embankment base 1, with an isosceles trapezoidal cross-section, a top width of 3m, a slope of 1:1.5 on the seaward side, and a slope of 1:1.5 on the leeward side.

[0088] The seaward slope 3, located on the ocean side of the embankment core 2, comprises, from top to bottom, a sedimentation area 31, a sediment collection platform 32, and an anti-erosion area 33. Sedimentation area 31, located at the top of the seaward slope 3, has a slope of 1:1.5 and a thickness of 1.2 m. The anti-erosion area 33, located at the bottom of the seaward slope 3, abuts the embankment foundation 1 and has a slope of 1:1.5. Sediment collection platform 32, with a horizontal width of 6.0 m, is located between sedimentation area 31 and anti-erosion area 33, connecting them.

[0089] The seaward slope 4 is laid on the side of the embankment core 2 away from the ocean, with a slope of 1:1.5 and a thickness of 1.0 m.

[0090] The dike top 5 is set at the top of the dike core 2, with a triangular cross-section and a width gradually increasing from the top to the bottom. The slope on the side close to the seaward slope 3 is 1:1.5, and the slope on the side close to the away from the sea slope 4 is 1:3. The bottom is respectively in contact with the top of the sedimentation area 31, the top of the dike core 2 and the top of the away from the sea slope 4.

[0091] Diversion grooves 34 are arranged at intervals on the surface of the deposition area 31. Each diversion groove 34 is arranged at intervals along the slope direction of the deposition area 31, and includes a main groove 341 and branch grooves 342 extending from the center of the main groove 341 to both sides.

[0092] Example 7:

[0093] A device for protecting offshore wind power pile foundations from scour under a reciprocating flow, characterized by comprising:

[0094] Embankment 1.

[0095] The embankment core 2 is set on the embankment base 1, with an isosceles trapezoidal cross-section, a top width of 3m, a slope of 1:1.5 on the seaward side, and a slope of 1:1.5 on the leeward side.

[0096] The seaward slope 3, located on the ocean side of the embankment core 2, comprises, from top to bottom, a sedimentation area 31, a sediment collection platform 32, and an anti-erosion area 33. Sedimentation area 31, located at the top of the seaward slope 3, has a slope of 1:1.5 and a thickness of 1.2 m. The anti-erosion area 33, located at the bottom of the seaward slope 3, abuts the embankment foundation 1 and has a slope of 1:1.5. Sediment collection platform 32, with a horizontal width of 6.0 m, is located between sedimentation area 31 and anti-erosion area 33, connecting them.

[0097] The seaward slope 4 is laid on the side of the embankment core 2 away from the ocean, with a slope of 1:1.5 and a thickness of 1.0 m.

[0098] The dike top 5 is set at the top of the dike core 2, with a triangular cross-section and a width gradually increasing from the top to the bottom. The slope on the side close to the seaward slope 3 is 1:1.5, and the slope on the side close to the away from the sea slope 4 is 1:3. The bottom is respectively in contact with the top of the sedimentation area 31, the top of the dike core 2 and the top of the away from the sea slope 4.

[0099] Diversion grooves 34 are arranged at intervals on the surface of the deposition area 31. Each diversion groove 34 is arranged at intervals along the slope direction of the deposition area 31, and includes a main groove 341 and branch grooves 342 extending from the center of the main groove 341 to both sides.

[0100] A grid guide plate 35 is provided at the connection between the sedimentation area 31 and the sediment collection platform 32. The grid guide plate 35 is made of mutually intersecting corrosion-resistant steel plates, and cells with a pore size of 30 cm are formed between the strip structures.

[0101] Example 8:

[0102] A device for protecting offshore wind power pile foundations from scour under a reciprocating flow, characterized by comprising:

[0103] Embankment 1.

[0104] The embankment core 2 is set on the embankment base 1, with an isosceles trapezoidal cross-section, a top width of 3m, a slope of 1:1.5 on the seaward side, and a slope of 1:1.5 on the leeward side.

[0105] The seaward slope 3, located on the ocean side of the embankment core 2, comprises, from top to bottom, a sedimentation area 31, a sediment collection platform 32, and an anti-erosion area 33. Sedimentation area 31, located at the top of the seaward slope 3, has a slope of 1:1.5 and a thickness of 1.2 m. The anti-erosion area 33, located at the bottom of the seaward slope 3, abuts the embankment foundation 1 and has a slope of 1:1.5. Sediment collection platform 32, with a horizontal width of 6.0 m, is located between sedimentation area 31 and anti-erosion area 33, connecting them.

[0106] The seaward slope 4 is laid on the side of the embankment core 2 away from the ocean, with a slope of 1:1.5 and a thickness of 1.0 m.

[0107] The dike top 5 is set at the top of the dike core 2, with a triangular cross-section and a width gradually increasing from the top to the bottom. The slope on the side close to the seaward slope 3 is 1:1.5, and the slope on the side close to the away from the sea slope 4 is 1:3. The bottom is respectively in contact with the top of the sedimentation area 31, the top of the dike core 2 and the top of the away from the sea slope 4.

[0108] Diversion grooves 34 are arranged at intervals on the surface of the deposition area 31. Each diversion groove 34 is arranged at intervals along the slope direction of the deposition area 31, and includes a main groove 341 and branch grooves 342 extending from the center of the main groove 341 to both sides.

[0109] A grid guide plate 35 is provided at the connection between the sedimentation area 31 and the sediment collection platform 32. The grid guide plate 35 is made of mutually intersecting corrosion-resistant steel plates, and cells with a pore size of 30 cm are formed between the strip structures.

[0110] A retention layer 36 is laid on the surface of the sediment collection platform 32. The retention layer 36 includes a 20 cm thick basalt gravel layer laid on the surface of the sediment collection platform 32 and a 10 cm thick, 15 cm pore diameter high-density polyethylene mesh mat laid on top of the basalt gravel layer.

[0111] Depressed areas 37 are provided at intervals on the surface of the sediment collection platform 32. The depressed areas 37 are shallow dish-shaped, with a maximum depth of 10 cm, a radius of 25 cm, and a spacing of 80 cm.

[0112] Bionic grass 44 is laid on the surface of the back-sea slope 4. The bionic grass 44 is made of high-strength, corrosion-resistant polyester fiber, with a grass height of 15 cm, a plant spacing of 20 cm, and a coverage rate of 85%.

[0113] Example 9:

[0114] A device for protecting offshore wind power pile foundations from scour under a reciprocating flow, characterized by comprising:

[0115] Embankment 1.

[0116] The embankment core 2 is set on the embankment base 1, with an isosceles trapezoidal cross-section, a top width of 3m, a slope of 1:1.5 on the seaward side, and a slope of 1:1.5 on the leeward side.

[0117] The seaward slope 3, located on the ocean side of the embankment core 2, comprises, from top to bottom, a sedimentation area 31, a sediment collection platform 32, and an anti-erosion area 33. Sedimentation area 31, located at the top of the seaward slope 3, has a slope of 1:1.5 and a thickness of 1.2 m. The anti-erosion area 33, located at the bottom of the seaward slope 3, abuts the embankment foundation 1 and has a slope of 1:1.5. Sediment collection platform 32, with a horizontal width of 6.0 m, is located between sedimentation area 31 and anti-erosion area 33, connecting them.

[0118] The seaward slope 4 is laid on the side of the embankment core 2 away from the ocean, with a slope of 1:1.5 and a thickness of 1.0 m.

[0119] The dike top 5 is set at the top of the dike core 2, with a triangular cross-section and a width gradually increasing from the top to the bottom. The slope on the side close to the seaward slope 3 is 1:1.5, and the slope on the side close to the away from the sea slope 4 is 1:3. The bottom is respectively in contact with the top of the sedimentation area 31, the top of the dike core 2 and the top of the away from the sea slope 4.

[0120] A stone cushion layer 21 is provided between the embankment core 2 and the seaward slope 3, and between the embankment core 2 and the seaward slope 4. The stone cushion layer 21 is made of natural stones with a maximum stone particle size of 0.6m, which are laid and compacted in layers and grouted with cement mortar, with an average thickness of 0.6m.

[0121] A set of bottom protections 22 are installed on both sides of the embankment core 2. These bottom protections 22 have a parallelogram cross-section and an average thickness of 0.6m. They are installed on the embankment foundation 1 on either side of the embankment core 2, abutting the outer edges of the erosion protection zone 33 and the seaward slope 4. The seaward side bottom protection abutting the erosion protection zone 33 is 6m wide, while the shoreside side bottom protection abutting the seaward slope 4 is 4m wide.

[0122] A set of prisms 23 are also provided on both sides of the embankment core 2. The prisms 23 are prismatic structures with a parallelogram cross-section. They are fixed to the upper surface of the bottom protection 22 parallel to the embankment core, abutting the anti-erosion area 33 and the seaward slope 4. The top surface width is 0.6m and the height is 0.8m.

[0123] Diversion grooves 34 are arranged at intervals on the surface of the deposition area 31. Each diversion groove 34 is arranged at intervals along the slope direction of the deposition area 31, including a main groove 341 and branch grooves 342 extending from the center of the main groove 341 to both sides. The cross-section of the main groove 341 and the branch groove 342 is semicircular.

[0124] A grid guide plate 35 is provided at the connection between the sedimentation area 31 and the sediment collection platform 32. The grid guide plate 35 is made of mutually intersecting corrosion-resistant steel plates, and cells with a pore size of 30 cm are formed between the strip structures.

[0125] A retention layer 36 is laid on the surface of the sediment collection platform 32. The retention layer 36 includes a 20 cm thick basalt gravel layer laid on the surface of the sediment collection platform 32 and a 10 cm thick, 15 cm pore diameter high-density polyethylene mesh mat laid on top of the basalt gravel layer.

[0126] Depressed areas 37 are provided at intervals on the surface of the sediment collection platform 32. The depressed areas 37 are shallow dish-shaped, with a maximum depth of 10 cm, a radius of 25 cm, and a spacing of 80 cm.

[0127] Bionic grass 44 is laid on the surface of the back-sea slope 4. The bionic grass 44 is made of high-strength, corrosion-resistant polyester fiber, with a grass height of 15 cm, a plant spacing of 20 cm, and a coverage rate of 85%.

[0128] Sink experiment:

[0129] Experiments were conducted in a wave tank with reference to JTJ / T234-2001 “Wave Model Test Procedure” and JTS154-2018 “Breakwater and Bank Protection Design Code”. The submerged breakwater and pile foundation models were set up with a geometric scale of 1:25, and the reciprocating flow period was simulated to be 2.0s and the wave height to be 0.08m.

[0130] The wave flume used in this experiment is 40m long, 0.8m wide, and 1.0m high. A 0.2m-thick layer of bottom mud was laid and scraped flat on the bottom of the flume, and then filled with water at a height of 0.4m. A wave generator was installed at one end of the flume to simulate reciprocating flow. A circular steel column with a diameter of 0.6m was placed at the other end to simulate an offshore wind turbine pile. A scaled-down model of a submerged dike was placed in the center of the flume, 5m away from the circular steel column. Furthermore, a digital elevation model (DEM) device was installed within the flume to obtain three-dimensional sedimentary landforms and cross-sectional sedimentary variation characteristics.

[0131] This experiment was divided into nine experimental groups, corresponding to the devices in Examples 1 to 9. Under the same wave conditions, the sediment retention rate, scour pit range, and maximum scour depth of each experimental group were tested. Each element in the test was repeated three times, and the final calculation results were averaged. The experimental results are shown in the following table:

[0132] Table 1 Water tank test results data table

[0133]

[0134] The sediment retention rate refers to the percentage of sediment intercepted by the submerged dike relative to the total amount of sediment entering the dike. The formula is: Sediment retention rate = [(Sediment entering the dike) - (Sediment leaving the dike)] / (Sediment entering the dike) × 100%. Specifically, before the experiment, the sediment volumes on the seaward and pile sides of the dike were measured, denoted as V1 and V2. After the experiment, the sediment volumes on the seaward and pile sides of the dike were measured, denoted as V3 and V4. The amount of sediment entering the dike is V1 - V3, and the amount of sediment leaving the dike is V2 - V4.

[0135] The scour pit area refers to the horizontal projection of the area below the datum depth threshold at the end of the experiment. The initial level of the sediment at the bottom of the datum before the experiment is used as the datum. In this experiment, a depth threshold of 1 mm is used, meaning that any area on the pile side that is 1 mm below the datum after the test is considered scour-affected.

[0136] The maximum scour depth refers to the vertical distance from the deepest point of the scour area at the bottom of the flume to the reference surface after the experiment.

[0137] In Experimental Groups 1 and 2, sediment retention rates increased slightly, while the scour pit area and maximum scour depth decreased. Example 2, based on Example 1, added seaward and backward slopes, and a triangular crest. The slope structure of the seaward and backward slopes, along with the triangular crest, disperses the energy of the water as it approaches the submerged dike, mitigating scour. However, this effect is limited, primarily due to the lack of an effective mechanism to intercept and guide sediment.

[0138] In experimental groups 2 and 3, the sediment retention rate was significantly improved, and the scour pit area and maximum scour depth were greatly reduced. Based on Example 2, Example 3 added a sedimentation area, a sediment collection platform (2.0m wide) and an anti-scour area to the seaward slope. The newly added sedimentation area, sediment collection platform and anti-scour area in Example 3 constitute a system that actively intercepts and retains sediments. The sedimentation area slows down the water flow and promotes sediment settling; the collection platform provides space for sediment accumulation; and the anti-scour area protects the bottom of the submerged dike from direct scouring.

[0139] In Experimental Groups 3, 4, and 5, as the width of the sediment collection platform increased, the sediment retention rate continued to increase, while the scour pit area and maximum scour depth continued to decrease. The primary effect of increasing the width of the sediment collection platform is to increase the sediment retention area. This larger area allows more sediment to be intercepted and retained, reducing the amount of sediment reaching the wind turbine foundation and, in turn, reducing the depth and extent of scour.

[0140] In Experimental Groups 4 and 6, sediment retention increased slightly, while the scour pit area and maximum scour depth decreased slightly. Diversion channels can effectively direct water flow, changing its path and velocity. By installing diversion channels in the sedimentation area, some water can be diverted around the sediment, reducing flow velocity and the scouring force on the sediment, thereby improving sediment retention. However, the effect was not as significant as expanding the sediment collection platform.

[0141] Sediment retention rates increased slightly in Experimental Groups 6 and 7, while scour pit area and maximum scour depth decreased slightly. The grating deflectors intercepted some larger sediment particles, which accumulated on the grating, reducing the amount of sediment reaching downstream and protecting the scour prevention zone from scour.

[0142] In Experimental Groups 7 and 8, sediment retention rates significantly increased, while scour pit area and maximum scour depth decreased significantly. The retention layer increased sediment friction by increasing surface roughness and porosity; the depressions created additional sediment accumulation areas; and the bionic grass increased the surface roughness of the back-to-sea slope, reducing flow velocity there. Together, these effects significantly improved scour prevention.

[0143] In Experimental Groups 8 and 9, the sediment retention rate increased further, while the scour pit area and maximum scour depth decreased further. The stone cushion layer strengthened the connection between the embankment core and the seaward and backward slopes, preventing slippage or displacement between the embankment core and the slopes. The bottom protection significantly enhanced the protection of the bottom of the seaward slope, preventing scour from the bottom of the seaward slope. The prism structure increased the scour resistance of the embankment core, effectively dispersing the energy of the water flow and reducing the scouring effect of the water flow on the embankment core. The working function strengthened the structural stability, protected the embankment core bottom, and dispersed the water flow energy, ultimately significantly improving the anti-scour performance of the device.

[0144] The above description is based on the ideal embodiment of the present invention. Based on the above description, relevant personnel can make various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the content of the specification and must be determined according to the scope of the claims.

Claims

1. A device for protecting offshore wind power pile foundations from scour under reciprocating flow, characterized in that: include: Embankment (1); The embankment core (2) is arranged on the embankment base (1) and has a trapezoidal cross section; The seaward slope (3) is laid on the side of the embankment core (2) close to the ocean, and comprises, from top to bottom, a sedimentation area (31), a sediment collection platform (32), and an anti-erosion area (33); the sedimentation area (31) is located at the top of the seaward slope (3), with a slope of 1:1.5 to 1:3; the anti-erosion area (33) is located at the bottom of the seaward slope (3), with the bottom abutting against the embankment base (1), and a slope of 1:1 to 1:1.5; the sediment collection platform (32) is located between the sedimentation area (31) and the anti-erosion area (33), connecting the sedimentation area (31) and the anti-erosion area (33); The seaward slope (4) is laid on the side of the embankment (2) away from the sea, with a slope of 1:1.5 to 1:3; The dike top (5) is arranged at the top of the dike core (2), has a triangular cross section, and its width gradually increases from the top to the bottom. Its bottom abuts against the top of the sedimentation area (31), the top of the dike core (2), and the top of the back-sea slope (4), respectively.

2. The device for protecting offshore wind power pile foundation from scour under reciprocating flow according to claim 1, characterized in that: The width of the sediment collection platform (32) is 1.5 to 3 times the width of the embankment core (2).

3. The scour protection device for offshore wind power pile foundations under reciprocating flow, according to claim 2, is characterized in that: Diversion grooves (34) are arranged at intervals on the surface of the deposition area (31); each diversion groove (34) is arranged at intervals along the slope direction of the deposition area (31), and includes a main groove (341) and branch grooves (342) extending from the center of the main groove (341) to both sides.

4. The device for protecting offshore wind power pile foundation from scour under reciprocating flow according to claim 3, characterized in that: A grid guide plate (35) is provided at the connection between the sedimentation area (31) and the sediment collection platform (32); the grid guide plate (35) is composed of mutually intersecting strip structures, and cells with an aperture of 20 to 40 cm are formed between the strip structures.

5. The device for protecting offshore wind power pile foundation from scour under reciprocating flow according to claim 4, characterized in that: A retention layer (36) is laid on the surface of the sediment collection platform (32); the retention layer (36) includes one or more of a basalt gravel layer and a high-density polyethylene grid mat; wherein the particle size of the basalt gravel layer is 5 to 20 cm and the thickness is 10 to 30 cm; the pore size of the high-density polyethylene grid mat is 10 to 20 cm and the thickness is 5 to 15 cm.

6. The device for protecting offshore wind power pile foundation from scour under reciprocating flow, according to claim 5, characterized in that: The surface of the sediment collection platform (32) is provided with recessed areas (37) at intervals; the recessed areas (37) are in the shape of shallow saucers, with a depth of 0 to 10 cm, a diameter of 20 to 30 cm, and a spacing of 50 to 80 cm.

7. The device for protecting offshore wind power pile foundation from scour under reciprocating flow, according to claim 6, characterized in that: Bionic grass (44) is laid on the surface of the seaward slope (4).

8. The device for protecting offshore wind power pile foundation from scour under reciprocating flow, according to claim 2, is characterized in that: A block stone cushion layer (21) is provided between the embankment core (2) and the seaward slope (3), and between the embankment core (2) and the seaward slope (4).

9. The device for protecting offshore wind power pile foundation from scour under reciprocating flow, according to claim 8, characterized in that: The embankment core (2) also includes a set of bottom protection (22); the bottom protection (22) has a parallelogram cross section and a thickness of 0.6 to 1.2 m, and is respectively arranged on the embankment base (1) located on both sides of the embankment core (2), and abuts against the outer edges of the seaward slope (3) and the seaward slope (4); among them, the bottom protection abutting the seaward slope (3) is the seaward bottom protection, with a width of 6 to 10 m; the bottom protection abutting the seaward slope (4) is the shoreward bottom protection, with a width of 4 to 6 m.

10. The device for protecting offshore wind power pile foundation from scour under reciprocating flow, according to claim 9, characterized in that: The embankment core (2) also includes a group of prisms (23); the prisms (23) are prismatic structures with a parallelogram cross section, and the long sides are parallel to the embankment core and fixed on the upper surface of the bottom protection (22), respectively contacting the seaward slope (3) and the seaward slope (4); the top surface width of the prisms (23) is 2 to 4 meters, and the thickness is 2 to 4 meters.

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