Local thickening device and method for reducing large-diameter single-pile scouring pit of offshore wind turbine

Abstract

The invention relates to a local thickening device and method for reducing a large-diameter single-pile scouring pit of an offshore wind turbine, and belongs to the field of treatment of large-diameter single-pile scouring pits of offshore wind turbines. The thickening device comprises a first half-circle steel pipe, a second half-circle steel pipe and a steel pipe butt joint and fastening component. And the half-circle steel pipe I and the half-circle steel pipe II are mutually spliced and wrapped on a local pile body of the single-pile foundation scouring pit through steel pipe butt joint and fastening components to form a thickening layer. According to the local thickening device for reducing the large-diameter single-pile scouring pit of the offshore wind turbine, a traditional pile foundation scouring pit treatment mode can be replaced, and the engineering amount and the engineering cost of scouring pit backfilling are reduced to a great extent; by utilizing the material advantages of large dead weight, strong permeability, large friction force between blocks and low production cost of the waste concrete building material bulk blocks, the residual sandy soil can be protected from being scoured, the bearing capacity of the soil body can be improved, and the pile foundation can be prevented from being scoured again and damaged; and a very economical and feasible treatment scheme is provided for recycling of the building waste concrete.

Description

Technical Field

[0001] The invention relates to a local thickening device and a thickening method for reducing the scouring pit of a large-diameter single pile of an offshore wind turbine, and belongs to the field of treatment of the scouring pit of a large-diameter single pile of an offshore wind turbine. Background Art

[0002] Large-diameter single pile foundation is the most mature foundation form for offshore wind turbines. It is usually used in shallow waters with a water depth of 20 to 30 meters and a burial depth of 25 to 35 meters. For offshore wind turbine foundations using large-diameter single piles, under the action of complex cyclic loads such as waves and currents, the water flow conditions around the pile foundation change, resulting in scour pits. In particular, affected by the reciprocating tide, local scour on the pile side is obvious. The maximum depth of common scour pits is 1 to 2 times the diameter of the pile foundation, and the range of the scour pit is 2 to 4 times the diameter of the pile foundation. For the large-diameter single piles of offshore wind turbines that have been built, the existing methods for dealing with scour pits, such as backfilling the entire scour pit range with solidified soil, and stone throwing to repair and prevent scour, all have problems such as high cost and limited construction, and are also prone to adverse effects on the marine environment. Summary of the invention

[0003] The purpose of the present invention is to solve the problem of significantly increasing the horizontal lateral displacement and rotation angle of the single pile under the action of complex dynamic loads such as wind, waves and currents for an already built large-diameter single pile foundation of an offshore wind turbine when a scour pit exists. A method is provided to increase the thickness of the pile body within the depth range of the scour pit and partially backfill the scour pit to eliminate the decrease in resonance frequency caused by the scour pit and reduce the rotation angle of the pile top.

[0004] The present invention adopts the following technical solution:

[0005] The local thickening device for reducing the scouring pit of a large-diameter single pile of an offshore wind turbine according to the present invention,

[0006] It includes a half-circle steel pipe one, a half-circle steel pipe two, and steel pipe butt joint and fastening components;

[0007] A half circle of steel pipe one and a half circle of steel pipe two are joined together and fastened components to wrap around a local pile body of the scour pit of the single pile foundation to form a thickened layer.

[0008] The local thickening device for reducing the scouring pit of a large-diameter single pile of an offshore wind turbine according to the present invention, the steel pipe docking and fastening component comprises a docking end head 1 and a docking end head 2;

[0009] The first butt end is a fixed end with a pin hole, and the second butt end is a hinged ear with a pin hole;

[0010] Along the two arc-shaped edge portions of the half-circle steel pipe 1 and the half-circle steel pipe 2, magnetized circles matching the arc-shaped edge portions are respectively provided;

[0011] The half-circle steel pipe 1 and the half-circle steel pipe 2 are respectively provided with a butt joint end 1 and a butt joint end 2;

[0012] A fixed end point of a butt joint end on the first half-circle steel pipe is matched and fixed with a hinge ear portion of a butt joint end on the second half-circle steel pipe through a pin shaft.

[0013] The local thickening device for reducing the scouring pit of a large-diameter single pile of an offshore wind turbine of the present invention comprises two butt joint ends 1 arranged opposite to each other along the two end edges of the outer arc surface of the half-circle steel pipe 1, and the two butt joint ends 1 are respectively located on the same side end surface of the outer arc surface of the half-circle steel pipe 1;

[0014] Two butt joint ends 1 and 2 are arranged oppositely along the two end edges of the outer arc surface of the half-circle steel pipe 2; the two butt joint ends 1 or the two butt joint ends 2 are located on the same side end surface of the outer arc surface of the half-circle steel pipe 2.

[0015] The local thickening device for reducing the scouring pit of a large-diameter single pile of an offshore wind turbine according to the present invention, the steel pipe docking and fastening components include a fastening force buckle and a connecting arc;

[0016] The fastening force buckle and the connecting arc intersect with each other to form an independently rotating hinge structure;

[0017] The fastening and forcing buckle is connected with the butt joint end at one side edge of the half-circle steel pipe through a pin shaft.

[0018] The local thickening device for reducing the scour pit of a large-diameter single pile of an offshore wind turbine described in the present invention comprises a butt joint 1 at the edge of one end of a half-circle steel pipe and a butt joint 2 at the edge of one end of a half-circle steel pipe. The butt joint 2 is hinged to each other through a pin shaft.

[0019] The local thickening device for reducing the scour pit of a large-diameter single pile of an offshore wind turbine described in the present invention has magnetized circles arranged on the upper and lower sides of the half-circle steel pipe one and the half-circle steel pipe two to achieve a soft connection with the original pile foundation structure to assist in installation.

[0020] The local thickening device for reducing the scour pit of a large-diameter single pile of an offshore wind turbine described in the present invention has a buffer rubber cushion layer on the mutual contact surface of the butt end head 1 and the butt end head 2.

[0021] The thickening method of the local thickening device for reducing the scouring pit of a large-diameter single pile of an offshore wind turbine according to the present invention comprises the following steps:

[0022] A method for thickening a local thickening device for reducing the scouring pit of a large-diameter single pile of an offshore wind turbine is characterized by the following steps:

[0023] S1. Use bolts to connect half circle steel pipe 1 and half circle steel pipe 2 in advance;

[0024] S2. Pre-install a fixing fastener 1 and a fixing fastener 2 on a butt joint end 1 of a half-circle steel pipe 1 or a half-circle steel pipe 2;

[0025] S3, transporting the half circle steel pipe 1 and the half circle steel pipe 2 assembled in step S2 to the location where the pile foundation needs to be reinforced;

[0026] S4, using magnetizing circle 14, attach half circle steel pipe 1 and half circle steel pipe 2 to the pile body by magnetism, half close them on the pile body, and complete pre-installation;

[0027] S5, butt the half-circle steel pipe 1 and the half-circle steel pipe 2 in the semi-closed state, close the half-circle steel pipe 1 and the half-circle steel pipe 2 with the fixing fastener 2, and lock them with bolts. At this time, a certain gap is maintained between the half-circle steel pipe 1 and the half-circle steel pipe 2 and the pile body;

[0028] S6. Slowly hang and sink the connected half-circle steel pipe 1 and half-circle steel pipe 2 to the mud surface at the bottom of the scouring pit;

[0029] S7. The force-added buckle is tightened by pulling with a cable or underwater operation, and the buffer rubber cushion layer is fully squeezed to make the half circle steel pipe 1 and the half circle steel pipe 2 tightly connected;

[0030] S8. Using existing scour pit management technology, partially backfill the scour pit, with the backfill depth only being half of the scour pit depth.

[0031] Beneficial Effects

[0032] The local thickening device for reducing the scour pit of a large-diameter single pile of an offshore wind turbine provided by the present invention can replace the traditional pile foundation scour pit treatment method, greatly reducing the engineering volume and engineering cost of backfilling the scour pit; utilizing the material advantages of waste concrete building materials such as large deadweight, strong permeability, large friction between blocks, and low production cost, it is beneficial to protect the remaining sand and soil from being scoured, improve the soil bearing capacity, and prevent the pile foundation from being scoured again; providing a very economical and feasible treatment plan for the recycling of construction waste concrete.

[0033] The local thickening device for reducing the scour pit of a large-diameter single pile of an offshore wind turbine provided by the present invention has a half-circle steel pipe with a pre-supported structure. The magnetized ring arranged on the half-circle steel pipe can greatly help the alignment of the device during the installation process, and can also assist in improving the adhesion of the half-circle steel pipe to the pile foundation, thereby further improving the stability of the installation.

[0034] The thickening method of the local thickening device for reducing the scour pit of a large-diameter single pile of an offshore wind turbine adopted in the present invention provides a simple and reliable installation method for the device; the docking section of the device faces the main wave flow direction, and while reinforcing the connection, it produces a certain flow disturbance effect, eliminates the stress concentration effect that may be caused by structural mutations, and reduces the impact of water flow on the pile foundation and the scouring around the pile.

[0035] The carbon dioxide produced during the entire process of pile foundation repair is greatly reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a schematic diagram of the installation of a local thickening device for reducing the scour pit of a large-diameter single pile of an offshore wind turbine according to the present invention;

[0037] Figure 2 A schematic diagram of the structure of a half-circle steel pipe of a local thickening device for reducing the scouring pit of a large-diameter single pile of an offshore wind turbine according to the present invention;

[0038] Figure 3 This is a schematic diagram of the structure of a half-circle steel pipe of the local thickening device for reducing the scouring pit of a large-diameter single pile of an offshore wind turbine according to the present invention;

[0039] Figure 4 A schematic diagram of the steps and structure of the butt joint between a half-circle steel pipe and a steel pipe and the pre-connection of fastening components for a local thickening device for reducing the impact of scour pits on large-diameter monopiles of built offshore wind turbines according to the present invention;

[0040] Figure 5 It is a schematic diagram of the pre-connection steps and structure of the half-circle steel pipe 1 and the half-circle steel pipe 2 of the present invention;

[0041] Figure 6 It is a schematic diagram of the on-site closing and installation steps of the thickening method of the local thickening device for reducing the scour pit of a large-diameter single pile of an offshore wind turbine according to the present invention;

[0042] In the figure: 1 is half-circle steel pipe 1, 2 is half-circle steel pipe 2, 3 is steel pipe docking and fastening components, 4 is waste concrete partially backfilled in the scouring pit, 11 is docking end 1, 21 is docking end 2, 13 is a buffer rubber cushion, 14 is a magnetized ring, 31 is a fastening force buckle, and 32 is a connecting arc. DETAILED DESCRIPTION

[0043] In order to make the purpose and technical solution of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] like Figure 1 As shown: a local thickening device for reducing the scour pit of a large-diameter single pile of an offshore wind turbine, comprising a half-circle steel pipe 1, a half-circle steel pipe 2, and a steel pipe butt joint and fastening component 3; the half-circle steel pipe 1 and the half-circle steel pipe 2 are spliced ​​together and wrapped around the local pile body of the scour pit of the single pile foundation through the steel pipe butt joint and fastening component 3 to form a thickening layer.

[0045] like Figure 2 , Figure 3 As shown: the steel pipe butt joint and fastening member 3 includes a butt joint end 11 and a butt joint end 21; the butt joint end 11 is a fixed end point with a pin hole, and the butt joint end 21 is a hinged ear portion with a pin hole;

[0046] The half-circle steel pipe 1 and the half-circle steel pipe 2 are respectively provided with a butt end 11, a butt end 21, and a magnetizing circle 14; the fixed end of the butt end 11 on the half-circle steel pipe 1 is matched and fixed with the hinge ear of the butt end 21 on the half-circle steel pipe 2 through a pin. The length of the half-circle steel pipe 1 and the half-circle steel pipe 2 is the required reinforcement depth of the original pile foundation; its inner diameter is the same as the outer diameter of the original pile foundation, and the wall thickness is determined by the reinforcement strength of the pile foundation.

[0047] Along the two arc-shaped edge portions of the half-circle steel pipe 1 and the half-circle steel pipe 2, magnetized circles 14 matching the arc-shaped edge portions are respectively provided to achieve a soft connection with the original pile foundation structure and assist in installation.

[0048] The edge of the pipe wall of the half-circle steel pipe 1 is provided with two groups of symmetrical butt joint ends 11; the edge of the pipe wall of the half-circle steel pipe 2 is provided with two groups of asymmetrical butt joint ends 11 and 21; both the butt joint ends 11 and 21 are provided with through bolt holes.

[0049] A butt joint end 11 at one end edge of a half-circle steel pipe 1 and a butt joint end 21 at one end edge of a half-circle steel pipe 2 are hinged to each other through a pin shaft.

[0050] like Figure 4 , Figure 5 As shown: the steel pipe docking and fastening component 3 includes a fastening force buckle 31 and a connecting arc 32; the fastening force buckle 31 and the connecting arc 32 intersect with each other to form an independently rotating hinge structure; the fastening force buckle 31 intersects with the docking end 11 at the edge of one side of the half-circle steel pipe 1 through a pin. A buffer rubber cushion layer 13 is provided on the contact surface between the docking end 11 and the docking end 21.

[0051] like Figure 6 As shown: A method for thickening a local thickening device for reducing the scouring pit of a large-diameter single pile of an offshore wind turbine, the steps are:

[0052] Step 1: Before on-site installation, use bolts to connect the butt end 11 and butt end 21 on one side of a set of half-circle steel pipe 1 and half-circle steel pipe 2 in advance;

[0053] Step 2: Before on-site installation, use bolts to connect the butt end 11 on the other side of the half-circle steel pipe 1 with the butt end 11 of the steel pipe and the fastening buckle 31 of the fastening member 3, and connect the arc 32;

[0054] Step 3, transporting a set of semi-connected half-circle steel pipe 1 and half-circle steel pipe 2 that have completed the pre-installation step to the required reinforced pile foundation;

[0055] Step 4, half-close a set of half-connected half-circle steel pipe 1 and half-circle steel pipe 2 that have completed the pre-installation step on the pile body, and use the magnetization circle 14 to magnetically attach the half-circle steel pipe 1 and the half-circle steel pipe 2 to the pile body, and half-close them on the pile body. The specific closing position can be determined according to the on-site situation, and the pre-installation is completed;

[0056] Step 5, further align a set of half-connected half-circle steel pipe 1 and half-circle steel pipe 2 in the semi-closed state, so that the remaining bolt holes of the connecting arc 32 installed on the half-circle steel pipe 1 are aligned and overlapped with the remaining bolt holes on the other connecting end 11 of the half-circle steel pipe 2, and install the bolt group on site to connect and fix them;

[0057] Step 6, slowly sinking a set of half-circle steel pipe 1 and half-circle steel pipe 2 to the mud surface at the bottom of the scouring pit after the connection is completed;

[0058] Step 7, tighten the force-added buckle 31 by pulling with a cable or underwater operation, and fully squeeze the buffer rubber cushion layer 13 to make the half circle of steel pipe 1 and the half circle of steel pipe 2 2 tightly connected;

[0059] Step 8: After the installation of the half circle of steel pipe 1 and the half circle of steel pipe 2 is completed, the scour pit is partially backfilled by using the existing scour pit treatment technology, and the backfill depth is only half of the scour pit depth.

[0060] The innovation of the present invention lies in that, through the device and method of the present invention, the influence of existing scouring pits on the large-diameter single pile foundation of offshore wind turbines can be reduced, the decrease in resonance frequency caused by scouring pits can be eliminated, and the pile top angle can be reduced; a scouring pit treatment method that can replace all backfilling is provided, including pile foundation thickening and partial backfilling, which greatly reduces the cost of pile foundation reinforcement and repair, speeds up the treatment speed, and enhances the treatment effect; a simple and reliable device installation method is provided, which reduces the difficulty of underwater construction; a method for recycling and reusing waste concrete is provided, which reduces the material cost while greatly reducing the carbon emissions of the industrial production of backfill materials.

[0061] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A local thickening device for reducing the scouring pit of a large diameter single pile of an offshore wind turbine, characterized in that : It comprises a half-circle steel pipe one (1), a half-circle steel pipe two (2), and a steel pipe butt joint and fastening component (3); A half circle of steel pipe one (1) and a half circle of steel pipe two (2) are joined together by steel pipe butt joint and fastening components (3) to wrap around a partial pile body of a single pile foundation scouring pit to form a thickening layer.

2. The local thickening device for reducing the scour pit of a large-diameter single pile of an offshore wind turbine according to claim 1, Features: The steel pipe butt-jointing and fastening component (3) comprises a butt-jointing end head 1 (11) and a butt-jointing end head 2 (21); The butt end 1 (11) is a fixed end point with a pin hole, and the butt end 2 (21) is a hinged ear with a pin hole; The half-circle steel pipe 1 (1) and the half-circle steel pipe 2 (2) are respectively provided with a butt joint end 1 (11) and a butt joint end 2 (21); Along the two arc-shaped edge portions of the half-circle steel pipe one (1) and the half-circle steel pipe two (2), magnetized circles (14) matching the arc-shaped edge portions are respectively provided; The fixed end point of the butt joint end head 1 (11) on the half-circle steel pipe 1 (1) and the hinge ear part of the butt joint end head 2 (21) on the half-circle steel pipe 2 (2) are matched and fixed by a pin shaft.

3. The local thickening device for reducing the scour pit of a large-diameter single pile of an offshore wind turbine according to claim 2, Features: Two butt joint ends (11) are arranged opposite to each other along the two end edges of the outer arc surface of the half-circle steel pipe (1), and the two butt joint ends (11) are respectively located on the same side end surface of the outer arc surface of the half-circle steel pipe (1); Two butt joint ends 1 (11) and two butt joint ends 2 (21) are arranged opposite to each other along the two end edges of the outer arc surface of the half-circle steel pipe 2 (2); the two butt joint ends 1 (11) or the two butt joint ends 2 (21) are located on the same side end surface of the outer arc surface of the half-circle steel pipe 2 (2).

4. The local thickening device for reducing the scour pit of a large-diameter single pile of an offshore wind turbine according to claim 1 or 3, characterized in that: The steel pipe butt-jointing and fastening component (3) comprises a fastening force-adding buckle (31) and a connecting arc (32); The fastening force buckle (31) and the connecting arc (32) intersect with each other to form an independently rotatable hinge structure; The tightening force buckle (31) is connected to a butt joint end (11) at one side edge of the half-circle steel pipe (1) through a pin shaft.

5. The local thickening device for reducing the scour pit of a large-diameter single pile of an offshore wind turbine according to claim 2 or 3, characterized in that: The butt joint end head (11) at one end edge of the half-circle steel pipe (1) and the butt joint end head (21) at one end edge of the half-circle steel pipe (2) are hinged to each other through a pin shaft.

6. The local thickening device for reducing the scour pit of a large-diameter single pile of an offshore wind turbine according to claim 2 or 3, characterized in that: A buffer rubber cushion layer (13) is provided on the contact surfaces between the butt joint end head 1 (11) and the butt joint end head 2 (21).

7. A method for thickening a local thickening device for reducing the scour pit of a large-diameter single pile of an offshore wind turbine according to any one of claims 1 to 6, characterized in that: Here are the steps: A method for thickening a local thickening device for reducing the scouring pit of a large-diameter single pile of an offshore wind turbine is characterized by the following steps: S1. Use bolts to connect half circle steel pipe one (1) and half circle steel pipe two (2) in advance; S2. Pre-installing a fixing fastener 1 (31) and a fixing fastener 2 (32) on the butt joint end 1 (11) of the half-circle steel pipe 1 (1) or the half-circle steel pipe 2 (2); S3, transporting the half circle of steel pipe 1 (1) and the half circle of steel pipe 2 (2) assembled in step S2 to the location where the pile foundation needs to be reinforced; S4, using the magnetizing ring (14), the half circle of steel pipe 1 (1) and the half circle of steel pipe 2 (2) are attached to the pile body by magnetism, and half closed on the pile body to complete the pre-installation; S5, butting the half-circle steel pipe 1 (1) and the half-circle steel pipe 2 (2) in the semi-closed state, closing the half-circle steel pipe 1 (1) and the half-circle steel pipe 2 (2) with the fixing fastener 2 (32), and locking them with bolts, at this time, a certain gap is maintained between the half-circle steel pipe 1 (1) and the half-circle steel pipe 2 (2) and the pile body; S6. Slowly lower the connected half-circle steel pipe 1 (1) and half-circle steel pipe 2 (2) to the mud surface at the bottom of the scouring pit; S7. The force-added buckle (31) is tightened by pulling with a cable or underwater operation, and the buffer rubber cushion layer (13) is fully squeezed to make the half circle of steel pipe 1 (1) and the half circle of steel pipe 2 (2) tightly connected; S8. Using existing scour pit management technology, partially backfill the scour pit, with the backfill depth only being half of the scour pit depth.

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