Tensioning method for asymmetric structure precast arm segment and y-shaped floating type wind turbine foundation

Abstract

The application discloses a kind of asymmetric structure prefabricated member arm section tensioning method and Y type floating wind turbine foundation, belong to offshore wind power construction technical field.Prefabricated member arm section includes multiple assembled standard prefabricated members, the cross section of standard prefabricated member is waist round, including the bottom plate hole, top plate hole, web hole and circular arc plate hole that are all provided with steel strand, and tensioning method includes: steel flange is arranged at the end of prefabricated member arm section, the steel strand of part web hole and part circular arc hole is tensioned, to fix steel flange;The steel strand of all top plate hole and first part bottom plate hole is tensioned, wherein, first part bottom plate hole is the multiple bottom plate holes that are arranged at intervals and along first plane symmetrically;The steel strand of all top plate hole and first part bottom plate hole is tensioned;The steel strand of remaining bottom plate hole except first part is tensioned, improve the tensioning success rate of prefabricated member arm section, effectively avoid to damage prefabricated member arm section structure.

Description

Technical Field

[0001] This invention relates to the field of offshore wind power construction technology, and in particular to a method for tensioning the boom segments of asymmetric prefabricated components and a Y-type floating wind turbine foundation. Background Technology

[0002] The Y-type floating wind turbine foundation comprises two inclined precast concrete arm segments and one vertical precast concrete arm segment. Each arm segment is assembled from multiple standard precast components. After assembly, tensioning is required to ensure the internal prestress of the precast components meets technical requirements. The precast components are oval-shaped with multiple ducts. The duct diameters are large in the bottom slab, small in the top slab, and medium in the arc-shaped slab. Correspondingly, the bottom slab ducts have more steel strand bundles, while the top slab ducts have fewer. In related technologies, conventional bridge section tensioning methods, i.e., symmetrical synchronous tensioning, can easily lead to inconsistent prestress values ​​between the top and bottom slabs of the precast component, resulting in cracking. Furthermore, the number of ducts in the oval-shaped precast components is significantly larger than in bridges, making it more difficult to achieve the required prestress in the ducts. Summary of the Invention

[0003] The purpose of this invention is to provide a method for tensioning precast arm segments of asymmetrical structures and a Y-shaped floating wind turbine foundation, thereby improving the success rate of tensioning precast arm segments and effectively avoiding damage to the precast arm segment structure.

[0004] To achieve this objective, the present invention adopts the following technical solution:

[0005] A tensioning method for an asymmetric precast component arm segment, comprising multiple assembled standard precast components. Each standard precast component has an oval cross-section and includes a base plate, a top plate, two web plates, and two arc plates. The top plate and the base plate are connected at both ends by the two arc plates to form an oval shape. The two arc plates are symmetrical along a first plane. The two web plates are located within the oval shape and connect the top plate and the base plate. The base plate has multiple bottom plate holes, the top plate has multiple top plate holes, the arc plates have multiple arc holes, and the web plates have multiple web plate holes. The diameter of the bottom plate holes is larger than the diameter of the top plate holes, thus forming an asymmetric structure for the precast component arm segment. Steel strands are threaded through the bottom plate holes, the top plate holes, the arc holes, and the web plate holes. Tensioning the steel strands within the holes causes the precast component arm segment to bend downwards. The tensioning method includes:

[0006] The steel flange is placed at the end of the precast component arm section, and the steel strands of some of the web holes and some of the arc holes are tensioned to fix the steel flange.

[0007] Tensioning is performed on the steel strands of all the top plate holes and the first part of the bottom plate holes to achieve initial pre-tightening, wherein the first part of the bottom plate holes are multiple bottom plate holes that are spaced apart and symmetrically arranged along the first plane;

[0008] The steel strands in all the top plate holes and the first portion of the bottom plate holes are tensioned to achieve axial tensioning;

[0009] The steel strands in the remaining holes of the base plate, excluding the first part, are tensioned to achieve eccentric tensioning.

[0010] In some possible implementations, the precast component arm has three segments: OA, OB, and OC. The OA, OB, and OC segments are connected in a Y-shape, and the OA and OB segments are symmetrically arranged. The OA, OB, and OC segments are tensioned respectively.

[0011] In some possible implementations, during initial pre-tightening,

[0012] For sections OA and OB: the multiple top plate holes are divided into two groups, and the bottom plate holes in the first part are divided into three groups. The top plate holes in each group are spaced apart and symmetrically arranged along the first plane, and the bottom plate holes in each group are spaced apart and symmetrically arranged along the first plane. The steel strands of the two groups of top plate holes and the three groups of bottom plate holes are tensioned alternately to achieve initial pre-tension.

[0013] For the OC segment: the multiple top plate holes and the first part of the bottom plate holes are divided into three groups. The top plate holes in each group are spaced apart and symmetrically arranged along the first plane. The bottom plate holes in each group are spaced apart and symmetrically arranged along the first plane. The steel strands of the three groups of top plate holes and the three groups of bottom plate holes are tensioned alternately to achieve initial pre-tension.

[0014] In some possible implementations, during initial pre-tightening,

[0015] For sections OA and OB: the steel strands of the first set of top plate holes, the second set of top plate holes, and the first set of top plate holes are tensioned sequentially, and tensioned to 10%, 10%, and 30% of the tension control stress of the steel strands, respectively;

[0016] For the OC segment: the steel strands of the first set of top plate holes, the second set of top plate holes, and the third set of top plate holes are tensioned sequentially, and each is tensioned to 10% of the tension control stress of the steel strand.

[0017] In some possible implementations, during axial tensioning, the plurality of top plate holes are divided into three groups, with the top plate holes in each group spaced apart and symmetrically arranged along a first plane. The steel strands in the first group of top plate holes and the first portion of the bottom plate holes are tensioned simultaneously, the steel strands in the second group of top plate holes and the first portion of the bottom plate holes are tensioned simultaneously, and the steel strands in the third group of top plate holes and the first portion of the bottom plate holes are tensioned simultaneously.

[0018] In some possible implementations, during axial tensioning,

[0019] For sections OA and OB: the steel strands of the three sets of top plate holes are tensioned to 100% of the tension control stress, and the steel strands of the first part of the bottom plate holes are tensioned three times and finally tensioned to 60% of the tension control stress.

[0020] For the OC section: the steel strands of the three sets of top plate holes are tensioned to 100% of the tension control stress, and the steel strands of the first part of the bottom plate holes are tensioned three times and finally tensioned to 100% of the tension control stress.

[0021] In some possible implementations, during eccentric tensioning,

[0022] For sections OA and OB: the steel strands in the first part of the bottom plate holes are tensioned from 60% to 100% of the tension control stress. The remaining bottom plate holes, excluding the first part of the bottom plate holes, are divided into two parts. The steel strands in the two parts of the bottom plate holes are pre-tightened and then tensioned to 100% of the tension control stress.

[0023] For the OC section: the remaining bottom plate holes, excluding the first part of the bottom plate holes, are divided into two parts, and the steel strands in the two parts of the bottom plate holes are initially pre-tightened and then tensioned to 100% of the tension control stress.

[0024] In some possible implementations, temporary tensioning structures are provided between each pair of segments OA, OB, and OC; the bottom of the precast arm segment is supported by a retractable hydraulic cylinder; and between the axial tensioning step and the eccentric tensioning step, the following is also included:

[0025] Dismantle the temporary tensioning structure;

[0026] The retractable hydraulic cylinders at the bottom of sections OA, OB, and OC are adjusted to adapt to the shapes of sections OA, OB, and OC after eccentric tensioning.

[0027] In some possible implementations, axial tensioning includes:

[0028] The steel strands in the remaining arc holes and remaining web holes are tensioned to 100% of the tension control stress.

[0029] The Y-type floating wind turbine foundation is manufactured using the asymmetric prefabricated component arm tensioning method described in any of the above descriptions.

[0030] The beneficial effects of this invention are:

[0031] This invention provides a method for tensioning asymmetrical precast component arm segments and a Y-type floating wind turbine foundation. Through fixed steel flanges, initial pre-tensioning, axial tensioning, and eccentric tensioning—that is, tensioning the top and bottom plate holes in stages—it facilitates control of the actual tension stress, ensuring that the actual tension stress and the tension control stress of the steel strands are kept within a preset range. Furthermore, staged tensioning facilitates checking the reliability of the tools or equipment used, avoiding stress abrupt changes due to tool or equipment problems that could lead to tension control errors, causing tensile stress in the top plate and potentially cracking of the top plate joints. This improves the success rate of precast component arm segment tensioning and effectively avoids damage to the precast component arm segment structure. The implementation process is clear, the application scope is wide, and it has good potential for widespread adoption. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of a Y-shaped floating wind turbine foundation;

[0033] Figure 2 This is a flowchart of the tensioning method for the arm segments of asymmetric precast structures;

[0034] Figure 3 This is a schematic diagram of the cross-section of the precast arm section used to illustrate the web holes and arc holes used to fix the steel flange;

[0035] Figure 4 This is a schematic diagram of the OA and OB sections used to illustrate one set of top plate holes during initial pre-tightening;

[0036] Figure 5 This is a schematic diagram of the OA and OB sections used to illustrate the first set of bottom plate holes during initial pre-tightening;

[0037] Figure 6 This is a schematic diagram of the precast component arm section cross-section used to illustrate the bottom plate holes and one set of top plate holes during axial tensioning;

[0038] Figure 7 This is a schematic diagram of the OC section used to illustrate the remaining bottom plate holes for eccentric tensioning.

[0039] In the picture:

[0040] 1. OA section; 2. OB section; 3. OC section; 4. Web plate; 41. Web plate hole; 5. Circular arc plate; 51. Circular arc hole; 6. Top plate; 61. Top plate hole; 7. Bottom plate; 71. Bottom plate hole; 8. Standard precast component. Detailed Implementation

[0041] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0043] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0044] like Figures 1-7 As shown, Figure 1 This is a schematic diagram of a Y-shaped floating wind turbine foundation, which includes OA section 1, OB section 2 and OC section 3, with OA section 1 and OB section 2 arranged symmetrically. Figure 3 This is a schematic diagram of the cross-section of the precast component arm section, used to illustrate the web holes and arc holes used to fix the steel flange. The parts marked in black are the web holes 41 and arc holes 51 used to fix the steel flange. Figure 4 This is a schematic diagram of the OA and OB sections used to illustrate one set of top plate holes during initial pre-tightening. The holes marked with circles are one set of top plate holes 61, and the holes not marked with circles are another set. Figure 5 This is a schematic diagram of the OA and OB sections used to illustrate the first set of bottom plate holes during initial pre-tightening. The holes marked with circles are one set of bottom plate holes 71. Figure 6This is a schematic diagram of the precast arm section section used to illustrate the bottom plate holes and one set of top plate holes during axial tensioning. The holes marked in black in the top plate holes 61 are one set of top plate holes 61 in the three groups, and the holes marked in black in the bottom plate holes 71 are the first part of the bottom plate holes 71. Figure 7 This is a schematic diagram of the OC section section used to illustrate the remaining bottom plate holes for eccentric tensioning. The part marked in black in the precast arm section section is the first part of the bottom plate hole 71.

[0045] The precast arm section includes multiple assembled standard precast components 8. The cross-section of the standard precast component 8 is oval. The standard precast component 8 includes a bottom plate 7, a top plate 6, two web plates 4 and two arc plates 5. The top plate 6 and the bottom plate 7 are connected at both ends by the two arc plates 5 to form an oval shape. The two arc plates 5 are symmetrical along the first plane. The two web plates 4 are located inside the oval shape and connect the top plate 6 and the bottom plate 7. The base plate 7 has multiple base plate holes 71, the top plate 6 has multiple top plate holes 61, the arc plate 5 has multiple arc holes 51, and the web plate 4 has multiple web holes 41. The diameter of the base plate holes 71 is larger than the diameter of the top plate holes 61. Steel strands are threaded through the base plate holes 71, top plate holes 61, arc holes 51, and web holes 41. The larger the hole diameter, the more steel strands are threaded through the hole. That is, the number of steel strands threaded through the base plate holes 71, top plate holes 61, arc holes 51, and web holes 41 decreases sequentially, thus forming an asymmetrical structure for the precast component arm segment. By tensioning the steel strands, the precast component arm segment is bent downwards.

[0046] like Figure 2 As shown, this embodiment provides a method for tensioning the arm segment of an asymmetric precast structure, including the following steps:

[0047] S100. The steel flange is placed at the end of the precast component arm section, and the steel strands of some web plate holes 41 and some arc-shaped holes 51 are tensioned to fix the steel flange; wherein, some web plate holes 41 and some arc-shaped holes 51 are... Figure 3 The parts marked in black in the cross-section of the precast component arm shown are the parts shown in the image.

[0048] S200. Tension the steel strands in all the top plate holes 61 and the first part of the bottom plate holes 71 to achieve initial pre-tensioning. The first part of the bottom plate holes 71 consists of multiple bottom plate holes 71 spaced apart and symmetrically arranged along the first plane. Figure 7 The parts marked in black in the cross-section of the precast component arm shown are the parts shown in the image.

[0049] S300, Tension the steel strands of all the top plate holes 61 and the first part of the bottom plate holes 71 to achieve axial tension;

[0050] S400, Tension the steel strands in the remaining bottom plate holes 71, excluding the first part, to achieve eccentric tensioning.

[0051] By using fixed steel flanges, initial pre-tensioning, axial tensioning, and eccentric tensioning—that is, tensioning the top plate hole 61 and the bottom plate hole 71 in stages—it is easier to control the actual tension stress, ensuring that the actual tension stress and the tension control stress of the steel strands are kept within the preset range. Furthermore, staged tensioning facilitates checking the reliability of the tools or equipment used for tensioning, avoiding stress abrupt changes due to tool or equipment problems that could lead to tension control errors, causing tensile stress in the top plate 6, and potentially causing cracking at the joints of the top plate 6. This improves the success rate of tensioning the precast component arm segments and effectively avoids damage to the precast component arm segment structure. The implementation process is clear, has a wide range of applications, and has good potential for widespread adoption.

[0052] For example, the base plate 7 has 33 evenly distributed base plate holes 71, the top plate 6 has 27 evenly distributed top plate holes 61, the arc plate 5 has 7 evenly distributed arc holes 51, and the two arc plates 5 have a total of 14 arc holes 51. The web plate 4 has 8 evenly distributed web holes 41, and the two web plates 4 have a total of 16 web holes 41. Therefore, the precast arm section has a total of 90 holes. The diameter of the base plate holes 71 is 130 mm, the diameter of the top plate holes 61 is 90 mm, the diameter of the arc holes 51 is 90 mm, and the diameter of the web holes 41 is 70 mm.

[0053] like Figure 3 As shown, one arc hole 51 is selected on each of the two arc plates 5 and four web holes 41 are selected on each of the two web plates 4 for fixing to the steel flange. Optionally, the steel strands in the arc holes 51 and web holes 41 are tensioned to 100% of the tension control stress. The first part of the bottom plate holes 71 is one-third of the bottom plate holes 71, that is, the bottom plate holes 71 are divided into three groups, each group with 11 bottom plate holes 71. The three groups of bottom plate holes 71 are arranged at intervals, one of which is the first part of the bottom plate holes 71.

[0054] The precast component has three arm segments: OA segment 1, OB segment 2, and OC segment 3. OA segment 1, OB segment 2, and OC segment 3 are connected in a Y-shape. OA segment 1 and OB segment 2 are symmetrically arranged. Tensioning is performed on OA segment 1, OB segment 2, and OC segment 3 respectively, thereby achieving the tensioning of the Y-shaped structure. This embodiment uses a Y-shaped structure as an example for illustrative explanation.

[0055] Before tensioning the steel strands in sections OA1, OB2, and OC3, and all the top plate holes 61 and bottom plate holes 71, step S201 is performed: Pre-tightening the remaining arc holes 51. The pre-tightening sequence is to pre-tighten each arc hole 51 from the middle to the top and bottom sides, until the tensioning control stress of the steel strands reaches 10%.

[0056] In one embodiment, during the initial pre-tensioning in step S200, for segments OA1 and OB2: the multiple top plate holes 61 are divided into two groups, and the first portion of the bottom plate holes 71 are divided into three groups (e.g., the number of bottom plate holes 71 in the three groups are 4, 4, and 3 respectively). The top plate holes 61 in each group are spaced apart and symmetrically arranged along the first plane, and the bottom plate holes 71 in each group are spaced apart and symmetrically arranged along the first plane. The steel strands of the two groups of top plate holes 61 and the three groups of bottom plate holes 71 are alternately tensioned to achieve initial pre-tensioning. The above-mentioned symmetrical arrangement of each group of top plate holes 61 and each group of bottom plate holes 71 along the first plane can be understood as symmetrical or approximately symmetrical. When grouping, the number of holes can be evenly distributed or unevenly distributed, without limitation. Figure 4 and Figure 5 As shown, Figure 4 Holes 61 in the top plate marked with circles belong to one group, while holes not marked with circles belong to another group. Figure 5 The holes marked with circles on the bottom plate 71 are one set; the other two sets are selected adaptively based on the description.

[0057] For OC segment 3: Multiple top plate holes 61 and the first set of bottom plate holes 71 are divided into three groups. The top plate holes 61 in each group are spaced apart and symmetrically arranged along the first plane. The bottom plate holes 71 in each group are also spaced apart and symmetrically arranged along the first plane. The steel strands of the three groups of top plate holes 61 and three groups of bottom plate holes 71 are alternately tensioned to achieve initial pre-tension. The symmetrical arrangement of each group of top plate holes 61 and each group of bottom plate holes 71 along the first plane can be understood as symmetrical or approximately symmetrical. The number of holes can be evenly or unevenly distributed during grouping; no limitation is imposed.

[0058] Multiple top plate holes 61 and the first set of bottom plate holes 71 are grouped separately. The top plate holes 61 in each group are spaced apart and symmetrically arranged along the first plane, and the bottom plate holes 71 in each group are also spaced apart and symmetrically arranged along the first plane. The steel strands in the multiple groups of top plate holes 61 and bottom plate holes 71 are alternately tensioned to achieve initial pre-tension. By dividing the top plate holes 61 and bottom plate holes 71 into multiple groups, multiple tensioning of the bottom plate 7 and top plate 6 is achieved, facilitating control of the actual tension stress. Alternating tensioning of the top plate holes 61 and bottom plate holes 71 avoids the risk of falling objects injuring people during simultaneous work at different levels. Furthermore, the completion of pre-tensioning of the bottom plate holes 71 is considered the end point.

[0059] For sections OA1 and OB2: the steel strands in the first set of top plate holes 61, the second set of top plate holes 61, and the first set of top plate holes 61 are tensioned sequentially, and tensioned to 10%, 10%, and 30% of the tension control stress of the steel strands, respectively. Optionally, the steel strands in the three sets of bottom plate holes 71 are tensioned sequentially, all tensioned to 10% of the tension control stress of the steel strands. Specifically, the following steps are included:

[0060] S211. Tension the steel strands in the first set of top plate holes 61 to 10% of the tension control stress of the steel strands.

[0061] S212. Tension the steel strands in the first set of bottom plate holes 71 to 10% of the tension control stress of the steel strands.

[0062] S213. Tension the steel strands in the second set of top plate holes 61 to 10% of the tension control stress of the steel strands.

[0063] S214. Tension the steel strands in the second set of bottom plate holes 71 to 10% of the tension control stress of the steel strands.

[0064] S215. Tension the steel strands in the first set of top plate holes 61 again, and tension them to 30% of the tension control stress of the steel strands.

[0065] S216. Tension the steel strands in the third set of bottom plate holes 71 to 10% of the tension control stress of the steel strands.

[0066] For OC segment 3: The steel strands in the first group of top plate holes 61, the second group of top plate holes 61, and the third group of top plate holes 61 are tensioned sequentially, and each is tensioned to 10% of the tension control stress of the steel strand. Optionally, the steel strands in the three groups of bottom plate holes 71 are tensioned sequentially, and each is tensioned to 10% of the tension control stress of the steel strand. Specifically, the following steps are included:

[0067] S221. Tension the steel strands in the first set of top plate holes 61 to 10% of the tension control stress of the steel strands.

[0068] S222, Tension the steel strands in the first set of bottom plate holes 71, and tension them to 10% of the tension control stress of the steel strands;

[0069] S223. Tension the steel strands in the second set of top plate holes 61 to 10% of the tension control stress of the steel strands.

[0070] S224. Tension the steel strands in the second set of bottom plate holes 71 to 10% of the tension control stress of the steel strands.

[0071] S225. Tension the steel strands in the third set of top plate holes 61 to 10% of the tension control stress of the steel strands.

[0072] S226. Tension the steel strands in the third set of bottom plate holes 71 to 10% of the tension control stress of the steel strands.

[0073] During axial tensioning in step S300, the multiple top plate holes 61 are divided into three groups. The top plate holes 61 in each group are spaced apart and symmetrically arranged along the first plane. The steel strands of the first group of top plate holes 61 and the first portion of the bottom plate holes 71 are tensioned simultaneously; the steel strands of the second group of top plate holes 61 and the first portion of the bottom plate holes 71 are tensioned simultaneously; and the steel strands of the third group of top plate holes 61 and the first portion of the bottom plate holes 71 are tensioned simultaneously. For example... Figure 6 As shown, the top plate hole 61 marked in black is one of the three groups of top plate holes 61, and the bottom plate hole 71 marked in black is the first part of the bottom plate holes 71.

[0074] For sections OA1 and OB2: the steel strands in the three sets of top plate holes 61 are tensioned to 100% of the tension control stress, and the steel strands in the first part of the bottom plate holes 71 are tensioned three times to 60% of the tension control stress; specifically, the following steps are included:

[0075] S311. Tension the steel strands of the first set of top plate holes 61 to 100% of the tension control stress of the steel strands; tension the steel strands of the first part of the bottom plate holes 71 to 24% of the tension control stress of the steel strands.

[0076] S312. Tension the steel strands of the second set of top plate holes 61 to 100% of the tension control stress of the steel strands; tension the steel strands of the first set of bottom plate holes 71 again to 42% of the tension control stress of the steel strands.

[0077] S313. Tension the steel strands of the third set of top plate holes 61 to 100% of the tension control stress of the steel strands; Tension the steel strands of the first set of bottom plate holes 71 for the third time to 60% of the tension control stress of the steel strands.

[0078] For OC segment 3: the steel strands of the three sets of top plate holes 61 are tensioned to 100% of the tension control stress, and the steel strands of one set of bottom plate holes 71 are tensioned three times and tensioned to 100% of the tension control stress.

[0079] S321. Tension the steel strands of the first set of top plate holes 61 to 100% of the tension control stress of the steel strands; tension the steel strands of the first part of the bottom plate holes 71 to 40% of the tension control stress of the steel strands.

[0080] S322. Tension the steel strands in the second set of top plate holes 61 until the tension control stress of the steel strands reaches 100%; then tension the steel strands in the first set of bottom plate holes 71 again until the tension control stress of the steel strands reaches 70%.

[0081] S323. Tension the steel strands in the third set of top plate holes 61 until the tension control stress of the steel strands reaches 100%; Tension the steel strands in the first set of bottom plate holes 71 for the third time until the tension control stress of the steel strands reaches 100%.

[0082] During axial tensioning in step S300, the method further includes tensioning the steel strands in the remaining arc holes 51 and the remaining web holes 41, both tensioned to 100% of the tension control stress. Taking segments OA1 and OB2 as examples, the remaining web holes 41 are divided into two groups, with the remaining arc holes 51 forming one group. Step S311 further includes tensioning the steel strands in the first group of web holes 41, tensioning them to 100% of the steel strand tension control stress; Step S312 further includes tensioning the steel strands in the second group of web holes 41, tensioning them to 100% of the steel strand tension control stress; Step S313 further includes tensioning the steel strands in the arc holes 51, tensioning them to 100% of the steel strand tension control stress.

[0083] Temporary tensioning structures are provided between each pair of OA segment 1, OB segment 2, and OC segment 3. The bottom of the precast component arm is supported by a retractable hydraulic cylinder. Between step S300 (axial tensioning) and step S400 (eccentric tensioning), the following is also included:

[0084] S1000, Remove the temporary tensioning structure to allow the precast arm segments, namely OA segment 1, OB segment 2 and OC segment 3, to deform freely;

[0085] S2000: Adjust the retractable hydraulic cylinders at the bottom of segments OA1, OB2, and OC3 to adapt to the shapes of segments OA1, OB2, and OC3 after eccentric tensioning, i.e., to a downward bending state. By adjusting after axial tensioning in step S300, the axial tensioning stage of the precast component arm segment is extended as much as possible, allowing the precast component arm segment to store more preload and preventing cracking of the segment joints.

[0086] like Figure 7 As shown, the holes 71 marked in black on the base plate are the first part of the base plate holes 71, and the unmarked holes are the remaining base plate holes 71 excluding the first part. During eccentric tensioning in step S400, for segments OA1 and OB2: the steel strands of the first part of the base plate holes 71 are tensioned from 60% to 100% of the tension control stress; the remaining base plate holes 71 excluding the first part are divided into two parts, and the steel strands of both parts of the base plate holes 71 are initially pre-tightened before being tensioned to 100% of the tension control stress. Specifically, the following steps are included:

[0087] S411, Tensile the steel strands in the first part of the bottom plate hole 71 from 60% to 100% of the tension control stress;

[0088] S412. Pre-tighten the steel strands in the bottom plate holes 71 of both parts.

[0089] S413. Tension the steel strands in the bottom plate hole 71 of the second part to 100% of the tension control stress;

[0090] S414. Tension the steel strands in hole 71 of the third part of the bottom plate to 100% of the tension control stress.

[0091] For OC segment 3: Divide the remaining bottom plate holes 71, excluding the first part of the bottom plate holes 71, into two groups, and pre-tighten the steel strands of the two groups of bottom plate holes 71, and then tension them to 100% of the tension control stress.

[0092] S421. Initially tighten the steel strands in the bottom plate holes 71 of both parts;

[0093] S422, Tension the steel strands in the bottom plate hole 71 of the second part to 100% of the tension control stress;

[0094] S423. Tension the steel strands in hole 71 of the third part of the bottom plate to 100% of the tension control stress.

[0095] The Y-type floating wind turbine foundation is a Y-shaped structure made using the aforementioned asymmetric prefabricated arm tensioning method. By improving the tensioning success rate and reducing the problem of cracking at the top slab joint, the production cost is reduced.

[0096] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for tensioning the arm segment of an asymmetric precast structure, characterized in that, The precast arm section includes multiple assembled standard precast components (8). The cross-section of the standard precast component (8) is oval. The standard precast component (8) includes a bottom plate (7), a top plate (6), two web plates (4), and two arc plates (5). The top plate (6) and the two ends of the bottom plate (7) are connected by the two arc plates (5) to form an oval shape. The two arc plates (5) are symmetrical along a first plane, which is a plane of symmetry perpendicular to the straight side of the oval standard precast component (8). The two web plates (4) are located inside the oval shape and connect the top plate (6) and the bottom plate (7). The bottom plate (7) The precast component has multiple bottom plate holes (71), multiple top plate holes (61), multiple arc holes (51), and multiple web holes (41). The diameter of the bottom plate holes (71) is larger than that of the top plate holes (61), thus forming an asymmetrical structure for the precast component arm segment. Steel strands are threaded through the bottom plate holes (71), the top plate holes (61), the arc holes (51), and the web holes (41). The precast component arm segment is bent downwards by tensioning the steel strands in the holes. The tensioning method includes: The steel flange is placed at the end of the precast arm section, and the steel strands of some of the web holes (41) and some of the arc holes (51) are tensioned to fix the steel flange. Tensioning is performed on the steel strands of all the top plate holes (61) and the first part of the bottom plate holes (71) to achieve initial pre-tightening, wherein the first part of the bottom plate holes (71) consists of a plurality of bottom plate holes (71) spaced apart and symmetrically arranged along the first plane; Tensioning is performed on the steel strands of all the top plate holes (61) and the first portion of the bottom plate holes (71) to achieve axial tensioning; The steel strands in the bottom plate holes (71) excluding the first part are tensioned to achieve eccentric tensioning.

2. The method for tensioning the arm segment of an asymmetric precast structure according to claim 1, characterized in that, The precast component arm has three segments, namely OA segment (1), OB segment (2) and OC segment (3). The OA segment (1), OB segment (2) and OC segment (3) are connected in a Y-shape. The OA segment (1) and OB segment (2) are symmetrically arranged, and the OA segment (1), OB segment (2) and OC segment (3) are tensioned respectively.

3. The method for tensioning the arm segment of an asymmetric precast structure according to claim 2, characterized in that, During the initial tightening, For OA segment (1) and OB segment (2): the multiple top plate holes (61) are divided into two groups, and the bottom plate holes (71) of the first part are divided into three groups. The top plate holes (61) of each group are spaced apart and symmetrically arranged along the first plane, and the bottom plate holes (71) of each group are spaced apart and symmetrically arranged along the first plane. The steel strands of the two groups of top plate holes (61) and the three groups of bottom plate holes (71) are alternately tensioned to achieve initial pre-tension. For OC segment (3): the multiple top plate holes (61) and the first part of the bottom plate holes (71) are divided into three groups. The top plate holes (61) of each group are spaced apart and symmetrically arranged along the first plane. The bottom plate holes (71) of each group are spaced apart and symmetrically arranged along the first plane. The steel strands of the three groups of top plate holes (61) and the three groups of bottom plate holes (71) are tensioned alternately to achieve initial pre-tension.

4. The method for tensioning the arm segment of an asymmetric precast structure according to claim 3, characterized in that, During the initial tightening, For OA segment (1) and OB segment (2): the steel strands of the first set of top plate holes (61), the second set of top plate holes (61) and the first set of top plate holes (61) are tensioned sequentially, and tensioned to 10%, 10% and 30% of the tension control stress of the steel strands, respectively; For OC segment (3): the steel strands of the first set of top plate holes (61), the second set of top plate holes (61) and the third set of top plate holes (61) are tensioned in sequence, and all are tensioned to 10% of the tension control stress of the steel strands.

5. The method for tensioning the arm segment of an asymmetric precast structure according to claim 2, characterized in that, During axial tensioning, the multiple top plate holes (61) are divided into three groups. The top plate holes (61) in each group are spaced apart and symmetrically arranged along the first plane. The steel strands of the first group of top plate holes (61) and the first part of the bottom plate holes (71) are tensioned simultaneously. The steel strands of the second group of top plate holes (61) and the first part of the bottom plate holes (71) are tensioned simultaneously. The steel strands of the third group of top plate holes (61) and the first part of the bottom plate holes (71) are tensioned simultaneously.

6. The method for tensioning the arm segment of an asymmetric precast structure according to claim 5, characterized in that, During axial tensioning, For OA segment (1) and OB segment (2): the steel strands of the three sets of top plate holes (61) are tensioned to 100% of the tension control stress, and the steel strands of the first part of the bottom plate holes (71) are tensioned three times and finally tensioned to 60% of the tension control stress; For OC segment (3): the steel strands of the three sets of top plate holes (61) are tensioned to 100% of the tension control stress, and the steel strands of the first part of the bottom plate holes (71) are tensioned three times and finally tensioned to 100% of the tension control stress.

7. The method for tensioning the arm segment of an asymmetric precast structure according to claim 6, characterized in that, During eccentric tensioning, For OA segment (1) and OB segment (2): the steel strands in the first part of the bottom plate hole (71) are tensioned from 60% to 100% of the tension control stress. The remaining bottom plate hole (71) is divided into two parts, and the steel strands in the two parts of the bottom plate hole (71) are initially pre-tightened and then tensioned to 100% of the tension control stress. For OC segment (3): Divide the remaining bottom plate hole (71) into two parts, and pre-tighten the steel strands of the two bottom plate holes (71) respectively, and then tension them to 100% of the tension control stress.

8. The method for tensioning the arm segment of an asymmetric precast structure according to claim 2, characterized in that, Temporary tensioning structures are provided between each pair of OA segment (1), OB segment (2), and OC segment (3). The bottom of the precast component arm is supported by a retractable hydraulic cylinder. Between the axial tensioning step and the eccentric tensioning step, the following is also included: Dismantle the temporary tensioning structure; Adjust the retractable hydraulic cylinders at the bottom of OA segment (1), OB segment (2) and OC segment (3) to adapt to the shapes of OA segment (1), OB segment (2) and OC segment (3) after eccentric tensioning.

9. The method for tensioning the arm segment of an asymmetric precast structure according to any one of claims 1-8, characterized in that, During axial tensioning, the following are included: The steel strands in the remaining arc holes (51) and remaining web holes (41) are tensioned. The remaining arc holes (51) and remaining web holes (41) are the remaining holes excluding the tensioning holes of the previously fixed steel flange, and are all tensioned to 100% of the tensioning control stress.

10. A Y-type floating wind turbine foundation, characterized in that, It is manufactured using the tensioning method for the asymmetric precast arm segment as described in any one of claims 1-9.

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