An onshore wind power full-fabricated foundation structure and method

Abstract

The application discloses a full-assembled foundation structure and method for land wind power, and relates to the technical field of wind power, and can be used for wind power construction. The foundation structure comprises a prefabricated assembly body which is formed by circumferentially splicing a plurality of prefabricated modules, wherein the prefabricated module comprises a bottom plate, a rib beam arranged on the bottom plate, and a column located in the inner circle of the bottom plate; column grouting is filled between the columns of adjacent prefabricated modules; rib beam grouting is filled between the rib beams of adjacent prefabricated modules; a column anchor plate is pre-embedded on the column; a rib beam inner anchor plate and a rib beam outer anchor plate are pre-embedded on the rib beam in the radial direction; anchor bolt holes are formed in the column anchor plate, the rib beam inner anchor plate and the rib beam outer anchor plate; prestressed anchor bolts are arranged in the anchor bolt holes of adjacent prefabricated modules; and the prestressed anchor bolts are tensioned after the column grouting and the rib beam grouting are completed, so that the adjacent prefabricated modules are circularly prestressed and compactly constrained.

Description

Technical Field

[0001] This invention relates to wind energy engineering and onshore wind power foundation structures, specifically to a fully prefabricated onshore wind power foundation structure and construction method. Background Technology

[0002] With the large-scale development and grid connection of wind farms, the foundation engineering of large onshore wind turbine generators has become a key factor affecting project cost, construction progress, and operational reliability. Traditional onshore wind turbine foundations mostly employ gravity or pile foundation structures cast in place. These processes require continuous pouring of large volumes of concrete, complex formwork and reinforcement fabrication and installation, long curing times, and on-site quality control. Consequently, the construction cycle is long, the on-site civil engineering workload is substantial, and the foundations are easily affected by weather and construction conditions, posing significant challenges to project organization and quality assurance. To improve construction efficiency and quality control, prefabricated wind turbine foundations, which are manufactured in factories and assembled on-site, have been gradually promoted in recent years. Factory production improves the consistency of component quality and shortens on-site construction time, significantly reducing the amount of on-site pouring and some construction risks.

[0003] However, existing prefabricated foundations still reveal several problems in practice that restrict their promotion and reliability. First, wind turbine foundations need to withstand large horizontal moments and long-term cyclic loads. If prefabricated modules cannot effectively form a continuous circumferential force-bearing system, stress concentration can easily occur at the joints, inducing crack propagation and fatigue failure, affecting overall mechanical performance and safety. Second, existing component connection methods are relatively simple. Methods such as mechanical connections, local grouting, or rebar butt welding often only achieve fixation and force transmission at local locations in engineering, making it difficult to achieve uniform circumferential constraint and prestressing treatment. This, to some extent, limits the performance of prefabricated foundations in terms of load-bearing capacity, stiffness, and fatigue resistance. Furthermore, the process sequence and quality control requirements for connection construction are high. If grouting, butt welding, and prestressing treatment are not implemented according to strict process organization, defects such as incomplete grouting, poor bonding, or prestress loss can easily occur, thus affecting the stress transmission and long-term stability of the structure. Finally, the durability of joints and grouting layers should not be overlooked. If gaps exist or the grouting quality is insufficient, water erosion, freeze-thaw cycles, or corrosion of steel anchors will accelerate local deterioration, increase later maintenance costs, and shorten the service life of the foundation. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing prefabricated foundations in terms of joint integrity, connection reliability, and durability, and to provide a fully prefabricated foundation structure and method for onshore wind power. This foundation structure has four pre-installed anchor plates on the inner side of the columns and the inner and outer sides of the ribs. It employs a construction sequence of grouting followed by tensioning the prestressed anchors to achieve circumferential connection and prestressed constraint of the prefabricated modules. Through the synergistic effect of the circumferentially distributed anchor plates and prestressed anchors, this invention significantly improves joint integrity, connection reliability, and durability while maintaining prefabricated construction efficiency and component quality consistency, thus better meeting the requirements of large wind turbine foundations for overall mechanical performance and long-term safety.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] A fully prefabricated foundation structure for onshore wind power includes:

[0007] The prefabricated assembly is composed of several prefabricated modules circumferentially spliced ​​together. Each prefabricated module includes a base plate, ribs set on the base plate, and columns located in the inner circle of the base plate. Column grouting is used to fill the spaces between the columns of adjacent prefabricated modules. Rib grouting is used to fill the spaces between the ribs of adjacent prefabricated modules. Column anchor plates are pre-embedded on the columns, and inner and outer anchor plates are pre-embedded radially on the ribs. Anchor bolt holes are provided on the column anchor plates, inner and outer anchor plates of the ribs.

[0008] Prestressed anchors are inserted into the anchor holes corresponding to adjacent precast modules; the prestressed anchors are tensioned after the grouting of the column and the rib is completed, so that the adjacent precast modules form a circumferential prestressed compression constraint.

[0009] Furthermore, the anchor plate of the pedestal, the inner anchor plate of the rib beam, and the outer anchor plate of the rib beam are provided with anchor plate shear studs for fastening.

[0010] Furthermore, grooves are provided on the joint surfaces of adjacent prefabricated modules.

[0011] Furthermore, a sealing groove is provided at the edge of the joint, with a built-in sealing strip.

[0012] This invention also provides a construction method for a fully prefabricated foundation structure for onshore wind power, comprising the following steps:

[0013] First, before assembling each prefabricated module, sealing strips are installed in the sealing grooves at the joints of the columns, ribs, and base plates; then, each prefabricated module is hoisted and positioned at the positioning line for assembly, ensuring the integrity of the sealing strips during the assembly process.

[0014] Secondly, clean the debris in the gaps between adjacent precast modules; continuously inject grout from the bottom area into the joints to ensure that the grout fills the gaps, so as to form column grouting and rib beam grouting respectively;

[0015] Finally, prestressed anchor bolts are inserted into the anchor bolt holes of the column anchor plate, the inner anchor plate of the rib beam, and the outer anchor plate of the rib beam. After the grouting of the column and the grouting of the rib beam are completed, the prestressed anchor bolts are tensioned in sequence according to the middle layer, the bottom layer, and the top layer, so that the adjacent precast modules are pressed together and form circumferential prestressed constraints.

[0016] Compared with the prior art, the beneficial effects of the technical solution of the present invention are:

[0017] 1. By using the anchor plates of the pedestal, the inner anchor plates of the rib beams, and the outer anchor plates of the rib beams in conjunction with the prestressed anchor bolts, the isolated precast sections are forcefully compressed along the circumference to form a continuous circumferential force path, overcoming the defect of existing technologies that are difficult to achieve uniform constraint around the entire circumference; and significantly improving the overall stiffness and torsional performance of the foundation structure.

[0018] 2. The process of first filling the joints of each prefabricated module with grout and then tensioning the prestressed anchors effectively eliminates the voids in the joints and improves the bonding conditions, avoiding local stress concentration under long-term cyclic load of the wind turbine; reducing the risk of crack generation and propagation, and improving fatigue resistance.

[0019] 3. By combining circumferential prestressing clamping with sealing grooves and sealing strips at the joints, a two-pronged approach effectively blocks the channels for external water erosion, thereby inhibiting freeze-thaw cycles and steel corrosion. This improves long-term durability and reduces maintenance requirements.

[0020] 4. Because of the groove at the joint, the solid key formed after grouting can be deeply fitted with the component, ensuring the continuity of shear force transmission and improving the shear capacity of the joint.

[0021] 5. The anchor plates of the pedestal, the inner anchor plates of the rib beams, and the outer anchor plates of the rib beams are reliably connected to the pedestal and the rib beams respectively through anchor plate shear studs. This can improve the anti-slip capability between the anchor plates and the precast modules, and enable the tension force of the prestressed anchor bolts to be stably transmitted to the precast modules, thereby enhancing the reliability of the anchoring connection.

[0022] 6. The rib beams are provided with inner and outer anchor plates along the radial direction, so that the inner and outer sides of the rib beam joints are both subject to circumferential prestressing constraints. This helps to improve the stress coordination of the rib beam joints and reduce the risk of joint opening under bending moment and torque.

[0023] 7. The prestressed anchors are tensioned sequentially in the middle, lower and upper regions, so that the circumferential prestress is gradually applied to the precast assembly. This helps to reduce local eccentric stress and uneven deformation, and improves the overall stress uniformity after the precast modules are connected.

[0024] 8. By combining factory prefabrication of modules, on-site assembly, joint grouting, and prestressing tension, the amount of on-site wet work and curing waiting time can be reduced, and the consistency of prefabricated module processing quality and on-site construction efficiency can be improved. Attached Figure Description

[0025] Figure 1 This is a three-dimensional view of the basic structure provided by the present invention;

[0026] Figure 2 This is a top view of the basic structure provided by the present invention;

[0027] Figure 3 This is a top view of the interconnected state of the prefabricated modules provided by the present invention;

[0028] Figure 4 This is a perspective view of the single prefabricated module provided by the present invention;

[0029] Figure 5 This is a side view of the prefabricated module provided by the present invention;

[0030] Figure 6 This is a schematic diagram of the side groove of the prefabricated module provided by the present invention; Detailed Implementation

[0031] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention.

[0032] Example 1

[0033] This embodiment provides a fully prefabricated foundation structure for onshore wind power, including:

[0034] Prefabricated foundation 1 is formed by circumferentially splicing several prefabricated modules. Prefabricated foundation 1 is a wind turbine foundation structure assembled on site using prefabricated modules. The assembly of each prefabricated module is achieved through module disassembly and connection design.

[0035] The prefabricated module includes a base plate 4, rib beams 3 mounted on the base plate 4, and columns 2 located within the inner ring of the base plate 4. The columns 2 serve as vertical load-bearing and concentrated force transfer components between the tower and the foundation, transferring vertical, bending moment, and torsional loads to the rib beams 3 and the base plate 4. They are typically hollow, segmented, and assembled. The rib beams 3 radially transfer the bending moment, horizontal load, and shear force concentrated at the columns 2 to the base plate 4, contributing to the foundation's circumferential stiffness and torsional resistance. They are generally trapezoidal, fan-shaped prefabricated sections to provide the necessary bending and shear bearing capacity and stiffness. The base plate 4 bears and distributes the loads from the rib beams and columns, forming a force-bearing surface in contact with the ground and transferring horizontal forces and torques to the ground or pile foundations through friction and anchoring.

[0036] The columns 2 of adjacent prefabricated modules are filled with column grouting 5; column grouting 5 realizes continuous contact and bonding between prefabricated modules, thereby ensuring reliable load transfer, eliminating voids and stress concentration, and improving joint durability and the mechanical properties of the overall structure.

[0037] The space between the ribs 3 of adjacent prefabricated modules is filled with rib grout 6; the rib grout 6 fills the joints of the adjacent prefabricated ribs 3 with high-performance grouting material, connecting several thin-walled prefabricated sections into a thicker, continuous integral rib body, increasing the cross section and improving bending and torsional stiffness and force transmission capacity.

[0038] A column anchor plate 7 is pre-embedded on column 2. The column anchor plate 7 is a steel plate used to circumferentially anchor the grouted part of column 2. The precast section is pressed by tensioning the prestressed anchor bolts to form a circumferential connection, which enhances the integrity of the joint and the overall stress transmission.

[0039] Rib beam 3 is pre-embedded radially with inner anchor plate 8 and outer anchor plate 9. The inner anchor plate 8 and outer anchor plate 9 are used to circumferentially anchor the rib beam after grouting. The precast section is pressed together by prestressed anchor bolts to form a continuous circumferential connection, which improves the integrity of the joint and the force transmission performance. The arrangement of two rows of anchor plates radially facilitates construction quality control and further enhances the overall integrity and stress coordination.

[0040] Anchor plate shear studs are provided on the column anchor plate 7, the inner anchor plate 8 of the rib beam, and the outer anchor plate 9 of the rib beam for fastening. The column anchor plate 7 is fastened to the column 2 via column anchor plate shear studs 11, and the inner anchor plate 8 and the outer anchor plate 9 of the rib beam are fastened to the rib beam 3 via rib beam anchor plate shear studs 10. The rib beam anchor plate shear studs 10 and the column anchor plate shear studs 11 are used to reliably transfer shear force and lock the pre-embedded anchor plates to the foundation concrete of the column 2 and the rib beam 3.

[0041] Anchor bolt holes 12 are provided on the column anchor plate 7, the inner anchor plate 8 of the rib beam, and the outer anchor plate 9 of the rib beam for inserting prestressed anchor bolts 13. The prestressed anchor bolts 13 on the column anchor plate 7 and the inner anchor plate 8 of the rib beam are arranged in layers along the height direction. The prestressed anchor bolts 13 on the outer anchor plate of the rib beam are arranged in two layers, both located in the lower region. The prestressed anchor bolts 13 are tensioned after the grouting of the column grouting 5 and the grouting of the rib beam 6 is completed, so that the adjacent precast modules generate circumferential compressive stress and tighten the joint.

[0042] The inner anchor plate 8 and the outer anchor plate 9 of the rib beam are both embedded inside the rib beam 3, which distinguishes them from the anchor plate 7 of the pedestal.

[0043] Preferably, grooves 14 are provided on the joint surfaces of adjacent precast modules. These grooves are used to form solid keys after grouting, which are embedded with the components and transmit shear force, effectively improving the shear bearing capacity and force transmission continuity of the precast module joints.

[0044] A sealing groove 15 is reserved at the edge of the joint, with an internal sealing strip to ensure the integrity and sealing during the assembly process.

[0045] Example 2

[0046] Based on the same inventive concept, this application also provides a construction method based on the above-mentioned fully prefabricated onshore wind power foundation structure, specifically including the following:

[0047] (1) Prefabricated module processing: prefabricated modules are designed and manufactured according to structural design requirements;

[0048] (2) When fabricating precast modules, anchor bolt holes should be installed on each column anchor plate, inner anchor plate of the rib beam, and outer anchor plate of the rib beam, and positioning and temporary support should be provided to prevent displacement or deformation during pouring. The horizontal and verticality of the holes must be checked and adjusted before pouring;

[0049] (3) Excavation and backfilling of the foundation pit. The excavation of the foundation pit shall be carried out after the site is leveled. The plane position of the foundation shall be determined on site according to the coordinates of the center point of the wind turbine foundation.

[0050] (4) Foundation cushion layer pouring: The foundation cushion layer is poured on the surface of the excavated and leveled soil layer to prepare the site for the assembly of prefabricated modules.

[0051] (5) Basic positioning: After the subbase construction is completed, positioning lines are drawn and positioning components are installed. After the positioning process is completed, the prefabricated modules are hoisted, and the prefabricated modules are accurately placed at the positioning lines during hoisting.

[0052] (6) Structural assembly: Before assembling each structure, sealing strips are installed at the sealing grooves 15 of the columns, ribs and base plates to ensure the integrity of the sealing strips during the assembly process.

[0053] (7) Grouting between columns: Before grouting, clean the debris from the gaps between adjacent precast modules; and pre-embed cylindrical foam structures at the prestressing duct locations of the columns and ribs to prevent grout from entering and clogging the prestressing ducts. During grouting, continuously inject grout from the bottom of the joint gap in designated areas to fully fill the joint gap, forming grouting structures for the columns and ribs respectively.

[0054] (8) Prestressing tensioning: Prestressing anchors are inserted into the anchor holes of the column anchor plate, the inner anchor plate of the rib beam, and the outer anchor plate of the rib beam. The prestressing anchors on the column anchor plate and the inner anchor plate of the rib beam are arranged in layers along the height direction, and the prestressing anchors on the outer anchor plate of the rib beam are arranged in two layers, both located in the lower region. After the column grouting and the rib beam grouting are completed, the prestressing anchors in the middle region are tensioned first, then the prestressing anchors in the lower region are tensioned, and finally the prestressing anchors in the upper region are tensioned. The two layers of prestressing anchors on the outer anchor plate of the rib beam are tensioned in the lower region so that the adjacent precast modules are pressed together and form a circumferential prestressing constraint.

[0055] This invention is not limited to the embodiments described above. The above description of specific embodiments is intended to illustrate and explain the technical solutions of this invention. The specific embodiments described above are merely illustrative and not restrictive. Without departing from the spirit and scope of the claims, those skilled in the art can make many specific modifications based on the teachings of this invention, and these modifications all fall within the scope of protection of this invention.

Claims

1. A fully prefabricated foundation structure for onshore wind power, characterized in that, include: The prefabricated assembly is composed of several prefabricated modules spliced ​​circumferentially. Each prefabricated module includes a base plate (4), rib beams (3) set on the base plate (4), and columns (2) located in the inner circle of the base plate (4). Column grouting (5) is filled between the columns (2) of adjacent prefabricated modules. Rib beam grouting (6) is filled between the rib beams (3) of adjacent prefabricated modules. Column anchor plates (7) are pre-embedded on the columns (2), and inner rib beam anchor plates (8) and outer rib beam anchor plates (9) are pre-embedded radially on the rib beams (3). Anchor bolt holes (12) are opened on the column anchor plates (7), inner rib beam anchor plates (8), and outer rib beam anchor plates (9). The prestressed anchor bolt (13) is inserted into the anchor bolt hole (12) corresponding to the adjacent precast module; the prestressed anchor bolt (13) is tensioned after the grouting of the column (5) and the grouting of the rib beam (6) is completed, so that the adjacent precast modules form a circumferential prestressed compression constraint.

2. The fully prefabricated onshore wind power foundation structure according to claim 1, characterized in that, Anchor plate shear studs are provided on the column anchor plate (7), the inner anchor plate (8) of the rib beam and the outer anchor plate (9) of the rib beam for fastening.

3. The fully prefabricated onshore wind power foundation structure according to claim 1, characterized in that, A groove (14) is provided on the joint surface of adjacent prefabricated modules.

4. The fully prefabricated onshore wind power foundation structure according to claim 1, characterized in that, A sealing groove (15) is reserved at the edge of the joint, with a built-in sealing strip.

5. A construction method for a fully prefabricated onshore wind power foundation structure as described in any one of claims 1-4, characterized in that, Includes the following steps: First, before assembling each prefabricated module, a sealing strip is installed in the sealing groove (15) at the joint of the column (2), rib beam (3) and base plate (4); then, each prefabricated module is hoisted and set at the positioning line for assembly, and the integrity of the sealing strip is ensured during the assembly process. Secondly, clean the debris from the gaps between adjacent prefabricated modules; Continuous grouting is performed from the bottom area joint to ensure that the grout fills the gap, so as to form column grouting (5) and rib beam grouting (6) respectively. Finally, prestressed anchor bolts (13) are inserted into the anchor bolt holes (12) of the column anchor plate (7), the inner anchor plate (8) of the rib beam and the outer anchor plate (9) of the rib beam; after the grouting of the column (5) and the grouting of the rib beam (6) are completed, the prestressed anchor bolts (13) are tensioned in sequence according to the middle layer, the bottom layer and the top layer, so that the adjacent precast modules are pressed together and form circumferential prestressed constraints.

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