Rock area wind tower combined foundation

Abstract

The utility model relates to the technical field of wind tower foundations, in particular to a combined foundation of a wind tower in a rock area. Comprising an original foundation, a top table is arranged at the top of the original foundation, a first hidden beam is annularly arranged on the periphery of the top table, a plurality of anchor bolts are annularly arranged on the first hidden beam, and the anchor bolts are anchored into the original foundation; a new foundation is poured on the side face of the original foundation and connected with the original foundation and the first hidden beams through steel bars. Second hidden beams are arranged on the periphery of the original foundation in the circumferential direction, a plurality of prestress assemblies are evenly arranged on the second hidden beams, and the lower portions of the prestress assemblies are anchored into the rock soil layer. The combined foundation provided by the utility model is improved on the basis of the original foundation, the service life of the original foundation and facilities is prolonged and the resources are utilized to a greater extent, various problems in the prior art are comprehensively solved, and technical support is provided for obtaining and implementing future wind power upgrading and reconstruction projects.

Description

Technical Field

[0001] The utility model relates to the technical field of wind tower foundations, in particular to a combined foundation for a wind tower in rocky areas. Background Art

[0002] In June 2023, the National Energy Administration issued the "Management Measures for Wind Farm Renovation, Upgrading, and Decommissioning." These measures encourage wind farms under 1.5 MW and connected to the grid for more than 15 years to undergo renovation, upgrading, and decommissioning. In response to these measures, many older wind farms across China are planning capacity upgrades or expansions. In the future, wind farm renovation and upgrading will be a key development direction for wind power renewable energy.

[0003] At present, in wind farm wind turbine renovation projects, the existing wind turbine foundation is basically demolished and a new foundation is built. This method has the following disadvantages:

[0004] (1) The relevant departments for the approval of wind farm upgrade and renovation projects will consider approving them as new construction projects. The current market new energy indicators are relatively scarce, making approval difficult;

[0005] (2) The relevant departments for the approval of wind farm upgrade and reconstruction projects will consider approving them as new projects. The existing on-grid electricity price will not be settled according to the original electricity price, and relevant national subsidies will not be enjoyed, which will have a significant impact on operation and maintenance benefits;

[0006] (3) The original foundation is demolished. The capacity of a single unit in the upgrade and renovation project is large. The existing foundation red line does not meet the requirements and new land acquisition approval is required;

[0007] (4) The demolition of a large number of existing foundations involves the disposal of solid waste from the existing foundations, which makes environmental protection approval difficult;

[0008] (5) The original foundation was demolished, and a large number of the original foundation, roads and other facilities were abandoned, which was economically weak and affected the project cost and construction period.

[0009] Based on the above drawbacks, some universities and research institutes are conducting research on in-situ transformation based on the original foundation, but most of the research results are still at the stage of scheme and local analysis, and there is no mature advanced technology. Therefore, the present utility model is proposed. Utility Model Content

[0010] The purpose of the utility model is to provide a combined foundation for wind towers in rocky areas. The combined foundation is modified on the original foundation to extend the life and resource utilization of the original foundation and facilities to the greatest extent, comprehensively solve a series of problems existing in the existing technology such as environmental protection, land acquisition, construction period, investment, etc., and provide technical guarantee for the acquisition and implementation of future wind power upgrade and transformation projects.

[0011] The utility model provides a combined foundation for a wind tower in a rocky area, comprising an original foundation, a top platform being provided on the top of the original foundation, a first hidden beam being provided in a circumferential direction around the top platform, a plurality of anchor bolts being provided in a circumferential direction around the first hidden beam, and the anchor bolts being anchored into the interior of the original foundation; a new foundation being cast on the side of the original foundation, and the new foundation being connected to the original foundation and the first hidden beam through steel bars; a second hidden beam being provided in a circumferential direction around the original foundation, a plurality of prestressed assemblies being evenly provided on the second hidden beam, and the lower part of the prestressed assembly being anchored into the rocky soil layer.

[0012] Furthermore, a plurality of circumferential steel bars and a plurality of radial steel bars are provided inside the new foundation, the circumferential steel bars are anchored into the interior of the original foundation, and the radial steel bars are anchored into the interior of the first hidden beam.

[0013] Furthermore, the top of the first hidden beam is more than 1 meter higher than the outdoor floor; the top of the new foundation is at least 500 mm lower than the outdoor floor; the top of the second hidden beam is lower than the outdoor floor and higher than the top of the new foundation.

[0014] Furthermore, a sidewall bottom of the second concealed beam is provided with an armpit, and the armpit is connected to the bottom of the original foundation.

[0015] Furthermore, the height of the added armpit is between 0-1500 mm; the bottom end of the second hidden beam is located lower than the bottom end of the original foundation.

[0016] Furthermore, a polystyrene board is provided at the bottom of the second hidden beam.

[0017] Furthermore, the prestressed assembly includes prestressed anchor cables and prestressed anchor bolts, and a plurality of the prestressed anchor cables and a plurality of the prestressed anchor bolts are evenly arranged along the circumferential direction of the second concealed beam.

[0018] Furthermore, a temporary protection device is provided above the prestressed assembly.

[0019] Furthermore, the temporary protection device includes a protective cover, a fixing bolt is provided on the protective cover, a threaded hole is provided on the top of the second hidden beam, and the fixing bolt is connected to the threaded hole.

[0020] Furthermore, the protective cover is provided with an inspection port, and a sealing plate is hinged at the inspection port.

[0021] In summary, compared with the prior art, the present invention has the following advantages:

[0022] The technical solution of the present invention is to cast a new top platform and a new foundation on the original foundation of the wind tower, and to set a first hidden beam and a second hidden beam in a circumferential direction, and to set a prestressed assembly on the second hidden beam. The diameter of the original foundation does not change much, and the requirements of the original foundation red line can be met, the overall strength is increased, and the overall rigidity of the overall foundation is guaranteed by the arranged anchor bolts, steel bars and prestressed assemblies. The combined foundation provided by the present invention is transformed on the original foundation, thereby improving the bearing capacity of the original foundation and avoiding various disadvantages of demolishing the original foundation and building a new foundation in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 A top view of the modular foundation in Example 1 of the present utility model;

[0025] Figure 2 This is a cross-sectional view of the modular foundation in Example 1 of the present utility model;

[0026] Figure 3 This is a schematic structural diagram of the protective cover in Example 2 of the present utility model;

[0027] Figure 4 A top view of the modular foundation in Example 2 of the present utility model;

[0028] Figure 5 This is a cross-sectional view of the combined foundation in Example 2 of the present utility model.

[0029] Explanation of the accompanying numbers: 1-original foundation; 2-second hidden beam; 201-haunch; 202-phenylene board; 301-prestressed anchor cable; 302-prestressed anchor bolt; 303-protective cover; 3031-fixing bolt; 3032-inspection port; 3033-sealing plate; 4-new foundation; 5-top platform; 6-first hidden beam; 601-anchor bolt; 7-wind tower; 8-outdoor floor. DETAILED DESCRIPTION

[0030] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments. Obviously, the embodiments described are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0031] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0032] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present utility model, "multiple" means two or more, unless otherwise clearly and specifically defined. In addition, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a communication between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to the specific circumstances.

[0033] Example 1

[0034] A combined foundation for wind towers in rocky areas, such as Figure 1 and Figure 2 As shown, it includes the original foundation 1, the top platform 5, the first hidden beam 6, the new foundation 4, and the second hidden beam 2, wherein the first hidden beam 6 is provided with a plurality of anchor bolts 601, and the second hidden beam 2 is provided with a plurality of prestressed assemblies.

[0035] The original foundation 1 is a truncated cone-shaped foundation. The outer surface of the original foundation 1 is roughened, and new steel bars are welded to the steel bars in the original foundation 1 and then inserted into the newly built foundation. This allows the newly built foundation and the original foundation 1 to bear the force together, forming a combined foundation to ensure overall rigidity.

[0036] A new roof platform 5 is cast on the top platform of the existing foundation 1. A first concealed beam 6 is circumferentially arranged around the roof platform 5. The steel bars within the first concealed beam 6 are securely connected to the anchor cage within the existing foundation 1. Multiple anchor bolts 601 are circumferentially arranged on the first concealed beam 6, anchored into the interior of the existing foundation 1. In this embodiment, the first concealed beam 6 is provided with two inner and outer rings of anchor bolts: the inner ring of anchor bolts is located inside the wind tower 7, and the outer ring of anchor bolts is located outside the wind tower 7. The height of the first concealed beam 6 is determined by the length of the anchor bolts 601. Generally, the top of the first concealed beam 6 is positioned at least one meter above the outdoor floor 8.

[0037] A new foundation 4 is cast alongside the existing foundation 1 and connected to the existing foundation 1 and the first concealed beam 6 via rebar. Multiple circumferential and radial rebars are installed at the top of the new foundation 4. The circumferential rebar is anchored into the existing foundation 1, while the radial rebar is anchored into the first concealed beam 6. The top of the new foundation 4 is flat and parallel to the outdoor floor 8. The top of the new foundation 4 is at least 500mm below the outdoor floor 8, facilitating the surface covering with greenery after the in-situ renovation of the entire foundation is completed. The new foundation 4 is also connected to the second concealed beam 2 via rebar.

[0038] A second concealed beam 2 is installed circumferentially around the existing foundation 1. This beam is connected to the existing foundation 1 via rebar. The top of this beam is lower than the outdoor floor 8 and higher than the top of the new foundation 4 to prevent the prestressed components on this beam from wading through water. The bottom of this beam is lower than the bottom of the existing foundation 1. A gusset 201 is installed on the bottom sidewall of this beam, connecting to the bottom of the existing foundation 1. The height and inclination of this gusset are determined by calculation and are generally between 0 and 1500 mm. A polystyrene board 202 is installed at the bottom of this beam.

[0039] A plurality of prestressed assemblies are arranged on the top of the second hidden beam 2, and the prestressed assemblies include prestressed anchor cables 301 and prestressed anchor bolts 302. The plurality of prestressed anchor cables 301 and the plurality of prestressed anchor bolts 302 are evenly arranged along the circumferential direction of the second hidden beam 2, and the prestressed anchor cables 301 and prestressed anchor bolts 302 of each prestressed assembly are located on the same radius of the second hidden beam 2. During installation, the prestressed anchor cables 301 are located on the inside, and the prestressed anchor bolts 302 are located on the outside, and their positions can also be interchanged. The prestressed assembly can also be designed as needed to have a plurality of prestressed anchor cables 301 and a plurality of prestressed anchor bolts 302 cross-distributed. The lower parts of the prestressed anchor cables 301 and the prestressed anchor bolts 302 are anchored into the rock and soil layer, and the anchoring depth can be calculated and determined according to design requirements.

[0040] Practical Application

[0041] A 1.5MW wind turbine was upgraded to a 6.25MW unit. The original foundation was a 15m diameter cone-shaped gravity foundation on rock with a redline width of 17m. The original foundation steel and concrete volume was approximately 350m 3 .

[0042] If the original foundation is demolished and a new foundation is built, the wind load bending moment will be more than three times the original bending moment of 46,000 kNm after the 1.5MW unit is upgraded to a 6.25MW unit. The diameter of the new foundation will be about 22 meters, and the amount of concrete required will be about 750m3. 3 , and the new foundation will exceed the original foundation red line, and conventional technology will not be able to solve the land acquisition restriction problem.

[0043] The technical solution provided by the utility model is used to transform the original foundation into a combined foundation. The width of the second hidden beam is only 0.8m, and the diameter of the combined foundation is about 16.6m. It is within the red line range, solving the problem of land acquisition restrictions, and the amount of concrete used in the transformation is about 300m 3 , saving 450m3 of reinforced concrete compared to conventional technology 3 , saving about 60% of the engineering workload, with obvious results.

[0044] Example 2

[0045] A combined foundation for a wind tower in a rocky area. The technical solution in this embodiment is basically the same as that in Example 1, except that a temporary protection device is provided above the prestressed assembly in this embodiment to ensure the connection stability and reliability of the prestressed anchor cable 301 and the prestressed anchor bolt 302.

[0046] like Figure 3 As shown, the temporary protection device in this embodiment includes a square protective cover 303. The four corners of the protective cover 303 are respectively provided with through holes, and the through holes are threaded with fixing bolts 3031. The top of the second hidden beam 2 is provided with threaded holes corresponding to the through holes. When installing, the fixing bolts 3031 are directly tightened with the threaded holes. After re-applying prestress after one year, the protective cover 303 is removed, and concrete is poured on the top of the second hidden beam 2 to bury the prestressed anchor cable 301 and prestressed anchor bolt 302. Figure 4 As shown, the width of the protective cover 303 in this embodiment is greater than the width of the second hidden beam 2, and the top of the protective cover 303 is higher than the outdoor floor 8, as shown in FIG. Figure 5 As shown. Figure 4 and Figure 5 The structures of the fixing bolts 3031 and the sealing plate 3033 are omitted.

[0047] An inspection port 3032 is provided on the top wall of the protective cover 303, to which a sealing plate 3033 is hinged, for convenient inspection of the prestressed anchor cable 301 and the prestressed anchor bolt 302. The sealing plate 3033 and the protective cover 303 are locked by a locking member, such as a spring latch in the prior art.

[0048] Taking into account that the wind tower foundation is subjected to the dynamic effect of wind load for a long time, the foundation is mainly controlled by the bending moment of wind load. The bending moment of the new unit is generally more than twice the original bending moment. The wind tower combined foundation provided by the utility model is improved on the original basis, and a top platform, a first hidden beam and a new foundation, a second hidden beam are set, and the original foundation is expanded. Through the prestressed assembly, the good tensile performance of the prestressed anchor cable and the prestressed anchor bolt are fully utilized to greatly reduce the bottom area of the foundation. In the upgrade and renovation project, it can meet the requirement that the foundation of a single machine does not exceed the red line, and effectively reduce the project cost and construction period, and extend the life and resource utilization of the existing foundation and facilities to the greatest extent, and comprehensively solve the series of problems existing in the existing technology such as environmental protection, land acquisition, construction period, investment, etc., and provide technical guarantee for the acquisition and implementation of future wind power upgrade and renovation projects.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A combined foundation for a wind tower in a rocky area, characterized in that: The invention comprises an original foundation (1), a top platform (5) is provided on the top of the original foundation (1), a first hidden beam (6) is provided around the top platform (5), a plurality of anchor bolts (601) are provided around the first hidden beam (6), and the anchor bolts (601) are anchored into the interior of the original foundation (1); a new foundation (4) is cast on the side of the original foundation (1), and the new foundation (4) is connected to the original foundation (1) and the first hidden beam (6) through steel bars; a second hidden beam (2) is provided around the original foundation (1), a plurality of prestressed assemblies are evenly provided on the second hidden beam (2), and the lower part of the prestressed assemblies is anchored into the rock soil layer.

2. The rocky area wind tower combined foundation according to claim 1 is characterized in that: The new foundation (4) is provided with a plurality of circumferential steel bars and a plurality of radial steel bars. The circumferential steel bars are anchored into the interior of the original foundation (1), and the radial steel bars are anchored into the interior of the first concealed beam (6).

3. The rocky area wind tower combined foundation according to claim 1, characterized in that: The top of the first hidden beam (6) is more than 1 meter higher than the outdoor floor; the top of the new foundation (4) is at least 500 mm lower than the outdoor floor; the top of the second hidden beam (2) is lower than the outdoor floor and higher than the top of the new foundation (4).

4. The rocky area wind tower combined foundation according to claim 1, characterized in that: The bottom of the side wall of the second concealed beam (2) is provided with an added arm (201), and the added arm (201) is connected to the bottom of the original foundation (1).

5. The rocky area wind tower combined foundation according to claim 4, characterized in that: The height of the added arm (201) is between 0 and 1500 mm; the bottom end of the second concealed beam (2) is located lower than the bottom end of the original foundation (1).

6. The rocky area wind tower combined foundation according to claim 1, characterized in that: A polystyrene plate (202) is provided at the bottom of the second hidden beam (2).

7. The rocky area wind tower combined foundation according to claim 1, characterized in that: The prestressed assembly comprises a prestressed anchor cable (301) and a prestressed anchor bolt (302), and a plurality of the prestressed anchor cables (301) and a plurality of the prestressed anchor bolts (302) are evenly arranged along the circumferential direction of the second concealed beam (2).

8. The rocky area wind tower combined foundation according to claim 7, characterized in that: A temporary protection device is provided above the prestressed assembly.

9. The rocky area wind tower combined foundation according to claim 8, characterized in that: The temporary protection device comprises a protection cover (303), a fixing bolt (3031) is provided on the protection cover (303), a threaded hole is provided on the top of the second concealed beam (2), and the fixing bolt (3031) is connected to the threaded hole.

10. The rocky area wind tower combined foundation according to claim 9, characterized in that: The protective cover (303) is provided with an inspection port (3032), and a sealing plate (3033) is hinged at the inspection port (3032).

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