Gravity type fan foundation

Abstract

The utility model relates to the technical field of fan foundations, and provides a gravity type fan foundation which comprises a cushion layer, a plurality of fan foundations and a plurality of fan foundations. The main body is arranged on the cushion layer, and a cylindrical first core filling area is arranged in the middle of the main body; the second core filling area is cylindrical, is arranged between the cushion layer and the main body and is used for filling a light material, and the second core filling area and the first core filling area are coaxially arranged and have the same section radius; the second core filling area used for being filled with the light materials is additionally arranged in the center of the bottom of the body, the stress mode of the bottom of the foundation is changed, stress distribution of the bottom of the foundation is changed into annular bottom face distribution from traditional circular full-area distribution, and the center area does not transmit loads to the foundation any more; load is concentrated in the annular area on the edge of the foundation, the load density in the annular area is increased in unit area, the minimum pressure of the bottom of the foundation is effectively improved, the stability of the foundation is enhanced, and the risk that the bottom of the foundation is disengaged is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of fan foundations, in particular to a gravity-type fan foundation. Background Art

[0002] At present, the commonly used onshore wind turbine foundations mostly adopt reinforced concrete extended foundations. These foundation forms are still traditional conical or cylindrical gravity foundations. The foundation form is simple, the amount of foundation concrete used is large, and the weight is heavy. Although the connection between the wind turbine tower and the foundation and the foundation can be achieved by applying prestress to anchor bolts or anchor rods, the wind turbine still has the risk of overturning together with the foundation under large bending moment loads.

[0003] Moreover, with the rapid growth of the single-unit capacity of onshore wind turbine models, the current maximum single-unit capacity of onshore wind turbine models has exceeded 10MW. As a result, the tower diameter has also increased, and the corresponding foundation top diameter has also increased. As a result, the plane size of the foundation has also increased rapidly, and the infrastructure construction cost has increased. Utility Model Content

[0004] The utility model provides a gravity-type fan foundation, which is used to solve the problem of unreliable stability of the fan foundation in the prior art.

[0005] The utility model provides a gravity fan foundation, comprising:

[0006] cushion layer;

[0007] A main body is provided on the cushion layer, wherein a cylindrical first core-filling area is provided in the middle of the main body;

[0008] The second core-filling area is cylindrical and is arranged between the cushion layer and the main body for filling with lightweight materials. The second core-filling area is coaxial with the first core-filling area and has the same cross-sectional radius.

[0009] According to the gravity wind turbine foundation provided by the present invention, a reserved space is provided in the middle of the cushion layer, the second core filling area is provided in the reserved space, and the reserved space is further provided with a covering layer.

[0010] According to the gravity wind turbine foundation provided by the present invention, the main body includes a core area and an edge area, the bottom of the edge area is connected to the cushion layer, the bottom of the core area is connected to the covering layer, and the first core filling area is arranged in the middle of the core area.

[0011] According to the gravity fan foundation provided by the present invention, a core filling area bottom plate is further provided in the middle of the main body, and the core filling area bottom plate is provided at the bottom of the first core filling area and contacts the covering layer.

[0012] According to the gravity wind turbine foundation provided by the present invention, a plurality of anchor bolts are provided in the main body, the plurality of anchor bolts are arranged around the first core filling area, and the bottoms of the anchor bolts are arranged in the reserved space.

[0013] According to the gravity fan foundation provided by the present invention, a mounting hole is provided at the top of the main body. The number of the mounting holes is the same as that of the anchor bolts and the positions correspond one to one. The top of the anchor bolt is located in the mounting hole, and the mounting hole is used for pouring grouting material.

[0014] According to the gravity fan foundation provided by the present invention, the distance between the edge of the first core filling area and the mounting hole is equal to the width of the mounting hole.

[0015] According to the gravity fan foundation provided by the present invention, the thickness h of the bottom plate of the core filling area is greater than 1m.

[0016] According to the gravity fan foundation provided by the utility model, the bottom plate of the core filling area is a cast-in-place reinforced concrete plate.

[0017] According to the gravity fan foundation provided by the present invention, a steel mesh is provided in the bottom plate of the core filling area, and the diameter of the steel mesh is larger than the diameter of the first core filling area.

[0018] The present invention provides a gravity wind turbine foundation. By adding a second core-filled area for lightweight material at the center of the bottom of the main body, the force pattern at the foundation base is changed, optimizing the stress state of the foundation. This prevents the central area from directly transmitting load to the foundation, and the force distribution at the foundation base is transformed from the traditional circular full-area distribution to an annular bottom surface distribution. Since the central area no longer transmits load, the load is concentrated in the annular area at the edge of the foundation. This increases the load density per unit area within the annular area, thereby increasing the effective contact pressure at the foundation base. By changing the force pattern at the foundation base from a circular full-area distribution to an annular bottom surface distribution, the minimum pressure pkmin at the foundation base is effectively increased, thereby enhancing the foundation's stability and reducing the risk of the foundation base coming loose. This design also reduces concrete usage and construction costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1It is a structural schematic diagram of a gravity fan foundation provided by an embodiment of the utility model.

[0021] Figure 2 This is a longitudinal section of a gravity fan foundation provided by an embodiment of the present utility model.

[0022] Figure 3 yes Figure 2 A partial enlarged view of .

[0023] Figure 4 It is a schematic diagram of the force distribution of the basic annular bottom surface provided by an embodiment of the present utility model.

[0024] Figure 5 It is a schematic diagram of the force distribution of the circular full-area bottom of the foundation in the prior art.

[0025] Reference numerals:

[0026] 1. Pad layer; 11. Reserve space;

[0027] 2. Main body; 21. Core area; 22. Peripheral area;

[0028] 3. First core filling area; 4. Second core filling area; 5. Covering layer; 6. Bottom plate of core filling area;

[0029] 61. Steel mesh; 7. Anchor bolt; 8. Mounting hole. DETAILED DESCRIPTION

[0030] To make the purpose, technical solutions, and advantages of the present invention more clear, the following will be combined with the accompanying drawings to clearly and completely describe the technical solutions of the present invention. Obviously, the embodiments described are only some 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 embodiments of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely for the convenience of describing the embodiments of the present invention and to simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0032] In traditional gravity wind turbine foundation design, the foundation bottom is usually a circular full-area force distribution, and the entire foundation bottom evenly bears the load from the upper structure. However, in some cases, especially in the central area, due to the low stress level of the concrete, this area may not be able to effectively transfer the load to the foundation, resulting in negative pressure or detachment at the bottom of the foundation.

[0033] The following combination Figure 1-Figure 5 The utility model describes a gravity fan foundation.

[0034] This embodiment provides a gravity fan foundation, such as Figure 1-Figure 4 As shown, it includes: a cushion layer 1, a main body 2 and a second core filling area 4.

[0035] The cushion layer 1 may be made of concrete, for example, C20 concrete, and may be 100 mm thick. The specific thickness and concrete strength may be selected according to the environment category and specifications.

[0036] The main body 2 can be made of C40 concrete and is positioned on the cushion layer 1. A cylindrical first core-filling area 3 is provided in the middle of the main body 2. A cylindrical second core-filling area 4 is provided between the cushion layer 1 and the main body 2 and is filled with a lightweight material, such as a lightweight, low-strength foam board. The second core-filling area 4 is coaxial with the first core-filling area 3 and has the same cross-sectional radius. In other words, the second core-filling area 4 is located at the bottom center of the main body 2, coaxial with the second core-filling area 4, and has the same cross-sectional dimensions.

[0037] With this arrangement, the present invention changes the stress pattern at the bottom of the foundation by adding a second core-filling area 4 for filling with lightweight material at the bottom center of the main body 2, optimizing the stress state of the foundation. This prevents the central area from directly transmitting load to the foundation, and the stress distribution at the bottom of the foundation changes from the traditional circular full-area distribution to an annular bottom surface distribution. Since the central area no longer transmits load, the load is concentrated in the annular area at the edge of the foundation. This increases the load density per unit area within the annular area, thereby increasing the effective contact pressure at the bottom of the foundation. By changing the stress pattern at the bottom of the foundation from a circular full-area distribution to an annular bottom surface distribution, the minimum pressure pkmin at the bottom of the foundation is effectively increased, thereby enhancing the stability of the foundation and reducing the risk of the foundation bottom detaching. At the same time, this design also reduces the amount of concrete used and lowers construction costs.

[0038] Preferably, the filling material for the first core-filling area 3 is a low-cost, readily available material with a high bulk density, such as sand, gravel, or backfill soil. The material in the first core-filling area 3 is compacted as much as possible to increase weight while maintaining the same volume. This arrangement reduces the amount of concrete used in the low-stress area compared to traditional solutions, further saving concrete material and costs.

[0039] In some specific embodiments, a reserved space 11 is provided in the middle of the cushion layer 1, the second core filling area 4 is provided in the reserved space 11, and the reserved space 11 is further provided with a covering layer 5. Figure 2 As shown, the groove formed by the sinking in the middle of the cushion layer 1 serves as the reserved space 11, the second core filling area 4 is arranged in the reserved space 11, and is located in the middle of the reserved space 11, and the covering layer 5 is a cast concrete layer, which is used to cover the second core filling area 4 after filling with lightweight materials, and cover the remaining space in the reserved space 11. The covering layer 5 protects the core filling material to prevent it from being damaged or shifted during the construction process, thereby ensuring the integrity and effectiveness of the core filling material.

[0040] In this embodiment, the main body 2 includes a core area 21 and an edge area 22. The first core filling area 3 is arranged in the middle of the core area 21. The bottom of the edge area 22 is connected to the cushion layer 1, and the bottom of the core area 21 is connected to the cover layer 5. Figure 2 As shown, the opening size of the reserved space 11 can be set to be no smaller than the bottom size of the core area 21 , so that the bottom of the core area 21 contacts the cover layer 5 , while the edge area 22 directly contacts the cushion layer 1 .

[0041] Furthermore, a core filling area bottom plate 6 is provided at the bottom of the first core filling area 3 , the core filling area bottom plate 6 is in contact with the cover layer 5 , and the core filling area bottom plate 6 is a cast-in-situ reinforced concrete slab.

[0042] In this way, the cast-in-place reinforced concrete slab can evenly transfer the load from the superstructure and avoid local stress concentration. This uniform stress distribution helps to improve the overall bearing capacity of the foundation.

[0043] In addition, by setting up cast-in-place reinforced concrete slabs, the amount of concrete used in low-stress areas is reduced, thereby lowering construction costs.

[0044] Specifically, the thickness h of the core filling area bottom plate 6 is greater than 1 m. A steel mesh 61 is provided in the core filling area bottom plate 6 . The diameter of the steel mesh 61 is greater than the diameter of the first core filling area 3 and extends toward the surrounding core area 21 .

[0045] In this way, by arranging a cast-in-place reinforced concrete slab at the bottom of the first core filling area 3, the overall stiffness of the foundation is increased, and the core filling area bottom plate 6 is tightly combined with the main body 2 to form an integral structure, thereby improving the bending and shearing resistance of the foundation and reducing the risk of structural deformation and damage. The thicker core filling area bottom plate 6 can better resist external loads and internal stresses, especially dynamic loads under wind action, thereby enhancing the bending stiffness of the foundation and making it more stable under dynamic loads.

[0046] In this embodiment, the steel mesh 61 is arranged in the slab, which means that a mesh formed by welding plain round steel bars or ribbed steel bars is arranged in the slab of the building structure according to certain specifications and requirements. By arranging the steel mesh 61 in the slab, the steel mesh 61 can effectively disperse and transfer stress, improve the crack resistance and durability of the concrete slab, prevent the generation and expansion of cracks, and extend the service life of the structure. The design of the steel mesh 61 extending into the core area 21 enhances the connection strength between the various parts of the foundation, ensuring the integrity and stability of the structure.

[0047] In some embodiments, the radius of the steel mesh 61 is at least 35d larger than the radius of the first core filling area 3, where d is the diameter of the round steel bars that make up the steel mesh 61. That is, the steel mesh 61 can extend to the surrounding area and extend into the surrounding core area 21. The steel mesh 61 extends into the core area 21 by no less than 35d. This arrangement ensures good bonding and anchoring between the steel bars and concrete, allowing the steel bars to effectively transfer stress and enhance the connection strength between the various parts of the foundation.

[0048] In this embodiment, a plurality of anchor bolts 7 are passed through the main body 2 . The plurality of anchor bolts 7 are arranged around the first core-filling area 3 , and the bottoms of the anchor bolts 7 are arranged in the reserved space 11 .

[0049] In this way, multiple anchor bolts 7 are arranged around the first core filling area 3 to form an evenly distributed support system, so that the load can be evenly transferred to various parts of the foundation, avoiding local stress concentration. The anchor bolts 7 pass through the foundation body 2 and are firmly connected thereto, thereby enhancing the tensile and shear resistance of the foundation body 2. This connection method enables the foundation to better resist external loads, especially dynamic loads under wind action; by setting the bottom of the anchor bolt 7 in the reserved space 11, it is ensured that the anchor bolt 7 can be firmly fixed in the foundation. The existence of the reserved space 11 makes the installation of the anchor bolt 7 more precise and reduces construction errors.

[0050] In some embodiments, a mounting hole 8 is provided at the top of the main body 2. The number of mounting holes 8 is the same as that of the anchor bolts 7 and their positions correspond one to one. The top of the anchor bolt 7 is located in the mounting hole 8. The mounting hole 8 is used for pouring grouting materials, such as epoxy resin grouting or non-shrinkage cement-based grouting. These materials have excellent bonding properties and durability, can ensure a tight connection between the anchor bolt 7 and the foundation main body 2, and can provide additional anti-corrosion protection to prevent the anchor bolt 7 from being corroded during long-term use, especially in a humid or corrosive environment.

[0051] The specific installation process is: inject high-strength grouting material evenly into the hole until the grouting material completely fills the hole. During the grouting process, care should be taken to eliminate bubbles to ensure that the grouting material is in full contact with the hole wall and the surface of the anchor bolt 7; after that, nuts and washers can be installed on the top of the anchor bolt 7, with specifications matching the anchor bolt 7, and the nuts are tightened to ensure that the anchor bolt 7 is firmly fixed on the foundation body 2.

[0052] In this way, the top of the anchor bolt 7 is fixed by high-strength grouting material, which can fully fill the gap between the anchor bolt 7 and the foundation body 2, ensuring a tight connection between the anchor bolt 7 and the foundation body 2. After being fixed by the grouting material, it is connected to the top of the anchor bolt 7 by a bolt, thereby enhancing the connection strength between the anchor bolt 7 and the foundation body 2 and improving the integrity of the structure.

[0053] In this embodiment, the distance B between the edge of the first core-filling area 3 and the mounting hole 8 is equal to the width B of the mounting hole 8 .

[0054] Such a setting makes the construction process more precise and reduces construction errors. The consistent spacing and width make it easier to control the position and depth of the anchor bolts 7 during construction, improve the structural quality, and also improve the construction efficiency, ensuring the connection strength between the anchor bolts 7 and the foundation body 2. The appropriate distance allows the grouting material to fully fill the hole, enhances the fixing effect of the anchor bolts 7, improves the tensile and shear resistance of the anchor bolts 7, and prevents pull-out or shear damage under external loads such as wind. This design ensures that the distance between the edge of the first core filling area 3 and the mounting hole 8 is moderate, neither too large nor too small, which helps to maintain the integrity and integrity of the structure, makes the distribution of the anchor bolts 7 in the foundation more even, and avoids local stress concentration.

[0055] This embodiment also discloses a method for constructing a gravity wind turbine foundation, comprising:

[0056] Step 1: Pour the concrete of the cushion layer 1.

[0057] In this embodiment, a 100 mm thick C20 concrete cushion layer 1 is poured at a predetermined location. The specific thickness and concrete strength of the cushion layer 1 should be selected according to the environmental category and design specifications to provide a flat and solid foundation for the wind turbine foundation.

[0058] Step 2: Install prestressed anchor bolts 7.

[0059] Specifically, by reserving holes in the cushion layer 1, the position and size of the holes should match the design of the anchor bolt 7; insert the anchor bolt 7 into the reserved holes, remove dust and debris in the holes, and use high-strength grouting material to evenly inject the holes until the grouting material completely fills the holes and overflows the surface, ensuring that it hardens and solidifies within the specified time.

[0060] Step 3: Install the material of the second core filling area 4 and then pour the concrete of the cover layer 5.

[0061] Specifically, the material for the second core-filling zone 4, such as a lightweight, low-strength foam board, is installed in the reserved space 11 in the middle of the cushion layer 1. Concrete for the cover layer 5 is poured over the core-filling material, ensuring that the thickness and concrete strength of the cover layer 5 meet the design requirements. This arrangement reduces the amount of concrete used in the low-stress area, lowers the weight of the foundation, and improves material utilization.

[0062] Step 4: Tie up the steel mesh 61 in the bottom plate 6 of the core filling area and the steel bars in other areas, and install the foundation formwork.

[0063] Specifically, a steel mesh 61 is tied to the bottom of the first core-fill area 3, extending into the core area 21 by at least 35 times the diameter of the steel bars. Rebars in other areas are then tied, ensuring that the position and quantity of the steel bars meet the design requirements. The foundation formwork is then installed, ensuring that its position and dimensions meet the design requirements and that it is firm and flat. This arrangement ensures the structural strength and stability of the foundation body 2.

[0064] Step 5: Pour concrete into the foundation body 2. The purpose is to form the foundation body 2 and ensure the integrity and stability of the foundation.

[0065] Specifically, pour the foundation body 2 concrete according to the design requirements to ensure the uniformity and density of the concrete. During the pouring process, attention should be paid to eliminating bubbles, ensuring sufficient contact between the concrete and the steel bars and formwork, and properly curing the poured concrete to ensure that it hardens and solidifies within the specified time.

[0066] Step 6: After the foundation reaches the demoulding strength, remove the foundation formwork to ensure that the shape and size of the foundation body 2 meet the design requirements.

[0067] Step 7: Fill and compact the material in the first core filling area 3. The purpose is to further reduce the amount of concrete used in the low stress area and improve the stability of the foundation and the material utilization rate.

[0068] Specifically, the first core filling area 3 is filled with cheap and easily available materials, such as graded sand and gravel, backfill soil, etc., to ensure that the position and density of the filling materials meet the design requirements, and use appropriate compacting equipment to compact the filling materials to ensure that they gain more weight without changing their volume.

[0069] Through the above steps, this embodiment provides a method for constructing a gravity wind turbine foundation. The step-by-step construction ensures the orderliness and standardization of the construction process, and improves the construction efficiency and quality. The design sets a first core filling area 3 in the core area 21 of the foundation, and replaces part of the concrete with inexpensive and easily available materials such as graded sand and gravel, backfill soil, etc., thereby reducing the amount of concrete used and reducing costs. Moreover, since these core filling materials have a large bulk density, they can help improve the stability of the entire foundation; by setting a cast-in-place reinforced concrete slab under the first core filling area 3 and setting a second core filling area 4 filled with lightweight materials such as foam benzene boards under it, the force distribution pattern of the bottom of the foundation is changed, and the circular full-area force distribution of the bottom of the traditional gravity wind turbine foundation is transformed into an annular bottom surface force distribution, thereby increasing the minimum pressure pkmin of the bottom of the foundation. Figure 4 and Figure 5 , for the main body 2 with the same size, the minimum pressure pkmin of the annular bottom of the utility model is greater than the minimum pressure pkmin of the circular full-area bottom under the existing technology, thereby reducing the risk of the bottom of the foundation being detached, improving the overall stability and wind resistance of the foundation, and providing strong support for the economy and reliability of wind power generation projects.

[0070] The utility model provides a gravity core-filled fan foundation. The design optimizes the structural layout by rationally utilizing material properties, thereby achieving the purpose of cost savings and ensuring the safety of the structure.

[0071] In the description of the embodiments of the present invention, it should be noted that, unless otherwise specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present invention based on specific circumstances.

[0072] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "mode", "specific mode", or "some modes" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or mode are included in at least one embodiment or mode of the embodiment of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or mode. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or modes in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or modes and features of different embodiments or modes described in this specification without contradiction.

[0073] 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 aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A gravity fan foundation, characterized in that: include: cushion layer (1); A main body (2) is arranged on the cushion layer (1), and a cylindrical first core filling area (3) is provided in the middle of the main body (2); The second core filling area (4) is arranged in a cylindrical shape and is arranged between the cushion layer (1) and the main body (2) for filling with lightweight materials. The second core filling area (4) and the first core filling area (3) are arranged coaxially and have the same cross-sectional radius.

2. The gravity fan foundation according to claim 1, characterized in that: A reserved space (11) is provided in the middle of the cushion layer (1), the second core filling area (4) is provided in the reserved space (11), and the reserved space (11) is further provided with a covering layer (5).

3. The gravity fan foundation according to claim 2, characterized in that: The main body (2) comprises a core area (21) and an edge area (22), the bottom of the edge area (22) is connected to the cushion layer (1), the bottom of the core area (21) is connected to the cover layer (5), and the first core filling area (3) is arranged in the middle of the core area (21).

4. The gravity fan foundation according to claim 2, characterized in that: A core filling area bottom plate (6) is also provided in the middle of the main body (2), and the core filling area bottom plate (6) is provided at the bottom of the first core filling area (3) and in contact with the covering layer (5).

5. The gravity wind turbine foundation according to claim 2, characterized in that: A plurality of anchor bolts (7) are provided in the main body (2), the plurality of anchor bolts (7) are arranged around the first core filling area (3), and the bottoms of the anchor bolts (7) are arranged in the reserved space (11).

6. The gravity wind turbine foundation according to claim 5, characterized in that: The top of the main body (2) is provided with a mounting hole (8), the number of the mounting holes (8) is the same as that of the anchor bolts (7) and the positions correspond one to one, the top of the anchor bolt (7) is located in the mounting hole (8), and the mounting hole (8) is used for pouring grouting material.

7. The gravity wind turbine foundation according to claim 6, characterized in that: The distance B between the edge of the first core filling area (3) and the mounting hole (8) is equal to the width B of the mounting hole (8).

8. The gravity wind turbine foundation according to claim 4, characterized in that: The thickness of the core filling area bottom plate (6) is h>1m.

9. The gravity wind turbine foundation according to claim 4, characterized in that: The core filling area bottom plate (6) is a cast-in-place reinforced concrete plate.

10. The gravity wind turbine foundation according to claim 4, characterized in that: A steel mesh (61) is provided in the core-filling area bottom plate (6), and the diameter of the steel mesh (61) is larger than the diameter of the first core-filling area (3).

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