Composite land fan foundation

Abstract

The utility model provides a composite type land fan foundation, and relates to the technical field of fan foundations. The structure comprises a stand and a foundation slab, an extension part is formed between the periphery of the stand and the foundation slab, normal concrete is poured in the stand and the extension part, the foundation slab comprises a bottom layer, a main body layer and a top layer which are sequentially paved from bottom to top, the bottom layer and the top layer are made of slurry-rich concrete, and the main body layer is made of roller compacted concrete. The junction area of the extension part and the foundation slab forms a combination area, in the combination area, the extension part and the foundation slab are overlapped in a layered and crossed manner, and radial joint bars for connecting the extension part and the foundation slab are arranged in the combination area, so that close combination of dissimilar concrete interfaces can be realized, and the force transfer characteristic is good; the formwork erecting procedure of normal concrete in the stand and the extending part can be omitted, construction is convenient, and the construction efficiency is high.

Description

Technical Field

[0001] The utility model relates to the technical field of wind turbine foundations, in particular to a composite onshore wind turbine foundation. Background Art

[0002] With the continuous upgrade of the capacity of onshore wind turbine models, the size of wind turbine foundations and the amount of concrete and steel used have also increased. This has led to a significant increase in the cost of wind turbine foundations, reducing the economic efficiency of wind turbine foundations. At the same time, due to the increase in concrete volume, the vibration time during the concrete pouring construction of the wind turbine foundation becomes longer, which is prone to the formation of construction joints due to untimely material supply. On the one hand, this affects the safety of the wind turbine foundation, and on the other hand, the construction time and efficiency are difficult to meet normal engineering construction requirements. Generally, conventional large-volume concrete has a high cement content, large cross-sectional dimensions, and a significant hydration heat effect. Conventional concrete is prone to shrinkage due to temperature differences, causing cracks in the structure, making it difficult to ensure the structural strength and safety of the wind turbine foundation. At the same time, the temperature control requirements for wind turbine foundation construction are more stringent, which will reduce the economic efficiency of the wind turbine foundation.

[0003] Given the current state of the project, it's necessary to improve existing conventional concrete fans by adopting concrete materials with low hydration heat effects, low cost, and easy construction. Currently, RCC prioritizes cost efficiency and durability in material selection, and ease of construction and structural performance in mix design. Compared to conventional concrete, this technology can reduce fan foundation costs and improve construction efficiency while ensuring a safe and stable fan foundation structure.

[0004] For example, Chinese invention patent application CN114411796 A discloses a method for zoning the construction of concrete for onshore wind turbine foundations, in which roller-compacted concrete is constructed after the bottom steel bars are laid in the foundation pit, which will cause the steel bars to be affected by the rolling construction of the roller-compacted concrete and cause the steel bars to be displaced; roller-compacted concrete is used to construct the cantilever plate area, and a thin layer is continuously spread by a leveling machine, and then a small vibrating roller is used to compact it. The first top plate reinforcement is laid on the top of the roller-compacted concrete, and then the top deformed concrete is constructed. After the construction is completed, it is smoothed according to the foundation slope. The construction of this cone slope foundation structure is difficult, inefficient, and has poor construction effect; the groove paving method is used at the edge area away from the middle pier extension area to carry out deformed concrete construction in the edge area, among which deformed concrete can be used near the formwork, around the holes, and where the steel bars are arranged. This interface between different concretes has the disadvantages of poor bonding performance and poor force transmission. Utility Model Content

[0005] In view of the above shortcomings of the prior art, the technical problem to be solved by the present invention is to provide a composite onshore wind turbine foundation that is convenient to construct and efficient.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A composite onshore wind turbine foundation comprises a column and a foundation base plate, an extension portion is formed between the periphery of the column and the foundation base plate, normal concrete is poured into the column and the extension portion, the foundation base plate comprises a bottom layer, a main layer and a top layer paved in sequence from bottom to top, the bottom layer and the top layer are composed of slurry-rich concrete, the main layer is composed of roller-compacted concrete, the junction area between the extension portion and the foundation base plate constitutes a bonding area, within the bonding area, the extension portion and the foundation base plate are layered and cross-lapped, and radial dowel bars connecting the extension portion and the foundation base plate are provided in the bonding area.

[0008] Furthermore, a plurality of anchor bolt assemblies are installed in the platform column, and an anchor rod steel cage is provided on the periphery of each anchor bolt assembly.

[0009] Furthermore, a lower steel mesh connected to the column and the extension portion is provided in the bottom layer of the foundation slab.

[0010] Furthermore, an upper steel mesh connected to the column and the extension portion is provided on the interface between the main layer and the top layer of the foundation slab.

[0011] Preferably, the upper steel mesh is a segmented steel mesh with 2-4 segments.

[0012] Furthermore, the extension portion and the top surface of the base slab are on the same horizontal plane.

[0013] Furthermore, the radial width of the extension portion is not less than 1 m.

[0014] Furthermore, the thickness of the bottom layer and the top layer are both 200-400 mm.

[0015] Furthermore, the radial width of the bonding area is not less than 200 mm.

[0016] Furthermore, the radial inserted reinforcements are arranged in multiple layers from bottom to top.

[0017] The utility model has the following beneficial effects: the boundary area between the extension part of the fan foundation and the foundation bottom plate of the utility model constitutes a bonding area, the extension part and the foundation bottom plate in the bonding area are layered and cross-lapped, and radial dowel bars connecting the extension part and the foundation bottom plate are provided in the bonding area, which can achieve a tight bonding of the interface between different concretes and has good force transmission characteristics, and can save the formwork process of normal concrete in the pedestal and the extension part, and the construction is convenient and efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the elevation structure of the composite onshore wind turbine foundation of the utility model.

[0019] Figure 2 This is a schematic diagram of the planar structure of the composite onshore wind turbine foundation of the utility model.

[0020] Figure 3 This is a schematic diagram of the elevation structure of the foundation steel bars in this utility model.

[0021] Figure 4 It is a structural schematic diagram of the upper steel mesh in the utility model.

[0022] Figure 5 This is a schematic structural diagram of the combining area in one embodiment of the present invention.

[0023] Description of Reference Numerals

[0024] 1 Pillar

[0025] 2 Foundation slab

[0026] 21 bottom floor

[0027] 211 Lower steel mesh

[0028] 22 Main layer

[0029] 23 Top Floor

[0030] 3 Extension

[0031] 4 Radial dowels

[0032] 5 Anchor bolt assembly

[0033] 6 Anchor reinforcement cage

[0034] 7 Upper steel mesh

[0035] 8 Binding zone DETAILED DESCRIPTION

[0036] The following is a further detailed description of the specific embodiments of the present invention in conjunction with the accompanying drawings. These embodiments are only used to illustrate the present invention, and are not intended to limit the present invention.

[0037] In the description 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 directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific direction, be constructed, or operate in a specific direction. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0038] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" 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, indirect connections through an intermediate medium, and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0039] In addition, in the description of the present invention, unless otherwise specified, “a plurality of” means two or more.

[0040] Combine Figures 1 to 4 The utility model provides a composite onshore wind turbine foundation, including a column 1 and a foundation base plate 2. The foundation base plate 2 includes a bottom layer 21, a main layer 22 and a top layer 23 paved in sequence from bottom to top. The thickness of the bottom layer 21 and the top layer 23 are both 200-400mm. An extension portion 3 is formed between the periphery of the column 1 and the foundation base plate 2. The radial width of the extension portion 3 is not less than 1m, ensuring that the area with a larger stress distribution at the edge of the column 1 has sufficient cross-sectional strength. The extension portion 3 and the top surface of the foundation base plate 2 are on the same horizontal plane. The boundary area between the extension portion 3 and the foundation base plate 2 constitutes a bonding area 8. The radial width of the bonding area 8 is not less than 200mm.

[0041] like Figure 1 and 3Normal concrete is poured into the column 1 and the extension 3, and multiple anchor bolt assemblies 5 are installed in the column 1. The periphery of each anchor bolt assembly 5 is tied on-site with an anchor rod steel cage 6; the bottom layer 21 of the foundation slab 2 is provided with a lower steel mesh 211 connected to the column 1 and the extension 3. The lower steel mesh 211 is tied on-site to the anchor rod steel cage 6 in the foundation pit at one time. The main layer 22 of the foundation slab 2 is composed of roller-compacted concrete, and the bottom layer 21 and the top layer 23 of the foundation slab 2 are composed of rich slurry concrete. The rich slurry concrete has a stronger grip and bonding with the steel bars, which is conducive to improving the stability of the wind turbine foundation. The synergistic force of the rich slurry concrete and the steel bars in the foundation slab 2 can improve the strength of the foundation slab 2, and at the same time, it can avoid the influence of the rolling construction on the displacement of the steel mesh in the foundation slab 2 when using roller-compacted concrete. An upper steel mesh 7 connected to the column 1 and the extension 3 is provided at the interface between the main layer 22 and the top layer 23 of the foundation slab 2. The upper steel mesh 7 is a segmented steel mesh, which can be prefabricated and tied in a steel processing plant. The number of segments is 2-4. Since the upper steel mesh 7 is placed on the rolled concrete surface with low slump in the main layer 23, the structural steel bars on the edge side of the foundation slab 2 and the supporting horse stool bars and tie bars between the upper steel mesh 7 and the lower steel mesh 211 can be omitted, which can significantly save the amount of steel bars used in the wind turbine foundation and improve the economy of the wind turbine foundation construction project.

[0042] like Figure 5 As shown, within the joint area 8, the extension 3 and the foundation slab 2 are cross-jointed in layers, forming a tooth-shaped, staggered interface. Radial dowels 4 are provided in the joint area 8 to connect the extension 3 and the foundation slab 2. These dowels 4 are arranged in multiple layers from bottom to top, preferably with vertical intervals of approximately 600 mm. Each layer of radial dowels 4 radiates outward from the center of the column 1 and is evenly distributed. When the extension 3 and the foundation slab 2 are synchronously cross-jointed in layers, the staggered interface of the dissimilar concrete in the joint area 8 allows for a tight integration of the wind turbine foundation as a whole, resulting in excellent force transmission characteristics and eliminating the need for conventional concrete formwork.

[0043] In one embodiment, Figure 1 As shown, the wind turbine foundation adopts a double-layer cylindrical structure, and the extension part 3 is on the same horizontal plane as the top surface of the foundation bottom plate 2. Compared with the traditional wind turbine foundation adopts a three-section foundation structure with a conical slope, the upper surface of the cylindrical structure is horizontal, which is convenient for flattening and rolling construction, and convenient for the construction operation of the rolling equipment. Compared with traditional normal concrete vibration pouring, the construction speed is faster, the pouring operation time is saved, and the rolling effect is good.

[0044] The following describes in detail the construction method of the composite onshore wind turbine foundation of the present invention using a specific embodiment:

[0045] S1. Determine the mix ratio of normal concrete, roller-compacted concrete and rich slurry concrete through experiments, and excavate the foundation pit for the fan foundation.

[0046] S2. Install several anchor bolt assemblies 5 in the foundation pit and inside the platform column 1. Tie an anchor rod reinforcement cage 6 on site around each anchor bolt assembly 5, and connect the lower reinforcement mesh 211 to the anchor rod reinforcement cage 6 on site.

[0047] S3. First, rich slurry concrete is laid on the outer circle to form the bottom layer 21 of the foundation slab 2; then normal concrete is pumped into the inner circle for pouring and vibrating to form the bottom of the column 1 and the extension 3, and the outer circle of the extension 3 extends to above the bottom layer 21 of the foundation slab 2 to form an overlap; then, a layer of roller-compacted concrete is laid on the outer circle, and the inner circle of the roller-compacted concrete extends to above the poured normal concrete to form an overlap; in this way, normal concrete and roller-compacted concrete are laid upward layer by layer to form a mutually overlapping joint area 8 at the junction of the extension 3 and the foundation slab 2.

[0048] S4. After pouring normal concrete in the joint area 8 each time, place the radial dowel bar 4 on the normal concrete to connect the extension part and the foundation bottom plate, and then vibrate it obliquely with a vibrator.

[0049] S5. After the roller compacted concrete is laid and compacted, a crane is used to place the upper steel mesh 7 on the main layer 22 of the foundation slab 2, and the upper steel mesh 7 is tied and connected to the steel cage of the column 1 and the extension 3.

[0050] S6. Lay rich slurry concrete to form the top layer 23 of the foundation slab 2, vibrate and pour, and simultaneously pour normal concrete in the column 1 until it reaches the top of the column 1 and the pouring is completed. Simultaneously pour normal concrete in the extension part 3 until the extension part 3 and the top surface of the foundation slab 2 are on the same horizontal plane.

[0051] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and replacements can be made without departing from the technical principles of the present invention. These improvements and replacements should also be regarded as the scope of protection of the present invention.

Claims

1. A composite onshore wind turbine foundation, comprising a column (1) and a foundation base plate (2), wherein an extension portion (3) is formed between the periphery of the column (1) and the foundation base plate (2), and normal concrete is poured into the column (1) and the extension portion (3). The foundation base plate (2) comprises a bottom layer (21), a main body layer (22), and a top layer (23) which are paved in sequence from bottom to top, characterized in that: The bottom layer (21) and the top layer (23) are composed of rich slurry concrete, the main body layer (22) is composed of roller-compacted concrete, the boundary area between the extension part (3) and the base bottom plate (2) constitutes a bonding area (8), within the bonding area (8), the extension part (3) and the base bottom plate (2) are layered and cross-jointed, and radial dowel bars (4) connecting the extension part (3) and the base bottom plate (2) are provided in the bonding area (8).

2. The composite onshore wind turbine foundation according to claim 1, characterized in that: A plurality of anchor bolt assemblies (5) are installed in the platform column (1), and an anchor rod reinforcement cage (6) is provided on the periphery of each anchor bolt assembly (5).

3. The composite onshore wind turbine foundation according to claim 1, characterized in that: A lower steel mesh (211) connected to the platform column (1) and the extension portion (3) is provided in the bottom layer (21) of the foundation bottom plate (2).

4. The composite onshore wind turbine foundation according to claim 1, characterized in that: An upper steel mesh (7) connected to the platform column (1) and the extension portion (3) is provided on the interface between the main layer (22) and the top layer (23) of the foundation bottom plate (2).

5. The composite onshore wind turbine foundation according to claim 4, characterized in that: The upper steel mesh (7) is a segmented steel mesh, and the number of segments is 2-4.

6. The composite onshore wind turbine foundation according to claim 4, characterized in that: The extension portion (3) is on the same horizontal plane as the top surface of the base bottom plate (2).

7. The composite onshore wind turbine foundation according to claim 1, characterized in that: The radial width of the extension portion (3) is not less than 1 m.

8. The composite onshore wind turbine foundation according to claim 1, characterized in that: The thickness of the bottom layer (21) and the top layer (23) are both 200-400 mm.

9. The composite onshore wind turbine foundation according to claim 1, characterized in that: The radial width of the bonding area (8) is not less than 200 mm.

10. The composite onshore wind turbine foundation according to claim 1, characterized in that: The radial inserted ribs (4) are arranged in multiple layers from bottom to top.

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