Fan foundation structure based on squeezed branch piles

Abstract

The utility model provides a fan foundation structure based on squeezed branch piles, which belongs to the technical field of wind power engineering and comprises a main pile formed by reinforced concrete cast-in-place piles, a plurality of bearing discs are arranged on the side wall of the main pile along the length direction of the main pile, and a plurality of branch structures are further arranged on the side wall of the main pile. The thickness of the soil layer where the bearing disc is located is larger than four times of the width of the disc ring, and the thickness of the bearing layer of the branch structure is larger than three times of the length of the branch structure. The defects that a traditional pile foundation of a wind turbine generator mainly adopts a straight pile or a prefabricated pipe pile, the bearing capacity is insufficient, the anti-overturning performance is poor, and the anti-pulling performance is weak are overcome.

Description

Technical Field

[0001] This utility model belongs to the field of wind power engineering technology, and in particular relates to a wind turbine foundation structure based on extruded and expanded support piles. Background Technology

[0002] As the global energy structure shifts towards cleaner energy, wind power installed capacity continues to grow rapidly. Large-megawatt wind turbines now boast tower heights exceeding 150 meters and rotor diameters surpassing 200 meters, significantly increasing the vertical loads and horizontal overturning moments on the foundation structure. Simultaneously, offshore wind power projects are expanding into deeper waters, encountering increasingly complex geological conditions (such as alternating layers of soft soil, sand, and silty clay), placing higher demands on the bearing capacity, pull-out resistance, and dynamic stability of pile foundations.

[0003] Traditional pile foundations for wind turbines mainly use straight piles or precast pipe piles, which suffer from defects such as insufficient bearing capacity, poor overturning resistance, and weak pull-out resistance. Utility Model Content

[0004] The technical problem that this utility model needs to solve is that the traditional pile foundation of wind turbines mainly uses straight piles or precast pipe piles, which face defects such as insufficient bearing capacity, poor anti-overturning performance and weak pull-out performance.

[0005] The technical solution adopted by this utility model for a wind turbine foundation structure based on extruded and expanded pile discs is as follows:

[0006] A wind turbine foundation structure based on extruded and expanded bearing piles includes a main pile composed of reinforced concrete cast-in-place piles. The sidewall of the main pile is provided with several bearing plates along its own length, and the sidewall of the main pile is also provided with several branch structures. The thickness of the soil layer where the bearing plates are located is greater than 4 times the width of the bearing plate ring, and the thickness of the bearing layer of the branch structure is greater than 3 times the length of the branch.

[0007] A further improvement of this utility model is that the diameter of the main pile is 400-2000mm.

[0008] A further improvement of the present invention is that the branch structure includes multiple branch blocks arranged circumferentially on the side wall of the main pile, each branch block having a wedge-shaped cross-section, and the width of the branch block near the root of the main pile is greater than the width of its end.

[0009] A further improvement of this utility model is that the length of each branch block is 125-1000mm, and the width-to-length ratio of the branch block is ≥0.5.

[0010] A further improvement of this utility model is that the reinforcement ratio of the main pile is 0.3%-0.65%, and there is no steel reinforcement in the bearing plate and the branch structure.

[0011] A further improvement of this utility model is that the load-bearing plate and the branch structure are distributed alternately or in combination.

[0012] A further improvement of this utility model is that the bearing plate is a horizontal ring structure, and the width of the ring of the bearing plate is 50mm-300mm.

[0013] The technological advancements achieved by this utility model due to the adoption of the above technical solution are as follows:

[0014] The bearing plate and branch structure in this invention enhance the friction between the foundation structure and the surrounding soil, thereby increasing the bearing capacity of the foundation structure by 30%-50%. The bearing plate and branch structure also increase the contact area between the foundation structure and the surrounding soil, thus improving the uplift bearing capacity of the foundation structure. Furthermore, the bearing plate and branch structure disperse the horizontal load on the foundation structure, reducing the maximum bending moment by 20%-35% and minimizing the deformation of the main pile. Therefore, this invention achieves the effects of traditional pile foundations while shortening the length of the main pile, thereby reducing the amount of concrete used.

[0015] In this invention, the reinforcement ratio of the main pile is 0.3%-0.65%, and there is no steel reinforcement in the bearing plate and the branch structure. Therefore, the amount of steel used is reduced by 20%-45% compared with traditional pile foundations. Since the amount of concrete and steel used is reduced, the cost of this invention is reduced by 10%-20% compared with traditional pile foundations. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a wind turbine foundation structure based on an expanded and recessed pile according to an embodiment of the present invention.

[0017] Figure 2 This is a schematic diagram of a second embodiment of a wind turbine foundation structure based on an expanded and recessed pile, provided by this utility model.

[0018] Figure 3 and Figure 4 This is a schematic diagram of a third embodiment of a wind turbine foundation structure based on a squeezed-expanded support pile provided by this utility model.

[0019] In the attached diagram: 1. Main pile; 2. Bearing plate; 3. Branch structure; 31. Branch block. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings. In the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessarily obscuring the concept of this utility model.

[0021] First refer to Figures 1-4 It is understood that the present invention includes a main pile 1 vertically arranged in the stratum, the main pile 1 having a diameter of 400-2000mm, the main pile 1 being formed by concrete casting, and the reinforcement ratio of the main pile 1 being 0.3%-0.65%; the sidewall of the main pile 1 is provided with a plurality of bearing plates 2 and a plurality of branch structures 3 arranged along its height direction, the bearing plates 2 and the branch structures 3 being formed by concrete casting, and having no internal steel reinforcement; at the same time, the thickness of the soil layer where the bearing plates 2 are located is greater than 4 times the width of the bearing plate ring, and the thickness of the bearing layer where the branch structures 3 are located is greater than 3 times the length of the branch structures 3.

[0022] In this invention, each branch structure 3 includes multiple branch blocks 31 arranged circumferentially on the side wall of the main pile 1. The cross-section of each branch block 31 is wedge-shaped, and the width of the branch block 31 near the root of the main pile 1 is greater than the width of its end. Specifically, the length of each branch block 31 is 125-1000mm, and the width-to-length ratio of each branch block 31 is ≥0.5.

[0023] Each load-bearing plate 2 of this utility model is a horizontal ring structure. The width of the ring of the load-bearing plate 2 is 50mm-300mm, and a closed ring load-bearing surface is formed after the concrete is poured.

[0024] In this utility model, the load-bearing plate 2 and the branch structure 3 are distributed alternately or in combination.

[0025] In the specific installation of the above-mentioned utility model, firstly, a hole for pouring the main pile 1 is drilled in the ground, and then the soil is expanded by hydraulic extrusion machinery at different parts of the side of the hole to form a cavity. Concrete is poured into the cavity where the surrounding soil is compacted, so that the bearing plate 2, the branch structure 3 and the main pile 1 are tightly combined into one.

[0026] Example 1

[0027] like Figure 1 As shown, in this embodiment, the foundation structure of this application is applied to a soft soil foundation in a coastal wind farm. The geological conditions are a surface layer of silty clay (8m thick) and a middle layer of silty sand (12m thick). Specifically, the main pile 1 has a diameter of 1.2m, a pile length of 28m, and a reinforcement ratio of 0.5%. There are three bearing plates 2 arranged from top to bottom, located at 10m, 15m, and 20m of the main pile 1, respectively. The ring width of each bearing plate 2 is 150mm, and the diameter of the plate is 2.2m (1.83 times the diameter of the main pile 1).

[0028] In this embodiment, there are 6 sets of branch structures 3, located at 8m, 12m, 14m, 18m, 22m and 25m of the main pile 1 respectively; wherein, the length of each branch block 31 is 800mm, the root width of each branch block 31 is 500mm (width to length ratio is 0.625), and gradually narrows to a width of 300mm at the end.

[0029] Example 2

[0030] like Figure 2 As shown, in this embodiment, the foundation structure of this application is applied to a strongly weathered rock layer in a hilly wind farm. The geological conditions are a surface residual soil (5m thick) and a lower layer of strongly weathered sandstone. The main pile 1 has a diameter of 1.0m, a pile length of 18m, and a reinforcement ratio of 0.6%. There are two bearing plates 2 arranged from top to bottom, located at 6m and 12m of the main pile 1, respectively. The ring width of each bearing plate 2 is 100mm, and the diameter of the plate is 1.8m (1.8 times the diameter of the main pile 1).

[0031] In this embodiment, there are two sets of branch structures 3, located at 3m and 9m of the main pile 1 respectively. The length of each branch block 31 is 600mm, and the root width of each branch block 31 is 400mm (width to length ratio is 0.67), gradually narrowing to a width of 200mm at the end.

[0032] Example 3

[0033] like Figure 3 and Figure 4 As shown, this embodiment is based on embodiment one or embodiment two, combining the lowest branch structure 3 of embodiment one or embodiment two with the lowest load-bearing plate 2.

[0034] In the above embodiments, this utility model provides a wind turbine foundation structure based on a spur-expanded support pile. The support plate and branch structure in this utility model enhance the friction between the foundation structure and the surrounding soil, thereby increasing the bearing capacity of the foundation structure by 30%-50%. The support plate and branch structure also increase the contact area between the foundation structure and the surrounding soil, thus improving the uplift bearing capacity of the foundation structure. Simultaneously, the support plate and branch structure disperse the horizontal load on the foundation structure, reducing the maximum bending moment by 20%-35% and decreasing the deformation of the main pile. Therefore, this utility model achieves the effects of traditional pile foundations while shortening the length of the main pile, thereby reducing the amount of concrete used.

[0035] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the concept and scope of the present invention. Various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the design concept of the present invention should fall within the protection scope of the present invention. The technical content for which protection is sought in the present invention has been fully described in the claims.

Claims

1. A wind turbine foundation structure based on expanded and recessed piles, comprising a main pile (1) composed of reinforced concrete cast-in-place piles, characterized in that: The sidewall of the main pile (1) is provided with several bearing plates (2) along its own length direction, and the sidewall of the main pile (1) is also provided with several branch structures (3); wherein, the thickness of the soil layer where the bearing plate (2) is located is greater than 4 times the width of its own plate ring, and the thickness of the bearing layer of the branch structure (3) is greater than 3 times the length of the branch structure (3).

2. The wind turbine foundation structure based on expanded and displaced piles according to claim 1, characterized in that: The diameter of the main pile (1) is 400-2000mm.

3. The wind turbine foundation structure based on expanded and recessed piles according to claim 1, characterized in that: The branch structure (3) includes multiple branch blocks (31) arranged circumferentially on the side wall of the main pile (1). Each branch block (31) has a wedge-shaped cross section, and the width of the branch block (31) near the root of the main pile (1) is greater than the width of its end.

4. A wind turbine foundation structure based on expanded and displaced piles according to claim 3, characterized in that: Each of the branch blocks (31) has a length of 125-1000 mm, and the width-to-length ratio of the branch block (31) is ≥0.

5.

5. A wind turbine foundation structure based on expanded and displaced piles according to claim 1, characterized in that: The reinforcement ratio of the main pile (1) is 0.3%-0.65%, and there is no steel reinforcement in the bearing plate (2) and the branch structure (3).

6. A wind turbine foundation structure based on expanded and recessed piles according to claim 1, characterized in that: The load-bearing plate (2) and the branch structure (3) are distributed alternately or in combination.

7. A wind turbine foundation structure based on expanded and recessed piles according to claim 1, characterized in that: The load-bearing plate (2) is a horizontal ring structure, and the width of the ring of the load-bearing plate (2) is 50mm-300mm.

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