Fan foundation adopting novel excavation mode and construction method thereof

Abstract

The invention discloses a novel excavation type fan foundation and a construction method thereof, and belongs to the technical field of land wind power generation engineering, the novel excavation type fan foundation comprises a cylindrical main body foundation pit located underground and a plurality of footrills which are excavated from the side wall of the cylindrical main body foundation pit in the radial direction, and concrete is integrally poured in the foundation pit and the footrills to form an integrated fan foundation structure. During construction, firstly, the cylindrical main body foundation pit is vertically excavated downwards to the designed depth, then a footrill is tunneled on the side wall of the cylindrical main body foundation pit and is supported, then steel bars are bound, and concrete is integrally poured. According to the method, traditional large-area open excavation is changed into an innovative structure of combining the vertical foundation pit with the radial footrill, the earth excavation engineering amount and the land occupied area are remarkably reduced, damage to the environment is reduced, meanwhile, the construction cost is saved, the construction period is shortened, and comprehensive benefits are remarkable.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of land wind power generation engineering, and particularly relates to a novel wind turbine foundation with a new excavation mode and a construction method thereof. BACKGROUND

[0002] As an important part of clean energy, the infrastructure construction technology of wind power generation is increasingly valued. The wind turbine foundation is a permanent structure for supporting the tower, nacelle and blades of a wind turbine generator, and the safety and economy thereof are crucial to the entire wind farm project. At present, the wind turbine foundation commonly used in land wind farms is an expanded foundation, also known as a gravity foundation or a raft foundation. This foundation form disperses the load transmitted from the upper structure of the wind turbine to the ground soil body through a large-volume reinforced concrete plate.

[0003] As shown in Fig. 1-2 , the expanded foundation of the prior art generally includes a foundation column 2 buried in the ground and an expanded bottom plate 3 with a radius much larger than the foundation column. As shown in Fig. 3 , a huge conical frustum soil body 4 needs to be completely excavated during construction, i.e., the bottom surface diameter of the excavation is about 3D (D is the diameter of the foundation column 2), and the top surface diameter of the excavation is about 3D+2H (H is the excavation depth), thereby resulting in a huge excavation volume. The excavation volume V can be approximately expressed as: The existing expanded foundation and its excavation mode have the following significant disadvantages: (1) Large amount of earthwork: Since the soil under the entire expanded bottom plate 3 needs to be excavated, a large amount of excavation and subsequent backfill engineering is generated, which not only prolongs the construction period but also directly increases the construction cost; (2) Large land occupation area: The huge excavation range requires more land to be requisitioned, especially the benching performed during the excavation process to ensure the stability of the slope, which further expands the operation area and seriously damages the surface vegetation and original topography; (3) Great damage to the ecological environment: The large-scale excavation and land occupation will seriously damage the ecological environment of the project site, although ecological restoration will be performed later, the restoration period is long, the cost is high, and it is difficult to completely restore to the original state; (4) Increased construction period and cost: The above-mentioned large amount of earthwork, land requisition and ecological restoration measures will prolong the design and construction period of the project and significantly increase the overall construction investment of the project. SUMMARY

[0004] Therefore, the purpose of the present application is to provide a novel wind turbine foundation with a new excavation mode and a construction method thereof, which can significantly reduce the amount of earth excavation, reduce the land occupation area, reduce the damage to the environment and save costs.

[0005] To achieve the above objectives, the present invention provides the following technical solution: This invention first proposes a novel excavation method for wind turbine foundations, comprising: A cylindrical main foundation pit located underground; Multiple adits were excavated horizontally or nearly horizontally from the sidewalls of the cylindrical main pit; The adit extends radially to the designed expansion radius; the main foundation pit and the adit are equipped with a steel reinforcement frame, and are integrally cast with concrete to form an integrated wind turbine foundation structure.

[0006] Furthermore, the number of adits is set to at least three, which are evenly arranged along the sidewall of the cylindrical main pit.

[0007] Furthermore, the volume of the excavated conical platform soil in the cylindrical main foundation pit is: in: The excavation volume of the cylindrical main foundation pit; The bottom diameter of the integrated wind turbine foundation structure; This refers to the excavation depth.

[0008] This invention also proposes a novel excavation method for wind turbine foundation construction, comprising the following steps: Step 1: Excavate a cylindrical main foundation pit to the designed depth at the selected site according to the design radius; Step 2: Excavate multiple adits at selected locations on the sidewall of the foundation pit, and provide support during the excavation process; Step 3: Tie reinforcing bars in the foundation pit and adit; Step 4: Pour concrete as a whole to form an integrated wind turbine foundation structure.

[0009] Furthermore, the tunneling direction of the adit is horizontal or approximately horizontal.

[0010] Furthermore, the support methods include scaffolding and steel plate support.

[0011] Furthermore, the volume of the excavated conical platform soil in the cylindrical main foundation pit is: in: The excavation volume of the cylindrical main foundation pit; The bottom diameter of the integrated wind turbine foundation structure; This refers to the excavation depth.

[0012] The beneficial effects of this invention are as follows: The wind turbine foundation with novel excavation method and its construction method of this invention have the following technical effects: (1) Significantly reduce the amount of work and cost: This invention fundamentally reduces the amount of earthwork excavation and backfilling by changing the traditional large-area open excavation to an innovative structure of "cylindrical foundation pit + radial adit". Theoretical calculations show that, under the same conditions, its excavation volume is reduced by several times compared to the traditional extended foundation, which directly promotes a significant reduction in machine shifts, energy consumption, transportation and labor costs, and effectively controls the project cost. (2) Greatly reduce land occupation and ecological damage: The planar excavation area of ​​the foundation of this invention is reduced by several times compared with the traditional foundation, which greatly reduces the working surface and the scope of damage to the surface vegetation; this not only reduces the disturbance to the original surface, but also reduces the difficulty and cost of subsequent ecological restoration, and achieves environmentally friendly protection. (3) Optimize construction process and cycle: The construction process of the basic structure of this invention is simple and the goal is clear, avoiding the complex process and management difficulty of large-scale earthwork operations, which helps to shorten the construction cycle and improve the overall construction efficiency.

[0013] In summary, this invention, while ensuring structural safety, successfully solves the industry pain point of "large-scale excavation and filling" in traditional wind turbine foundations, achieving multiple beneficial effects of cost reduction, efficiency improvement, and environmental protection, with outstanding comprehensive benefits. Attached Figure Description

[0014] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the following figures are provided for illustration: Fig. 1 A schematic diagram of the existing extended foundation; Fig. 2 A top view of the existing extended base; Fig. 3 A schematic diagram of the excavation for the existing extended foundation; Fig. 4 This is a schematic diagram of the structure of the wind turbine foundation according to the novel excavation method of the present invention; Fig. 5 This is a perspective view of the wind turbine foundation using the novel excavation method described in this embodiment; Fig. 6 This is a flowchart of the wind turbine foundation construction method of the novel excavation method of the present invention; Fig. 7 This is a schematic diagram of the excavation for the wind turbine foundation in this embodiment.

[0015] Explanation of reference numerals in the attached figures: 1-Wind turbine tower; 2-Foundation column; 3-Extended base plate; 4-Frustum-shaped soil mass; 10-Cylindrical main foundation pit; 11-Adit; 13-Integrated wind turbine foundation structure; 131-Cylindrical main support column; 132-Adit filling foundation; 14-Conical platform soil. Detailed Implementation

[0016] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0017] like Fig. 4-5 As shown, the wind turbine foundation of this embodiment using the novel excavation method includes an integrated wind turbine foundation structure 13 located underground. Specifically, the integrated wind turbine foundation structure 13 consists of a cylindrical main column 131 located in the center and multiple adit filling foundations 132 extending radially from the side wall of the main column.

[0018] Specifically, the integrated wind turbine foundation structure 13 is a reinforced concrete monolith formed by binding steel bars and pouring concrete within a pre-excavated cylindrical main foundation pit 10 and multiple adits 11 excavated along its sidewalls. The cylindrical main support column 131 corresponds to the shape of the cylindrical main foundation pit 10 and is used to support the upper wind turbine tower 1. The adit filling foundation 132 corresponds to the shape of the adits 11, and its outward extension radius meets the design requirements of traditional extended foundation radius, thus providing sufficient anti-overturning moment.

[0019] In a preferred embodiment of this example, the number of adits 11 is set to at least four; in this example, the number of adits 11 is set to four. Specifically, the adits 11 are evenly and symmetrically arranged along the circumference of the sidewall of the cylindrical main foundation pit 10 to ensure the balance of foundation forces. During the excavation of the adits 11, scaffolding and steel plates are used for temporary support to prevent soil collapse and ensure construction safety.

[0020] like Fig. 6 As shown in the figure, the wind turbine foundation construction method of the novel excavation method in this embodiment includes the following steps.

[0021] Step 1: Excavate a cylindrical main foundation pit 10.

[0022] At the selected wind turbine location, according to the radius determined by the design drawings, mechanical equipment is used to excavate vertically downwards to form a cylindrical main foundation pit 10, and the excavation is carried out to the design depth H.

[0023] Specifically, such as Fig. 7 As shown, in this embodiment, the volume of soil in the excavation cone-shaped platform 14 of the cylindrical main foundation pit 10 is: in: The excavation volume of the cylindrical main foundation pit 10; The bottom diameter of the integrated wind turbine foundation structure 13; This refers to the excavation depth.

[0024] Step 2: Excavate the adit along the sidewall and provide support.

[0025] On the sidewall of the cylindrical main foundation pit 10, at predetermined locations, adits 11 are excavated into the surrounding soil in a horizontal or near-horizontal direction. As a preferred embodiment, at least three adits 11 are evenly distributed. During excavation, scaffolding and steel plates are used simultaneously to reliably support the top and sidewalls of the adits 11 until the length of the adits 11 reaches the designed extension radius. In this embodiment, four adits 11 are evenly distributed.

[0026] Step 3: Rebar tying.

[0027] The overall steel reinforcement frame is tied inside the already formed and supported cylindrical main foundation pit 10 and adit 11.

[0028] Step 4: Concrete pouring.

[0029] After the steel reinforcement cage is configured, concrete is poured continuously in one go to fill the cylindrical main foundation pit 10 and all adits 11. After curing and solidification, the integrated wind turbine foundation structure 13 is formed.

[0030] Once the concrete strength of the integrated wind turbine foundation structure 13 reaches the design requirements, the wind turbine tower 1 can be installed on the cylindrical main support column 131 at its top, thus completing the construction of the entire wind turbine foundation.

[0031] The wind turbine foundation and its construction method of the novel excavation method in this embodiment, through the structural design of combining the cylindrical main foundation pit 10 with the radial adit 11, greatly reduces the amount of earthwork excavation and the land area occupied while ensuring the foundation bearing capacity, thereby reducing the cost, shortening the construction period, and significantly reducing the damage to the site's ecological environment.

[0032] The above-described embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention. The scope of protection of the present invention is defined by the claims.

Claims

1. A novel excavation method for wind turbine foundations, characterized in that: include: A cylindrical main foundation pit located underground; Multiple adits were excavated horizontally or nearly horizontally from the sidewalls of the cylindrical main pit; The adit extends radially to the designed expansion radius; the main foundation pit and the adit are equipped with a steel reinforcement frame, and are integrally cast with concrete to form an integrated wind turbine foundation structure.

2. The wind turbine foundation according to the novel excavation method described in claim 1, characterized in that: The number of adits is set to at least 3, which are evenly arranged along the side wall of the cylindrical main pit.

3. The wind turbine foundation according to the novel excavation method described in claim 1, characterized in that: The volume of the excavated conical platform soil in the cylindrical main foundation pit is: in: The excavation volume of the cylindrical main foundation pit; The bottom diameter of the integrated wind turbine foundation structure; This refers to the excavation depth.

4. A novel excavation method for wind turbine foundation construction, characterized in that: Includes the following steps: Step 1: Excavate a cylindrical main foundation pit to the designed depth at the selected site according to the design radius; Step 2: Excavate multiple adits at selected locations on the sidewall of the foundation pit, and provide support during the excavation process; Step 3: Tie reinforcing bars in the foundation pit and adit; Step 4: Pour concrete as a whole to form an integrated wind turbine foundation structure.

5. The wind turbine foundation construction method according to the novel excavation method described in claim 4, characterized in that: The tunnel is excavated in a horizontal or near-horizontal direction.

6. The wind turbine foundation construction method according to the novel excavation method described in claim 4, characterized in that: The support methods include scaffolding and steel plate support.

7. The wind turbine foundation construction method according to the novel excavation method described in claim 4, characterized in that: The volume of the excavated conical platform soil in the cylindrical main foundation pit is: in: The excavation volume of the cylindrical main foundation pit; The bottom diameter of the integrated wind turbine foundation structure; This refers to the excavation depth.

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