A precast beam slab type fan foundation and a construction method thereof

Abstract

The application discloses a precast beam slab type fan foundation and a construction method thereof, which comprises a foundation slab, a foundation ring and a plurality of rib beams; the foundation ring is installed at the center of an inner ring; the foundation slab is fixedly spliced by an inner ring, a middle ring and an outer ring; the rib beam is composed of a profile steel, longitudinal steel bars arranged on the profile steel, stirrups arranged on the longitudinal steel bars and concrete poured outside; an inner prestress ring is arranged on the inner ring, a middle prestress ring is arranged on the middle ring and an outer prestress ring is arranged on the outer ring; a plurality of radial prestress steel wires penetrating through the inner ring, the middle ring and the outer ring are arranged on the foundation slab; the construction method comprises foundation slab construction, foundation ring construction and rib beam construction. The foundation avoids a large amount of concrete pouring operation on site, reduces the on-site workload, shortens the construction period, has strong bending resistance, durability and fatigue resistance and is convenient for construction operation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fan installation foundation structure, and particularly relates to a prefabricated beam plate type fan foundation and a construction method thereof. BACKGROUND

[0002] The wind turbine foundation is a concrete structure for fixing the unit, which not only bears the weight of the unit and the tower, but also resists the maximum overturning load of the unit to ensure the safe operation of the unit under various loads. The traditional wind turbine foundation usually adopts a pile cap type foundation, a section of the tower (foundation ring) is buried in the pile cap type foundation, and the tower flange and the foundation ring flange are connected when the unit is installed. The foundation construction needs to be poured in place, which requires a large amount of time for on-site steel binding, formwork support, concrete curing, etc.; the precision of on-site lofting and formwork support is difficult to guarantee, and since the wind field is located in a remote mountainous area, the transportation distance is long, and the transportation conditions are poor, the concrete cannot be used as commercial concrete, and usually on-site mixing is used. This leads to the quality of the mixed concrete being affected by many factors, and it is difficult to guarantee the quality of the mixed concrete. The authorized patent CN111411642B discloses a rib beam type fan foundation, which comprises: a foundation ring; a prefabricated module surrounding the foundation ring and fixedly connected with the foundation ring; wherein the prefabricated module comprises a plurality of convex prefabricated modules and a plurality of concave prefabricated modules alternately arranged along the circumference of the foundation ring. The present application reduces the proportion of wet work, shortens the construction period of the fan foundation during the installation of the wind turbine, and can save energy and protect the environment, but the structure is divided into a rib beam and a bottom plate as a whole, which is heavy and inconvenient to transport and install on site. SUMMARY

[0003] The present application aims to provide a prefabricated beam plate type fan foundation and a construction method thereof, which avoids a large amount of on-site concrete pouring work, reduces the on-site workload, shortens the construction period, has strong bending resistance, durability and fatigue resistance, and is convenient for construction.

[0004] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0005] A precast beam-slab type wind turbine foundation includes a foundation slab, a foundation ring fixedly mounted on top of the foundation slab, and multiple rib beams inclined between the foundation slab and the foundation ring. The foundation slab is formed by fixedly splicing an inner ring, a middle ring, and an outer ring. The inner ring is formed by splicing multiple inner units, the middle ring by splicing multiple middle units, and the outer ring by splicing multiple outer units. The foundation ring is installed at the center of the inner ring. The rib beams are composed of structural steel, longitudinal reinforcing bars on the structural steel, stirrups on the longitudinal reinforcing bars, and concrete poured on the outside. An inner prestressed ring is provided on the inner ring, a middle prestressed ring is provided on the middle ring, and an outer prestressed ring is provided on the outer ring. Multiple radial prestressed steel wires penetrating the inner, middle, and outer rings are provided on the foundation slab.

[0006] Preferably, the vertical cross-section of the inner unit is an inverted T-shape; stepped connecting parts are provided on both sides of the vertical part of the inner unit, and the axial position of two adjacent inner units is restricted by the stepped connecting parts.

[0007] Preferably, a transition steel ring is fixedly installed on the outside of the base ring, and one end of the rib beam is fixedly installed on the transition steel ring.

[0008] Preferably, the middle ring is fixedly connected to the inner ring and the outer ring via a snap-fit ​​connector; snap-fit ​​holes adapted to the snap-fit ​​connector are provided on the inner ring, middle ring, and outer ring.

[0009] Preferably, the snap-fit ​​component is a double trapezoid with larger ends and a smaller middle.

[0010] Preferably, the top of the vertical portion of the inner unit is provided with multiple right-angle connectors, and the other end of the multiple right-angle connectors is fixedly connected to the base ring.

[0011] Preferably, an inner pipe is pre-embedded in the inner ring, with both ends of the inner pipe obliquely crossing and protruding from the upper surface of the inner ring, and the inner prestressed ring is installed inside the inner pipe; a middle pipe is pre-embedded in the middle ring, with both ends of the middle pipe obliquely crossing and protruding from the upper surface of the middle ring, and the middle prestressed ring is installed inside the middle pipe; an outer pipe is pre-embedded in the outer ring, with both ends of the outer pipe obliquely crossing and protruding from the upper surface of the outer ring, and the outer prestressed ring is installed inside the outer pipe.

[0012] A construction method for a precast beam-slab type wind turbine foundation, the construction method comprising the following steps:

[0013] Step 1: Foundation slab construction. Construct a foundation platform in the area to be constructed, transport the prefabricated inner, middle, and outer rings to the construction site, and assemble them on-site according to the specified positions and angles. After installation, install the inner prestressed ring, middle prestressed ring, outer prestressed ring, and multiple radial prestressed steel wires, and finally apply prestress uniformly.

[0014] Step 2, base ring installation: transport the base ring to the construction site, hoist it onto the inner ring that was completed in the previous step, adjust the relative angle between the base ring and the inner ring, and fix the base ring and the inner ring together with right-angle connectors;

[0015] Step 3: Rib beam construction. Install both ends of the rib beams onto the foundation ring and foundation plate respectively. Adjust the position of each rib beam and temporarily fix it. Check the installation position of each rib beam until it is qualified. Secure it by welding or bolting.

[0016] In this invention, the construction method employs prefabricated structures and on-site construction, which improves the overall construction cycle. Dividing each structure into several units reduces the size, volume, and weight of components, significantly reducing the difficulty of component transportation and hoisting, and improving operational flexibility. The foundation slab evenly distributes the forces from the superstructure to the foundation soil, and its large surface area disperses the load, ensuring foundation stability. The rib beams enhance the spatial stability of the connection between the foundation slab and the foundation ring, effectively resisting bending moments and more effectively transferring the superstructure load to other parts of the foundation. The rib beams are assembled on-site, accommodating certain installation errors and facilitating on-site operations.

[0017] The inner prestressing ring, middle prestressing ring, outer prestressing ring, and radial prestressing wire are prestressed after the foundation slab is assembled, which gives the foundation slab strong structural stability and facilitates the transmission of force.

[0018] This construction method enables rapid on-site construction of wind turbine foundations, avoiding the problems of remote construction sites affecting construction schedules and quality. Precast components are manufactured in factories, unrestricted by on-site climate or location conditions, and can be carried out concurrently with other on-site construction processes. On-site assembly only requires assembling and prestressing the precast components, eliminating wet work processes, thus ensuring construction quality and shortening construction time. Factory production of precast components employs standardized production processes and quality inspection procedures, allowing for strict control over raw material quality, concrete mix proportions, and steel reinforcement processing and installation, effectively guaranteeing the overall quality of the wind turbine foundation and reducing the risk of wind turbine malfunctions or safety accidents due to foundation quality issues. Precast assembly construction reduces dust and noise pollution from on-site concrete mixing and pouring, while also reducing construction waste. Furthermore, the shortened construction period reduces energy consumption during construction, aligning with green building and sustainable development principles. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0020] Figure 2This is a schematic diagram of the internal monomer structure of the present invention;

[0021] Figure 3 This is a top view schematic diagram of the prestressed ring arrangement of the present invention;

[0022] In the diagram: 1. Foundation plate; 2. Foundation ring; 3. Rib beam; 4. Clip-on piece; 5. Connecting bolt; 6. Connecting plate; 7. Right-angle connector; 8. Transition steel ring; 10. Inner ring; 11. Middle ring; 12. Outer ring; 13. Stepped connection; 14. Inner prestressed ring; 15. Middle prestressed ring; 16. Outer prestressed ring; 17. Radial prestressed steel wire. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings:

[0024] like Figure 1 , Figure 2 and Figure 3 The diagram illustrates a precast beam-slab wind turbine foundation, comprising a foundation slab 1, a foundation ring 2 fixedly mounted on top of the foundation slab 1, and multiple rib beams 3 inclined between the foundation slab 1 and the foundation ring 2. The foundation slab 1 is constructed by fixedly splicing an inner ring 10, a middle ring 11, and an outer ring 12. When the foundation slab 1 is large, multiple middle rings 11 can be constructed. The inner ring 10 is composed of multiple inner units, the middle ring 11 is composed of multiple middle units, and the outer ring 12 is composed of multiple outer units. All inner, middle, and outer units are precast reinforced concrete components. These precast reinforced concrete components are prefabricated in a factory before construction.

[0025] An inner prestressing ring 14 is provided on the inner ring 10, a middle prestressing ring 15 is provided on the middle ring 11, and an outer prestressing ring 16 is provided on the outer ring 12. Specifically, an inner pipe is pre-embedded in the inner ring 10, with both ends of the inner pipe obliquely crossing and protruding from the upper surface of the inner ring 10. After multiple inner units are spliced ​​to form the inner ring 10, multiple corresponding middle pipes are closed. The inner prestressing ring 14 is installed inside the inner pipe, and prestress is applied to its ends and then sealed. A middle pipe is pre-embedded in the middle ring 11, with both ends of the middle pipe obliquely crossing and protruding from the upper surface of the middle ring 11. After multiple middle units are spliced ​​to form the middle ring 11, multiple corresponding middle pipes are closed. The middle prestressing ring 15 is installed inside the middle pipe, and prestress is applied to its ends and then sealed.

[0026] An outer pipe is pre-embedded in the outer ring 12. The two ends of the outer pipe obliquely cross and pass through the upper surface of the outer ring 12. After multiple outer units are spliced ​​together to form the outer ring 12, multiple corresponding outer pipes are closed. The outer prestressed ring 16 is installed in the outer pipe, and prestress is applied to the end and sealed.

[0027] Multiple radial prestressed steel wires 17 are installed on the base plate 1, passing through the inner ring 10, middle ring 11, and outer ring 12. Specifically, radial through holes are provided at corresponding positions of the inner ring 10, middle ring 11, and outer ring 12, and the radial prestressed steel wires 17 are installed in the corresponding radial through holes to apply prestress to the radial prestressed steel wires 17. This completes the application of prestress to the base plate 1, improving its durability and service life.

[0028] The vertical cross-section of the inner unit is an inverted T-shape. Stepped connecting portions 13 are provided on both sides of the vertical portion of the inner unit, restricting the axial position of adjacent inner units through these portions. The middle ring 11 is fixedly connected to the inner ring 10 and outer ring 12 via snap-fit ​​pieces 4. Snap-fit ​​holes adapted to the snap-fit ​​pieces 4 are provided on the inner ring 10, middle ring 11, and outer ring 12. After two corresponding snap-fit ​​holes are joined, the snap-fit ​​piece 4 is installed inside, achieving a fixed connection between adjacent inner rings 10 and middle ring 11, or middle ring 11 and outer ring 12. In a preferred embodiment, the snap-fit ​​piece 4 is a double trapezoidal structure, larger at both ends and smaller in the middle; it can also be dumbbell-shaped. A connecting platform is fixedly provided on the top side of the inner unit, and connecting bolts 5 are provided on the connecting platform. Two connected inner units are connected by multiple connecting plates 6, which connect corresponding two connecting bolts 5. The connecting plates 6 have oblong holes to accommodate certain installation errors and facilitate on-site construction.

[0029] The base ring 2 is installed at the center of the inner ring 10. Multiple right-angle connectors 7 are installed at the top of the vertical section of the inner unit, with the other ends of the connectors 7 fixedly connected to the base ring 2. Specifically, multiple anchor plates are pre-embedded at the top of the vertical section of the inner unit, and the right-angle connectors 7 are fixedly installed on the anchor plates by welding or bolts. Multiple anchor bolts are pre-embedded on the side of the base ring 2, and the other ends of the right-angle connectors 7 are fixedly connected to the anchor bolts.

[0030] The rib beam 3 consists of a steel section, multiple longitudinal reinforcing bars surrounding the steel section, stirrups fixed to the longitudinal reinforcing bars, and concrete poured on the outside. The steel section can be made of I-beams, cross-shaped steel, or other cross-sectional shapes. After fabrication, the steel section is exposed at both ends of the rib beam 3 for easy fixing to the foundation plate 1 and foundation ring 2. Alternatively, for easier connection, steel plates or blocks are fixedly installed at both ends of the rib beam 3 for welding to the foundation plate 1 and foundation ring 2. In a preferred embodiment, a transition steel ring 8 is fixedly installed on the outside of the foundation ring 2, and one end of the rib beam 3 is fixedly installed on the transition steel ring 8 by welding. Alternatively, a steel plate for connection to the rib beam 3 can be pre-embedded during the pouring of the foundation ring 2.

[0031] like Figure 1 , Figure 2 and Figure 3 The method shown is a construction method for a precast beam-slab type wind turbine foundation, which includes the following steps:

[0032] Step 1: Construction of foundation slab 1. A foundation platform is constructed in the area to be constructed. The prefabricated inner ring 10, middle ring 11, and outer ring 12 are transported to the construction site and assembled on-site according to the specified positions and angles. After installation, the entire structure is adjusted to ensure the upper surface of foundation slab 1 is flush. After installation, the inner prestressing ring 14, middle prestressing ring 15, outer prestressing ring 16, and multiple radial prestressing steel wires 17 are installed. Finally, prestress is applied uniformly.

[0033] Step 2: Install the base ring 2. Transport the base ring 2 to the construction site and hoist it onto the top of the inner ring 10 that was completed in the previous step. Adjust the relative angle between the base ring 2 and the inner ring 10, and fix the base ring 2 and the inner ring 10 together with the right-angle connector 7.

[0034] Step 3: Rib beam 3 construction. Install both ends of rib beam 3 on the foundation ring 2 and foundation plate 1 respectively. Adjust the position of each rib beam 3 and temporarily fix it. Check the installation position of each rib beam 3 until it is qualified. Tighten it by welding or bolt connection.

[0035] The above embodiments are merely illustrative of the concept and implementation of the present invention and are not intended to limit it. Under the concept of the present invention, technical solutions without substantial changes are still within the scope of protection.

Claims

1. A precast beam-slab type wind turbine foundation, comprising a foundation slab, a foundation ring fixedly disposed on the top of the foundation slab, and a plurality of rib beams inclinedly disposed between the foundation slab and the foundation ring, characterized in that: The base plate is fixedly spliced ​​together by an inner ring, a middle ring, and an outer ring. The inner ring is spliced ​​together by multiple inner units, the middle ring by multiple middle units, and the outer ring by multiple outer units. The base ring is installed at the center of the inner ring. The rib beam is composed of structural steel, longitudinal reinforcing bars on the structural steel, stirrups on the longitudinal reinforcing bars, and concrete poured on the outside. An inner prestressed ring is provided on the inner ring, a middle prestressed ring is provided on the middle ring, and an outer prestressed ring is provided on the outer ring. Multiple radial prestressed steel wires are provided on the base plate, penetrating the inner, middle, and outer rings. A transition steel ring is fixedly installed on the outside of the base ring, and one end of the rib beam is fixedly installed on the transition steel ring. The rib beam is composed of structural steel, multiple longitudinal reinforcing bars around the structural steel, stirrups fixed on the longitudinal reinforcing bars, and concrete poured on the outside.

2. The precast beam-slab type wind turbine foundation according to claim 1, characterized in that: The vertical cross-section of the inner unit is an inverted T-shape; stepped connecting parts are provided on both sides of the vertical part of the inner unit, and the axial position of two adjacent inner units is restricted by the stepped connecting parts.

3. The precast beam-slab type wind turbine foundation according to claim 1 or 2, characterized in that: The middle ring is fixedly connected to the inner ring and the outer ring via a snap-fit ​​connector; snap-fit ​​holes adapted to the snap-fit ​​connector are provided on the inner ring, middle ring, and outer ring.

4. The precast beam-slab type wind turbine foundation according to claim 3, characterized in that: The snap-fit ​​connector is a double trapezoid, larger at both ends and smaller in the middle.

5. The precast beam-slab type wind turbine foundation according to claim 2, characterized in that: Multiple right-angle connectors are provided at the top of the vertical part of the inner unit, and the other end of the multiple right-angle connectors is fixedly connected to the base ring.

6. The precast beam-slab type wind turbine foundation according to claim 1 or 5, characterized in that: An inner pipe is pre-embedded in the inner ring, with both ends of the inner pipe obliquely crossing and protruding from the upper surface of the inner ring. The inner prestressed ring is installed inside the inner pipe. A middle pipe is pre-embedded in the middle ring, with both ends of the middle pipe obliquely crossing and protruding from the upper surface of the middle ring. The middle prestressed ring is installed inside the middle pipe. An outer pipe is pre-embedded in the outer ring, with both ends of the outer pipe obliquely crossing and protruding from the upper surface of the outer ring. The outer prestressed ring is installed inside the outer pipe.

7. A construction method for a precast beam-slab wind turbine foundation as described in any one of claims 1 to 6, characterized in that: The construction method includes the following steps: Step 1: Foundation slab construction. Construct a foundation platform in the area to be constructed, transport the prefabricated inner, middle, and outer rings to the construction site, and assemble them on-site according to the specified positions and angles. After installation, install the inner prestressed ring, middle prestressed ring, outer prestressed ring, and multiple radial prestressed steel wires, and finally apply prestress uniformly. Step 2, base ring installation: transport the base ring to the construction site, hoist it onto the inner ring that was completed in the previous step, adjust the relative angle between the base ring and the inner ring, and fix the base ring and the inner ring together with right-angle connectors; Step 3: Rib beam construction. Install both ends of the rib beams onto the foundation ring and foundation plate respectively. Adjust the position of each rib beam and temporarily fix it. Check the installation position of each rib beam until it is qualified. Secure it by welding or bolting.

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