Steel reinforced concrete prestressed fan foundation and construction method

Abstract

The invention relates to the technical field of wind power generation, in particular to a steel reinforced concrete prestressed fan foundation and a construction method, and provides a new structure from the structural form by performing optimization design on a traditional gravity expansion type foundation, and the structure comprises an original fan foundation, a steel reinforced structure and a prestressed system. A foundation stand and a foundation circular truncated cone are arranged on the top of an original fan foundation, and a base plate of the foundation is arranged on the lowest portion of the foundation. The steel rib structure is composed of a profile steel component arranged in the foundation stand, a connecting sleeve connected to profile steel and a vertical erecting steel bar used for fixing the profile steel, and meanwhile corresponding stiffening ribs are arranged at the position of the connecting sleeve. The prestress system is composed of vertically-arranged anchor rods, anchor plates, anchor bolts and circumferential prestress steel bars, and the bearing capacity of the fan foundation can be effectively enhanced. The structure can effectively reduce the use amount of concrete and steel bars, and the steel ribs are high in bearing capacity and replace a large number of steel bars, so that the work amount is reduced, the construction period is shortened and the manufacturing cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of wind power generation, and in particular to a steel-framed concrete prestressed wind turbine foundation and a construction method. Background Art

[0002] Wind power generation is one of the most promising sustainable projects in the world. To ensure the sustainable development of wind power generation, the wind turbine foundation used to install and fix the wind turbine tower is the key. With the large-scale wind turbine units, the amount of engineering work on the wind turbine foundation is increasing.

[0003] At present, the common wind turbine foundation is generally composed of a wind turbine base plate, a wind turbine truss, a wind turbine column and multiple traditional steel bars. Multiple traditional steel bars are densely arranged on the wind turbine truss in an umbrella-shaped structure. The structure is complex and the amount of steel bars is large, which makes the foundation construction more difficult and the construction period longer, thus causing the cost of the wind turbine foundation to increase exponentially. In addition, the stress in some areas of the traditional wind turbine foundation is relatively concentrated, and there is a risk of steel bar fracture. Therefore, the traditional wind turbine foundation has hindered the development of the wind power industry. Optimizing the design of the configuration of the wind turbine foundation is an important direction for the development of wind power new energy. Summary of the invention

[0004] In order to overcome the deficiencies of the above-mentioned prior art, the present invention provides a steel-concrete prestressed fan foundation and a construction method. The structure and method can effectively reduce the amount of concrete and steel bars used. The present invention can solve the technical problems of the existing fan foundation having a complex structure, a large amount of structural steel bars used, a long construction period, a high cost, and easy breakage.

[0005] To achieve the above object, the present invention is implemented by the following technical solutions:

[0006] The present invention designs a steel-concrete prestressed wind turbine foundation, comprising a traditional wind turbine foundation, a steel-concrete structure and a prestressed system. Concrete is poured inside the traditional wind turbine foundation, the steel-concrete structure is arranged on the traditional wind turbine foundation, and the prestressed system is arranged in the concrete inside the traditional wind turbine foundation, so as to enhance the bearing capacity of the wind turbine foundation.

[0007] The steel frame structure includes a steel member, vertical reinforcement bars and a connecting sleeve, wherein the steel member is arranged on the outside of a conventional wind turbine foundation, the vertical reinforcement bars are arranged on the inside of the conventional wind turbine foundation and are located below the steel member, and the connecting sleeve is arranged on the steel member, and is used to connect the steel member and the vertical reinforcement bars;

[0008] The steel structure comprises a horizontal steel and two side steels. The horizontal steel is arranged outside a traditional wind turbine foundation. The two side steels are vertically arranged on both sides of the horizontal steel. The connecting sleeve is connected to the side steel on one side.

[0009] Preferably, the steel frame structure further includes a stiffening rib, which is arranged between two side steels and adjacent to the connecting sleeve.

[0010] Preferably, there are a plurality of steel-shaped members arranged in an umbrella shape on the outside of a traditional wind turbine foundation, and each steel-shaped member is arranged with a plurality of vertical standing steel bars, connecting sleeves and stiffening ribs.

[0011] Preferably, the diameter of the connecting sleeve is larger than the diameter of the vertical reinforcement bars.

[0012] Preferably, the conventional fan foundation comprises a fan base plate, a fan round platform and a fan column: the fan base plate is placed on the lowest side of the concrete, the fan round platform is placed above the fan base plate, and the top of the fan round platform is connected to the fan column;

[0013] Preferably, the height of the fan cone is lower than the outdoor floor, and the upper surface of the fan column is higher than the outdoor floor.

[0014] Preferably, the prestressed system includes anchor bolts, anchor plates, anchor rods, and annular prestressed steel bars. The anchor rods are vertically inserted into the concrete body. The anchor plates are two pieces, which are arranged at the upper and lower sides of the anchor rods, respectively. The anchor bolts are used to fix the anchor plates and the anchor rods. The annular prestressed steel bars are arranged on the fan round platform through the steel structure. The concrete is prestressed by the anchor plates placed at the upper and lower sides of the concrete and the anchor bolts fixed on the anchor plates.

[0015] Preferably, the calculation formula of the prestress in the prestress system is:

[0016] σ pe =σ con -σ 1 ;

[0017]

[0018] Where: pe is the effective prestress stress; σ con is the prestress control value; σ 1 is the prestress loss value; a, kx, μθ are obtained by looking up the table, E s is the elastic modulus of the steel strand; l is the length of the prestressed steel strand.

[0019] Preferably, there are several anchor bolts and anchor rods, which are evenly distributed on the anchor plate.

[0020] The present invention also provides a construction method of a steel-framed concrete prestressed fan foundation, comprising the following steps:

[0021] Lower the anchor cage, place the anchor bolts, anchor plates and anchor rods in the anchor cage respectively, lay corresponding steel bars around the anchor cage, and then lay vertical reinforcement bars in the vertical direction;

[0022] After the vertical reinforcement bars are lowered, the steel structure is installed, the connecting sleeve is welded to the steel structure in advance, the steel structure is arranged in an umbrella shape on the fan round platform of the traditional fan foundation, and the steel structure is placed on the fixed vertical reinforcement bars;

[0023] An annular prestressed steel bar is installed in the steel structure, and the annular prestressed steel bar passes through the steel structure and is arranged on the fan round platform;

[0024] Install the concrete mold around the fan bottom plate, then pour the concrete to obtain the concrete foundation body, and maintain the poured concrete foundation at the same time;

[0025] After the concrete reaches the design strength, prestress is applied to the hoop prestressing steel bars;

[0026] Install the wind turbine column. The upper surface of the wind turbine column is higher than the outdoor floor, which is convenient for installing the wind tower. The wind turbine column and the wind tower are connected by anchor bolts. The anchor rods extend downward to the bottom of the wind turbine foundation. Corresponding anchor plates are provided at the top and bottom of the wind turbine foundation. The designed prestress is applied to the anchor bolts so that the wind turbine foundation as a whole is tightly connected to the wind tower.

[0027] Beneficial effects:

[0028] The present invention relates to the technical field of wind power generation. An optimized design is performed on the basis of the traditional gravity expansion type, and a new structure is proposed in terms of structural form. The structure includes a traditional wind turbine foundation, a steel frame structure and a prestressed system. The top of the original wind turbine foundation is provided with a foundation column and a foundation truncated cone, and a foundation bottom plate is provided at the bottom of the foundation. The steel frame structure is composed of a steel section member arranged in the foundation column, a connecting sleeve connected to the steel section and a vertical erecting steel bar for fixing the steel section, and corresponding stiffening ribs are arranged at the connecting sleeve. The prestressed system is mainly composed of vertically arranged anchor rods, anchor plates, anchor bolts and circumferential prestressed steel bars, which can effectively enhance the bearing capacity of the wind turbine foundation.

[0029] According to the results of finite element calculation, compared with the traditional configuration, the maximum compressive stress of the steel bars in the optimized configuration is only 40% of the original, and the maximum tensile stress is only 64% of the original. In terms of construction, the steel skeleton structure replaces a large number of steel bars, which greatly reduces the density of steel bars in the anchor bolts, thereby reducing the difficulty of construction; at the same time, the amount of steel used in the optimized configuration is about 80% of the traditional configuration.

[0030] This structure can effectively reduce the amount of concrete and steel bars used, because steel frames have higher bearing capacity characteristics. At the same time, steel-framed concrete structures can also give full play to the material strength of concrete itself, thereby replacing a large number of steel bars, making the fan foundation structure simple and using less steel frames, thereby achieving the purpose of reducing engineering workload, shortening construction period and reducing construction costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the basic structure of the fan of the present invention.

[0032] Figure 2 for Figure 1 Schematic top view of .

[0033] Figure 3 for Figure 1 Schematic cross-section diagram of .

[0034] Figure 4 This is a three-dimensional schematic diagram of the steel structure.

[0035] Figure 5 The figure is a construction flow chart of the fan foundation of the present invention.

[0036] Figure 6 It is a schematic diagram of stress analysis of the fan foundation of the present invention.

[0037] Figure 7 Schematic diagram of the foundation structure of a traditional gravity fan.

[0038] Figure 8 Schematic diagram of stress analysis of traditional gravity fan foundation.

[0039] Reference numerals:

[0040] Traditional fan foundation: 1-fan base plate; 2-fan round platform; 3-fan platform column; 12-traditional structural steel bars;

[0041] Steel frame structure: 4-steel member (41-horizontal steel, 42-side steel); 8-vertical reinforcement; 9-connecting sleeve; 10-stiffening rib;

[0042] Prestressed system: 5-anchor bolt; 6-anchor plate; 7-anchor rod; 11-circumferential prestressed steel bar. DETAILED DESCRIPTION

[0043] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] At present, the common wind turbine foundation generally consists of a wind turbine base plate 1, a wind turbine truncated platform 2, a wind turbine column 3 and a plurality of traditional structural steel bars 12. The plurality of traditional structural steel bars 12 are densely arranged on the wind turbine truncated platform in an umbrella-like structure, and the structure is complex and the amount of structural steel bars is large. Figure 7 , 8 The figure shows a schematic diagram of the foundation structure of a traditional gravity fan and a schematic diagram of stress analysis. Some areas are colored red, where stress is relatively concentrated and there is a risk of steel bar breakage.

[0045] The construction method of the traditional gravity wind turbine foundation is as follows: after the anchor cage is lowered, the bottom plate reinforcement is first laid out, and the designed reinforcement is arranged radially and circumferentially. Due to the large design load of the bottom plate, more radial and circumferential reinforcements are required, resulting in a large number of reinforcements extending into the anchor cage, and the excess part of the reinforcement needs to be extended and bent at the anchor end, so as to form a denser distribution inside the anchor cage. After the bottom plate reinforcement is configured, the reinforcement at the top of the foundation needs to be configured, which is divided into radial reinforcement and circumferential reinforcement. In this process, a large number of reinforcements also extend into the interior of the anchor cage. After all the reinforcements are configured, the concrete mold needs to be installed, and then the concrete is poured and cured. Finally, the traditional gravity expansion wind turbine foundation is connected to the upper wind turbine tower through pre-buried anchor bolts.

[0046] The present invention relates to a steel-framed concrete prestressed wind turbine foundation and a construction method. An optimized design is performed on the basis of a traditional gravity expansion wind turbine, and a new steel-framed concrete prestressed wind turbine foundation structure is proposed. At the same time, multiple steel bars in the prior art are replaced with multiple steel frames composed of steel components. The structure can effectively reduce the amount of concrete and steel bars, because the steel frame has a higher bearing capacity characteristic, and the steel-framed concrete structure can also give play to the material strength of the concrete itself, thereby replacing a large number of steel bars, making the wind turbine foundation structure simple and the amount of steel frame less, thereby achieving the purpose of reducing the amount of engineering, shortening the construction period and reducing the cost.

[0047] like Figures 1 to 3 As shown in Figure 6, the present invention provides a steel-concrete prestressed wind turbine foundation, including a traditional wind turbine foundation, a steel structure and a prestressed system. Concrete is poured inside the traditional wind turbine foundation, the steel structure is arranged on the traditional wind turbine foundation, and the prestressed system is arranged in the concrete inside the traditional wind turbine foundation to enhance the bearing capacity of the wind turbine foundation.

[0048] like Figure 1 As shown, the traditional fan foundation includes a fan base plate 1, a fan table 2 and a fan column 3: the fan base plate 1 is placed on the lowest side of the concrete, the fan table 2 is placed above the fan base plate 1, and the top of the fan table 2 is connected to the fan column 3; the height of the fan table 2 is lower than the outdoor floor, and the upper surface of the fan column 3 is higher than the outdoor floor.

[0049] like Figures 2 to 3 As shown, the prestressed system includes anchor bolts 5, anchor plates 6, anchor rods 7, and annular prestressed steel bars 11. The anchor rods 7 are vertically inserted into the concrete body. The anchor plates 6 are two pieces, which are arranged on the upper and lower sides of the anchor rods 7, respectively. The anchor bolts 5 are used to fix the anchor plates 6 and the anchor rods 7. The concrete is prestressed by the anchor plates 6 placed on the upper and lower sides of the concrete and the anchor bolts 5 fixed on the anchor plates 6. The annular prestressed steel bars 11 are arranged on the fan cone 2 through the steel structure 4. There are a plurality of anchor bolts 5 and anchor rods 7, which are evenly distributed on the anchor plates 6.

[0050] The calculation formula of prestress in prestressed system is:

[0051] σ pe =σ con -σ 1 ;

[0052]

[0053] Where: pe is the effective prestress stress; σ con is the prestress control value; σ 1 is the prestress loss value; a, kx, μθ are obtained by looking up the table, E s is the elastic modulus of the steel strand; l is the length of the prestressed steel strand.

[0054] like Figure 4 As shown, the steel frame structure includes a steel member 4, a vertical erecting steel bar 8, a connecting sleeve 9, and a stiffening rib 10. The steel member 4 is arranged on the outside of the traditional wind turbine foundation, the vertical erecting steel bar 8 is arranged on the inside of the traditional wind turbine foundation, and is located below the steel member 4. The connecting sleeve 9 is arranged on the steel member 4, and the connecting sleeve 9 is used to connect the steel member 4 and the vertical erecting steel bar 8. The steel member 4 includes a horizontal steel 41 and two side steels 42. The horizontal steel 41 is arranged on the outside of the traditional wind turbine foundation. The two side steels 42 are vertically arranged on both sides of the horizontal steel 41, and the connecting sleeve 9 is connected to the side steel 42 on one side. The stiffening rib 10 is arranged between the two side steels 42 and is adjacent to the connecting sleeve 9. The steel member 4 is multiple, and is arranged in an umbrella shape parallel to the slope 2 of the wind turbine truncated table. Each steel member 4 is arranged with multiple vertical erecting steel bars 8, connecting sleeves 9, and stiffening ribs 10. The diameter of the connecting sleeve 9 is greater than the diameter of the vertical reinforcement bars 8 .

[0055] like Figure 5As shown, the present invention also provides a construction method of a steel-framed concrete prestressed wind turbine foundation. After the site around the wind turbine foundation is leveled and the soil is excavated, the construction of the steel-framed concrete prestressed wind turbine foundation in the present invention can be started. The specific steps are as follows:

[0056] The first step: lower the anchor cage, the anchor bolts 5, anchor plates 6 and anchor rods 7 are placed in the anchor cage, and then the corresponding steel bars are laid around the anchor cage. Then the vertical erection steel bars 8 are laid, and the vertical erection steel bars 8 should be laid vertically and meet the positioning requirements of the design.

[0057] Step 2: After the vertical reinforcement bars 8 are lowered, the steel members 4 should be installed. The steel members 4 are arranged in an umbrella shape on the fan truncated platform 2 of the traditional fan foundation, and the connecting sleeves 9 welded on the steel members 4 should be completed in the factory. The steel members 4 are placed on the fixed vertical reinforcement bars 8, and the required steel members 4 are placed one by one using a lifting device.

[0058] Step 3: Install the annular prestressed steel bars 11 in the steel structure 4. The annular prestressed steel bars 11 pass through the steel structure 4 and are arranged on the fan cone 2. The annular prestressed steel bars 11 should be stably fixed in the steel structure by anchors.

[0059] Step 4: Install concrete molds around the base plate to ensure that the subsequent concrete pouring can proceed smoothly, then pour the concrete to obtain the concrete foundation body, and at the same time maintain the poured concrete foundation.

[0060] Step 5: After the concrete reaches the designed strength, the annular prestressed steel bars 11 are prestressed.

[0061] Step 6: The upper surface of the wind turbine column 3 is higher than the outdoor floor, which is convenient for installing the wind turbine tower. The wind turbine column 3 is located above the foundation, and the wind turbine column 3 is connected to the wind turbine tower through anchor bolts 5. The anchor rods 7 extend downward to the bottom of the foundation. The top and bottom of the foundation are provided with corresponding anchor plates 6. The designed prestress is applied to the anchor bolts 5, so that the foundation as a whole is closely connected to the tower.

[0062] It should be understood that the specific order or hierarchy of steps in the process disclosed by the present invention is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process can be rearranged without departing from the scope of protection of the present disclosure. The attached method claims provide the elements of the various steps in an exemplary order and are not intended to be limited to the specific order or hierarchy described.

[0063] like Figure 6The figure shows the stress analysis diagram of the wind turbine foundation of the present invention. There is no red stress concentration area in the figure, so the strength is relatively high. According to the results of finite element calculation, compared with the traditional configuration, the maximum compressive stress of the steel bar in the optimized configuration is only 40% of the original, and the maximum tensile stress is only 64% of the original. In terms of construction, the steel frame structure replaces a large number of steel bars, thereby greatly reducing the density of the steel bars in the anchor bolts, thereby reducing the difficulty of construction; at the same time, the amount of steel used in the optimized configuration is about 80% of that in the traditional configuration.

[0064] The above description is only a description of the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention. Any changes or modifications made by any person skilled in the art based on the above disclosed technical contents shall be regarded as equivalent effective embodiments and shall fall within the scope of protection of the technical solution of the present invention.

Claims

1. A steel-reinforced concrete prestressed fan foundation, characterized in that: It comprises a traditional wind turbine foundation, a steel frame structure and a prestressed system, wherein concrete is poured inside the traditional wind turbine foundation, the steel frame structure is arranged on the traditional wind turbine foundation, and the prestressed system is arranged in the concrete inside the traditional wind turbine foundation; The steel frame structure comprises a steel structure (4), vertical reinforcement bars (8) and a connection sleeve (9); the steel structure (4) is arranged on the outside of a conventional wind turbine foundation; the vertical reinforcement bars (8) are arranged on the inside of the conventional wind turbine foundation and below the steel structure (4); the connection sleeve (9) is arranged on the steel structure (4); and the connection sleeve (9) is used to connect the steel structure (4) and the vertical reinforcement bars (8); The steel structure (4) comprises a horizontal steel (41) and two side steels (42), wherein the horizontal steel (41) is arranged on the outside of a conventional wind turbine foundation, and the two side steels (42) are vertically arranged on both sides of the horizontal steel (41), and the connecting sleeve (9) is connected to the side steel (42) on one side.

2. A steel-framed concrete prestressed wind turbine foundation as claimed in claim 1, characterized in that: The steel structure components (4) are multiple and are arranged in an umbrella shape on the outside of a traditional wind turbine foundation. Each steel structure component (4) is arranged with multiple vertical reinforcement bars (8), connecting sleeves (9) and stiffening ribs (10).

3. A steel-framed concrete prestressed wind turbine foundation as claimed in claim 2, characterized in that: The diameter of the connecting sleeve (9) is greater than the diameter of the vertically erected steel bars (8).

4. A steel-framed concrete prestressed wind turbine foundation as claimed in claim 3, characterized in that: The steel frame structure also includes a stiffening rib (10), wherein the stiffening rib (10) is arranged between two side steels (42) and is adjacent to the connecting sleeve (9).

5. A steel-framed concrete prestressed wind turbine foundation according to any one of claims 1 to 4, characterized in that: The conventional fan foundation comprises a fan base plate (1), a fan truncated platform (2) and a fan column (3): the fan base plate (1) is placed on the lowest side of the concrete, the fan truncated platform (2) is placed above the fan base plate (1), and the top of the fan truncated platform (2) is connected to the fan column (3).

6. A steel-framed concrete prestressed wind turbine foundation as claimed in claim 5, characterized in that: The height of the fan truncated platform (2) is lower than the outdoor floor, and the upper surface of the fan platform column (3) is higher than the outdoor floor.

7. A steel-framed concrete prestressed wind turbine foundation as claimed in claim 6, characterized in that: The prestressed system comprises anchor bolts (5), anchor plates (6), anchor rods (7), and annular prestressed steel bars (11); the anchor rods (7) are vertically inserted into the concrete body; the anchor plates (6) are divided into two pieces, which are arranged on the upper and lower sides of the anchor rods (7), respectively; the anchor bolts (5) are used to fix the anchor plates (6) and the anchor rods (7); and the annular prestressed steel bars (11) pass through the steel structure (4) and are arranged on the fan cone (2).

8. A steel-framed concrete prestressed wind turbine foundation as claimed in claim 7, characterized in that: The calculation formula of prestress in the prestress system is: s pe =s con -σ1; Where: pe is the effective prestress stress; σ con is the prestress control value; σ1 is the prestress loss value; a, kx, μθ are obtained by looking up the table, E s is the elastic modulus of the steel strand; l is the length of the prestressed steel strand.

9. A steel-framed concrete prestressed wind turbine foundation as claimed in claim 8, characterized in that: There are a plurality of anchor bolts (5) and anchor rods (7), which are evenly distributed on the anchor plate (6).

10. A construction method for a steel-framed concrete prestressed fan foundation, characterized in that: The following steps are involved: Lower the anchor cage, place the anchor bolts, anchor plates and anchor rods in the anchor cage respectively, lay corresponding steel bars around the anchor cage, and then lay vertical reinforcement bars in the vertical direction; After the vertical reinforcement bars are lowered, the steel structure is installed, the connecting sleeve is welded to the steel structure in advance, the steel structure is arranged in an umbrella shape on the fan round platform of the traditional fan foundation, and the steel structure is placed on the fixed vertical reinforcement bars; An annular prestressed steel bar is installed in the steel structure, and the annular prestressed steel bar passes through the steel structure and is arranged on the fan round platform; Install the concrete mold around the fan bottom plate, then pour the concrete to obtain the concrete foundation body, and maintain the poured concrete foundation at the same time; After the concrete reaches the design strength, prestress is applied to the hoop prestressing steel bars; Install the wind turbine column. The upper surface of the wind turbine column is higher than the outdoor floor, which is convenient for installing the wind tower. The wind turbine column and the wind tower are connected by anchor bolts. The anchor rods extend downward to the bottom of the wind turbine foundation. Corresponding anchor plates are provided at the top and bottom of the wind turbine foundation. The designed prestress is applied to the anchor bolts so that the wind turbine foundation as a whole is tightly connected to the wind tower.

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