A parameter determination method for an extended foundation of a wind turbine generator set and an extended foundation

Abstract

The present invention provides a method for determining parameters of an extended foundation of a wind turbine generator set and an extended foundation, which belongs to the field of wind power infrastructure construction, and includes the following steps: determining the most dangerous section data according to the extended foundation body data; determining the bottom surface resistance bending moment value, top surface resistance bending moment value, bottom surface design bending moment value and top surface design bending moment value of the extended foundation bottom plate according to the most dangerous section data; determining unnecessary points according to the bottom surface resistance bending moment value, top surface resistance bending moment value, bottom surface design bending moment value and top surface design bending moment value of the extended foundation bottom plate; determining the breakpoint position according to the preset anchoring distance of the unnecessary points; the breakpoint position is used to cut off the radial steel bars. The technical solution of the present invention realizes the reduction of the self-weight consumables of the radial steel bars of the reinforced concrete extended foundation, significantly reduces the investment in onshore wind farm construction projects in the new energy industry, and at the same time effectively implements the concept of energy conservation, emission reduction and low-carbon development.

Description

Technical Field

[0001] The present invention relates to the field of wind power infrastructure construction, and in particular to a parameter determination method of an extended foundation of a wind turbine generator set and an extended foundation. Background Art

[0002] As a renewable and clean energy, wind power generation is playing an increasingly important role in energy supply under the background of tight energy supply and policy support. As the height of wind turbine towers and the capacity of wind turbines are gradually increasing, and the wind load is always in a cyclical state due to the non-directional nature of wind, the wind turbine load transmitted to the bottom of the tower is gradually increasing. Therefore, large-capacity units have higher requirements on the wind turbine foundation stiffness, foundation bearing capacity, and wind turbine foundation stability.

[0003] For a long time, cast-in-place reinforced concrete extended foundations have been widely used in the foundations of wind turbines in onshore wind farms, and their forms mainly include circular and polygonal. The wind turbine foundation is subjected to the load transmitted from the self-supporting truncated conical load-bearing tower (or tower tube) of the wind turbine through the column, and the foundation reaction force is borne below. The working condition is like an inverted cantilever structure. After the foundation structure is subjected to force, bending failure is prone to occur near the sudden change in the cross-sectional height of the column. In order to ensure that the foundation of the wind turbine does not suffer bending failure, in addition to requiring the foundation to have a certain height, it is mainly adopted to configure a certain number of radial steel bars in the concrete foundation, and rely on the radial steel bars configured in the foundation to bear tensile stress, so that the reinforced concrete extended foundation can produce some bending without damage. At the same time, it is achieved to use a smaller foundation height to transmit the load through the column to a larger foundation area.

[0004] In actual projects, when calculating reinforced concrete extended foundations based on the assumption of linear distribution of reaction force on the bottom surface of the foundation, the influence of the overall bending of the foundation is not considered in the calculation of the foundation structure. The existing technology considers the influence of the overall bending by controlling the reinforcement of key parts and setting all radial reinforcements throughout the design without distinguishing between different situations. In addition, design engineers overemphasize structural safety and increase the radial reinforcement of the foundation, resulting in an excessively large reinforcement ratio of the foundation steel bars, which affects the project investment and natural resource energy consumption of the actual project. Summary of the invention

[0005] The present invention provides a method for determining parameters of an extended foundation of a wind turbine generator set and an extended foundation, which are used to solve the problems of reasonable steel bar configuration of the extended foundation and excessive steel bar reinforcement ratio.

[0006] In order to solve the above technical problems, the technical solution of the present invention is as follows:

[0007] A method for determining parameters of an extended foundation of a wind turbine generator system comprises the following steps:

[0008] Determine the most dangerous cross-section data based on the extended basic body shape data;

[0009] According to the most dangerous section data, determine the bottom surface resistance bending moment value, top surface resistance bending moment value, bottom surface design bending moment value and top surface design bending moment value of the extended foundation bottom plate;

[0010] Determine unnecessary points according to the bottom surface resistance bending moment value, the top surface resistance bending moment value, the bottom surface design bending moment value and the top surface design bending moment value of the extended foundation bottom plate;

[0011] Preset anchoring distances based on unnecessary points and determine breakpoint locations;

[0012] The breakpoint position is used to cut off the radial reinforcement.

[0013] Optionally, when the preset anchorage distance is in the tension zone, the preset anchorage tension distance of the Grade I steel bar is 25d; the preset anchorage tension distance of the Grade II steel bar is 30d; and the preset anchorage tension distance of the Grade III steel bar is 35d;

[0014] When the preset anchorage distance is in the compression zone, the preset anchorage compression distance of Grade I steel bars is 15d; the preset anchorage compression distance of Grade II steel bars is 15d; the preset anchorage compression distance of Grade III steel bars is 15d;

[0015] Where d is the diameter of the steel bar.

[0016] Optionally, by formula Obtain the bottom surface design bending moment value of the extended foundation slab;

[0017] By formula Obtain the design bending moment value of the top surface of the extended foundation slab;

[0018] By formula

[0019]

[0020] Obtain the most dangerous cross-section data of the extended foundation and the top and bottom surface resistance bending moment values ​​of the extended foundation bottom plate;

[0021] in, M is the design bending moment per unit arc length of the foundation slab under the basic combination of load effects, R is the base plate radius, q The top surface of the foundation slab is approximately uniformly loaded. P is the net reaction force of the circular foundation approximately uniformly distributed under the basic combination of load effects, is the column radius; is the coefficient, is the design value of concrete axial compressive strength, is the effective height of the section, is the design value of the compressive strength of ordinary steel bars, is the cross-sectional area of ​​the longitudinal ordinary steel bars in the compression zone, is the distance from the resultant force point of the longitudinal ordinary steel bars in the compression zone to the compression edge of the section, To resist the bending moment, is the design value of tensile strength of ordinary steel bars, is the cross-sectional area of ​​the longitudinal ordinary reinforcement in the tension zone.

[0022] Optionally, the ends of the tensile steel bars and the compressive steel bars in the extended foundation slab binding frame are provided with hooks.

[0023] Optionally, the minimum reinforcement ratio of the radial steel bars bearing the load on the bottom and top surfaces of the extended foundation slab is greater than or equal to 0.15%.

[0024] Optionally, the minimum diameter of the radial reinforcement bearing the bottom and top surfaces of the extended foundation slab is greater than or equal to 10 mm.

[0025] Optionally, the spacing between the radial reinforcements on the bottom and top surfaces of the extended foundation slab is greater than or equal to 100 mm and less than or equal to 200 mm.

[0026] Optionally, radial short steel bars are provided at the outer radial steel bars of the bottom surface and the top surface of the extended foundation slab, and the length of the radial short steel bars is preset to 1130 mm.

[0027] Optionally, the annular reinforcements of the extended foundation slab are preset at intervals according to their locations.

[0028] The present invention also provides a wind turbine expansion base, comprising:

[0029] Bottom hoop reinforcement;

[0030] The bottom radial reinforcement is fixedly connected to the bottom annular reinforcement;

[0031] The top surface annular reinforcement is arranged opposite to the bottom surface annular reinforcement;

[0032] The top surface radial reinforcement is fixedly connected to the top surface annular reinforcement;

[0033] The horse stool reinforcement is fixedly connected to the top surface annular reinforcement and the top surface radial reinforcement; the horse stool reinforcement supports the top surface annular reinforcement and the top surface radial reinforcement;

[0034] The cross-shaped steel bars are fixedly connected to the bottom radial steel bars;

[0035] The inner annular steel bars of the platform column are arranged opposite to the annular steel bars of the bottom surface;

[0036] The stirrups are fixedly connected to the cross steel bars and the inner annular steel bars of the column;

[0037] The anchor bolts are fixedly connected to the inner annular steel bars, the cross steel bars and the stirrups of the column;

[0038] The longitudinal reinforcement of the column is fixedly connected to the inner annular reinforcement of the column;

[0039] The radial short steel bars are fixedly connected to the bottom surface annular steel bars and the top surface annular steel bars to enhance the stability of the structure.

[0040] The above solution of the present invention includes at least the following beneficial effects:

[0041] The above scheme of the present invention includes the following steps: determining the most dangerous section data according to the extended foundation shape data; determining the bottom surface resistance bending moment value, top surface resistance bending moment value, bottom surface design bending moment value and top surface design bending moment value of the extended foundation bottom plate according to the most dangerous section data; determining unnecessary points according to the bottom surface resistance bending moment value, top surface resistance bending moment value, bottom surface design bending moment value and top surface design bending moment value of the extended foundation bottom plate; determining the breakpoint position according to the preset anchorage distance of the unnecessary points; the breakpoint position is used to cut off the radial reinforcement. The technical scheme of the present invention considers the influence on the overall bending of the foundation by controlling the reinforcement of key parts and distinguishing the radial reinforcement design from the non-full-length setting, and provides a fine and reasonable design method for the radial reinforcement of the reinforced concrete extended foundation of wind turbines in onshore wind farms while meeting the reinforcement requirements of relevant specifications. The radial steel structure adopts the design method of single-layer, double-layer or multi-layer on the bottom and top of the foundation. The reinforced concrete extended foundation has the characteristics of high tensile strength, strong bending resistance, and can effectively bear longitudinal loads and bending moments. It has simple structure, convenient use and maintenance, strong directionality, conducive to showing three-dimensional images, and easy to connect with the environment. This plan can save construction investment to a large extent, meet the requirements of carbon emission control, and reduce the content of greenhouse gases emitted, mitigating climate change. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a schematic diagram of a method for determining parameters of a wind turbine expansion foundation provided by an embodiment of the present invention;

[0043] Figure 2 It is an extended foundation body shape diagram of an extended foundation of a wind turbine generator set provided by an embodiment of the present invention;

[0044] Figure 3 It is a schematic diagram of the overall structure of an expansion foundation of a wind turbine generator set provided by an embodiment of the present invention;

[0045] Figure 4 is a cross-sectional view of the steel bar arrangement of an extended foundation of a wind turbine generator set provided by an embodiment of the present invention;

[0046] Figure 5The present invention provides a bottom plate bottom surface, top surface and top plate reinforcement diagram of an extended foundation of a wind turbine generator set provided by an embodiment of the present invention.

[0047] Description of reference numerals:

[0048] 1. Bottom surface annular reinforcement; 2. Bottom surface radial reinforcement; 3. Top surface annular reinforcement; 4. Top surface radial reinforcement; 5. Stool reinforcement; 6. Cross reinforcement; 7. Column inner annular reinforcement; 8. Stirrups; 9. Anchor bolts; 10. Column longitudinal reinforcement; 11. Short radial reinforcement. DETAILED DESCRIPTION

[0049] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0050] like Figure 1 As shown, an embodiment of the present invention provides a method for determining parameters of an extended foundation of a wind turbine generator system, comprising the following steps:

[0051] Step 11, determining the most dangerous cross-section data according to the extended basic body shape data;

[0052] Step 12: Determine the bottom surface resistance bending moment value, top surface resistance bending moment value, bottom surface design bending moment value and top surface design bending moment value of the extended foundation bottom plate according to the most dangerous section data;

[0053] Step 13, determining unnecessary points according to the bottom surface resistance bending moment value, top surface resistance bending moment value, bottom surface design bending moment value and top surface design bending moment value of the extended foundation bottom plate;

[0054] Step 14, determine the breakpoint position according to the preset anchoring distance of the unnecessary point;

[0055] Step 15: The breakpoint position is used to cut the radial reinforcement.

[0056] In this embodiment, if Figure 2 As shown, this technical solution meets the requirements of Article 7.2.4 of the "Design Specifications for Wind Turbine Foundations of Onshore Wind Farm Projects" NB / T10311-2019: The external dimensions of the extended foundation meet the requirements:

[0057]

[0058] In the formula, R is the base bottom radius, is the column radius, For foundation with variable cross-section height, the foundation bottom pressure can be considered as linear distribution.

[0059] This technical solution complies with the assumption that the reaction force at the bottom of the foundation is distributed in a straight line to calculate the reinforced concrete extended foundation, and the influence of the overall bending of the foundation is not considered in the calculation of the foundation structure; the influence of the overall bending is considered by controlling the reinforcement of key parts and distinguishing between radial reinforcement designs and non-full-length settings.

[0060] The design method of radial reinforcement structure of reinforced concrete extended foundation of wind turbine mainly considers three factors: bending calculation of the bottom and top surfaces of the foundation; verification of crack width of the bottom and top surfaces of the foundation; and minimum reinforcement ratio of the bottom and top surfaces of the foundation.

[0061] The number of radial reinforcements is based on the most dangerous section (the junction between the column and the foundation - The maximum bending moment is determined by

[0062] By formula

[0063]

[0064] The height of the concrete compression zone shall meet the following conditions: ; ;

[0065] Calculate the maximum bending moment of the most dangerous section, where is the thickness of the steel bar protective layer;

[0066] Under the condition that the bending strength of the cross section is ensured to be safe, the tensile radial reinforcement can be cut off near the wind turbine support; the radial reinforcement structure on the bottom and top surfaces of the foundation slab is designed to be non-through-length, that is, it is cut off at unnecessary positions; the number and position of the cut radial reinforcement are determined from the "resistance bending moment diagram", so that the bottom radial reinforcement of the typical control section of the foundation slab can be fully utilized.

[0067] Formula Obtain the bottom surface design bending moment value of the extended foundation slab;

[0068] By formula Obtain the design bending moment value of the top surface of the extended foundation slab;

[0069] By formula

[0070]

[0071] The height of the concrete compression zone shall meet the following conditions: ; ;

[0072] Obtain the top and bottom resistance moments of the extended foundation slab;

[0073] in, M is the design bending moment per unit arc length of the foundation slab under the basic combination of load effects, R is the base plate radius, q The top surface of the foundation slab is approximately uniformly loaded. P is the net reaction force of the circular foundation approximately uniformly distributed under the basic combination of load effects, is the column radius; is the coefficient, is the design value of concrete axial compressive strength, is the effective height of the section, is the design value of the compressive strength of ordinary steel bars, is the cross-sectional area of ​​the longitudinal ordinary steel bars in the compression zone, is the distance from the resultant force point of the longitudinal ordinary steel bars in the compression zone to the compression edge of the section, To resist the bending moment, is the design value of tensile strength of ordinary steel bars, is the cross-sectional area of ​​the longitudinal ordinary reinforcement in the tension zone.

[0074] Compare the design bending moment value with the resistance bending moment value. The place where the resistance bending moment is greater than the design bending moment is the unnecessary point of the radial reinforcement. Starting from the place where the bending moment design value and the resistance bending moment value are equal, reserve an anchorage distance, which is the location of the breakpoint.

[0075] The "resistance bending moment diagram" formed by the non-full-length radial steel bars actually arranged on the bottom and top surfaces of the foundation slab should envelop the "design bending moment diagram"; that is, after the radial steel bars are cut off, the length or number of the remaining radial steel bars is reduced, and the bending strength of the foundation section at the steel bar cut position will be reduced. However, as long as the "resistance bending moment diagram" is included in the "design bending moment diagram", the bending strength of the foundation section can be guaranteed.

[0076] The technical solution of the present invention considers the influence on the overall bending of the foundation by controlling the reinforcement of key parts and distinguishing the radial reinforcement design from the non-full-length setting. While meeting the reinforcement requirements of relevant specifications, it provides a fine and reasonable design method for radial reinforcement of the reinforced concrete extended foundation of wind turbines in onshore wind farms. The radial reinforcement structure in the solution adopts a single-layer, double-layer or multi-layer design method on the bottom and top surfaces of the foundation. The reinforced concrete extended foundation has the characteristics of high tensile strength and strong bending resistance, and can effectively withstand longitudinal loads and bending moments. It has a simple structure, is easy to use and maintain, has strong directionality, is conducive to showing a three-dimensional image, and is easy to connect with the environment. The solution can save construction investment to a large extent, meet the requirements of carbon emission control, and can reduce the content of greenhouse gases emitted, thereby mitigating climate change.

[0077] In an optional embodiment of the present invention, when the preset anchorage distance is in the tension zone, the preset anchorage tension distance of the Grade I steel bar is 25d; the preset anchorage tension distance of the Grade II steel bar is 30d; the preset anchorage tension distance of the Grade III steel bar is 35d;

[0078] When the preset anchorage distance is in the compression zone, the preset anchorage compression distance of Grade I steel bars is 15d; the preset anchorage compression distance of Grade II steel bars is 15d; the preset anchorage compression distance of Grade III steel bars is 15d;

[0079] Where d is the diameter of the steel bar.

[0080] In this embodiment, according to the requirements of the Code for Design of Concrete Structures (GB50010-2010), according to the position of the cut radial reinforcement, when the preset anchorage distance is in the tension zone, it is necessary to meet the preset anchorage tension distance of Class I reinforcement of 25d; the preset anchorage tension distance of Class II reinforcement is 30d; the preset anchorage tension distance of Class III reinforcement is 35d;

[0081] When the preset anchorage distance is in the compression zone, it is necessary to meet the requirements that the preset anchorage compression distance of Grade I steel bars is 15d; the preset anchorage compression distance of Grade II steel bars is 15d; and the preset anchorage compression distance of Grade III steel bars is 15d;

[0082] An optional embodiment of the present invention is to use the formula Obtain the bottom surface design bending moment value of the extended foundation slab;

[0083] By formula Obtain the design bending moment value of the top surface of the extended foundation slab;

[0084] By formula

[0085]

[0086] Obtain the most dangerous cross-section data of the extended foundation and the top and bottom surface resistance bending moment values ​​of the extended foundation bottom plate;

[0087] in, M is the design bending moment per unit arc length of the foundation slab under the basic combination of load effects, R is the base plate radius, q The top surface of the foundation slab is approximately uniformly loaded. P is the net reaction force of the circular foundation approximately uniformly distributed under the basic combination of load effects, is the column radius; is the coefficient, is the design value of concrete axial compressive strength, is the effective height of the section, is the design value of the compressive strength of ordinary steel bars, is the cross-sectional area of ​​the longitudinal ordinary steel bars in the compression zone, is the distance from the resultant force point of the longitudinal ordinary steel bars in the compression zone to the compression edge of the section, To resist the bending moment, is the design value of tensile strength of ordinary steel bars, is the cross-sectional area of ​​the longitudinal ordinary reinforcement in the tension zone.

[0088] In this embodiment, when calculating the bending bearing capacity of the reinforcement of the foundation slab, the bending moment value of the reinforcement on the bottom surface of the foundation slab can be calculated according to the cantilever structure that bears the uniformly distributed load. The design value of the bending moment per unit arc length at the surface can be calculated according to the net reaction force distribution of the foundation as follows:

[0089] By formula Get the design value of bending moment;

[0090] M is the design value of the bending moment per unit arc length of the foundation slab under the basic combination of load effects; R The radius of the base plate.

[0091] By formula Get P;

[0092] P is the net reaction of the nearly uniformly distributed foundation of the circular foundation under the basic combination of load effects, N is the design value of the vertical load acting on the top surface of the foundation under the basic combination of load effects, M is the design value of the total bending moment acting on the bottom surface of the foundation under the basic combination of load effects, A is the actual compression area of ​​the bottom surface of the foundation, and I is the moment of inertia of the bottom surface of the foundation.

[0093] The bending moment value of the reinforcement on the top surface of the foundation slab can be calculated as a cantilever member bearing a uniformly distributed load, and the radius of the foundation column The design value of the upper bending moment per unit arc length can be calculated as follows:

[0094] By formula Get the design value of the upper bending moment;

[0095] q is the approximately uniformly distributed load on the top surface of the foundation slab;

[0096] The circular foundation slab should be calculated according to the variable section position of radial and annular reinforcement. The bending moment of radial reinforcement per unit width can be 2 / 3M, and the bending moment of annular reinforcement per unit width can be 1 / 3M. The reinforcement calculation should comply with the relevant provisions of the current national standard "Code for Design of Concrete Structures".

[0097] By formula

[0098]

[0099] The height of the concrete compression zone shall meet the following conditions: ;

[0100] Obtain the most dangerous cross-section data of the extended foundation and the top and bottom surface resistance bending moment values ​​of the extended foundation bottom plate;

[0101] In an optional embodiment of the present invention, the ends of the tensile steel bars and the compressive steel bars in the extended foundation slab binding frame are provided with hooks.

[0102] In this embodiment, the hook at the end of the steel bar is a structural requirement. The first-grade steel bar has a smooth and round surface, and the concrete bond strength is insufficient, so the end of the steel bar must be bent 180 degrees. There is a certain friction between the ribbed steel bar and the concrete, so it is generally not necessary to bend. It is only bent when the anchorage length of the steel bar is insufficient and where the specification requires bending. The function of the hook is to increase the bonding force between the steel bar and the concrete, improve the anchoring capacity, avoid anchoring damage, and make the component firm and not damaged.

[0103] In an optional embodiment of the present invention, the minimum reinforcement ratio of the radial steel bars bearing the load on the bottom and top surfaces of the extended foundation slab is greater than or equal to 0.15%.

[0104] In this embodiment, referring to the specifications and corresponding calculation results, the minimum reinforcement ratio of the radial steel bars on the bottom and top surfaces of the extended foundation slab is greater than or equal to 0.15%.

[0105] In an optional embodiment of the present invention, the minimum diameter of the radial reinforcement bearing the bottom and top surfaces of the extended foundation slab is greater than or equal to 10 mm.

[0106] In this embodiment, referring to the specifications and corresponding calculation results, the minimum diameter of the radial reinforcement bearing the bottom and top surfaces of the extended foundation slab is greater than or equal to 10 mm.

[0107] In an optional embodiment of the present invention, the spacing between the radial reinforcements bearing the load on the bottom and top surfaces of the extended foundation slab is greater than or equal to 100 mm and less than or equal to 200 mm.

[0108] In this embodiment, referring to the specifications and corresponding calculation results, the spacing between the radial reinforcements on the bottom and top surfaces of the extended foundation slab is greater than or equal to 100 mm and less than or equal to 200 mm.

[0109] In an optional embodiment of the present invention, radial short steel bars are provided at the outer radial steel bars of the bottom surface and the top surface of the extended foundation slab, and the length of the radial short steel bars is preset to 1130 mm.

[0110] In this embodiment, the radial reinforcement increases in spacing as the distance from the column increases. From the perspective of force, the bending stress generated by the foundation reaction force remains unchanged, while the bending moment stress that the foundation can resist decreases as the distance increases. When the bending stress generated by the foundation reaction force exceeds the bending strength of the foundation, bending failure occurs. To prevent such failure, the bending stress (design bending moment value) on each vertical section of the foundation must be less than the bending strength of the section. According to this principle, the bending resistance of the section is enhanced and radial short reinforcement is added. At the same time, the radial short reinforcement can also play the role of fixing the annular reinforcement, giving full play to the role of the annular reinforcement in restraining the lateral expansion of concrete and resisting external shear force.

[0111] In an optional embodiment of the present invention, the annular reinforcements of the extended foundation slab are preset at intervals according to their locations.

[0112] In this embodiment, there is excellent bonding performance between the annular steel bars and the concrete in the compression zone of the extended foundation. When the extended foundation is bent and obliquely compressed, it restrains the lateral expansion deformation of the concrete in the bending and compression zone due to compression, so that the stress performance of the concrete in the compression zone is significantly improved, that is, it plays the role of a lateral restraining bar; when the extended foundation is subjected to pure shear and punching failure, the annular steel bars will play a role in resisting external shear force at the location where the cracks occur; therefore, different spacings are set according to the position of the annular steel bars 1 on the bottom surface of the extended foundation slab; the annular steel bars 1 on the outer periphery of the bottom surface of the extended foundation slab adopt a diameter of D28mm and a spacing of 140mm, the annular steel bars 7 close to the column position adopt a diameter of D28mm and a spacing of 200mm, and the annular steel bars 3 on the top surface of the extended foundation slab adopt a diameter of D28mm and a spacing of 140mm.

[0113] The present invention also provides a wind turbine expansion base, comprising:

[0114] Bottom hoop reinforcement 1;

[0115] The bottom radial steel bars 2 are fixedly connected to the bottom annular steel bars 1;

[0116] The top surface annular reinforcement 3 is arranged opposite to the bottom surface annular reinforcement 1;

[0117] The top surface radial reinforcement 4 is fixedly connected to the top surface annular reinforcement 3;

[0118] The horse stool reinforcement 5 is fixedly connected to the top surface annular reinforcement 3 and the top surface radial reinforcement 4; the horse stool reinforcement 5 supports the top surface annular reinforcement 3 and the top surface radial reinforcement 4;

[0119] The cross steel bars 6 are fixedly connected to the bottom radial steel bars 2;

[0120] The inner annular reinforcement 7 of the platform column is arranged opposite to the bottom annular reinforcement 1;

[0121] The stirrups 8 are fixedly connected to the cross steel bars 6 and the inner annular steel bars 7 of the column;

[0122] Anchor bolts 9 are fixedly connected to the inner annular steel bars 7, the cross steel bars 6 and the stirrups 8 of the column;

[0123] The longitudinal steel bars 10 of the platform column are fixedly connected to the inner annular steel bars 7 of the platform column;

[0124] The radial short steel bars 11 are fixedly connected to the bottom surface annular steel bars 1 and the top surface annular steel bars 3 to enhance the stability of the structure.

[0125] In this embodiment, Figure 2 As shown, the extended foundation radius R = 10400mm, the foundation edge height =800mm, foundation variable section height =2800mm, overall height of foundation =4500mm, column width =3400mm and anchor bolt width 2230mm are designed.

[0126] Figures 2 to 5 They are respectively the extended foundation shape diagram; the overall structural schematic diagram of the wind turbine extended foundation; the steel bar arrangement cross-section diagram of the wind turbine extended foundation; and the reinforcement diagrams of the bottom, top and top plates of the wind turbine extended foundation.

[0127] A radially reinforced non-full-length wind turbine expansion foundation and its reinforcement structure mainly include bottom plate bottom surface annular steel bars 1, bottom surface radial steel bars 2, top surface annular steel bars 3, top surface radial steel bars 4, horse stool bars 5, cross steel bars 6, column inner annular steel bars 7, stirrups 8, and column longitudinal steel bars 10.

[0128] The non-full-length bottom radial steel bars 2, the bottom circumferential steel bars 1 and the cross-cross steel bars 6 inside the anchor bolts 9 are tied together to form the bottom surface structure of the extended foundation, which is mainly used to improve the support force of the wind turbine foundation. The non-full-length top radial steel bars 4 and the top circumferential steel bars 3 on the top surface of the extended foundation bottom plate are tied together to form the top surface structure of the extended foundation bottom plate, which is mainly used to improve the torsion resistance of the wind turbine foundation. The spacing between the bottom circumferential steel bars 1 and the top circumferential steel bars 3, and the truncation positions and methods of the bottom radial steel bars 2 and the top radial steel bars 4 are all different; the steel bars on the top surface of the bottom plate are arranged in three dimensions, while the steel bars on the bottom surface of the bottom plate are arranged in a plane; the anchor bolts 9 are fixed by combining the circumferential steel bars 7, the stirrups 8 and the cross-cross steel bars 6 in the column. When the anchor bolts 9 are subjected to tension, the part above the lower anchor plate of the anchor bolts 9 will be uniformly stressed. The entire anchor bolt 9 is an elastic body without an interface between the elastic part and the rigid part, thereby avoiding stress concentration. Since prestress is applied to the anchor bolts 9, the concrete foundation is always in a compressive state. Therefore, the wind turbine foundation using prestressed anchor bolts 9 will not experience stress concentration and damage to the concrete on both sides of the foundation ring; the extended foundation is provided with horse stool reinforcement 5 to support the radial steel bars 4 and the top surface annular steel bars 3 on the bottom plate to ensure the torsional resistance of the wind turbine foundation.

[0129] If the radial steel bars 2 on the bottom surface of the extended foundation slab and the radial steel bars 4 on the top surface are designed for a full-length structure, the spacing between the steel bars in the column will be reduced, and cross steel bars 6 and annular steel bars 7 in the column will need to be set at the center of the bottom and top surfaces of the extended foundation slab and at the connection between the anchor bolts 9 and the foundation, so that the radial steel bar reinforcement ratio of the bottom and top slabs is too large, and the design bending moment diagram is much larger than the resistance bending moment diagram. According to the technical solution, the radial reinforcement 2 on the bottom surface of the extended foundation slab is cut off when it is close to the anchor bolt 9, the radial reinforcement 4 on the top surface is bent downward when it is close to the column, the reinforcement spacing between the top radial reinforcement 4 and the top annular reinforcement 3 is adjusted, and the radial reinforcement near the anchor bolt 9 inside the extended foundation is changed to the annular reinforcement 7 and stirrups 8 inside the column to fix the anchor bolt 9 and improve the torsional resistance of the foundation, and the anchorage length of the longitudinal reinforcement of the slab is lengthened when it meets the requirements of the specification, so that the spacing between the radial reinforcement 2 on the bottom surface of the extended foundation slab and the radial reinforcement 4 on the top surface is reduced, so as to achieve the effect that the resistance bending moment diagram covers the design bending moment diagram and the resistance bending moment diagram is close to the design bending moment diagram.

[0130] There is excellent bonding performance between the circumferential steel bars and the concrete in the compression zone of the extended foundation. When the extended foundation is subjected to bending and oblique compression failure, it restrains the lateral expansion deformation of the concrete in the bending and compression zone due to compression, so that the stress performance of the concrete in the compression zone is significantly improved, that is, it plays the role of a lateral restraining bar. When the extended foundation is subjected to pure shear and punching failure, the circumferential steel bars will play a role in resisting external shear force at the location where the cracks occur. Therefore, the design method for the circumferential steel bars of the extended foundation is as follows: the circumferential steel bars 1 on the bottom surface of the extended foundation slab are set at different spacings according to their positions. The outer circumferential steel bars 1 on the bottom surface of the extended foundation slab adopt a diameter of D28mm and a spacing of 140mm, the circumferential steel bars 7 close to the column position adopt a diameter of D28mm and a spacing of 200mm, and the circumferential steel bars 3 on the top surface of the extended foundation slab adopt a diameter of D28mm and a spacing of 140mm.

[0131] The radial reinforcement can withstand tensile stress, so that the reinforced concrete extended foundation can produce some bending without being damaged. The design method of the radial reinforcement of the extended foundation is as follows: the radial reinforcement 2 on the bottom surface of the base plate is arranged in an interval cut-off manner at the bolts and 1500mm away from the center of the base plate, and the radial reinforcement 4 on the top surface of the base plate is bent downward and deepened at the column. The deepened reinforcement is cut off at 1500mm away from the center of the foundation plane, and the downward bent reinforcement is cut off at the bolts.

[0132] The cross reinforcement 6 is a steel mesh with vertical and horizontal reinforcements arranged at a certain interval and at right angles to each other, and all intersections are welded. The cross reinforcement 6 will transmit force along the "cross" shape, and the force is evenly applied. It is not easy to be damaged by the anchoring effect with the concrete, and can better withstand tension and shear force. The denser spacing can improve the crack resistance of the extended foundation. The cross reinforcement is arranged at the position where the radial reinforcement is cut off at the bottom, middle and top of the extended foundation to reinforce the core concrete.

[0133] Since there is a certain height difference between the bottom steel bar and the top steel bar of the bottom plate, in order to ensure that the foundation can bear all the weight transmitted from the tower, and bear all the stress conditions including support, earthquake resistance, strong wind resistance, etc., it is necessary to maintain the effective height between the bottom steel bar and the top steel bar, so it is necessary to use the horse stool bar 5 between the bottom steel bar and the top steel bar for support. The horse stool bar 5 is in the shape of a "J", and is arranged in order along the radial steel bars with an interval of 1500mm. The height of different horse stool bars on the same row with the radial steel bars decreases from the center of the circle to the outer circumference, and the height of horse stool bars 5 in different rows at the same distance from the center of the circle is the same.

[0134] The radial reinforcements on the bottom and top surfaces of the extended foundation slab have larger spacing as they are farther from the center of the extended foundation plane. Short reinforcements 11 are set at intervals of 1130mm at the edges of the bottom and top surfaces to increase the bearing capacity and torsion and bending resistance. By increasing the reinforcement ratio of the peripheral radial reinforcements, the utilization rate of the reinforcement is effectively improved, achieving an effect in which the moment diagram of resistance is close to the design moment diagram.

[0135] The wind turbine foundation uses prestressed anchor bolts 9 to bear the upper load. The anchor bolts 9 are arranged in a circumferential manner to form an anchor bolt cage. In order to realize the hoisting of the upper tower, the concentricity and verticality of the anchor bolts 9 are extremely high. The intersection of the anchor bolts 9 and the foundation is fixed by the method of cross-cross steel bars 6 and the annular steel bars 7 in the column. The original radial steel bars and annular steel bars inside the anchor bolts 9 are replaced by a combination of annular steel bars 7 and stirrups 8 for fixing. On the one hand, radial steel bars and annular steel bars can fix the plane structure, and the combined structure of annular steel bars and stirrups can make the annular stirrups of each layer form a whole, reducing the risk of damage to the core concrete of the extended foundation; on the other hand, the reinforcement of the foundation is too large, so that the resistance bending moment diagram is much larger than the design bending moment diagram. The annular steel bars are arranged vertically through the length with a diameter of D16mm, an indirect length of 300mm, and a radius of 1500mm, 2000mm, 2500mm, and 3000mm respectively.

[0136] The radially reinforced non-full-length wind turbine extension foundation and its reinforcement structure of this scheme take into account the influence of overall bending by controlling the reinforcement at key positions and distinguishing between radial reinforcement designs and non-full-length settings. Under the premise of ensuring that the extension foundation will not be bent and damaged in actual projects, the reinforcement structure of the extension foundation is changed, which is conducive to reducing the self-weight and consumables of steel bars, significantly reducing the investment in onshore wind farm construction projects in the new energy industry, and practicing energy conservation, emission reduction, and low-carbon development.

[0137] In another embodiment of the present invention, the technical solution meets the requirements of carbon emission control and can reduce the content of greenhouse gases emitted, thereby mitigating climate change.

[0138] Usually the extended foundation radius R should be 1 / 12~1 / 8 of the wheel load height H. It is 1 / 40~1 / 25 of the wheel load height H, and the statistical theoretical analysis of engineering practice: the foundation edge height ≈R(1 / 11)≥600mm, theoretical column radius ≈R(1 / 3.05), foundation variable section height ≡(R– ) / 2.5≈0.269R. Figure 2 As shown, the base edge height is extended Minimum reinforcement ratio of radial reinforcement for concrete cross-sectional area With variable section height Minimum reinforcement ratio of radial reinforcement for concrete cross-sectional area ratio ≈1.04 .

[0139] The design of the single-side longitudinal radial reinforcement of the foundation slab reinforcement (including the bottom and top surfaces) is based on the existing technology and is set all the way through regardless of the situation. If the radial reinforcement ratio (bottom and top surfaces) of the concrete cross-sectional area at any variable cross-sectional height of the extended foundation is increased by ⊿ρ≡+0.01%; ≡800mm, R≡8800mm, ≡2367mm, ≡2885mm for theoretical calculation:

[0140] Then expand the base edge height Concrete cross-sectional area Radial reinforcement area (Bottom and top) add total ⊿ ≡⊿ρ·2πR ×2≈+4421×2 ;

[0141] Then expand the base edge height Concrete cross-sectional area Radial reinforcement area (Bottom and top) add total ⊿ ≡⊿ρ·2π ×2≈+4288×2 ;

[0142] When the radial reinforcement design uses a nominal reinforcement diameter of 28 mm, the theoretical calculation is performed:

[0143] Then expand the base edge height Concrete cross-sectional area Radial reinforcement weight (Bottom and top) add total ⊿ ≡⊿ ×7.85× Ton / mm≡2πR ×7.85× ×2 tons / m ≈ +0.0347×2 tons / m;

[0144] Then expand the base edge height Concrete cross-sectional area Radial reinforcement area (Bottom and top) add total ⊿ ≡⊿ ×7.85× Ton / mm≡2π ×7.85× ×2 tons / m ≈ +0.0337×2 tons / m;

[0145] According to the statistics of relevant organizations in 2020, the comprehensive energy consumption of steel enterprises per ton of steel is 545.27 kg of standard coal per ton. The theoretical calculation of the increase in the "comprehensive energy consumption" of steel enterprises by existing technologies is as follows:

[0146] If the base edge height is extended Concrete cross-sectional area Radial reinforcement weight (Bottom and top) add total ⊿ ≈+0.0347×2 tons / m, the "comprehensive energy consumption" of steel enterprises increases by 37.84 kg of standard coal / m.

[0147] If the base edge height is extended Concrete cross-sectional area Radial reinforcement area (Bottom and top) add total ⊿ ≈+0.0337×2 tons / m, the "comprehensive energy consumption" of steel enterprises increases by 36.75 kg of standard coal / m.

[0148] According to the existing data, the carbon emission reduction of this technical solution is theoretically calculated at 2.77 tons / ton of standard coal:

[0149] If the base edge height is extended Concrete cross-sectional area radial steel reinforcement weight: ton of steel "comprehensive energy consumption" reduction of 37.84 kg standard coal / m, so this technical solution reduces carbon emissions by 0.105 tons / m.

[0150] If the base edge height is extended Concrete cross-sectional area radial steel reinforcement weight: ton of steel "comprehensive energy consumption" reduction of 36.75 kg standard coal / m, so this technical solution reduces carbon emissions by 0.102 tons / m.

[0151] According to news materials: one ton of steel requires about 1.68 tons of iron ore; one ton of iron ore requires at least 2 tons of rock to be stripped; and one ton of steel produces 0.33 tons of slag. Theoretical calculation of the increase in natural resource energy consumption using existing technology:

[0152] If the base edge height is extended If the weight of radial reinforcement of concrete cross-sectional area increases by 0.0347×2 tons / m, the existing technology will increase the energy consumption of natural resources: 0.116 tons / m of iron ore, 0.233 tons / m of stripping rock, and 0.023 tons / m of slag.

[0153] If the base edge height is extended The weight of radial steel reinforcement in concrete cross-sectional area increases by 0.0337×2 tons / m; the existing technology increases the natural resource energy consumption: iron ore 0.113 tons / m, stripping 0.226 tons / m rock, slag 0.022 tons / m.

[0154] Similarly, for any variable cross-section height of the extended foundation Concrete cross-sectional area Radial reinforcement area (Bottom and top) minus total ⊿ ≡⊿ρ·2π ×2( ); Radial reinforcement weight (Bottom and top) minus total ⊿ ≡⊿ ×7.85× Ton / mm≡2π ×7.85× ×2 tons / mm≡2π ×7.85× ×2 tons / m; when the comprehensive energy consumption per ton of steel is 545.27 kg standard coal / ton, the “comprehensive energy consumption” is reduced by 2π ×4.28× ×2 kg standard coal / m; when carbon emissions are 2.77 tons / ton standard coal, carbon emissions are reduced by 2π ×1.186× ×2 tons / m; One ton of steel requires about 1.68 tons of iron ore. One ton of iron ore requires at least 2 tons of rock to be stripped. When one ton of steel is produced, 0.33 tons of slag is produced, which reduces the consumption of iron ore by 2π ×1.3188× ×2 tons / m, reducing rock removal by 2π ×2.6376× ×2 tons / m, reducing slag production by 2π ×2.591× ×2 tons / m.

[0155] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for determining parameters of an extended foundation of a wind turbine generator system, characterized in that: The following steps are involved: Determine the most dangerous cross-section data based on the expanded basic body shape data; According to the most dangerous section data, determine the bottom surface resistance bending moment value, top surface resistance bending moment value, bottom surface design bending moment value and top surface design bending moment value of the extended foundation bottom plate; determining unnecessary points according to the bottom surface resistance bending moment value, the top surface resistance bending moment value, the bottom surface design bending moment value, and the top surface design bending moment value of the extended foundation bottom plate; Preset anchoring distances based on unnecessary points and determine breakpoint locations; The breakpoint position is used to cut off the radial reinforcement; Among them, under the condition that the cross-section bending strength is guaranteed to be safe, the tensile radial reinforcement will be cut off near the wind turbine support; the radial reinforcement structure on the bottom and top surfaces of the foundation slab is designed as not full-length; Among them, the design bending moment value and the resistance bending moment value are compared. The place where the resistance bending moment is greater than the design bending moment is the unnecessary point of the radial reinforcement. The anchorage distance is reserved from the place where the design bending moment value and the resistance bending moment value are equal, which is the location of the breakpoint. Wherein, the ends of the tension steel bars and the compression steel bars in the extended foundation bottom plate binding skeleton are provided with hooks, and the hooks are 180-degree hooks; Among them, when the preset anchorage distance is in the tension zone, the preset anchorage tension distance of Grade I steel bars is 25d; the preset anchorage tension distance of Grade II steel bars is 30d; the preset anchorage tension distance of Grade III steel bars is 35d; When the preset anchorage distance is in the compression zone, the preset anchorage compression distance of Grade I steel bars is 15d; the preset anchorage compression distance of Grade II steel bars is 15d; the preset anchorage compression distance of Grade III steel bars is 15d; Where, d is the diameter of the steel bar; Among them, through the formula Obtain the bottom surface design bending moment value of the extended foundation slab; By formula Obtain the design bending moment value of the top surface of the extended foundation slab; By formula Obtain the most dangerous cross-section data of the extended foundation and the bending moment resistance values ​​of the top and bottom surfaces of the extended foundation base plate; in, M is the design bending moment per unit arc length of the foundation slab under the basic combination of load effects, R is the base plate radius, q The top surface of the foundation slab is approximately uniformly loaded. P is the net reaction force of the circular foundation under the basic combination of load effects, is the column radius; is the coefficient, is the design value of the concrete axial compressive strength, is the effective height of the section, is the design value of the compressive strength of ordinary steel bars, is the cross-sectional area of ​​the longitudinal ordinary steel bars in the compression zone, is the distance from the resultant force point of the longitudinal ordinary steel bars in the compression zone to the compression edge of the section, To resist the bending moment, is the design value of tensile strength of ordinary steel bars, is the cross-sectional area of ​​the longitudinal ordinary reinforcement in the tension zone; Among them, the circular foundation bottom plate should be calculated according to the variable section position of radial and circumferential reinforcement. The bending moment of radial reinforcement per unit width should be 2 / 3M, and the bending moment of circumferential reinforcement per unit width should be 1 / 3M.

2. The method for determining parameters of a wind turbine expansion foundation according to claim 1, characterized in that: The minimum reinforcement ratio of the radial steel bars on the bottom and top surfaces of the extended foundation slab is greater than or equal to 0.15%.

3. The method for determining parameters of a wind turbine expansion foundation according to claim 2, wherein: The minimum diameter of the radial reinforcement bearing the load on the bottom and top surfaces of the extended foundation slab is greater than or equal to 10 mm.

4. The method for determining parameters of a wind turbine expansion foundation according to claim 3, characterized in that: The spacing between the radial reinforcement bars on the bottom and top surfaces of the extended foundation slab is greater than or equal to 100 mm and less than or equal to 200 mm.

5. The method for determining parameters of a wind turbine expansion foundation according to claim 1, wherein: Radial short steel bars are provided at the outer radial reinforcements of the bottom and top surfaces of the extended foundation slab, and the length of the radial short steel bars is preset to be 1130 mm.

6. The method for determining parameters of a wind turbine expansion foundation according to claim 1, wherein: The circumferential reinforcements of the extended foundation slab are preset at intervals according to their locations.

7. A wind turbine expansion foundation, characterized in that: include: Bottom hoop reinforcement (1); The bottom radial steel bars (2) are fixedly connected to the bottom circumferential steel bars (1); The top surface annular steel bars (3) are arranged opposite to the bottom surface annular steel bars (1); The top surface radial steel bars (4) are fixedly connected to the top surface circumferential steel bars (3); The horse stool reinforcement (5) is fixedly connected to the top surface annular reinforcement (3) and the top surface radial reinforcement (4); the horse stool reinforcement (5) supports the top surface annular reinforcement (3) and the top surface radial reinforcement (4); The cross steel bars (6) are fixedly connected to the bottom radial steel bars (2); The inner annular steel bars (7) of the platform column are arranged opposite to the bottom annular steel bars (1); The stirrups (8) are fixedly connected to the cross steel bars (6) and the inner annular steel bars (7) of the platform column; Anchor bolts (9) are fixedly connected to the inner annular steel bars (7) of the platform column, the cross steel bars (6), and the stirrups (8); The longitudinal steel bars (10) of the platform column are fixedly connected to the inner annular steel bars (7) of the platform column; The radial short steel bars (11) are fixedly connected to the bottom surface annular steel bars (1) and the top surface annular steel bars (3) to enhance the stability of the structure; The circumferential reinforcement (1) on the bottom surface of the extended foundation slab is arranged at different intervals according to the position thereof. The circumferential reinforcement (1) on the outer bottom surface of the extended foundation slab adopts a diameter of D28mm and a spacing of 140mm. The circumferential reinforcement (7) on the inner side of the column near the column adopts a diameter of D28mm and a spacing of 200mm. The circumferential reinforcement (3) on the top surface of the extended foundation slab adopts a diameter of D28mm and a spacing of 140mm. The radial reinforcements (2) on the bottom surface of the bottom plate are arranged at intervals and cut off at the bolts and at a distance of 1500 mm from the center of the bottom plate. The radial reinforcements (4) on the top surface of the bottom plate are bent downwards and penetrated at intervals at the pedestal. The penetrated reinforcements are cut off at a distance of 1500 mm from the center of the foundation plane, and the downwardly bent reinforcements are cut off at the bolts. The radial reinforcement is cut according to the breakpoint position, and the breakpoint position is determined according to the preset anchorage distance of the unnecessary point; Among them, horse stool bars (5) are used between the bottom steel bars and the top steel bars for support; Among them, short steel bars (11) are arranged at intervals of 1130 mm at the edges of the bottom and top surfaces; The intersection of the anchor bolt (9) and the foundation is fixed by a method of cross-cross steel bars (6) and annular steel bars (7) inside the column. The original radial steel bars and annular steel bars inside the anchor bolt (9) are replaced with a combination of annular steel bars (7) inside the column and stirrups (8) for fixing. Among them, when the preset anchorage distance is in the tension zone, the preset anchorage tension distance of Grade I steel bars is 25d; the preset anchorage tension distance of Grade II steel bars is 30d; the preset anchorage tension distance of Grade III steel bars is 35d; When the preset anchorage distance is in the compression zone, the preset anchorage compression distance of Grade I steel bars is 15d; the preset anchorage compression distance of Grade II steel bars is 15d; the preset anchorage compression distance of Grade III steel bars is 15d; Where, d is the diameter of the steel bar; Among them, through the formula Obtain the bottom surface design bending moment value of the extended foundation slab; By formula Obtain the design bending moment value of the top surface of the extended foundation slab; By formula Obtain the most dangerous cross-section data of the extended foundation and the bending moment resistance values ​​of the top and bottom surfaces of the extended foundation base plate; in, M is the design bending moment per unit arc length of the foundation slab under the basic combination of load effects, R is the base plate radius, q The top surface of the foundation slab is approximately uniformly loaded. P is the net reaction force of the circular foundation under the basic combination of load effects, is the column radius; is the coefficient, is the design value of concrete axial compressive strength, is the effective height of the section, is the design value of the compressive strength of ordinary steel bars, is the cross-sectional area of ​​the longitudinal ordinary steel bars in the compression zone, is the distance from the resultant force point of the longitudinal ordinary steel bars in the compression zone to the compression edge of the section, To resist the bending moment, is the design value of tensile strength of ordinary steel bars, is the cross-sectional area of ​​the longitudinal ordinary reinforcement in the tension zone; Among them, the circular foundation bottom plate should be calculated according to the variable section position of radial and circumferential reinforcement. The bending moment of radial reinforcement per unit width should be 2 / 3M, and the bending moment of circumferential reinforcement per unit width should be 1 / 3M.

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