CN107829444B

CN107829444B - Wind turbine generator system prestressing force foundation structure

Info

Publication number: CN107829444B
Application number: CN201711084812.9A
Authority: CN
Inventors: 邓阳; 屈宋源; 斯静
Original assignee: PowerChina Chengdu Engineering Co Ltd
Current assignee: PowerChina Chengdu Engineering Co Ltd
Priority date: 2017-11-07
Filing date: 2017-11-07
Publication date: 2020-05-26
Anticipated expiration: 2037-11-07
Also published as: CN107829444A

Abstract

The invention discloses a prestressed foundation structure of a wind turbine generator, relates to the field of foundation structures of wind turbine generators, and solves the problems that the existing beam-slab type wind turbine generator foundation structure is adopted by a large wind turbine generator, the reinforcement ratio of a main beam is obviously increased, the cost is increased, the reinforcement interval is small, the construction operation is not facilitated, and the safety of structural concrete is influenced. The technical scheme adopted by the invention is as follows: wind turbine generator system prestressing force foundation structure, for the beam slab formula, including the soleplate, the soleplate middle part is the pillar, sets up the access hole in the pillar, and the girder that the form was dispersed to the equipartition around the pillar sets up the prestressing cable in the girder and replaces original vertical reinforcement, and foundation structure concrete mainly is prestressed concrete, and the prestressing cable adopts post-tensioning method stretch-draw, through the access hole, can get into the basis and carry out the maintenance work of prestressing cable. By introducing the idea of prestressed concrete, the steel consumption is reduced, the cost is saved, the construction is convenient, the pouring quality is ensured, and the maintenance is convenient.

Description

Wind turbine generator system prestressing force foundation structure

Technical Field

The invention relates to the field of foundation structures of wind turbine generators, in particular to a prestress foundation structure of a wind turbine generator.

Background

At present, shallow-buried gravity type extended foundations, namely conventional plate foundations, are widely adopted in onshore wind power generation projects, and the foundation type has the advantages of shallow excavation and fewer construction procedures during construction. To improve economy, the structural style of conventional slab foundations is optimized as beam slab foundations. Because the beam-slab foundation concrete has higher stress level, the compressive capacity and the tensile capacity of the reinforcing steel bar of the concrete can be more fully exerted, and the beam-slab foundation concrete has remarkable economic property. According to statistics, the beam-slab foundation is adopted for the upper structure of the same wind turbine generator in the same project, 10% of construction cost is saved compared with the conventional slab foundation, and the saving is about 10-15 ten thousand yuan.

Along with the development of the wind power industry, the wind turbine generator is developed towards a high hub and a large impeller, the wind turbine generator and the tower are used as an upper structure, the whole eccentric load is increased more, and the foundation of the lower structure wind turbine generator is subjected to larger eccentric load. In order to meet the calculation requirement of a foundation structure, the diameter of a beam-plate type foundation of the wind turbine generator is increased, and the span and the area of the bottom surface are greatly increased. In order to meet the checking calculation requirements of cracks and deflection of the large-span foundation concrete in a limit state, the reinforcement ratio of the foundation concrete is increased. The reinforcement ratio is increased only to meet the requirements of concrete cracking and deflection control, so that the engineering cost is greatly increased, and the construction quality is not favorably controlled.

As shown in fig. 1 and 2, the large-scale wind turbine generator adopts the existing beam-slab wind turbine generator foundation structure, the middle part of a foundation slab 1 is a cylindrical and solid pillar 2, the outer edge of the foundation slab 1 is the outline of a foundation body structure, an anchor bolt cage connected with a wind turbine generator tower is arranged in the pillar 2, divergent main beams 5 are uniformly distributed around the pillar 2, and the outer sides of two adjacent main beams 5 are connected by an edge small beam 7. And a hollow structure is arranged between every two adjacent main beams 5, and backfilling treatment is carried out during construction. For a large wind turbine generator, the diameter of a foundation slab 1 reaches 18-23 m, the diameter of a solid column 2 is 5-6 m, and in order to meet the checking calculation requirements of cracks and deflection of long-span foundation concrete in a limit state, the reinforcement ratio of the foundation concrete is increased by 0.08t/m³～0.14t/m³. In order to meet the section stress requirement of the longitudinal bar 9 in the main beam 5, the longitudinal bar 9 in the main beam 5 is selected

The steel bar (HRB400) and the calculation result shows that: in fig. 2, the width of the main beam 5 is 1100mm, the diameter of the column 2 is 5.4m, and the longitudinal rib 9 at the top of the main beam 5 comprises: upper row of 14

Reinforcing bars, middle row of 14

Reinforcing steel bar, bottom row 7

Reinforcing steel bars; the longitudinal ribs 9 at the bottom of the main beam 5 comprise: upper row of 7

The bottom row of 11 steel bars

And (5) reinforcing steel bars. On top of main beam 5

The net spacing of the steel bars can even reach 44 mm.

The design has the following defects: the diameter of the main beam steel bars is large, the net spacing of the longitudinal bars is small, and the net spacing of the steel bars on the upper part of the beam is not less than 1.5d, namely 48mm, according to the specification requirement; the distance between the steel bars at the lower part of the beam is not less than d, namely 32 mm. It is thus clear that girder longitudinal reinforcement is too dense, leads to the reinforcing bar to be difficult to the ligature regular, the concrete is difficult to vibrate closely knit, influences ligature and concrete placement, is unfavorable for guaranteeing foundation structure's construction quality, seriously influences structure safety. Secondly, because the span of the foundation structure is larger, the bending moment effect is larger, the reinforcement ratio of the foundation concrete is increased only to meet the control requirement of structural crack and deflection deformation, and because a large amount of redundant steel bars are added, the cost is not low in economy. Thirdly, the structural steel bars are not only too dense, but also have multiple types, and are not beneficial to ensuring the project construction period.

Disclosure of Invention

The invention provides a prestressed foundation structure of a wind turbine generator, which solves the problems that the existing beam-slab wind turbine generator foundation structure is adopted by a large wind turbine generator, the reinforcement ratio of a main beam is obviously increased in order to meet the checking calculation requirements of concrete cracks and deflection, the cost is increased, the distance between reinforcing steel bars is small, the construction operation is not facilitated, and the safety of structural concrete is influenced.

The technical scheme adopted by the invention for solving the technical problems is as follows: wind turbine generator system prestressing force foundation structure, for the beam slab formula, including the soleplate, the soleplate middle part is cylindric pillar, sets up the crab-bolt cage that is used for connecting a wind turbine generator system tower section of thick bamboo in the pillar, sets up the access hole in the pillar, the girder of form is dispersed to the equipartition around the pillar, the inside structure arrangement muscle that sets up of girder, the outside of two adjacent girders is connected by marginal trabecula, set up the mounting hole along the girder between the outside of each girder and the access hole, set up the prestressing force cable in the mounting hole.

Further, the method comprises the following steps: the mounting hole in the main beam is formed by a metal corrugated pipe, and a steel strand is arranged in the metal corrugated pipe and used as the prestressed steel cable. Specifically, the prestressed steel cables are arranged from the access hole of the pillar to the outer side of the main beam in an inclined and downward manner, one end of each prestressed steel cable located in the access hole is a fixed end, and one end of each prestressed steel cable located in the outer side of the main beam is a tensioning end. Specifically, only one prestressed steel cable is arranged in each main beam.

Specifically, the diameter of the access hole is 1000 mm.

The invention has the beneficial effects that: the prestressed foundation structure of the wind turbine generator is characterized in that an access hole is formed in original solid concrete in the center of a foundation pillar of the wind turbine generator, prestressed cables are installed in the access hole, the prestressed cables are arranged in a main beam to replace original longitudinal reinforcements, reinforcing reinforcements are distributed for a structure in the main beam, the foundation structure concrete is mainly prestressed concrete, the prestressed cables are stretched by a post-tensioning method, and the prestressed cables can enter the foundation to overhaul the prestressed cables through the access hole in the pillar.

Because the prestressed steel cable has the material characteristics of high tension and low relaxation, compared with a common steel bar (HRB400), when the prestressed steel cable is subjected to the same tension, the deformation of the prestressed steel cable is smaller than that of the common steel bar, and the prestressed steel cable can be flexibly arranged in a bundle without being influenced by space, so that the difficult problem that the binding of the steel bar and the vibration of the concrete are seriously influenced due to the over-dense longitudinal bars on the upper part of the main beam in the original scheme can be solved, and the pouring quality is ensured. In addition, the prestressed concrete has great advantages for controlling the structural deformation, after the concrete strength reaches the design requirement, the prestressed steel cables are gradually tensioned to the design value, and prestress is applied to the concrete from the two ends of the main beam, so that the tensile stress is not generated on the edges of the members in the working process, and the concrete is prevented from cracking.

The wind turbine generator system prestressed foundation structure can guarantee the stress requirement of a foundation concrete structure, greatly reduces the reinforcement ratio of the beam-slab wind turbine generator system foundation structure on the premise of guaranteeing the requirements of cracks and deflection, reduces the steel bar cost, solves the problem of excessive density of main beam steel bars, ensures that the main beam longitudinal bars are reasonably arranged, and has the advantages of simple construction operation, easy vibration and compaction of concrete pouring and contribution to guaranteeing the construction quality of concrete. The model of the non-main stressed steel bar of the foundation structure can be reinforced according to the structure, and the main stressed steel bar adopts a prestressed steel cable, so that the purpose of reducing the model of the structural steel bar is achieved, and the construction period is favorably ensured.

Drawings

Fig. 1 is a schematic plan view of a large-scale wind turbine generator with a conventional beam-slab wind turbine generator base structure.

FIG. 2 is a sectional view taken along line A-A in FIG. 1.

FIG. 3 is a schematic plan view of the wind turbine pre-stressed infrastructure of the present invention.

Fig. 4 is a sectional view taken along line B-B in fig. 3.

Fig. 5 is a cross-sectional view taken along line C-C in fig. 4. Parts, positions and numbers in the drawings: the structure comprises a foundation slab 1, a pillar 2, an anchor bolt cage 3, an access hole 4, a main beam 5, a structural reinforcement 6, an edge trabecula 7, a prestressed steel cable 8, a longitudinal reinforcement 9 and a metal corrugated pipe 10. The dimensions in FIGS. 1-5 are in mm, except where noted.

Detailed Description

The invention will be further explained with reference to the drawings.

As shown in fig. 3 to 5, the wind turbine prestressed foundation structure is a beam-slab type, and comprises a foundation slab 1, wherein the foundation slab 1 is circular, the outer edge of the foundation slab 1 is a basic body structure contour line, the middle part of the foundation slab 1 is a cylindrical table post 2, an anchor bolt cage 3 for connecting a first section of tower cylinder of the wind turbine is arranged in the table post 2, an access hole 4 is arranged in the table post 2, the diameter of the access hole 4 is suitable for people to enter, for example, the diameter is 1 meter, and later workers can conveniently enter the hollow structure of the table post 2 for maintenance. The main beams 5 in a divergent shape are uniformly distributed around the table column 2, the outer sides of two adjacent main beams 5 are connected by edge small beams 7, a triangular hollowed area is formed between two adjacent main beams 5, backfilling is carried out after the prestress foundation structure is completed, and the edge small beams 7 are connected to form a regular polygon.

A mounting hole is formed between the outer side of each main beam 5 and the inner access hole 4 of the table column 2 along the main beam 5, a prestressed steel cable 8 is arranged in the mounting hole, one end, located on the outer side of the main beam 5, of the prestressed steel cable 8 is a tensioning end, and one end, located in the access hole 4, of the prestressed steel cable 8 is a fixed end. The prestressed steel cables 8 in the main beam 5 are set according to the calculation result, and the prestressed steel cables 8 are obliquely arranged from the access hole 4 in the column 2 to the outer side of the main beam 5, as shown in fig. 4. The prestressed steel cables 8 replace longitudinal bars 9 in the original design scheme, and common steel bars in the main beam 5 are structural reinforcing bars 6. The mounting holes are formed after the main beam 5 is poured, by providing a metal bellows 10 in the main beam.

The prestressed steel cable 8 is a prestressed steel strand which has the material characteristics of high tension and low relaxation and can exert the characteristic of high tension. Specifically, a mounting hole is provided in each main beam 5, and a prestressed steel cable 8 is provided in the mounting hole, as shown in fig. 5. The prestressed steel cables 8 in the main beam 5 are arranged according to the calculated stress envelope curve, so that the stress requirements of the section are met. The prestressed steel cables 8 can be flexibly arranged, the total area of the cross section required by calculation is obviously reduced, namely, the structural stress requirement can be met by arranging a small amount of prestressed steel cables 8, the steel consumption is greatly reduced, and the cost is saved. The space between the steel bars in the wind turbine generator prestress foundation structure is reasonable, so that concrete can be poured conveniently, and the quality of a concrete foundation is ensured.

The wind turbine generator system prestressed foundation structure introduces the idea of prestressed concrete, reduces the steel consumption, saves the cost, is convenient for construction, ensures the quality and is convenient for later-period maintenance.

Claims

1. Wind turbine generator system prestressing force foundation structure for the beam slab formula, including soleplate (1), soleplate (1) middle part is cylindric pillar (2), its characterized in that: set up in pillar (2) and be used for connecting crab-bolt cage (3) of a wind turbine generator system tower section of thick bamboo, set up access hole (4) in pillar (2), girder (5) of form are dispersed to the equipartition around pillar (2), girder (5) inside sets up structure arrangement of reinforcement (6), the outside of two adjacent girders (5) is connected by marginal trabecula (7), set up the mounting hole along girder (5) between the outside of each girder (5) and access hole (4), set up prestressing cable (8) in the mounting hole.

2. The wind turbine prestressed infrastructure of claim 1, characterized in that: the mounting hole in the main beam (5) is formed by a metal corrugated pipe (10), and a steel strand is arranged in the metal corrugated pipe (10) and serves as the prestressed steel cable (8).

3. The wind turbine prestressed infrastructure of claim 1, characterized in that: the prestressed steel cable (8) is obliquely and downwards arranged from the access hole (4) of the pillar (2) to the outer side of the main beam (5), one end, located in the access hole (4), of the prestressed steel cable (8) is a fixed end, and one end, located in the outer side of the main beam (5), of the prestressed steel cable is a tensioning end.

4. The wind turbine prestressed infrastructure of claim 1, characterized in that: only one prestressed steel cable (8) is arranged in each main beam (5).

5. The wind turbine prestressed infrastructure of claim 1, characterized in that: the diameter of the access hole (4) is 1000 mm.