Wind driven generator foundation for adjusting differential settlement

Abstract

The utility model provides a wind driven generator foundation capable of adjusting differential settlement, which relates to the technical field of fan foundation design and comprises a gravity type foundation, a lime soil cushion layer, a raft foundation and a pile foundation which are sequentially arranged from top to bottom. A targeted grouting bag is arranged between the raft foundation and the gravity type foundation, and the targeted grouting bag is connected with a grouting pipe embedded in the gravity type foundation; through holes are reserved in the gravity type foundation, high-strength anchor bolts are pre-buried, and grooves are preset; a raft foundation and a pile foundation are combined to form a counter-force foundation, concrete supporting columns are placed in reserved through holes, jacks are placed on the concrete supporting columns and make contact with counter-force steel plates, and the counter-force steel plates are fixed to high-strength anchor bolts through nuts. The utility model solves the problems of insufficient counter force provided by a counter force foundation, uncontrollable grouting range and incapability of meeting the construction requirement of a high-capacity fan of the original fan foundation differential settlement adjusting device, and has the advantages of more reasonable structure, high strength of each component, capability of meeting the construction requirement of the high-capacity fan and wide application range.

Description

Technical Field

[0001] The utility model relates to the technical field of wind turbine foundation design, and in particular to a wind turbine foundation for adjusting differential settlement, especially when the foundation is located in a soft soil layer such as soft soil, backfill soil, etc., so as to achieve safe and effective adjustment of foundation differences. Background Art

[0002] The statements in this section merely provide background information related to the present disclosure and do not necessarily constitute prior art.

[0003] With the use and development of new clean energy, wind power generation has taken a prominent position. Onshore wind turbines have made significant progress, with many of these being constructed on soft soil, backfill, and other low-quality strata. Wind turbines require high accuracy in differential settlement, so differential settlement must be avoided when constructing wind turbine foundations on soft soil, backfill, and other weak strata. Wind turbines are tall structures, and if differential settlement occurs in their lower foundations, the upper unit, under the influence of loads such as the nacelle and wind, will generate a large eccentric bending moment, further increasing the differential settlement of the lower foundation and potentially causing the wind turbine to tilt. Therefore, differential settlement in wind turbine foundations requires adjustment. However, existing methods for adjusting differential settlement in wind turbine foundations are often costly, complex, and ineffective.

[0004] The inventors discovered that in the prior art, the wind turbine foundation provides insufficient reaction force, the grouting range is uncontrollable, and it cannot meet the needs of large-capacity wind turbine construction. In the invention patent with publication number CN209798856U, a leveling device for adjusting the differential settlement of the wind turbine foundation is disclosed. It is proposed to arrange multiple leveling devices at the inner edge of the wind turbine foundation and use an independent raft foundation as a reaction foundation to level the wind turbine foundation. However, the reaction foundation proposed in this invention has shortcomings. The reaction foundation is in the form of an independent foundation. Due to its plane size limitations, the correction reaction force it can provide is limited, making it difficult to meet the correction requirements of large-capacity wind turbines. When the correction load is large and the soil layer is relatively weak, the reaction foundation is prone to sudden and rapid development of settlement and cannot provide sufficient correction reaction force. In the invention patent with publication number CN113833012A, a pile-type adjustable wind turbine foundation and wind turbine system are disclosed. It is proposed to use piles, pedestals, and columns to form a support structure to level the wind turbine foundation without destroying the original wind turbine foundation structure. However, this invention has a complex structure and high maintenance cost. Utility Model Content

[0005] In order to address the deficiencies of the prior art, the present disclosure provides a wind turbine foundation capable of adjusting differential settlement, so as to improve the ability of the wind turbine foundation reaction structure to adapt to different geological conditions.

[0006] The technical solution adopted in this utility model is:

[0007] A wind turbine foundation for adjusting differential settlement comprises a gravity foundation, a lime-soil cushion layer, a raft foundation and a pile foundation arranged in sequence from top to bottom; a targeted grouting bag is provided between the raft foundation and the gravity foundation, and the targeted grouting bag is connected to a grouting pipe pre-buried in the gravity foundation; the gravity foundation has reserved through holes, pre-buried high-strength anchor bolts and preset grooves; when differential settlement adjustment is required, the raft foundation and the pile foundation are combined to form a reaction foundation, concrete support columns are placed in the reserved through holes, jacks are placed on the concrete support columns, the jacks are in contact with reaction steel plates, and the reaction steel plates are fixed to high-strength anchor bolts via nuts.

[0008] Furthermore, when differential settlement adjustment is not required, the concrete cover with the additional steel ring is placed above the through hole reserved for the gravity foundation, with the edge aligned with the preset groove.

[0009] Furthermore, the concrete cover with the additional steel ring is provided with a preset pull ring.

[0010] Furthermore, a threaded cap is provided on the upper portion of the grouting pipe pre-buried in the gravity foundation.

[0011] Furthermore, the raft foundation and the pile foundation jointly constitute a reaction foundation. The size of the raft foundation is not greater than 3m×3m, the diameter of the pile foundation is not greater than 600mm, and the length of the pile foundation is not greater than 5m.

[0012] Furthermore, a lime soil cushion layer with a thickness of 3m is set below the bottom of the gravity foundation to reinforce the soil at the bottom of the wind turbine foundation.

[0013] Furthermore, the diameter of the reserved through hole is larger than the diameter of the concrete support column, leaving a gap of 100 to 150 mm.

[0014] Furthermore, pre-buried high-strength anchor bolts use tensile anchor bolts of grade 8.8 or above.

[0015] Compared with the prior art, the wind turbine foundation differential settlement adjustment device provided by the present invention has the following beneficial effects:

[0016] 1. The wind turbine foundation provided by the present invention adopts a composite foundation structure, which newly adds a ash soil cushion layer, a pile foundation, high-strength anchor bolts embedded in the wind turbine foundation, and targeted grouting bags. When the stratum where the wind turbine foundation is located is a soft soil layer, the ash soil cushion layer controls the uniform force on the bottom of the wind turbine foundation to reduce the uneven settlement of the soil layer at the bottom of the foundation. The pile foundation provides sufficient supporting reaction force to achieve the supporting force required for differential settlement adjustment. The high-strength anchor bolts embedded in the wind turbine foundation provide sufficient strength to prevent breakage during the differential settlement adjustment process. The targeted grouting bags effectively control the grouting reinforcement range between the wind turbine foundation and the raft foundation during the differential settlement adjustment process.

[0017] 2. The utility model newly adds a concrete cover structure with an additional steel ring. When the wind turbine foundation does not need to be adjusted for differential settlement, the concrete cover with the additional steel ring prevents water leakage from the through holes of the foundation except in the differential settlement adjustment stage.

[0018] 3. The gravity foundation in the present invention has reserved through holes, and pre-buried high-strength anchor bolts and preset grooves. The reserved through holes and pre-buried high-strength anchor bolts facilitate quick installation and adjustment, improve construction efficiency and flexibility of correction operations, and enable reaction force to be provided quickly and effectively when differential settlement adjustment is carried out.

[0019] 4. The utility model effectively prevents leakage and contamination of grouting materials during the process of adjusting differential settlement by providing a threaded cap plug on the upper part of the grouting pipe pre-buried in the gravity foundation. The design of the threaded cap plug not only ensures the sealing of the grouting process, but also facilitates the rapid opening and closing of the grouting pipe when needed, thereby achieving precise control of the grouting amount. In addition, the use of the threaded cap plug also improves the safety of the operation. During grouting operations, due to the high grouting pressure, if there are no effective sealing measures, the grouting material may suddenly spray out, causing a safety hazard. The threaded cap plug can be firmly locked on the grouting pipe and can remain stable even in a high-pressure environment, ensuring the safety of construction workers. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings, which constitute a part of the present disclosure, are used to provide a further understanding of the present disclosure. The exemplary embodiments of the present disclosure and their descriptions are used to explain the present disclosure and do not constitute an improper limitation to the present disclosure.

[0021] Figure 1 It is a cross-sectional schematic diagram of the wind turbine foundation differential settlement adjustment device disclosed in the present utility model;

[0022] Figure 2 It is a plan view of the wind turbine foundation differential settlement regulating device disclosed in the present utility model;

[0023] Figure 3 This is a schematic diagram of the wind turbine foundation differential settlement adjustment device disclosed in the present utility model when differential settlement adjustment is required;

[0024] Figure 4 This is a schematic diagram of the wind turbine foundation differential settlement adjustment device disclosed in the present utility model when differential settlement adjustment is not required.

[0025] In the figure: 1. Gravity foundation; 2. Raft foundation; 3. Pile foundation; 4. Lime-soil cushion; 5. Grouting pipe; 6. Threaded cap plug; 7. Targeted grouting bag; 8. High-strength anchor bolt; 9. Nut; 10. Jack; 11. Concrete support column; 12. Reaction steel plate; 13. Hole; 14. Groove; 15 Concrete cover. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0027] See also Figures 1 to 4 The utility model provides a wind turbine foundation for adjusting differential settlement. A plurality of adjustment points are evenly arranged along the circumference on the inner edge of the wind turbine gravity foundation. The adjustment components include a pile foundation 3, a raft foundation 2, reserved through holes 13 evenly arranged along the circumference on the inner edge of the gravity foundation, a foundation pre-embedded high-strength anchor bolt 8, a foundation pre-embedded targeted grouting pipe 5, a reaction steel plate 12, a support column 11, a jack 10, a preset targeted grouting bag 7 between the raft foundation 2 and the gravity foundation 1, and a reserved groove 14 around the reserved through holes in the foundation. A ash soil cushion layer 4 is added below the force foundation, and the top of the embedded high-strength anchor bolt 8 is fixed by a nut 9. The targeted grouting pipe 5 embedded in the foundation is filled with a plug 6. When the foundation needs to be leveled, a support column 11 is placed in the reserved through hole 8, and a jack 10 is placed above the support column 11. A reaction steel plate 12 is placed above the jack 10. The reaction steel plate 12 is fixed to the embedded high-strength anchor bolt 8 in the foundation and locked by the nut 9. There is no need to level the foundation, and a concrete cover 15 with an additional steel ring is placed on the groove 14 around the reserved through hole in the foundation.

[0028] The specific implementation steps are as follows:

[0029] Calculate the upper wind turbine load and external load to determine the size of the wind turbine foundation. According to the size of the wind turbine foundation, determine the number of through holes 13 reserved in the wind turbine foundation of the wind turbine foundation differential settlement adjustment component, the size of the raft foundation 2, the size of the pile foundation 3, and the range of the jack 10. It is recommended that the number of through holes 13 reserved in the wind turbine foundation be greater than 8 and arranged symmetrically along the circumference of the foundation. The range of the jack 10 is recommended to be 400-800t.

[0030] Calculate the lifting force required for adjusting the differential settlement of the upper wind turbine unit and wind turbine foundation to determine the size and reinforcement of the raft foundation 2. Determine the size and reinforcement of the pile foundation 3 according to the ground conditions of the wind turbine foundation. It is recommended that the size of the raft foundation 2 be no larger than 3×3m. It is recommended that the size of the pile foundation 3 be no larger than 600mm in diameter and no larger than 5m in length according to the soil layer. The raft foundation 2 has anti-shear and local pressure-bearing properties. The pile foundation 3 and raft foundation 2 are pre-constructed at the corresponding positions of the through holes 13 reserved in the wind turbine foundation.

[0031] A targeted grouting bag 7 is arranged between the wind turbine foundation and the raft foundation, and a lime soil cushion layer 4 is laid within 3m of the bottom of the wind turbine foundation to improve the bearing properties of the soil layer.

[0032] A through hole 13 is reserved in the wind turbine foundation. The hole diameter is recommended to be 350-600mm. Multiple high-strength anchor bolts 8 are embedded along the outer circumference of the hole. It is recommended to use prestressed anchor bolts of grade 8.8 or above. At the same time, a grouting pipe 5 is embedded outside the hole. A threaded cover 6 is used on the reserved hole 13 and the upper part of the grouting pipe 5 to prevent damage. The wind turbine foundation is cast and a groove 14 is reserved along the outer circumference of the through hole. The groove width is recommended to be 50mm.

[0033] A concrete cap 15 with a steel ring is added to the reserved trench 14 for the through hole and reinforced with steel tie bolts. If differential settlement adjustment is not required for the wind turbine foundation, the concrete cap with the steel ring is placed above the reserved through hole 13 of the foundation, with the outer steel ring aligned with the reserved trench 14 outside the wind turbine foundation through hole. The ground is then backfilled with soil to level it.

[0034] When differential settlement of the wind turbine foundation requires adjustment, excavate the backfill soil above the reserved hole for the wind turbine foundation, use the pull bolts to lift the concrete cover 15 with the additional steel ring, place the concrete support column 11 in the foundation hole, place the jack 10 above the support column 11. It is recommended to use a jack 10 of 400 to 800 tons, and use the nut 9 to connect the reaction steel plate 12 to the anchor bolt 8 embedded in the wind turbine foundation.

[0035] The fan foundation is adjusted using the jack 10 to achieve the inclination required by the specification, and the jack load is maintained when the inclination meets the requirement.

[0036] Open the threaded cap plug 6 of the pre-buried grouting pipe 5, and grout the targeted grouting bag 7 preset at the bottom of the fan foundation. After the slurry reaches the predetermined strength, clean the grouting pipe and place the plug. Remove the reaction steel plate 12, jack 10, and concrete support column 1, put back the concrete cover 15 with an additional steel ring, and backfill the foundation soil.

[0037] The working principle of this utility model is as follows: adding a lime soil cushion layer allows the soil at the bottom of the wind turbine foundation to settle evenly to reduce uneven settlement of the soil layer. Setting up a pile foundation plus a raft foundation can provide sufficient support reaction force. After differential settlement of the wind turbine foundation occurs, the support column is placed in the reserved hole of the foundation and a jack is placed on the upper part. The reaction steel plate is fixed with a nut. The load is applied by the jack to adjust the inclination of the wind turbine foundation to meet the specification requirements. After the inclination meets the requirements, the load is maintained. The pre-buried grouting pipe is combined with a targeted grouting bag to carry out directional grouting reinforcement between the wind turbine foundation and the raft foundation. Finally, the wind turbine foundation is adjusted to meet the differential settlement requirements. This structure can effectively adjust the differential settlement of the wind turbine foundation, meet the requirements of wind turbine construction in soft soil strata, is more economical, has a simple structure, and can meet the construction needs of wind turbine projects.

[0038] In the description of this specification, the terms "connect", "install", "fix", "set", etc. are understood in a broad sense. For example, "connection" can be a fixed connection or an indirect connection through an intermediate component without affecting the relationship between components and the technical effect. It can also be an integral connection or a partial connection. As in this example, for ordinary technicians in this field, the specific meanings of the above terms in this utility model or utility model can be understood according to specific circumstances.

[0039] The above is only a preferred specific implementation method of the present invention, but the protection scope of the present invention is not limited to this. Any technician familiar with the technical field within the technical scope disclosed by the present invention can make equivalent replacements or changes based on the technical solution and utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A wind turbine foundation for adjusting differential settlement, characterized in that: It includes a gravity foundation, lime-soil cushion, raft foundation, and pile foundation arranged in sequence from top to bottom; a targeted grouting bag is provided between the raft foundation and the gravity foundation, and the targeted grouting bag is connected to the pre-buried grouting pipe of the gravity foundation; the gravity foundation is provided with reserved through holes, pre-buried high-strength anchor bolts, and preset grooves; When differential settlement adjustment is required, the raft foundation and the pile foundation are combined to form a reaction foundation. Concrete support columns are placed in the reserved through holes, and jacks are placed on the concrete support columns. The jacks are in contact with the reaction steel plates, and the reaction steel plates are fixed with nuts and high-strength anchor bolts.

2. The wind turbine foundation for adjusting differential settlement according to claim 1, characterized in that: When no differential settlement adjustment is required, the concrete cover with an additional steel ring is placed above the through hole reserved for the gravity foundation, with the edge aligned with the preset groove.

3. The wind turbine foundation for adjusting differential settlement according to claim 2, characterized in that: The concrete cover with the additional steel ring is provided with a preset pull ring.

4. The wind turbine foundation for adjusting differential settlement according to claim 1, characterized in that: A threaded cap is provided on the upper portion of the pre-buried grouting pipe of the gravity foundation.

5. The wind turbine foundation for adjusting differential settlement according to claim 1, characterized in that: The raft foundation and the pile foundation jointly constitute a reaction foundation. The size of the raft foundation is not greater than 3m×3m, the diameter of the pile foundation is not greater than 600mm, and the length of the pile foundation is not greater than 5m.

6. The wind turbine foundation for adjusting differential settlement according to claim 1, characterized in that: The lime soil cushion layer is set 3m thick below the bottom of the gravity foundation to reinforce the soil at the bottom of the wind turbine foundation.

7. The wind turbine foundation for adjusting differential settlement according to claim 1, characterized in that: The diameter of the reserved through hole is larger than the diameter of the concrete support column, leaving a gap of 100 to 150 mm.

8. The wind turbine foundation for adjusting differential settlement according to claim 1, characterized in that: The embedded high-strength anchor bolts are tensile anchor bolts of grade 8.8 or above.

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