Foundation treatment method for arranging flywheel energy storage device in collapsible loess area

Abstract

The invention belongs to the technical field of civil engineering in the field of flywheel energy storage of a thermal power plant, and discloses a foundation treatment method for arranging a flywheel energy storage device in a collapsible loess area, the surface of a collapsible loess layer is excavated downwards by 2-3 m, and then a cast-in-situ bored pile of a flywheel ground well is constructed downwards on the surface excavated for the first time; second-time excavation is conducted downwards on the area, corresponding to the flywheel ground well, of the surface obtained after first-time excavation, the second-time excavation is conducted to the elevation of the lower portion of a bottom plate of the flywheel ground well, then a virtual pile part is chiseled away, the flywheel ground well is constructed on the upper portion of a cast-in-situ bored pile, backfill soil is used for first-time backfill to the height of the surface obtained after first-time excavation, and the flywheel ground well is constructed; and then a lime soil layer is applied to the surface subjected to first excavation, then backfilling is conducted through backfill soil for the second time till the bottom elevation of the terrace is reached, and then the terrace is hardened. The method is short in construction period and low in engineering cost, adopts a foundation treatment scheme combining the cast-in-situ bored piles and lime soil, and is particularly suitable for the characteristics of flywheel energy storage project buildings.

Description

Technical Field

[0001] The invention belongs to the field of civil engineering technology in the field of flywheel energy storage in thermal power plants, and also belongs to the field of foundation treatment of building structures, and specifically relates to a foundation treatment method for setting a flywheel energy storage device in a collapsible loess area. Background Art

[0002] As the world moves towards low-carbon and sustainable energy development, energy storage technology has become a key support. As an advanced physical energy storage method, flywheel energy storage has shown great application potential in many fields such as power system peak-shaving and valley-filling, new energy grid connection, distributed energy microgrid, rail transit energy recovery and uninterruptible power supply (UPS) due to its many advantages such as high power density, fast charging and discharging, long life and environmental friendliness. With the continuous advancement of technology, flywheel energy storage systems are gradually moving from theoretical research to large-scale engineering practice, and their market size is also showing a steady growth trend.

[0003] As the basic link for the implementation of flywheel energy storage systems, civil engineering is directly related to the safety, stability and operating efficiency of the entire system. From geological surveys and surrounding environmental considerations during site selection and planning, to bearing capacity and vibration control in foundation design, to layout optimization of building structures, space utilization, and coordinated design of supporting facilities, every civil engineering detail plays a decisive role in whether the flywheel energy storage system can operate long-term and reliably. Reasonable civil engineering design can effectively reduce the construction cost of the system, shorten the construction period, and improve the overall benefits of the system; otherwise, it may lead to safety hazards, operational failures, and even huge economic losses in the project.

[0004] Therefore, the research on civil engineering design of flywheel energy storage is of great practical significance. On the one hand, it helps to fill the gap in the current systematic research in the field of civil engineering of flywheel energy storage and provide scientific and comprehensive theoretical guidance for subsequent engineering practice; on the other hand, it can promote the deep integration of flywheel energy storage technology and civil engineering, accelerate the implementation and promotion of flywheel energy storage projects, and provide strong guarantees for energy transformation, grid optimization and sustainable development.

[0005] The primary task of selecting a flywheel energy storage site is to conduct a detailed survey of the geographical and geological conditions, which is the cornerstone for ensuring the long-term and stable operation of the flywheel energy storage system. Before selecting a site, it is necessary to conduct an in-depth study of the local geological survey report to fully understand key information such as the stratum structure, rock and soil characteristics, and groundwater level. According to the "Geotechnical Engineering Investigation Code" (GB 50021-2001), a scientific assessment of the stability and suitability of the site is conducted to ensure that the selected site can withstand the dynamic and static loads of the flywheel energy storage system during operation, and to avoid equipment failures or safety accidents caused by foundation settlement, uneven deformation, and other problems. Especially for loess areas prone to wetting, foundation treatment methods are particularly important.

[0006] The collapsible soil layer in the proposed plant site is mainly the ② layer of loess-like silt, which is distributed on the upper part of the site foundation soil and is about 40m thick. The correction coefficient is obtained from the field immersion test to calculate the collapsibility. According to the evaluation of Table 4.4.7 in 4.4.7 of the "Building Code for Collapsible Loess Areas" (GB50025-2004), the plant site is a self-weight collapsible loess site, and the foundation collapsibility level is Ⅱ (medium) to Ⅵ (very serious), with VI (very serious) as the main one. The lower limit of the collapsibility is the bottom of the ② layer and the top of the ③ pebble layer.

[0007] The characteristics of flywheel energy storage structures are as follows: the flywheel well load is large, the burial depth is deep, the bottom of the foundation is marked at 5-7.8m, the flywheel well has very high requirements for settlement and inclination, the transformer prefabricated cabin foundation and the flywheel cooling system foundation have small loads and shallow burial depths, and the bottom elevation of the foundation can be greater than the permafrost line, generally about -1~2m, and the equipment foundation and flywheel cooling system have very low requirements for settlement and inclination. Flywheel energy storage projects in thermal power plants are generally new projects in the later stage. There are fewer suitable sites to choose from, and they need to be close to the main plant to avoid reducing the cable connection length, etc., to reduce project investment. Therefore, the layout sites that can be selected are limited, the site plane size is small, and there are many existing buildings and structures in the surrounding area. According to the "Building Code for Collapsible Loess Areas", the plane treatment range of collapsible loess foundations shall comply with the following provisions: 1. When it is a local treatment, the treatment range should be larger than the area of ​​the bottom surface of the foundation. In non-self-weight collapsible loess sites, each side should exceed 1 / 4 of the width of the bottom surface of the foundation and should not be less than 0.50m; in self-weight collapsible loess sites, each side should exceed 3 / 4 of the width of the bottom surface of the foundation and should not be less than 1m.

[0008] 2. When the whole area is treated, the treatment range should be larger than the area of ​​the ground floor of the building and exceed the width of the outer edge of the building's outer wall foundation. Each side should not be less than 1 / 2 of the thickness of the treated soil layer and should not be less than 2m.

[0009] According to the "Building Code for Collapsible Loess Areas", the commonly used treatment methods for collapsible loess foundations are: cushion method, strong tamping method, compaction method, and pre-watering method. Each side should not be less than 1 / 2 of the treated soil layer thickness, which is 20m. There are many buildings around the renovation project, so there is no such large implementation space. Summary of the invention

[0010] In order to solve the problems existing in the prior art, the purpose of the present invention is to provide a foundation treatment method for setting a flywheel energy storage device in a collapsible loess area. The present invention has a short construction period and low engineering cost. It adopts a foundation treatment solution combining bored cast-in-place piles and 3:7 lime-soil, which is particularly suitable for the characteristics of the flywheel energy storage project structure.

[0011] To achieve the above purpose, the technical solution adopted by the present invention is as follows: A foundation treatment method for setting a flywheel energy storage device in a collapsible loess area includes the following steps: The first excavation is carried out downward from the surface of the collapsible loess layer, with a depth of 2 to 3 m. Then, bored cast-in-place piles of the flywheel well are implemented downward from the surface after the first excavation. After the bored cast-in-place piles are implemented, the second excavation is carried out downward from the surface after the first excavation and the corresponding area of ​​the flywheel well. The second excavation is carried out to the lower elevation of the bottom plate of the flywheel well. Then, the virtual pile part is chiseled out, and then the flywheel well is implemented on the upper part of the bored cast-in-place piles. After the implementation of the flywheel well is completed, the first backfill is carried out with backfill soil. The first backfill is carried out to the surface height after the first excavation. Then, a gray soil layer is implemented on the surface after the first excavation. After that, the second backfill is carried out on the gray soil layer. The second backfill is carried out to the bottom elevation of the floor, and then the hardened floor is implemented.

[0012] Preferably, the height of the flywheel well does not exceed 7.5m, and the height of the flywheel well exposed from the hardened floor does not exceed 300mm.

[0013] Preferably, the thickness of the ash soil layer is 1-2 m.

[0014] Preferably, the height of the lime soil layer from the surface of the collapsible loess layer is 2 to 3 m.

[0015] Preferably, the ash soil layer adopts 3:7 ash soil.

[0016] Preferably, the bored cast-in-place piles penetrate deep into the bottom of the collapsible loess layer and extend into the bottom of the collapsible loess layer for a length not less than 1 times the pile diameter.

[0017] Preferably, after the ash soil layer is implemented, the flywheel transformer prefabricated cabin foundation and the flywheel cooling system foundation are implemented on the surface of the ash soil layer, and then the ash soil layer is backfilled for the second time.

[0018] Preferably, during the first backfill and the second backfill, the backfill soil is required to be compacted layer by layer, with the layer thickness not greater than 300 mm, the compaction coefficient not less than 0.96, and the characteristic value of the bearing capacity not less than 180 kPa.

[0019] Preferably, the backfill soil is plain soil, and the organic matter content in the plain soil does not exceed 5%.

[0020] The present invention also provides a foundation for setting a flywheel energy storage device in a collapsible loess area obtained by the foundation treatment method for setting a flywheel energy storage device in a collapsible loess area according to the present invention.

[0021] The patent of this invention has the following beneficial effects: The invention discloses a foundation treatment method for setting a flywheel energy storage device in a collapsible loess area. Compared with the commonly used treatment methods for collapsible loess foundations in the "Building Code for Collapsible Loess Areas", the treatment soil layer thickness and treatment soil layer range are reduced, and the method is more suitable for similar renovation projects with smaller site space, and has the characteristics of low construction cost and short construction period. This method can reduce the impact of the strong tamping method on the operating unit, greatly save construction time, and meet the urgent construction period requirements of the renovation project. Compared with the conventional renovation hammer sinking pipe hole lime soil compaction pile foundation method, it can save about 200,000 yuan in construction costs and save about 10 days of construction period. The original excavation depth of the flywheel well exceeds 5m, which belongs to the scope of the sub-project with greater danger exceeding a certain scale. It should be specially designed by a construction unit with relevant qualifications, and experts must be organized to conduct special demonstration. The first large-scale excavation is to the bottom of the 3:7 lime soil, and the second local excavation is to the bottom of the flywheel well. The depth of both excavations does not exceed 5m, and no special design and expert special demonstration are required. The invention discloses a foundation treatment method for setting a flywheel energy storage device in a collapsible loess area, which can be put into use in multiple flywheel energy storage projects to achieve good economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A plan view of a foundation for setting a flywheel energy storage device in a collapsible loess region according to an embodiment of the present invention; Figure 2 It is an elevation view of the foundation for setting up a flywheel energy storage device in a collapsible loess area in an embodiment of the present invention.

[0023] Among them, 1 is the flywheel well, 2 is the collapsible loess layer, 3 is the bored cast-in-place pile, 4 is the gray soil layer, 5 is the backfill soil, 6 is the hardened floor, 7 is the flywheel transformer prefabricated cabin foundation, and 8 is the flywheel cooling system foundation. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Combination Figure 1 and Figure 2 The present embodiment provides a foundation treatment method for setting a flywheel energy storage device in a collapsible loess area, including the following process: The first excavation was carried out downward from the surface of the collapsible loess layer 2. The depth of the first excavation was 2-3 m. At this time, the bottom position of the downward excavation was the lime soil layer 4 (see Figure 2) bottom, so the depth of the first excavation does not exceed 5m; then the bored pile 3 of the flywheel well 1 is implemented downward on the surface after the first excavation, and after the bored pile 3 is implemented, the surface after the first excavation (that is, Figure 2 The second excavation is carried out downward from the bottom of the lime soil layer 4 shown in the figure to the corresponding area of ​​the flywheel well 1. The second excavation is carried out to the lower elevation of the bottom plate of the flywheel well 1. Therefore, the depth of the second excavation does not exceed 5m. Then the virtual pile part (i.e. Figure 2 In the above step, the part between the bottom plate of the flywheel well 1 and the bottom of the lime soil layer 4 on the bored pile 3 implemented in the above step) is used to implement the flywheel well 1 on the upper part of the bored pile 3 (the virtual pile part has been removed at this time). After the flywheel well 1 is implemented, the first backfilling is carried out with backfill soil, and the first backfilling is carried out to the surface height after the first excavation (that is, backfilling to Figure 2 The bottom of the lime layer 4, that is, Figure 2 The backfill soil 5 at the bottom is shown in the figure, and then the lime soil layer 4 is implemented on the surface after the first excavation (including the surface after the first backfill), and then the second backfill is performed on the lime soil layer 4 (i.e., backfilling to Figure 2 The portion between the top of the lime soil layer 4 and the hardened floor 6, that is, Figure 2 The backfill soil 5 at the upper part is shown in the figure), the second backfill is carried out to the bottom elevation of the floor, and then the floor is hardened 6.

[0026] The above scheme of the present invention is applicable to the case where the height of the flywheel well 1 does not exceed 7.5m. After the final construction is completed, the height of the flywheel well 1 exposed from the hardened floor 6 does not exceed 300mm. In the above scheme of the present invention, the thickness of the ash soil layer 4 is 1~2m. The height of the ash soil layer 4 from the surface of the collapsible loess layer 2 is 2~3m. In other words, when the thickness of the ash soil layer 4 is 2m, the thickness of the secondary backfill soil layer above the ash soil layer 4 is 0~1m. When the thickness of the secondary backfill soil layer is 0m, the hardened floor 6 can be directly implemented on the surface of the ash soil layer 4 without backfilling soil.

[0027] As a preferred embodiment of the present invention, in the above embodiment of the present invention, the lime soil layer 4 uses 3:7 lime soil. The bored cast-in-place pile 3 penetrates into the bottom of the collapsible loess layer 2 and extends into the bottom of the collapsible loess layer 2 by a length not less than 1 times the pile diameter. After the implementation of the lime soil layer 4 is completed, the flywheel transformer prefabricated cabin foundation 7 and the flywheel cooling system foundation 8 are implemented on the surface of the lime soil layer 4, and then the lime soil layer 4 is backfilled for the second time.

[0028] In the above scheme of the present invention, the backfill soil adopts plain soil, and the organic matter content in the plain soil does not exceed 5%. When performing the first backfill and the second backfill, the backfill soil is required to be compacted in layers, and the layer thickness is not more than 300mm, the compaction coefficient is not less than 0.96, and the characteristic value of the bearing capacity is not less than 180kPa. After the backfill soil is backfilled through the above process, the uniformity and density of the backfill soil can be guaranteed. If the one-time backfill is too thick, the lower layer may not be fully compacted, resulting in uneven settlement. Layered processing can ensure that the density of each layer meets the standard, reduce voids, and improve overall stability. Layered compaction can also effectively improve the bearing capacity, prevent post-construction settlement, and avoid structural cracking. At the same time, good compaction can reduce water penetration and improve anti-seepage performance. In addition, layered construction can also reduce the load of mechanical equipment and avoid inefficiency or damage to equipment caused by excessively thick soil layers.

[0029] Example In this embodiment, the height of the flywheel well 1 is 7.5m. After the final construction is completed, the height of the flywheel well 1 exposed from the hardened floor 6 is 300mm. The lime soil layer 4 uses 3:7 lime soil and has a thickness of 1.5m.

[0030] like Figure 1 and Figure 2 As shown, a foundation treatment method for setting a flywheel energy storage device in a collapsible loess area in this embodiment includes the following process: First, the entire collapsible loess layer area was mechanically excavated for the first time on a large scale to Figure 2 The ash soil layer 4 shown (the ash soil layer 4 has not yet been implemented, and the description here needs to be combined with Figure 2 , intended to illustrate the depth of the first large-scale mechanical excavation) at the bottom. In this embodiment, the depth of the first large-scale mechanical excavation is 2.5m.

[0031] Secondly, the bored cast-in-place pile 3 of the flywheel well 1 is implemented at the bottom plane position of the first excavation, and the pile top elevation of the bored cast-in-place pile 3 is controlled at the bottom of the flywheel well 1. After the pile position of the flywheel well 1 is located, the hole-making equipment should be flat and stable after it is in place to ensure that it does not tilt or move during construction. The hole-making equipment should have a clear scale to control the drilling advance to ensure that the verticality of the hole meets the design requirements. During the overall production or segmented production, transportation and lifting of the steel cage, measures should be taken to prevent overall deformation and distortion. The steel cage should be slowly hoisted in line with the center of the pile hole, and immediately fixed after reaching the designed position, and the upper edge of the steel cage should be fixed firmly to the hole casing. After the steel cage is in place, the concrete must be poured in a timely and continuous manner, and the concrete pouring speed must be controlled to ensure that broken piles, shrinkage, etc. do not occur. Finally, the implementation of bored cast-in-place pile 3 is realized.

[0032] Once again, after the bored piles 3 are completed, the slope is cut and excavated in the corresponding area of ​​the flywheel well 1 (i.e., the second excavation is performed), and the excavation is performed to the lower elevation of the bottom plate of the flywheel well 1. In this embodiment, the depth of the second excavation is 4.5m (less than 5m). At this time, a part of the bored piles 3 that have been implemented is above the lower elevation of the bottom plate of the flywheel well 1, so it is necessary to chisel out the virtual pile part (i.e., the part of the bored piles 3 that have been implemented that is located above the lower elevation of the bottom plate of the flywheel well 1 is chiseled out), and the vertical compressive bearing capacity of the foundation pile and the integrity of the pile body are dynamically tested.

[0033] Then, tie the steel bars, support the formwork, and pour the reinforced concrete bottom plate and side walls to implement the flywheel well 1. After the flywheel well 1 is implemented, the formwork is further removed and the foundation pit is backfilled to -2.5m around (that is, the first backfill is carried out here). Again, the 3:7 ash soil in the leveling area is replaced to the bottom of the flywheel transformer prefabricated cabin foundation 7 and the flywheel cooling system foundation 8 (that is, the ash soil layer 4 is implemented, and the thickness of the ash soil layer 4 is 1.5m). After that, the equipment foundations such as the flywheel transformer prefabricated cabin foundation 7 and the flywheel cooling system foundation 8 are further implemented. Finally, backfill with plain soil (that is, the second backfill is carried out, and the backfill depth is 1.0m) to the bottom elevation of the hardened floor. When performing the first and second backfilling, the backfill soil is required to be compacted layer by layer, the layer thickness is not more than 300mm, the compaction coefficient is ≥0.96, and the bearing capacity characteristic value is ≥180kPa. The organic matter content in the backfill soil shall not exceed 5%, and the backfill soil shall not be mixed with construction waste, cultivated soil, silty soil or soil containing chemical corrosive substances.

[0034] Finally, 200mm thick C30 concrete was used to harden the floor 6.

[0035] It is important to note that when constructing the foundation, the construction unit should take effective measures to reduce the hydration heat to ensure that the equipment foundation and related concrete structures do not crack. The concrete surface in contact with the soil is coated with epoxy asphalt coating with a thickness of ≥300μm.

[0036] The 3:7 lime soil used in the above scheme of the present invention is also called Sanqi lime soil, which is a building material with high strength prepared by lime and clay in a volume ratio of 3:7. The Sanqi lime soil used in the present invention has the characteristics of low cost: because lime and plain soil are common materials, they are cheaper than cement. Moreover, Sanqi lime soil has good impermeability: that is, lime and soil react to form a dense calcium silicate gel, and the generated calcium silicate gel can be used as a dense waterproof layer, which can play a role in waterproofing and moisture-proofing; Sanqi lime soil also has low compressibility, and has good bearing capacity after compaction. It is compacted at its optimal moisture content (moisture content is 18%-22%), and the dry density reaches 1.6-1.7g / cm³; and the bearing capacity is good, and the 28-day unconfined compressive strength is ≥0.8MPa, which is equivalent to the strength of C15 concrete. In terms of environmental protection, lime is a natural material and is more environmentally friendly than industrial materials. The construction is also flexible, and it can be mixed on site or mixed in the factory to meet the needs of different projects. In addition, it has low maintenance cost, good durability and long-term stability.

[0037] It can be seen from the above scheme of the present invention that the present invention adopts a foundation treatment scheme combining bored cast-in-place piles 3 and 3:7 ash soil (i.e., ash soil layer 4), which is a further supplement to the commonly used foundation treatment methods in collapsible loess areas in the "Building Code for Collapsible Loess Areas": cushion method, strong tamping method, compaction method, and pre-watering method. The present invention adopts a foundation treatment scheme combining bored cast-in-place piles 3 and 3:7 ash soil (i.e., ash soil layer 4), which is particularly suitable for the characteristics of the flywheel energy storage project. The technical scheme of the present invention is also characterized in that the flywheel well 1 with a large load set in the collapsible loess layer 2 area adopts a bored cast-in-place pile 3 foundation treatment method. The present invention adopts a foundation treatment method of replacing 3:7 ash soil for the flywheel transformer prefabricated cabin foundation 7 and the flywheel cooling system foundation 8 with a small load set in the collapsible loess layer 2 area. In the prior art, the original excavation depth of the flywheel well 1 exceeds 5m, which belongs to the scope of the sub-project with a greater risk of exceeding a certain scale. It should be specially designed by a construction unit with relevant qualifications, and experts must be organized to conduct special demonstration; while in the present invention, the first large-scale excavation is to the bottom of the 3:7 gray soil (i.e., gray soil layer 4), the first excavation depth is 2.5m, and the second local excavation is to the bottom of the flywheel well 1, the second excavation depth is 4.5m, and the depth of both excavations does not exceed 5m, so there is no need for special design and expert special demonstration. In the above scheme of the present invention, the 3:7 gray soil is set on the top of the collapsible loess layer 2, and the thickness meets the requirements of the specification.

[0038] In summary, the above scheme of the present invention effectively overcomes the shortcomings of the commonly used treatment methods for collapsible loess foundations in the prior art.

[0039] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A foundation treatment method for installing a flywheel energy storage device in a collapsible loess area, characterized in that: The process includes the following: A first excavation is carried out downward from the surface of the collapsible loess layer (2), the depth of the first excavation being 2 to 3 m, and then bored cast-in-place piles (3) of the flywheel well (1) are constructed downward from the surface after the first excavation. After the bored cast-in-place piles (3) are constructed, a second excavation is carried out downward from the surface after the first excavation and the corresponding area of ​​the flywheel well (1), the second excavation is carried out to the lower elevation of the bottom plate of the flywheel well (1), and then the virtual pile part is chiseled out, and then the flywheel well (1) is constructed on the upper part of the bored cast-in-place piles (3). After the flywheel well (1) is constructed, a first backfilling is carried out with backfill soil, the first backfilling is carried out to the surface height after the first excavation, and then a gray soil layer (4) is constructed on the surface after the first excavation, and then a second backfilling is carried out on the gray soil layer (4), the second backfilling is carried out to the ground bottom elevation, and then a hardened ground (6) is constructed.

2. A foundation treatment method for installing a flywheel energy storage device in a collapsible loess area according to claim 1, characterized in that: The height of the flywheel well (1) does not exceed 7.5m, and the height of the flywheel well (1) exposed above the hardened floor (6) does not exceed 300mm.

3. A foundation treatment method for installing a flywheel energy storage device in a collapsible loess area according to claim 1, characterized in that: The thickness of the ash soil layer (4) is 1~2m.

4. A foundation treatment method for installing a flywheel energy storage device in a collapsible loess area according to claim 1, characterized in that: The height of the gray soil layer (4) from the surface of the collapsible loess layer (2) is 2 to 3 m.

5. The method for foundation treatment of installing a flywheel energy storage device in a collapsible loess region according to claim 1, characterized in that: The lime soil layer (4) uses 3:7 lime soil.

6. A foundation treatment method for installing a flywheel energy storage device in a collapsible loess area according to claim 1, characterized in that: The bored cast-in-place pile (3) penetrates deep into the bottom of the collapsible loess layer (2) and extends into the bottom of the collapsible loess layer (2) by a length not less than 1 times the pile diameter.

7. A foundation treatment method for installing a flywheel energy storage device in a collapsible loess area according to claim 1, characterized in that: After the ash soil layer (4) is completed, the flywheel transformer prefabricated cabin foundation (7) and the flywheel cooling system foundation (8) are implemented on the surface of the ash soil layer (4), and then the ash soil layer (4) is backfilled for the second time.

8. The method for treating a foundation for installing a flywheel energy storage device in a collapsible loess region according to claim 1, characterized in that: During the first and second backfilling, the backfill soil is required to be compacted layer by layer, with the layer thickness not exceeding 300mm, the compaction coefficient not less than 0.96, and the characteristic value of the bearing capacity not less than 180kPa.

9. The method for treating a foundation for installing a flywheel energy storage device in a collapsible loess region according to claim 1, characterized in that: The backfill soil shall be plain soil, and the organic matter content in the plain soil shall not exceed 5%.

10. A foundation for setting a flywheel energy storage device in a collapsible loess area obtained by the foundation treatment method for setting a flywheel energy storage device in a collapsible loess area according to any one of claims 1 to 9.

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