Annular shear wall-spiral anchor composite structure foundation and construction method

Abstract

The application provides a circular shear wall-spiral anchor composite structure foundation and a construction method, and belongs to the technical field of electric power engineering.The upper reinforced concrete slab and the lower reinforced concrete slab are respectively located at the upper part and the lower part of the circular shear wall foundation, the prestressed longitudinal tendon is located in the circular shear wall foundation and is connected with the flange plate of the steel pipe pole through the foundation bolt after penetrating through the upper reinforced concrete slab; the anchor rod of the spiral anchor is connected with the spiral anchor joint after penetrating through the lower reinforced concrete slab, the bottom of the prestressed longitudinal tendon is connected with the spiral anchor joint, and the spiral anchor joint is connected with the spiral anchor joint reinforcing bar embedded in the circular shear wall foundation; the application can effectively reduce the foundation burying depth, thereby reducing the amount of reinforced concrete, reducing the excavation depth, and reducing the construction cost, the labor cost and the transportation cost.

Description

Technical Field

[0001] This invention relates to the field of power engineering technology, and in particular to a ring shear wall-spiral anchor composite structure foundation and its construction method. Background Technology

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

[0003] Currently, steel pipe poles are widely used in the field of power transmission as an important power equipment for overhead transmission lines. Steel pipe poles have low wind pressure resistance and high cross-sectional bending stiffness, which significantly reduces the self-weight of the tower and reduces the foundation force.

[0004] The inventors discovered that if a pile foundation is used, the foundation stress is relatively small. However, in order to meet the structural requirements, the diameter of the pile foundation needs to be larger than the bottom diameter of the steel pipe pole, and the pile length needs to be greater than or equal to three times the bottom diameter. The design value is much greater than the actual load it can bear, resulting in a large amount of material waste and increasing construction costs and construction difficulty. Similarly, if a stepped rigid foundation is used, it will also result in a large amount of material waste.

[0005] The following table illustrates examples of a 220kV steel pipe pole foundation using both pile foundations and stepped rigid foundations, as shown in the table below. The foundation forces are:

[0006] Fz / kN Fx / kN Fy / kN Mx / kN.m Mz / kN.m My / kN.m 600 600 0 0 0 22223

[0007] The outer diameter of the bottom of the steel pipe pole is 4.0m. To meet structural requirements, when using a pile foundation, the pile diameter is 4.6m and the pile length is 13.8m. When using a stepped foundation, the upper dimension is 4.6m. To meet the anchorage length requirements of the anchor bolts and the bearing capacity requirements, the foundation height and bottom diameter of the stepped foundation must meet relevant requirements. The comparison of material quantities for the two types of foundations and the pile foundation considering only the foundation force is shown in the table below:

[0008]

[0009]

[0010] It can be seen that the steel pipe pole foundations used in the current project are subjected to unreasonable stress, resulting in a large amount of waste. Summary of the Invention

[0011] To address the shortcomings of existing technologies, this invention provides a circular shear wall-spiral anchor composite structure foundation and construction method. Based on the similar stress characteristics of the foundation and the shear wall, the upper stirrups of the shear wall can effectively resist the upper shear force, and the prestressed continuous reinforcement can effectively resist the bending moment, thereby improving the load-bearing capacity of the structure. The spiral anchor has advantages such as high pull-out strength, simple construction, and recyclability, which can effectively reduce the foundation embedment depth, thereby reducing the amount of reinforced concrete used, reducing the excavation depth, and thus reducing construction costs, labor costs, and transportation costs.

[0012] To achieve the above objectives, the present invention adopts the following technical solution:

[0013] In a first aspect, the present invention provides a composite foundation for annular shear wall-spiral anchor structure.

[0014] A composite foundation structure of annular shear wall and spiral anchor includes: steel pipe rods, anchor bolts, upper reinforced concrete slab, foundation prestressed continuous reinforcement bars, annular shear wall foundation, spiral anchor joint reinforcement bars, lower reinforced concrete slab and spiral anchor;

[0015] The upper reinforced concrete slab and the lower reinforced concrete slab are located at the upper and lower parts of the annular shear wall foundation, respectively. The prestressed continuous reinforcement bars are located inside the annular shear wall foundation and pass through the upper reinforced concrete slab before being connected to the flange plate of the steel pipe rod through anchor bolts.

[0016] The anchor rod of the helical anchor passes through the lower reinforced concrete slab and is connected to the helical anchor joint. The bottom of the prestressed continuous reinforcement is connected to the helical anchor joint, and the helical anchor joint is connected to the helical anchor joint reinforcement embedded in the annular shear wall foundation.

[0017] As a further limitation of the first aspect of the present invention, a concrete pile is arranged in the hollow center of the annular shear wall foundation, and the space between the concrete pile and the inner wall of the annular shear wall foundation is filled with soil and compacted.

[0018] As a further limitation of the first aspect of the present invention, both the upper reinforced concrete slab and the lower reinforced concrete slab are cast and connected to the annular shear wall foundation.

[0019] As a further limitation of the first aspect of the present invention, the reinforced concrete slab at the bottom of the foundation and the spiral anchor are integrally cast, and the reinforcing bars connecting the spiral anchor joint are integrally cast with the annular foundation.

[0020] As a further limitation of the first aspect of the present invention, the anchor rod of the spiral anchor is provided with equally spaced anchor discs, and the end of the anchor rod of the spiral anchor is a conical anchor head.

[0021] As a further limitation of the first aspect of the present invention, the reinforcing bar of the spiral anchor joint is connected to the threaded hole of the spiral anchor joint.

[0022] As a further limitation of the first aspect of the present invention, the spiral anchor is integrally cast with the foundation pit bottom slab.

[0023] As a further limitation of the first aspect of the invention, the central axes of the steel pipe rod, the spiral anchor, and the reinforcing bar of the spiral anchor joint are all parallel to each other.

[0024] As a further limitation of the first aspect of the invention, the lower part of the helical anchor is driven into a soil layer with better bearing capacity, and the anchor plate provides pull-out resistance, the interaction between the anchor rod and the soil layer and its own stiffness provide bending and lateral resistance to the structure above the anchor rod.

[0025] Secondly, the present invention provides a construction method for the annular shear wall-spiral anchor composite structure foundation described in the first aspect, comprising the following steps:

[0026] Excavation of the foundation pit, construction of spiral anchor screwing, and construction of connection between spiral anchor joint steel bars and prestressed continuous bars;

[0027] Construction of bottom reinforced concrete slab, formwork and pouring of annular shear wall, construction of concrete piles, backfilling of soil in the middle of annular shear wall foundation, and compaction in layers;

[0028] The upper reinforced concrete slab was supported and constructed, the backfill soil was compacted in layers, and the anchor bolts were installed.

[0029] Compared with the prior art, the beneficial effects of the present invention are:

[0030] 1. This invention innovatively proposes a ring shear wall-spiral anchor composite foundation. Compared with traditional foundations, this foundation structure is more material-saving, stronger, and has better safety and stability. The combination of spiral anchor and ring shear wall structure demonstrates significant creativity in applying shear wall structure to the foundation field. Combining traditional spiral anchor with ring shear wall makes the stress form of the structure more diversified, fully utilizes the stress performance of shear wall structure, and makes the structure safer and more reliable.

[0031] 2. This invention adopts a spiral anchor structure, which is simple to process and manufacture, has low construction difficulty, saves labor, and reduces construction time. The design of filling the middle of the ring foundation can save the amount of concrete and steel reinforcement; this structure effectively reduces the amount of foundation materials used, reduces earthwork excavation, reduces construction difficulty, and is more environmentally friendly.

[0032] 3. The present invention adopts a spiral anchor structure, which is simple to process and manufacture, has low construction difficulty, can save labor, shorten the construction period, and has certain construction and environmental benefits; the spiral anchor can make the structure sit in a soil layer with better bearing capacity, reduce the foundation depth and foundation pit excavation, and improve economic efficiency.

[0033] 4. This invention applies shear wall structures to the field of foundation structures, making full use of the stress performance of shear wall structures and improving the bearing capacity of foundations; applying shear wall structures to the field of foundation structures, making full use of the stress performance of shear wall structures and improving the bearing capacity of foundations.

[0034] 5. Compared with traditional foundations, the foundation type proposed in this invention effectively reduces the amount of foundation materials used, reduces earthwork excavation, lowers construction difficulty, and is more environmentally friendly; the use of prestressed anchor bolts improves the stress performance of the annular shear wall concrete and enhances its crack resistance.

[0035] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0036] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0037] Figure 1 This is a cross-sectional view of the annular shear wall-spiral anchor composite structure foundation provided in Embodiment 1 of the present invention;

[0038] Figure 2 This is a 1-1 cross-sectional view provided in Embodiment 1 of the present invention;

[0039] Figure 3 This is a detailed drawing of the basic flange plate connection provided in Embodiment 1 of the present invention;

[0040] Figure 4 Detailed drawing of the spiral anchor joint provided in Embodiment 1 of the present invention;

[0041] Figure 5 This is a plan view of the foundation of the annular shear wall-spiral anchor composite structure provided in Embodiment 1 of the present invention;

[0042] In the diagram: 1. Steel pipe pole; 2. Anchor bolt; 3. Upper reinforced concrete slab; 4. Continuous prestressed reinforcement bars for the foundation; 5. Circular shear wall foundation; 6. Spiral anchor joint reinforcement bars; 7. Lower reinforced concrete slab; 8. Spiral anchor; 9. Backfill in the middle of the circular foundation; 10. Spiral anchor joint; 11. Anchor plate; 12. Anchor rod; 13. Conical anchor head; 14. Concrete pile; d1. Thickness of upper reinforced concrete slab; d2. Thickness of circular foundation; d3. Length of spiral anchor joint reinforcement bars; d4. Thickness of lower reinforced concrete slab; d5. Diameter of upper circular foundation slab; d6. Wall thickness of circular foundation; d7. Diameter of backfill in the middle of circular foundation; d8. Spacing of equidistant anchor plates; d9. Anchor plate diameter; d10. Diameter of spiral anchor joint; d11. Spacing between joint reinforcement bars and through reinforcement bars; d12. Spiral anchor spacing; d13. Diameter of lower foundation slab. Detailed Implementation

[0043] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0044] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0045] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0046] Example 1:

[0047] To address the design and construction challenges of large-diameter steel pipe pole foundations in soft soil areas, this embodiment provides a ring-shaped shear wall-spiral anchor composite foundation. Based on the similar stress characteristics of the foundation and the shear wall, the upper stirrups of the shear wall effectively resist the upper shear force, while the prestressed continuous reinforcement effectively resists bending moments, thus improving the structure's load-bearing capacity. The spiral anchor offers advantages such as high pull-out strength, simple construction, and recyclability, effectively reducing the foundation depth. This reduces the amount of reinforced concrete used and the excavation depth, thereby lowering construction, labor, and transportation costs. The hollow section in the ring-shaped shear wall is filled with concrete piles and compacted soil to ensure the load-bearing capacity of the central part, further reducing construction costs. The upper prestressed continuous reinforcement is connected to flange plates using anchor bolts. Compared to traditional foundation types, this ring-shaped shear wall-spiral anchor composite foundation exhibits better load-bearing performance, effectively reduces construction costs and difficulty, and achieves significant economic and environmental benefits.

[0048] Specifically, the annular shear wall-spiral anchor composite structure foundation of this embodiment, such as... Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, it mainly includes: a ring shear wall foundation 5, an upper reinforced concrete slab 3, a concrete pile 14, a lower reinforced concrete slab 7, a spiral anchor 8, and an anchor bolt 2.

[0049] The annular shear wall foundation 5 is connected to the large-diameter steel pipe rod 1 above. The wall of the annular shear wall foundation 5 has sufficient thickness to ensure the anchorage length of the anchor bolts 2, avoiding the use of solid structures to embed the anchor bolts, thus greatly improving economic efficiency.

[0050] In this embodiment, the annular shear wall foundation 5, the upper reinforced concrete slab 3, the concrete piles 14, and the lower reinforced concrete slab 7 form a spatial frame shear wall structure, which can resist the bending moment and horizontal force on the foundation to a limited extent.

[0051] In this embodiment, the spiral anchor 8 includes a conical anchor head 13, anchor discs 11 arranged at equal intervals, anchor rods 12, and a spiral anchor joint 10 with drilled holes and threaded wire.

[0052] In this embodiment, the upper part of the annular shear wall foundation 5 is connected to the flange plate of the steel pipe rod by anchor bolts 2. A concrete pile 14 is driven into the hollow center of the annular shear wall foundation 5. The gap between the concrete pile 14 and the annular shear wall foundation 5 is filled with soil 9 in the middle of the annular foundation and compacted. The upper and lower parts of the annular shear wall foundation 5 are connected to the post-cast concrete slab to maintain the integrity of the foundation and provide resistance to punching shear and bending shear.

[0053] In this embodiment, the lower reinforced concrete slab 7 and the spiral anchor 8 are integrally cast. Holes are drilled in the upper part of the spiral anchor joint 10, and the spiral anchor joint reinforcement 6 is threaded. The spiral anchor joint reinforcement 6 is cast together with the annular shear wall foundation 5 to improve the local strength at the connection between the foundation and the spiral anchor and prevent overall failure caused by local damage at the connection between the foundation and the spiral anchor. Prestress is applied to the continuous reinforcement to improve the bearing capacity.

[0054] In this embodiment, the lower part of the spiral anchor 8 is driven into a soil layer with better bearing capacity, and the anchor plate 11 provides pull-out resistance. The interaction between the anchor rod 12 and the soil, as well as its own stiffness, provides a certain degree of bending and lateral resistance to the upper structure.

[0055] In this embodiment, the stirrups of the annular shear wall foundation 5 can resist shear force, and the prestressed continuous reinforcement can effectively resist bending moment.

[0056] In this embodiment, based on the foundation stress characteristics, the thickness of the shear wall structure increases with the increase of the burial depth, thus better exerting the bearing capacity; the application of the spiral anchor 8 can effectively reduce the foundation burial depth and the excavation depth of the foundation pit. The spiral anchor 8 can be driven into the soil layer with just the right bearing capacity to improve the structural bearing capacity. The concrete pile 14 is driven into the center of the annular shear wall foundation 5 and the soil is filled and compacted, which can not only effectively improve the bearing capacity of the weak middle part, but also save the amount of concrete used, thereby achieving better economic benefits.

[0057] In this embodiment, the spiral anchor joint reinforcement 6 can strengthen the node connection strength and improve the structural stability. The spiral anchor 8 is subjected to a large vertical force and has high requirements for pull-out resistance. The value should be calculated according to the specifications.

[0058] In this embodiment, the anchor plate joint 10 can be appropriately increased to enhance the overall structure. The tapered anchor head 13 mainly serves to facilitate construction, and a value of 100mm is recommended. The diameter of the anchor rod 12 can be 100mm, and the thickness of the anchor rod 12 can be 10mm.

[0059] In this embodiment, the spiral anchor 8 is integrally cast with the foundation pit bottom slab, and the exposed length of the spiral anchor joint reinforcement 6 can be 400mm.

[0060] Example 2:

[0061] This embodiment provides a construction method for a ring shear wall-spiral anchor composite structure foundation, including the following processes:

[0062] (1) Excavation of foundation pit; (2) Construction of spiral anchor screwing; (3) Construction of joint reinforcement and prestressed continuous reinforcement connection; (4) Construction of bottom reinforced concrete slab and ring shear wall formwork and pouring; (5) Construction of concrete piles; (6) Backfilling of the ring shear wall foundation in the middle and compacting in layers; (7) Construction of upper reinforced concrete slab formwork; (8) Compaction of backfill soil in layers; (9) Construction of anchor bolts.

[0063] This invention can fully utilize the pull-out resistance of the anchor plate, significantly reduce the foundation embedment depth and the amount of concrete reinforcement, and also significantly reduce on-site wet work, effectively shorten the construction period, reduce environmental pollution and labor demand, thus having significant environmental and social benefits.

[0064] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A circular shear wall-spiral anchor composite structure foundation, characterized in that, At least including: The structure consists of steel pipe poles, anchor bolts, an upper reinforced concrete slab, prestressed continuous reinforcement bars in the foundation, a ring shear wall foundation, spiral anchor joint reinforcement bars, a lower reinforced concrete slab, and spiral anchors. The upper and lower reinforced concrete slabs are located above and below the ring shear wall foundation, respectively. The prestressed continuous reinforcement bars in the foundation are located within the ring shear wall foundation and extend through the upper reinforced concrete slab before being connected to the flange plate of the steel pipe poles via anchor bolts. The anchor rod of the spiral anchor passes through the lower reinforced concrete slab and connects to the spiral anchor joint. The bottom of the prestressed continuous reinforcement bars in the foundation connects to the spiral anchor joint. The spiral anchor joint connects to the spiral anchor joint reinforcement bars embedded in the ring shear wall foundation. The spiral anchor joint reinforcement bars connect to the threaded holes of the spiral anchor joint. The lower reinforced concrete slab of the foundation and the spiral anchor are integrally cast, and the spiral anchor joint reinforcement bars are integrally cast with the ring foundation. A concrete pile is arranged in the hollow center of the annular shear wall foundation, and the space between the concrete pile and the inner wall of the annular shear wall foundation is filled with compacted soil.

2. The annular shear wall-spiral anchor composite structure foundation as described in claim 1, characterized in that, Both the upper and lower reinforced concrete slabs are connected to the annular shear wall foundation during casting.

3. The annular shear wall-spiral anchor composite structure foundation as described in claim 1, characterized in that, The bolt of a spiral anchor has equally spaced anchor discs, and the end of the bolt is a tapered anchor head.

4. The annular shear wall-spiral anchor composite structure foundation as described in claim 1, characterized in that, The central axes of the steel pipe pole, the spiral anchor, and the reinforcing bars of the spiral anchor joint are all parallel to each other.

5. The annular shear wall-spiral anchor composite structure foundation as described in claim 1, characterized in that, The lower part of the helical anchor is driven into a soil layer with better bearing capacity, and the anchor plate provides pull-out resistance. The interaction between the anchor and the soil layer, as well as its own stiffness, provides bending and lateral resistance to the structure above the anchor.

6. A construction method for a ring shear wall-spiral anchor composite structure foundation as described in any one of claims 1-5, comprising the following processes: excavation of the foundation pit; spiral anchor tightening construction; connection construction of spiral anchor joint reinforcement and foundation prestressed continuous reinforcement; formwork and pouring construction of the lower reinforced concrete slab and ring shear wall; concrete pile construction; backfilling and compaction of the intermediate soil of the ring shear wall foundation; formwork and construction of the upper reinforced concrete slab; backfilling and compaction of the soil in layers; and anchor bolt construction.

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