Narrow-base-pile deflection pile cap foundation

Abstract

The application relates to a narrow-base tower deflection pile cap foundation. The application is suitable for the technical field of narrow-base tower foundation of power transmission lines. The application aims to provide a narrow-base tower deflection pile cap foundation. The technical scheme adopted by the application is as follows: a narrow-base tower deflection pile cap foundation comprises a cap buried below the ground, a connecting column structure vertically arranged on the top of the cap and used for connecting the tower leg of the narrow-base tower, and a group of inclined piles vertically arranged on the bottom of the cap, wherein the group of inclined piles is arranged correspondingly to the tower leg of the narrow-base tower and is eccentrically arranged, so that the bending moment caused by the partial horizontal load of the upper part can be offset.

Description

Technical Field

[0001] This utility model relates to the field of narrow-base tower foundation technology for power transmission lines, and in particular to a narrow-base tower inclined pile cap foundation. Background Technology

[0002] With the acceleration of urbanization, power line corridors are becoming increasingly congested, especially in large cities. How to efficiently and safely erect transmission lines within limited space has become a pressing issue. Traditional transmission line towers, due to their steep leg slopes (typically 3 to 15 degrees), occupy a large area and are difficult to adapt to the compact layout requirements of urban environments. In contrast, narrow-base towers, with their gentler leg slopes (generally no more than 5 degrees), have smaller root openings, significantly reducing ground space requirements and making them an ideal choice for urban environments.

[0003] However, the conventional foundation types for narrow-base towers are slab foundations and pile foundations. In practical applications, narrow-base towers also face a series of challenges: Conventional slab foundations require large-scale earthwork excavation, which not only occupies a large area but is also easily affected by urban underground pipelines and facilities during construction, increasing coordination difficulties and construction complexity. In addition, to meet the requirements for bending and overturning resistance of the foundation, it is often necessary to increase the size and depth of the base slab, which further increases the workload and cost.

[0004] For monopile foundations, the independent load-bearing method of each tower leg limits their application under narrow root opening conditions, especially when structural requirements such as pile spacing of not less than three times the pile diameter are difficult to achieve within the small root opening range of narrow-base towers. Therefore, pile foundations with pile caps are usually required to connect the individual piles, but this leads to increased material usage and higher costs.

[0005] In urban areas, the dense underground pipe networks and limited space place higher demands on construction technology. The design and construction of deep foundations not only disrupt existing infrastructure but may also pose risks due to insufficient geological exploration. Summary of the Invention

[0006] The technical problem to be solved by this utility model is to provide a narrow-base tower inclined pile cap foundation in view of the above-mentioned problems.

[0007] The technical solution adopted in this utility model is: a narrow-base tower inclined pile cap foundation, comprising: A foundation is a structure buried below ground level. The connecting column structure is vertically installed on the top of the foundation and is used to connect the tower legs of the narrow base tower. The inclined pile group structure is inclined at the bottom of the pile cap. The inclined pile group structure is arranged corresponding to the tower legs of the narrow base tower, and the inclined pile group structure is eccentrically arranged, which can offset the bending moment caused by part of the horizontal load above.

[0008] Through the aforementioned technical means, the tower legs of the narrow-base tower are connected by a connecting column structure, and the pile cap is used to connect the connecting column structure and the inclined pile group structure to form a whole. The inclined pile group structure is arranged at an inclination, making the inclined pile group structure eccentrically designed relative to the top tower leg. This can offset the bending moment caused by part of the horizontal load in the upper part, thereby reducing the pile foundation size. This structure does not require a large amount of earthwork excavation, and effectively saves materials while ensuring sufficient overturning resistance.

[0009] In some embodiments, the connecting column structure includes four short columns, which are located on the top of the foundation. The top of the short columns is connected to the bottom of the legs of the narrow-base tower, and the steel reinforcement structure inside the short columns extends into the foundation.

[0010] In some embodiments, the inclined pile group structure includes four eccentric inclined piles connected to the bottom of the pile cap. The steel reinforcement structure inside the eccentric inclined piles extends into the pile cap. The eccentric inclined piles correspond one-to-one with the short columns. The center of the top of the eccentric inclined piles is offset from the center of gravity of the tower leg by a predetermined distance.

[0011] In some embodiments, the preset distance is 0.2m to 0.4m.

[0012] In some embodiments, the inclination angle of the eccentric inclined pile is 5° to 15°.

[0013] In some embodiments, the short column is a circular or square structure.

[0014] In some embodiments, the support platform is square, with each side extending 0.5m to 0.8m beyond the short column.

[0015] The beneficial effects of this utility model are: 1. In this application, the connecting column structure, the pile cap, and the inclined pile group structure are integrated through steel reinforcement anchoring and concrete pouring to achieve overall stress distribution, which enhances the cooperative stress-bearing capacity. The connecting column structure and the pile cap can jointly resist the upper load, while the lower inclined pile group structure is eccentrically arranged, which can offset the bending moment caused by part of the upper horizontal load. Compared with traditional straight piles, the foundation stability and overall anti-overturning performance are improved. Compared with traditional pile foundations or slab foundations, the pile cap size is smaller and the pile spacing is more compact, which can also reduce the amount of earthwork excavation, reduce the amount of concrete and steel reinforcement, and reduce the foundation cost. Attached Figure Description

[0016] Figure 1 This is a structural diagram of this application.

[0017] Figure 2 yes Figure 1 Cross-sectional view along direction 1-1.

[0018] Explanation of reference numerals in the attached figures: 1. Foundation; 2. Short column; 3. Eccentric inclined pile.

[0019] This specification includes references to "one embodiment" or "implementation". The use of the phrase "in one embodiment" or "in an embodiment" does not necessarily refer to the same embodiment. Specific features, structures, or characteristics may be combined in any suitable manner consistent with this disclosure.

[0020] The term "comprising" is open-ended. As used in the appended claims, it does not exclude additional structures or steps. Detailed Implementation

[0021] To enable those skilled in the art to better understand the present invention, the technical solution of the present invention will be further described below with reference to specific embodiments.

[0022] Example 1: Combination Figure 1 and Figure 2 As shown, this embodiment is a narrow-base tower inclined pile cap foundation, including a pile cap 1, a connecting column structure, and an inclined pile group structure. The pile cap 1 is buried below ground level. The connecting column structure is vertically mounted on the top of the pile cap 1, and is used to connect the tower legs of the narrow-base tower. The inclined pile group structure is inclined at the bottom of the pile cap 1, and is arranged correspondingly to the tower legs of the narrow-base tower. The inclined pile group structure is eccentrically arranged, which can offset the bending moment caused by part of the horizontal load above.

[0023] In some implementations, the connecting column structure includes four short columns 2, which are located on top of the foundation 1. The top of the short columns 2 is at least partially exposed above the ground and is connected to the bottom of the legs of the narrow-base tower. The steel reinforcement structure inside the short columns 2 extends into the foundation 1.

[0024] Furthermore, in this embodiment, the foundation 1 is square, with each side extending 20.5m to 0.8m beyond the short column, and the thickness of the foundation 1 is 0.4m to 1.0m.

[0025] Furthermore, the short column 2 is a circular or square structure with a side length or diameter of 0.6m to 1.0m and a height of 0.5m to 1m.

[0026] Compared to traditional pile foundations or slab foundations, the pile cap 1 in this embodiment is smaller and the pile spacing is more compact, meeting the requirements of narrow foundations and small tower base openings. This reduces the amount of earthwork excavation, making it suitable for operations in confined urban spaces. Pile hole construction can be completed using rotary drilling rigs or manual drilling, and the technology is mature. At the same time, it reduces the amount of concrete and steel reinforcement used, lowers the foundation cost, and improves economic efficiency.

[0027] In some implementation schemes, the inclined pile group structure includes four eccentric inclined piles 3, which are connected to the bottom of the pile cap 1. The steel reinforcement structure inside the eccentric inclined piles 3 extends into the pile cap 1. The eccentric inclined piles 3 correspond one-to-one with the short columns 2. The center of the top of the eccentric inclined piles 3 is offset from the center of gravity of the tower leg by a preset distance d. Specifically, in this embodiment, the preset distance d is 0.2m to 0.4m.

[0028] Furthermore, in this embodiment, the inclination angle of the eccentric inclined pile 3 is determined according to the force requirements, and the inclination angle of the eccentric inclined pile 3 is generally 5°~15°.

[0029] For the eccentric inclined pile 3, an eccentric arrangement is adopted. When the top center of the eccentric inclined pile 3 is offset from the center of gravity of the tower leg by a certain distance, under the action of horizontal load, a moment opposite to the direction of the applied bending moment will be generated in the foundation due to the existence of eccentricity. This moment caused by eccentricity helps to partially offset the bending moment transmitted from the superstructure, thereby enhancing the overturning stability of the entire foundation.

[0030] The eccentric inclined pile 3 is arranged at an angle. When the eccentric inclined pile 3 is inclined at a certain angle, the pile body can not only bear the vertical load, but also resist the horizontal force more effectively. According to the adjustment of the inclination angle of the eccentric inclined pile 3, its axial force can be closer to the direction of the main load that needs to be borne, thereby improving the resistance to horizontal load and reducing the bending moment caused by horizontal force.

[0031] The implementation principle of a narrow-base, inclined pile cap foundation is as follows: The four tower legs are connected by the pile cap 1 and short columns 2, forming a strong overall structure that can collectively resist the upper load. At the same time, the eccentric inclined piles 3 at the bottom can offset part of the bending moment caused by the horizontal load above, thereby reducing the size of the pile foundation and saving materials. Moreover, compared with traditional straight piles, the eccentric inclined piles 3 have a more reasonable stress distribution and can exert a greater resistance to overturning.

[0032] Compared to conventional open-cut slab foundations, the foundation structure in this embodiment does not require extensive earthwork excavation; it only needs to meet the depth and area requirements of the pile cap 1. Furthermore, compared to ordinary pile cap 1 foundations, due to the eccentric and inclined design, the pile cap 1 is smaller in size, the piles under the pile cap 1 are shorter, and the overall integrity is better. Its load-bearing performance is compatible with the tower, and it uses less material, saving costs.

[0033] Example 2: This embodiment describes a construction method for a narrow-base, inclined pile cap foundation, applied to the narrow-base, inclined pile cap foundation in Embodiment 1, and includes the following steps: During foundation construction, earthwork excavation was carried out according to the designed dimensions of the foundation 1, and the excavation depth was controlled to ensure that the design elevation was reached.

[0034] When excavation reaches the bottom elevation of the foundation 1, the pile hole is formed by manual excavation or rotary drilling rig according to the top center and inclination angle of the eccentric inclined pile 3.

[0035] Then the steel cage of the eccentric inclined pile 3 is lowered into the pile hole and concrete is poured. After that, the steel reinforcement of the pile cap 1 and the upper short column 2 are tied and the formwork is erected, and then concrete is poured.

[0036] The above are all preferred embodiments of this utility model, and are not intended to limit the scope of protection of this utility model. Therefore, all equivalent changes made to the structure, shape and principle of this utility model should be covered within the scope of protection of this utility model.

Claims

1. A narrow-foundation-pile deflection pile cap foundation, characterized by, include: The foundation (1) is buried below ground level; The connecting column structure is vertically installed on the top of the foundation (1) and is used to connect the tower legs of the narrow base tower. The inclined pile group structure is inclinedly set at the bottom of the foundation (1). The inclined pile group structure is arranged corresponding to the tower legs of the narrow base tower. The inclined pile group structure is eccentrically arranged, which can offset the bending moment caused by part of the horizontal load above.

2. The narrow-foundation-pile deflection pile-cap foundation according to claim 1, characterized in that: The connecting column structure includes four short columns (2), which are located on the top of the foundation (1). The top of the short columns (2) is connected to the bottom of the legs of the narrow base tower. The steel reinforcement structure inside the short columns (2) extends into the foundation (1).

3. The narrow-base, inclined pile cap foundation according to claim 2, characterized in that: The inclined pile group structure includes four eccentric inclined piles (3), which are connected to the bottom of the foundation (1). The steel reinforcement structure inside the eccentric inclined piles (3) extends into the foundation (1). The eccentric inclined piles (3) correspond one-to-one with the short columns (2). The center of the top of the eccentric inclined piles (3) is offset from the center of gravity of the tower leg by a predetermined distance.

4. A narrow-base, inclined pile cap foundation according to claim 3, characterized in that: The preset distance is 0.2m to 0.4m.

5. A narrow-base, inclined pile cap foundation according to claim 3, characterized in that: The inclination angle of the eccentric inclined pile (3) is 5°~15°.

6. A narrow-base, inclined pile cap foundation according to claim 2, characterized in that: The short column (2) is circular or square in structure.

7. A narrow-base, inclined pile cap foundation according to claim 2, characterized in that: The foundation (1) is square, with each side extending 0.5m to 0.8m beyond the short column (2).

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