Small uplift pile foundation

Abstract

The small uplift pile foundation comprises a plurality of batter piles, a center pile, stirrups and a concrete body, the upper sections of the batter piles and the center pile intersect in different planes, the batter piles are evenly distributed around the circumference of the central axis of the center pile, and the stirrups are arranged on the upper sections of the batter piles and connected with all the batter piles in a bundled mode; a concrete body poured with concrete is arranged, and all the inclined pile upper sections, the stirrups and the center pile are fixedly connected into a whole. The uplift pile foundation depends on the overall gravity of foundation soil blocks in an area radiated by the multiple inclined piles and the friction effect between the side walls of the piles and a soil body, the pressure bearing capacity and the uplift resistance of the uplift pile foundation are greatly improved, and the cost of the uplift pile foundation is superior to that of a conventional pile foundation.

Description

Technical Field

[0001] The present application belongs to the technical field of construction engineering foundations, and specifically relates to a small-scale pull-out pile foundation. Background Art

[0002] In the field of engineering technology for the installation of outdoor equipment or devices such as photovoltaic projects, pile foundations are often used to cope with the complex and changeable geological conditions. Common pile foundations include: prefabricated steel piles, prefabricated or cast-in-place reinforced concrete piles, cast-in-place concrete piles, etc.

[0003] The pull-out resistance of this type of pile foundation mainly depends on the friction between the pile side wall and the soil, and the pull-out resistance is limited. The pull-out resistance is often increased by increasing the diameter or length of the pile, which increases the cost of the pile foundation. Summary of the invention

[0004] In order to reduce the cost of pile foundations and improve their pressure-bearing and pull-out resistance, the present application proposes a small pull-out resistant pile foundation, which relies on the overall gravity of the foundation soil in the area radiated by multiple inclined piles, as well as the friction between the pile side walls and the soil. Its pressure-bearing and pull-out resistance are greatly enhanced. Under the same bearing capacity, the material cost is reduced by about 15%.

[0005] To achieve the above objectives, this application provides the following technical solutions:

[0006] The small pull-out pile foundation described in the present application includes multiple inclined piles and a central pile, stirrups and a concrete body. The inclined piles and the central piles are crossed in different planes. The multiple inclined piles are evenly distributed around the circumference of the central axis of the central pile. Stirrups are provided on the upper sections of the inclined piles to tie and connect all the inclined piles. The concrete body is cast with concrete, which consolidates all the upper sections of the inclined piles and the stirrups with the central pile into a whole. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 This is a three-dimensional schematic diagram of the small-scale pull-out pile foundation described in this application, taking three inclined piles as an example;

[0008] Figure 2 This is a vertical view and a top view of the small-scale pull-out pile foundation described in this application, taking three inclined piles as an example;

[0009] Figure 3 This is a schematic diagram of the central axis of the central pile and the inclined piles described in this application, taking three inclined piles as an example;

[0010] Figure 4 A schematic diagram of the central pile described in this application;

[0011] Figure 5 This is a schematic diagram of the inclined pile described in this application.

[0012] The serial numbers in the above drawings are explained as follows:

[0013] 1 - Inclined pile, 2 - Central pile, 3 - Stirrup, 4 - Concrete body. Specific implementation mode

[0014] Combined with the above drawings, the specific implementation mode of the small uplift pile foundation described in this application is as follows:

[0015] Precast the Figure 4 Shown Z - shaped cross - section long - strip member as the central pile 2, which is divided into an installation section, a concrete - casting section and a soil - entering section from top to bottom. The installation section is provided with installation holes, and multiple through - holes are arranged on the Z - shaped web plate of the concrete - casting section. The soil - entering section is a Z - shaped torsion pile, and the torsion angle α around its central axis, α>0°, preferably α = 180°;

[0016] Precast the Figure 5 Shown multiple identical Z - shaped cross - section long - strip members as the inclined piles 1. The upper section of it is the concrete - casting section, and multiple through - holes are arranged on the Z - shaped web plate;

[0017] As Figure 2 Shown, drive the above - mentioned central pile 2 vertically into the ground along its central axis, perpendicular to the horizontal plane, and drive multiple inclined piles 1 into the ground at an angle A with the horizontal plane. The upper section of the inclined pile 1 is cross - faced with the central pile 2. The upper section of the inclined pile 1 is provided with stirrups 3 which are tied and connected to all the inclined piles 1; Pour concrete on - site to form the concrete body 4, and consolidate the upper sections of all the inclined piles 1 and the stirrups 3 with the concrete - casting section of the central pile 2 into a whole.

[0018] As Figure 3 Shown, the central axis of the inclined pile 1 and the central axis of the central pile 2 are skew lines. Multiple inclined piles 1 are evenly distributed in a circle with the central axis of the central pile 2 as the center, and their upper sections and the concrete - casting section of the central pile 2 are all within the pouring range of the concrete body 4;

[0019] The range of the angle A between the inclined pile 1 and the horizontal plane is 30° - 60°; The number of inclined piles 1≥2; The minimum distance between the axis of the inclined pile 1 and the axis of the central pile 2 which are skew and non - intersecting is 0<K<one - quarter of the minimum diameter of the concrete body 4.

[0020] The concrete body 4 is cylindrical or can also be polygonal - prismatic, and its central axis is concentric with the central axis of the central pile 2.

[0021] The lengths of the inclined pile 1 and the central pile 2 are set according to the specific geological conditions and the requirements of bearing pressure and uplift resistance. The torsion angle of the soil - entering section of the central pile 2 is set according to the pile length and the geological conditions.

[0022] As Figure 2 Shown, the completed - poured concrete body 4 can be all or part above the ground, or can be all below the ground. When it is all above the ground, its bottom surface should not be separated from the ground.

[0023] Compared with the existing conventional concrete piles, the small-scale pull-out pile foundation described in this application has the following beneficial effects:

[0024] Relying on the overall gravity of the foundation soil in the area radiated by the multiple inclined piles 1, and the friction between the side walls of the central pile 2 and all the inclined piles 1 and the soil, the bearing capacity and pull-out resistance of the overall pile foundation are greatly enhanced;

[0025] By arranging the upper section of the inclined pile 1 and the central pile 2 in different planes, the structure is more compact, and the volume of the concrete body 4 can be reduced without affecting the consolidation effect. Therefore, the cost of the pile foundation is better than that of the conventional pile foundation.

[0026] The inclined pile 1 can be made of sheet metal, steel bars or steel sections. When a sheet metal pile is used, its cross-sectional shape, in addition to the above-mentioned Z-shaped, other modified forms should also be included in the protection scope of this application.

[0027] The central pile 2 may be a sheet metal straight pile, a steel bar pile or a profile pile in addition to the twisted pile.

[0028] It should be noted that the above embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the core technical principles of the present application, similar embodiments obtained by others without creative work should all fall within the protection scope of the present application.

Claims

1. A small pull-out pile foundation, characterized by: The invention comprises a plurality of inclined piles (1) and a central pile (2), stirrups (3) and a concrete body (4), wherein the inclined piles (1) and the central pile (2) are both long strip-shaped components, and the central pile (2) is driven vertically into the ground along the direction of its central axis and is perpendicular to the horizontal plane; the inclined piles (1) are driven into the ground at an angle A to the horizontal plane and cross the central pile (2) at different planes; the plurality of inclined piles (1) are evenly distributed around the circumference of the central axis of the central pile (2), and stirrups (3) are provided on the upper sections of the inclined piles (1) and are tied and connected with all the inclined piles (1); and the concrete body (4) cast by concrete consolidates the upper sections of all the inclined piles (1) and the stirrups (3) with the central pile (2) into a whole.

2. The small-scale anti-pulling pile foundation according to claim 1 is characterized in that: The central pile (2) is a long strip member with a Z-shaped cross section, and is divided from top to bottom into an installation section, a concrete construction section and an earth-embedded section; the installation section is provided with an installation hole and is located on the concrete body (4); the concrete construction section is located within the pouring range of the concrete body (4), and a plurality of through holes are provided on its Z-shaped plate; the earth-embedded section is a Z-shaped twisted pile, twisted around its central axis at a certain angle, and the twisting angle is set according to the pile length and geological conditions.

3. The small-scale anti-pulling pile foundation according to claim 1 is characterized in that: The inclined pile (1) is a long strip member with a Z-shaped cross section, the upper section of which is a concrete section, and a plurality of through holes are arranged on the Z-shaped web, which are located within the pouring range of the concrete body (4); the lower section is driven into the ground.

4. The small-scale anti-pulling pile foundation according to claim 1 is characterized in that: The angle A between the inclined pile (1) and the horizontal plane is in the range of 30° to 60°.

5. The small-scale anti-pulling pile foundation according to claim 1 is characterized in that: The number of the inclined piles (1) is ≥2.

6. The small-scale anti-pulling pile foundation according to claim 1 is characterized in that: The minimum distance K>0 between the axis of the inclined pile (1) and the axis of the central pile (2) that are not in the same plane and do not intersect, is less than one quarter of the minimum diameter of the concrete body (4).

7. The small-scale anti-pulling pile foundation according to claim 1 is characterized in that: The concrete body (4) is cylindrical or polygonal, with its axis being concentric with the axis of the center pile (2).

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