Self-locking connecting structure and construction method of steel-concrete composite hollow pile foundation for photovoltaic support

Abstract

The present application relates to a kind of self-locking connection structure of photovoltaic support steel and concrete combined hollow pile foundation and its construction method, including concrete hollow pile, variable diameter assembly and vertical column;The variable diameter assembly of the present application can ensure the concentricity of the vertical column for installing photovoltaic support and concrete hollow pile;In this way, as long as the position of concrete hollow pile and pre-buried bolt is accurate, the position of vertical column can also reach certain accuracy, which is conducive to photovoltaic support installation;And concrete hollow pile, variable diameter assembly, vertical column can be manufactured in advance in factory, guarantee manufacturing precision, also shorten construction period;The concrete hollow pile, variable diameter assembly and vertical column of the construction method can be manufactured in advance in factory, guarantee construction quality, reduce construction period.

Description

Technical Field

[0001] This invention relates to the technical field of photovoltaic support construction, and in particular to a self-locking connection structure and construction method for a steel-concrete composite hollow pile foundation for photovoltaic supports. Background Technology

[0002] Photovoltaic (PV) mounting systems are primarily installed in vast areas such as tidal flats and shallow seas. These areas are frequently subject to strong winds. Therefore, centralized PV systems require the implantation of underground piles to enhance their wind resistance. For example, patent CN221919498U discloses a composite pile foundation for PV systems suitable for desert regions. This composite pile foundation includes outer piles and inner piles to improve the piles' bearing capacity. However, the outer piles require on-site casting; before the outer piles harden, a portion of a pre-formed inner pile is vertically inserted into the outer pile, forming a single unit. When the inner pile is inserted into the outer pile, it is difficult to ensure concentricity and accurate connection with the PV system, which is detrimental to the installation of the PV system. Summary of the Invention

[0003] The purpose of this invention is to solve the above-mentioned problems and provide a self-locking connection structure and construction method for a steel-concrete composite hollow pile foundation for photovoltaic supports.

[0004] The technical solution of this invention is: a self-locking connection structure for a steel-concrete composite hollow pile foundation for photovoltaic supports, comprising a concrete hollow pile, a diameter-changing assembly, and a vertical column. The diameter-changing assembly includes a centering sleeve, a flange, a diameter-changing component, guide screws, and a centering spring. Embedded bolts are pre-embedded in the concrete hollow pile, distributed circumferentially around the axis of the centering sleeve. The upper end of the centering sleeve is fixedly connected to the bottom surface of the flange, and the centering sleeve is concentrically positioned with the inner hole of the concrete hollow pile. The upper ends of the pre-embedded bolts pass through the top surface of the flange, and are threaded with connecting nuts that abut against the flange. The diameter-changing component is aligned with the axis of the centering sleeve. The structure is circumferentially distributed, including a vertical arc-shaped plate and a fan-shaped hook. A guide screw runs radially through the sidewall of the centering sleeve from the outside in, threadedly connecting to the midpoint of the horizontal section of the vertical arc-shaped plate. A vertical column is inserted vertically into the flange, abutting against the inner wall of the vertical arc-shaped plate. The centering spring is compressed, fitted around the guide screw, with one end abutting against the inner wall of the centering sleeve and the other end abutting against the outer wall of the vertical arc-shaped plate. The inner wall of the hollow concrete pile has an annular hook groove. The fan-shaped hook is fixed to the lower end of the vertical arc-shaped plate, extending into the hook groove. The distance the fan-shaped hook extends into the hook groove is less than the compression of the centering spring.

[0005] Furthermore, the lower edge of the vertical column is chamfered.

[0006] Furthermore, the flange has an insertion hole at its center that is concentric with the centering sleeve; the upper end of the vertical column extends outward to form a mounting plate with an area larger than the insertion hole.

[0007] Furthermore, the insertion hole is concentrically arranged with the centering sleeve, and the inner diameter of the insertion hole is equal to the outer diameter of the vertical column.

[0008] Furthermore, several guide screws are arranged along the axial direction of the centering sleeve.

[0009] Furthermore, the inner diameter of the inner wall of the vertical arc-shaped plate is equal to the outer diameter of the vertical column.

[0010] Furthermore, the inner wall of the hook groove is covered with a reinforced thin steel plate.

[0011] Furthermore, the hollow concrete pile is a precast structure.

[0012] Furthermore, the sides of adjacent vertical curved plates are matched accordingly.

[0013] A construction method for a self-locking connection structure of a steel-concrete composite hollow pile foundation for photovoltaic supports, as described above, includes the following steps: (1) Precast concrete hollow piles, assemble variable diameter components and manufacture vertical columns in the factory; (2) Transport the hollow concrete piles, variable diameter components, and vertical columns to the project site; (3) Pressing in hollow concrete piles: Drill holes along the marked lines on the project site, and use static pressing method to press the hollow concrete piles into the designed depth along the drilled holes so that the top surface of the hollow concrete piles reaches the design elevation. (4) Install the reducing assembly on the hollow concrete pile: Insert the centering sleeve into the inner hole of the hollow concrete pile, and let the pre-embedded bolts pass through the corresponding connection holes of the flange. Use the connecting nuts to press the flange tightly against the top surface of the hollow concrete pile. (5) Install the vertical column: Insert the vertical column between the reducing parts, hammer the top mounting plate of the vertical column until the mounting plate abuts against the flange, and weld the flange to the mounting plate. (6) Install photovoltaic brackets above the mounting plate.

[0014] The beneficial effects of this invention are: (1) The variable diameter component of the present invention can ensure the concentricity of the vertical column of the photovoltaic bracket and the hollow concrete pile; thus, as long as the position of the hollow concrete pile and the pre-embedded bolt is accurate, the position of the vertical column can also reach a certain accuracy, which is beneficial to the installation of the photovoltaic bracket; and the hollow concrete pile, the variable diameter component and the vertical column can all be manufactured in advance in the factory, ensuring manufacturing accuracy and shortening the construction cycle.

[0015] (2) The reinforced thin steel plate of the present invention improves the surface contact strength of the hook groove and ensures that the hook groove and the fan-shaped hook work stably.

[0016] (3) The concrete hollow piles, variable diameter components and vertical columns of this construction method can be manufactured in the factory in advance, which ensures the construction quality and reduces the construction cycle. Attached Figure Description

[0017] Figure 1 This is a side view of the self-locking connection structure of the steel-concrete composite hollow pile foundation for photovoltaic support according to the present invention; Figure 2 yes Figure 1 AA section view; Figure 3 yes Figure 2 BB section view; Figure 4 This is a 3D view of the variable diameter assembly; Figure 5 This is a perspective view of the self-locking connection structure of the steel-concrete composite hollow pile foundation for photovoltaic support according to the present invention. Figure 6 This is a flowchart of the construction method for the self-locking connection structure of the steel-concrete composite hollow pile foundation for photovoltaic brackets in Example 3; Figure 7 This is a structural schematic diagram of step ① in the construction method of the self-locking connection structure of the steel-concrete composite hollow pile foundation for photovoltaic support in Example 3; Figure 8 yes Figure 7 A three-dimensional image; Figure 9 This is a structural schematic diagram of step ④ in the construction method of the self-locking connection structure of the steel-concrete composite hollow pile foundation for photovoltaic support in Example 4; Figure 10 yes Figure 9 A three-dimensional image; In the diagram: 01. Inner upper template, 02. Inner lower template, 03. Outer template, 031. Circular plate, 032. Through hole, 1. Concrete hollow pile, 11. Embedded bolt, 12. Connecting nut, 13. Hook groove, 131. Reinforcing thin steel plate, 21. Centering sleeve, 22. Flange, 221. Insertion hole, 222. Connecting hole, 231. Vertical arc plate, 232. Fan-shaped hook, 24. Guide screw, 25. Centering spring, 3. Vertical column, 31. Chamfer, 32. Mounting plate. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0019] In the description of this invention, it should be noted that the terms "upper", "middle", "lower", "inner", "outer", "both sides", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the purpose of simplifying the description of this invention and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0020] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0021] Example 1 See Figure 1-5The self-locking connection structure of the steel-concrete composite hollow pile foundation for photovoltaic support of the present invention includes a concrete hollow pile 1, a diameter-changing assembly, and a vertical column 3; the diameter-changing assembly includes a centering sleeve 21, a flange 22, a diameter-changing component, a guide screw 24, and a centering spring 25; the concrete hollow pile 1 is pre-embedded with pre-embedded bolts 11 distributed circumferentially around the axis of the centering sleeve 21; in this embodiment, there are 6 pre-embedded bolts 11 on the same concrete hollow pile 1; the upper end of the centering sleeve 21 is fixedly connected to the bottom surface of the flange 22 and is concentrically arranged with the inner hole of the concrete hollow pile 1; the upper end of the pre-embedded bolts 11 passes through the flange. On the top surface of the flange 22, a threaded connecting nut 12 is fitted to abut against the flange 22; the connection between the flange 22 and the pre-embedded bolts 11 ensures that the centering sleeve 21 is concentric with the concrete hollow pile 1; the reducing component is circumferentially distributed relative to the axis of the centering sleeve 21, including a vertical arc plate 231 and a fan-shaped hook 232; the guide screw 24 penetrates the side wall of the centering sleeve 21 radially from the outside to the inside, and is threadedly connected to the midpoint of the horizontal section of the vertical arc plate 231; the guide screw 24 slides with the centering sleeve 21, providing guidance for the radial movement of the reducing component and also limiting the reducing diameter. The vertical position of the component; the vertical column 3 is vertically inserted into the flange 22, abutting against the inner wall of the vertical arc plate 231, driving the reducing component to move radially outward along the centering sleeve 21; the centering spring 25 is in a compressed state, fitted outside the guide screw 24, with one end abutting against the inner wall of the centering sleeve 21 and the other end abutting against the outer wall of the vertical arc plate 231; the inner wall of the concrete hollow pile 1 is provided with an annular hook groove 13; the fan-shaped hook part 232 is fixed to the lower end of the vertical arc plate 231; because the vertical position of the reducing component is restricted, the fan-shaped hook part 232 can safely extend into the hook groove 13, realizing the connection between the concrete hollow pile 1 and the vertical The vertical self-locking of column 3 improves the pull-out resistance of the foundation; the top surface of column 3 is used to install photovoltaic brackets; all centering springs 25 are synchronously extended and retracted, and column 3 can ensure concentricity with centering sleeve 21 and inner hole of hollow concrete pile 1, thereby ensuring a certain positional accuracy, which is beneficial to the installation of photovoltaic brackets; the distance of the fan-shaped hook 232 into the hook groove 13 is less than the compression of centering spring 25; when the vertical column 3 is no longer supported, the centering spring 25 pushes the diameter-changing component inward, so that the fan-shaped hook 232 does not contact the hook groove 13, and the diameter-changing component can be smoothly inserted into hollow concrete pile 1.

[0022] Compared with the prior art, the variable diameter component of the present invention can ensure the concentricity of the vertical column 3 of the photovoltaic bracket and the hollow concrete pile 1. In this way, as long as the position of the hollow concrete pile 1 and the pre-embedded bolt 11 is accurate, the position of the vertical column 3 can also reach a certain accuracy, which is beneficial to the installation of the photovoltaic bracket. The hollow concrete pile 1, the variable diameter component, and the vertical column 3 can all be manufactured in advance in the factory, ensuring manufacturing accuracy and shortening the construction cycle.

[0023] The lower edge of the vertical column 3 is chamfered 31 so that the vertical column 3 can be inserted between the diameter changers, thereby pressing the diameter changers outward.

[0024] The flange 22 has an insertion hole 221 concentric with the centering sleeve 21; the vertical column 3 is inserted between the reducing parts through the insertion hole 221; the upper end of the vertical column 3 extends outward to form a mounting plate 32 with an area larger than the insertion hole 221; the mounting plate 32 increases the vertical limit of the vertical column 3 on the one hand, and increases the contact area with the photovoltaic bracket on the other hand, which is beneficial to the connection of the photovoltaic bracket.

[0025] The mounting plate 32 is a square plate to fit the connecting base plate of the photovoltaic bracket; if necessary, the orientation of the mounting plate 32 can be rotated to fit the orientation of the connecting base plate of the photovoltaic bracket.

[0026] The vertical cross-section of the hook groove 13 is trapezoidal; the vertical cross-section of the fan-shaped hook 232 is triangular; the long base of the trapezoid is located at the inner groove opening of the hook groove 13, and the hypotenuse is located at the bottom of the hook groove 13; the hypotenuse of the triangle corresponds to the hypotenuse of the trapezoid; thus, if the fan-shaped hook 232 is lower than the design position due to manufacturing error or installation error, the bottom of the hook groove 13 can guide the fan-shaped hook 232, allowing the fan-shaped hook 232 to smoothly enter the interior of the hook groove 13.

[0027] The insertion hole 221 is concentrically set with the centering sleeve 21; the inner diameter of the insertion hole 221 is equal to the outer diameter of the vertical post 3; the insertion hole 221 and the vertical post 3 have a vertical sliding fit, which provides guidance for the vertical insertion of the vertical post 3 and ensures that all fan-shaped hooks 232 are stably inserted into the hook groove 13.

[0028] Several guide screws 24 are arranged along the axial direction of the centering sleeve 21 to improve the vertical limiting ability of the centering sleeve 21 for the reducing component, ensure the stable inward and outward extension of the reducing component, and increase the friction between the reducing component and the vertical column 3, ensuring that the vertical column 3 and the reducing component are in a stable abutting state. In this embodiment, there are two guide screws 24 on the same vertical arc plate 231.

[0029] The inner diameter of the vertical arc plate 231 is equal to the outer diameter of the vertical column 3, which increases the contact area between the vertical column 3 and the inner wall of the vertical arc plate 231, thereby improving the stability of the vertical column 3 against the inner wall of the vertical arc plate 231.

[0030] The inner wall of the hook groove 13 is covered with a reinforcing thin steel plate 131 to improve the surface contact strength of the hook groove 13 and ensure that the hook groove 13 and the fan-shaped hook 232 work stably. There are several ways to cover the inner wall of the hook groove 13 with the reinforcing thin steel plate 131; for example, to manufacture an elastic band with a cross-section matching the inner wall of the hook groove 13, and then make the ends of the elastic band overlap to form an annular band; to change the degree of overlap of the elastic band so that the outer diameter of the annular band is smaller than the inner diameter of the concrete hollow pile 1; to send the annular band into the hook groove 13 position in the inner hole of the concrete hollow pile 1, and to loosen the constraint on the ends of the annular band; the annular band expands outward due to elasticity and fits into the inside of the hook groove 13; or to use the reinforcing thin steel plate 131 for formwork support when the concrete hollow pile 1 is poured; and to leave the reinforcing thin steel plate 131 when the formwork is removed.

[0031] The working principle of this embodiment is as follows: The connection between the pre-embedded bolt 11 and the flange 22 ensures that the centering sleeve 21 is concentric with the concrete hollow pile 1; the guide screw 24 slides with the centering sleeve 21, providing guidance for the radial movement of the reducing component and also limiting the vertical position of the reducing component; the vertical column 3 is vertically inserted into the flange 22 and abuts against the inner wall of the vertical arc plate 231, driving the reducing component to move radially outward along the centering sleeve 21; because the vertical position of the reducing component is restricted, the fan-shaped hook 232 can safely extend into the hook groove 13 to achieve the mixing The vertical self-locking of the concrete hollow pile 1 and the vertical column 3 improves the pull-out resistance of the foundation; the top surface of the vertical column 3 is used to install the photovoltaic bracket; all the centering springs 25 are synchronously extended and retracted, and the vertical column 3 can ensure that it is concentric with the centering sleeve 21 and the inner hole of the concrete hollow pile 1, thereby ensuring a certain positional accuracy, which is conducive to the installation of the photovoltaic bracket; when the vertical column 3 is no longer supported, the centering spring 25 pushes the diameter-changing component inward, so that the fan-shaped hook 232 does not contact the hook groove 13, and the diameter-changing component can be smoothly inserted into the concrete hollow pile 1.

[0032] Example 2 Example 2 is basically the same as Example 1, and the similarities will not be repeated. The difference is that the concrete hollow pile 1 is prefabricated, which can be poured in the factory in advance and then transported to the site for construction, thus reducing the construction cycle.

[0033] The upper edge of the reinforcing thin steel plate 131 extends upward; the lower edge of the reinforcing thin steel plate 131 extends downward; the reinforcing thin steel plate 131 can participate in the support of the precast concrete hollow pile 1, and has a high bonding capacity with the inner wall of the hook groove 13.

[0034] The side edges of adjacent vertical arc plates 231 are matched accordingly; when the vertical column 3 is not inserted between the reducing components, the centering spring 25 naturally extends outward; in addition to the bolt head of the guide screw 24 limiting the outward extension stroke of the centering spring 25, the abutting of the side edges of adjacent vertical arc plates 231 also limits the outward extension of the centering spring 25, ensuring that all vertical arc plates 231 can be assembled into a complete ring. On the one hand, this provides a reference point when the vertical column 3 is inserted; on the other hand, the reducing components are in a relatively stable state after assembly, making it easy to transport them from the factory to the project site. In this way, the reducing components can also be manufactured in advance in the factory, ensuring manufacturing and assembly accuracy, and reducing the construction cycle.

[0035] Example 3 See Figure 6-8 A construction method for a self-locking connection structure of a steel-concrete composite hollow pile foundation for a photovoltaic support, as described in Embodiment 2, includes the following steps: (1) Precast concrete hollow piles 1, assemble variable diameter components and manufacture vertical columns 3 in the factory.

[0036] See Figure 7-8 The pouring of the hollow concrete pile 1 requires an inner upper formwork, an inner lower formwork, and an outer formwork; all three formworks are cylindrical; the lower end of the inner upper formwork is fitted with an integral reinforcing thin steel plate 131, which is inserted into the inner lower formwork; the reinforcing thin steel plate 131 is horizontally limited; the inner upper and inner lower formworks are also provided with annular steps corresponding to the reinforcing thin steel plate 131; the reinforcing thin steel plate 131 is vertically limited; the outer formwork is fitted over the inner upper formwork, and an annular plate extends inward from the top; the annular plate has a through-hole for the pre-embedded bolts 11 to pass through. The holes are used to ensure the precise positioning of the pre-embedded bolts 11 relative to the outer formwork. Before pouring the hollow concrete pile 1, the concentricity of the outer formwork and the inner upper formwork is repeatedly checked using a steel ruler. The distance from the top edge of the inner upper formwork to the top edge of the outer formwork is measured at multiple points using a steel ruler. If the results of multiple measurements are all within the allowable error, it can be determined that the inner upper formwork and the outer formwork meet the concentricity requirements. This ensures the positional accuracy of the pre-embedded bolts 11 relative to the inner hole of the hollow concrete pile 1. After pouring, the distance between the pre-embedded bolts 11 and the inner hole of the hollow concrete pile 1 is inspected. All components of the variable diameter assembly and the vertical column 3 are machined; after machining, the forming quality of all components of the variable diameter assembly and the vertical column 3 is inspected. The various components of the variable diameter assembly are assembled together, and the assembly quality is inspected. After passing inspection, the concrete hollow pile 1, the variable diameter assembly, and the vertical column 3 can be shipped to the project site.

[0037] (2) Transport the concrete hollow pile 1, the diameter-changing component, and the vertical column 3 to the project site.

[0038] (3) Press in the hollow concrete pile 1.

[0039] The project site was marked with drilling holes, and the concrete hollow pile 1 was pressed into the designed depth along the drilled hole using the static pile driving method; the top surface of the concrete hollow pile 1 reached the design elevation.

[0040] (4) Install the variable diameter assembly on the concrete hollow pile 1.

[0041] Insert the centering sleeve 21 into the inner hole of the hollow concrete pile 1; the pre-embedded bolts 11 pass out from the corresponding connection holes 222 of the flange 22; use the connecting nut 12 to press the flange 22 tightly against the top surface of the hollow concrete pile 1 to ensure that the centering sleeve 21 is concentric with respect to the inner hole of the hollow concrete pile 1. (5) Install vertical column 3. Insert the vertical column 3 between the reducing parts; hammer the top mounting plate 32 of the vertical column 3 until the mounting plate 32 abuts against the flange 22; rotate the mounting plate 32 according to the installation status of the photovoltaic bracket so that the photovoltaic bracket can be stably placed on the mounting plate 32; weld the flange 22 to the mounting plate 32.

[0042] (6) Install a photovoltaic bracket above the mounting plate 32.

[0043] The photovoltaic bracket can be directly welded onto the mounting plate 32, or bolts can be installed on the mounting plate 32 to connect it to the base plate of the photovoltaic bracket.

[0044] Compared with the prior art, the concrete hollow pile 1, the variable diameter component and the vertical column 3 of the present invention can be manufactured in the factory in advance, which can ensure construction quality and shorten the construction cycle.

[0045] Example 4 See Figure 9-10 Example 4 is basically the same as Example 2, and the similarities will not be repeated. The difference is that in step (1), the side edges of adjacent vertical arc plates 231 are matched accordingly; when the vertical column 3 is not inserted between the diameter-changing parts, the centering spring 25 naturally extends outward; in addition to the bolt head of the guide screw 24 being able to limit the outward extension stroke of the centering spring 25, the side edges of adjacent vertical arc plates 231 abutting each other can also limit the outward extension of the centering spring 25, ensuring that all vertical arc plates 231 can be assembled into a complete ring. On the one hand, this is beneficial to have a reference when the vertical column 3 is inserted. On the other hand, after the diameter-changing assembly is assembled, it is in a relatively stable state, which is convenient for transportation from the factory to the project site. In this way, the diameter-changing assembly can also be manufactured in the factory in advance to ensure manufacturing accuracy and assembly accuracy, and also reduce the construction cycle.

[0046] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A self-locking connection structure for a steel-concrete composite hollow pile foundation for photovoltaic supports, characterized in that, The system includes a hollow concrete pile (1), a reducing assembly, and a vertical column (3). The reducing assembly includes a centering sleeve (21), a flange (22), a reducing element, a guide screw (24), and a centering spring (25). The hollow concrete pile (1) has pre-embedded bolts (11) arranged circumferentially around the axis of the centering sleeve (21). The upper end of the centering sleeve (21) is fixed to the bottom surface of the flange (22), and the centering sleeve (21) is concentrically positioned with the inner hole of the hollow concrete pile (1). The upper end of the pre-embedded bolts (11) passes through the top surface of the flange (22), and is threaded with a connecting nut (12) that abuts against the flange (22). The reducing element is circumferentially distributed relative to the axis of the centering sleeve (21), including a vertical arc plate (231) and a fan-shaped hook (232). The guide screw (24) runs radially through the side wall of the centering sleeve (21) from the outside to the inside and is threaded to the midpoint of the horizontal section of the vertical arc plate (231); the vertical column (3) is vertically inserted into the flange (22) and abuts against the inner wall of the vertical arc plate (231); the centering spring (25) is in a compressed state and is fitted outside the guide screw (24), with one end abutting against the inner wall of the centering sleeve (21) and the other end abutting against the outer wall of the vertical arc plate (231); the inner wall of the concrete hollow pile (1) is provided with an annular hook groove (13); the fan-shaped hook (232) is fixed to the lower end of the vertical arc plate (231) and extends into the hook groove (13); the distance that the fan-shaped hook (232) extends into the hook groove (13) is less than the compression of the centering spring (25).

2. The self-locking connection structure of the steel-concrete composite hollow pile foundation for photovoltaic support according to claim 1, characterized in that, The lower edge of the vertical column (3) is chamfered (31).

3. The self-locking connection structure of the steel-concrete composite hollow pile foundation for photovoltaic support according to claim 1, characterized in that, The flange (22) has an insertion hole (221) at its center that is concentric with the centering sleeve (21); the upper end of the vertical column (3) extends outward to form a mounting plate (32) with an area larger than the insertion hole (221).

4. The self-locking connection structure of the steel-concrete composite hollow pile foundation for photovoltaic support according to claim 3, characterized in that, The insertion hole (221) is concentrically set with the centering sleeve (21), and the inner diameter of the insertion hole (221) is equal to the outer diameter of the vertical column (3).

5. The self-locking connection structure of the steel-concrete composite hollow pile foundation for photovoltaic support according to claim 1, characterized in that, Several guide screws (24) are arranged along the axial direction of the centering sleeve (21).

6. The self-locking connection structure of the steel-concrete composite hollow pile foundation for photovoltaic support according to claim 1, characterized in that, The inner diameter of the inner wall of the vertical arc plate (231) is equal to the outer diameter of the vertical column (3).

7. The self-locking connection structure of the steel-concrete composite hollow pile foundation for photovoltaic support according to claim 1, characterized in that, The inner wall of the hook groove (13) is covered with a reinforced thin steel plate (131).

8. The self-locking connection structure of the steel-concrete composite hollow pile foundation for photovoltaic support according to claim 7, characterized in that, The hollow concrete pile (1) is a precast structure.

9. The self-locking connection structure of the steel-concrete composite hollow pile foundation for photovoltaic support according to claim 1, characterized in that, The sides of adjacent vertical curved plates (231) are matched.

10. A construction method for a self-locking connection structure of a steel-concrete composite hollow pile foundation for a photovoltaic support as described in any one of claims 1-9, characterized in that, Includes the following steps: (1) Precast concrete hollow piles (1) in the factory, assemble variable diameter components and manufacture vertical columns (3). (2) Transport the hollow concrete piles (1), the variable diameter assembly, and the vertical column (3) to the project site; (3) Pressing in hollow concrete piles (1): Drill holes along the marked lines on the project site, and use static pressing method to press the hollow concrete piles (1) into the designed depth along the drilled holes so that the top surface of the hollow concrete piles (1) reaches the design elevation. (4) Install the reducing assembly on the hollow concrete pile (1): Insert the centering sleeve (21) into the inner hole of the hollow concrete pile (1), and the pre-embedded bolts (11) pass through the corresponding connection holes (222) of the flange (22). Use the connecting nut (12) to press the flange (22) tightly against the top surface of the hollow concrete pile (1). (5) Install the vertical column (3): Insert the vertical column (3) between the reducing parts, hammer the top mounting plate (32) of the vertical column (3) until the mounting plate (32) abuts against the flange (22), and weld the flange (22) to the mounting plate (32); (6) Install a photovoltaic bracket above the mounting plate (32).

Images