A combined pile foundation structure suitable for offshore fixed photovoltaic platform

Abstract

This invention belongs to the field of marine renewable clean energy and discloses a combined pile foundation structure suitable for offshore fixed photovoltaic platforms. It includes a solid-web pile foundation structure below the mudline and a truss-type pile foundation structure above the mudline. The solid-web and truss-type pile foundation structures are connected as a whole by connecting steel plates. The truss has multiple chords, and these chords are connected by welding multiple straight and diagonal truss web members to form the truss-type pile foundation structure. By using a truss structure to replace the solid-web piles above the mudline, and taking advantage of the smaller wave-facing area of ​​the truss members, wave forces and wind loads are reduced, thus achieving the goal of reducing the amount of steel used in the pile foundation.

Description

Technical Field

[0001] This invention belongs to the field of marine renewable clean energy, and relates to a pile foundation structure for a fixed marine photovoltaic platform, and more specifically to a combined pile foundation structure suitable for a fixed marine photovoltaic platform. Background Technology

[0002] Offshore fixed photovoltaic (PV) systems are an important component of developing renewable and clean energy at sea, and are widely applicable to intertidal zones and shallow coastal areas. In offshore fixed PV platforms, the pile foundation is a crucial structure supporting the platform, and its load-bearing capacity under various loads directly affects the stability and safety of the PV platform.

[0003] Currently, most pile foundations are single or multiple steel piles, typically with large, solid cross-sections. These pile foundations not only bear the load of the superstructure photovoltaic platform but also withstand wave flow and ice loads. The magnitude of wave flow and ice loads is positively correlated with the diameter of the large-diameter pile foundation. As the load on the photovoltaic platform increases, the pile foundation cross-section is enlarged to enhance the stability of the platform structure under wave forces and other loads. This, in turn, increases the wave flow and ice loads on the pile foundation, leading to a further increase in steel consumption and reduced structural economy. Summary of the Invention

[0004] Based on this, and in response to the problems raised in the background technology above, a combined pile foundation structure suitable for offshore fixed photovoltaic platforms is provided.

[0005] A truss structure is used instead of large-diameter solid-web steel piles to reduce the wave load. Large-diameter solid-web steel piles are used below the mud surface to improve the support of the foundation soil on the pile foundation; a truss column structure is used above the mud surface to reduce the area affected by the wave load, thereby reducing the wave load on the pile foundation and thus reducing the amount of steel used.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a combined pile foundation structure suitable for offshore fixed photovoltaic platforms, comprising a solid pile foundation structure below the mud surface and a truss pile foundation structure above the mud surface. The solid pile foundation structure and the truss pile foundation structure are connected by connecting steel plates to form an integral whole, so that the overall structure can achieve continuous and reliable force transmission. Truss-type pile foundation structures include: truss chords, straight web members, and diagonal web members connected to connecting steel plates; The truss has multiple chords, and the truss chords are connected by welding multiple straight web members and multiple diagonal web members to form a truss-type pile foundation structure. Compared with the traditional solid web structure, the pile section on the truss has a smaller flow-facing area, which can effectively reduce wave force and wind load.

[0007] By connecting steel plates, the cross-section is transformed from a solid web section to a truss structure, and the forces of the multiple limbs of the truss structure are more evenly concentrated and transferred to the pile foundation section, reducing stress abrupt changes and fatigue at the connection points, while improving the structural economy.

[0008] In a preferred embodiment, the present invention can be further configured as follows: the solid-web pile foundation structure and the connecting steel plate are connected by a full penetration weld, and a lower stiffening rib is provided between the solid-web pile foundation structure and the connecting steel plate; the truss chord and the connecting steel plate are connected by a full weld; an upper stiffening rib is provided between the truss chord and the connecting steel plate; a cross stiffening rib is provided at the top of the solid-web pile foundation structure, and the position of the cross stiffening rib corresponds to the positioning of the truss chord.

[0009] By adopting the above technical solutions, the overall structural strength is improved.

[0010] In a preferred embodiment, the present invention may be further configured such that the cross-sectional shape of the solid-web pile foundation structure includes circular and square shapes.

[0011] In a preferred embodiment, the present invention can be further configured such that the cross-section of the solid-web pile foundation structure includes a constant cross-section and a variable cross-section.

[0012] In a preferred embodiment, the present invention may be further configured such that the truss chords, straight web members, and diagonal web members are steel pipes with cross-sections including circular and square.

[0013] In a preferred embodiment, the present invention can be further configured such that the overall cross-section of the truss-type pile foundation structure includes a constant cross-section and a variable cross-section.

[0014] In a preferred embodiment, the present invention can be further configured such that the weld quality grade between the truss chord and the solid web pile foundation structure and the connecting steel plate is Grade 1.

[0015] In summary, the present invention has at least one of the following beneficial technical effects: 1. By using a truss structure to replace the solid piles above the mud surface, and taking advantage of the smaller wave-facing area of ​​the truss members, wave forces and wind loads are reduced, thereby reducing the amount of steel used in the pile foundation.

[0016] 2. Below the mudline at sea, a large-diameter solid-web steel pile structure is adopted. The soil constraint on the pile foundation is positively correlated with the pile diameter; the larger the diameter, the stronger the constraint on the pile foundation. This reduces the horizontal displacement of the pile top, thereby enhancing the overall stability of the pile foundation and achieving a more stable new type of combined pile foundation structure for offshore fixed photovoltaic platforms. Attached Figure Description

[0017] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the combined pile foundation of the present invention; Figure 2 This is a schematic diagram of the truss-type pile foundation of the present invention; Figure 3 This is a schematic diagram of the solid-web pile foundation of the present invention; Figure 4 This is a schematic cross-sectional view of the solid-web pile foundation of the present invention; Figure 5 This is a schematic cross-sectional view of the truss-type pile foundation of the present invention; Figure 6 This is a schematic diagram of the variable cross-section truss pile foundation of the present invention; Figure 7 This is a schematic diagram of the connecting steel plate structure of the present invention. Attached Figure

[0018] 1. Solid web pile foundation structure; 2. Truss pile foundation structure; 21. Truss chord; 22. Truss straight web member; 23. Truss diagonal web member; 3. Connecting steel plate; 4. Lower stiffening rib; 5. Upper stiffening rib; 6. Cross stiffening rib. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] exist Figure 1-7 In the illustrated embodiment, the present invention provides a technical solution: a combined pile foundation structure suitable for offshore fixed photovoltaic platforms, comprising a solid pile foundation structure 1, a truss pile foundation structure 2, and a connecting steel plate 3. The solid pile foundation structure 1 and the truss pile foundation structure 2 are connected as a whole by the connecting steel plate 3, so that the overall structure can achieve continuous and reliable force transmission.

[0021] In the specific implementation process, the solid-web pile foundation structure 1 is a steel cylindrical pile, mainly arranged in the area below sea level and below the mud surface. The solid-web pile foundation structure is inserted into the mud surface to form an embedded section, providing stable support for the upper platform. The top of the solid-web pile foundation structure 1 is provided with stiffening ribs 4 and cross stiffening ribs 6. The stiffening ribs 4 and cross stiffening ribs 6 are directly welded to the solid-web pile foundation structure 1 and the connecting steel plate 3, strengthening the connection between the solid-web pile foundation structure 1 and the connecting steel plate 3.

[0022] In the specific implementation process, the main chord of the truss-type pile foundation structure 2 consists of four hollow circular tubes (i.e., truss chords 21) as foundation components, and is arranged in sections by truss straight web members 22 and truss diagonal web members 23, forming a truss-type pile foundation structure through welding, and then assembled into a complete truss structure through welding. Stiffening ribs 5 are provided between the truss chords 21 and the connecting steel plates 3 to strengthen the connection between the truss chords 21 and the connecting steel plates 3. Compared with the traditional solid web structure, this structure has a smaller flow-facing area in the pile sections on the truss, which can effectively reduce wave forces and wind loads.

[0023] In the specific implementation process, the overall structure is assembled in the factory. The connecting steel plate 3 is hoisted to position and weld with the solid-web pile foundation structure 1, the lower stiffening rib 4, and the cross stiffening rib 6. The assembled truss unit is welded above the connecting steel plate 3 according to the position of the cross stiffening rib 6, thus achieving a firm connection between the solid-web pile foundation structure 1 and the truss pile foundation structure 2. After the overall welding is completed, it is transported to the sea for installation. The connecting steel plate 3 achieves the change of the cross section from a solid-web section to a truss structure, and makes the force of the multiple limbs of the truss structure more evenly concentrated and transferred to the pile foundation section, reducing stress abrupt changes and fatigue at the connection, while improving the structural economy.

[0024] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A combined pile foundation structure suitable for offshore fixed photovoltaic platforms, characterized in that: It includes a solid pile foundation structure located below the mud surface and a truss pile foundation structure located above the mud surface. The solid pile foundation structure and the truss pile foundation structure are connected by connecting steel plates to form an integral whole. The truss-type pile foundation structure includes: truss chords, truss straight web members, and truss diagonal web members connected to the connecting steel plates; The truss has multiple chords, and the truss chords are connected by welding multiple straight web members and multiple diagonal web members to form a truss-type pile foundation structure.

2. The combined pile foundation structure suitable for offshore fixed photovoltaic platforms according to claim 1, characterized in that: The solid-web pile foundation structure is connected to the connecting steel plate by a full penetration weld, and a lower stiffening rib is provided between the solid-web pile foundation structure and the connecting steel plate. The truss chord is connected to the connecting steel plate by a full weld, and an upper stiffening rib is provided between the truss chord and the connecting steel plate. A cross stiffening rib is provided at the top of the solid-web pile foundation structure, and the position of the cross stiffening rib corresponds to the positioning of the truss chord.

3. The combined pile foundation structure suitable for offshore fixed photovoltaic platforms according to claim 1, characterized in that: The cross-sectional shapes of the solid-web pile foundation structure include circular and square shapes.

4. The combined pile foundation structure suitable for offshore fixed photovoltaic platforms according to claim 1, characterized in that: The cross-section of the solid-web pile foundation structure includes constant cross-section and variable cross-section.

5. The combined pile foundation structure suitable for offshore fixed photovoltaic platforms according to claim 1, characterized in that: The truss chords, straight web members, and diagonal web members are made of steel pipes with circular and square cross-sections.

6. The combined pile foundation structure suitable for offshore fixed photovoltaic platforms according to claim 1, characterized in that: The overall cross-section of the truss-type pile foundation structure includes constant cross-section and variable cross-section.

7. The combined pile foundation structure suitable for offshore fixed photovoltaic platforms according to claim 1, characterized in that: The quality grade of the welds between the truss chords and the solid pile foundation structure and the connecting steel plates is Grade I.

Images