A fish belly type flexible photovoltaic support system and a construction method thereof

Abstract

The present application relates to photovoltaic power generation technical field, especially to a kind of fish belly type flexible photovoltaic support system and its construction method.Support system includes support system and bearing system;Support system includes side support structure, side support structure includes uplift foundation and compression foundation, uplift foundation is located at the outside of compression foundation, support column is set on compression foundation, uplift foundation is connected with support column by cable-stayed rod;Bearing system is installed on the support column at both ends, including load-bearing cable and reinforcing cable, photovoltaic module is installed on load-bearing cable, reinforcing cable has double cable that is arranged in vertical direction crossing, and in longitudinal direction, it is located in the middle of load-bearing cable.By the present application, it solves the problem of unreasonable stress of foundation, low construction efficiency, prestress loss and other problems, realizes 30-40 meters large-span without support across, while reducing construction difficulty and influence on ecological environment.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic power generation technology, and in particular to a fish-belly type flexible photovoltaic support system and its construction method. Background Technology

[0002] Photovoltaic support system technology is mainly used in the construction of photovoltaic power stations in complex terrains such as mountains and gullies. Traditional rigid supports, due to their large self-weight and limited span, usually require multiple intermediate supports when crossing wide gullies, resulting in a large amount of foundation construction and easy damage to surface vegetation. Flexible supports, on the other hand, use steel strands as the main load-bearing components and utilize prestressing tension to form a support structure with a certain deformation capacity, enabling larger spans. Among them, the fish-belly type flexible support arranges the upper and lower chord steel strands in an arc shape, connected by a strut in the middle to form a force-bearing structure resembling a fish belly, which has advantages in controlling deflection and improving load-bearing capacity.

[0003] Existing technology discloses a large-span fish-belly-shaped flexible photovoltaic support structure, which includes arc-shaped load-bearing cables and anti-arch stabilizing cables. The load-bearing cables support the photovoltaic modules, while the stabilizing cables control deformation under wind loads. The two ends of the load-bearing cables are anchored to the side span foundations, and the stabilizing cables are connected to the load-bearing cables via multiple supports, forming a spatial force-bearing system. Each span support is independently arranged, transferring the load to the ground through columns and foundations. The foundation design uses a single pile type, which is prone to problems such as pull-out failure or settlement in uneven soil layers in mountainous areas. Designing it according to the most unfavorable load would result in material waste. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this invention is to provide a fish-belly-shaped flexible photovoltaic support system to solve problems such as unreasonable foundation stress, low construction efficiency, and easy loss of prestress, thereby achieving unsupported crossings of large spans of 30-40 meters while reducing construction difficulty and impact on the ecological environment.

[0005] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions: A fish-belly-shaped flexible photovoltaic support system for installing photovoltaic modules includes: a support system and a load-bearing system; the support system includes an edge support structure, which includes a tensile foundation and a compressive foundation, the tensile foundation being located outside the compressive foundation, and a support column being provided on the compressive foundation, the tensile foundation being connected to the support column by a tie rod; the load-bearing system is installed on the support columns at both ends and includes a load-bearing cable and a reinforcing cable, the photovoltaic module being installed on the load-bearing cable, and the reinforcing cable having two cables arranged crosswise in the vertical direction and located in the middle of the load-bearing cable in the longitudinal direction.

[0006] Optionally, there are two tensile foundations and one compressive foundation, and the tensile foundations and compressive foundations are arranged in an isosceles triangle.

[0007] Optionally, the side support structures are located at both ends of the support system, and the support system further includes a middle support structure located in the middle of the two side support structures. The load-bearing cable and the reinforcing cable are both installed on the middle support structure.

[0008] Optionally, the reinforcing string includes a first string and a second string, wherein in the transverse direction, a portion of the first string is located above the second string, and a portion of the second string is located above the first string.

[0009] Optionally, the load-bearing string has two strands, which are arranged in parallel, and the two load-bearing strings and the two reinforcing strings are arranged in a T-shape in the longitudinal section.

[0010] Optionally, the load-bearing system further includes a support frame, the top of which is connected to the photovoltaic module, and the first and second cables are respectively installed at different vertical positions on the support frame.

[0011] Optionally, it also includes a wind-resistant system, which includes a wind-resistant foundation and wind-resistant cables. The wind-resistant cables are arranged longitudinally and perpendicular to the reinforcing chords. Both ends of the wind-resistant cables are installed on the wind-resistant foundation, and the wind-resistant cables are connected to the load-bearing chords and / or reinforcing chords.

[0012] Optionally, it also includes a wind-resistant system, which includes a wind-resistant foundation and wind-resistant cables. The wind-resistant cables are arranged longitudinally and perpendicular to the reinforcing chords. Both ends of the wind-resistant cables are installed on the wind-resistant foundation and connected to the support frame.

[0013] Optionally, the load-bearing cable is connected to the photovoltaic module via a mounting kit, which includes a pressure plate and a pressure plate. The pressure plate is clamped onto the load-bearing cable, and the pressure plate is mounted on the pressure plate. The pressure plate has two pieces, which are respectively pressed onto the structural components of two adjacent photovoltaic modules.

[0014] This invention also provides a construction method for a fish-belly type flexible photovoltaic support system, including: On the open ground outside the construction site, the load-bearing chords, reinforcing chords, and multiple supports are assembled into a fish-belly cable system according to the design drawings. The reinforcing chords include a first chord and a second chord arranged in a vertical direction. The top of the supports is connected to the load-bearing chords, and the bottom of the supports is connected to the reinforcing chords. The assembled fish-belly cable system is lifted as a whole between the two end support columns of the installed support system; Pass the end of the supporting chord and the end of the reinforcing chord through the mounting holes on the corresponding support column, and install a single-hole anchor head after fitting a spring on each end; The load-bearing and reinforcing cables are tensioned for the first time to bring the cable force to the first preset tension value, thus completing the structural forming. Install photovoltaic modules on the load-bearing cables; The load-bearing and reinforcing cables are tensioned a second time to bring the cable force to the second preset tension value in order to eliminate prestress loss.

[0015] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages: The support system of this invention, by setting up reinforcing cables and arranging double cables in a crisscrossing manner in the vertical direction to form a fish-belly-shaped load-bearing structure, can control the maximum deflection within 15 centimeters for a span of 30 meters. Secondly, through the functional design of the tensile and compressive foundations, combined with the connection of diagonal tie rods, the load is transferred along multiple paths. The tensile foundation specifically bears the upward force, the compressive foundation specifically bears the downward force, and the diagonal tie rods transfer the horizontal force, avoiding the risk of slippage caused by a single pile foundation bearing multiple loads simultaneously. The inner and outer foundation layout can flexibly adapt to the elevation differences on both sides of the ditch without excessive surface excavation.

[0016] Advantages of additional aspects of the invention will be set forth 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

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In addition, the dimensions or spacing between the components are exaggerated to show the position of each component, and the schematic diagrams are for illustrative purposes only.

[0018] Figure 1 This is a schematic plan view of the support system provided in an embodiment of the present invention; Figure 2 This is a schematic elevation view of the support system provided in an embodiment of the present invention; Figure 3 This is provided by the embodiments of the present invention. Figure 1 Enlarged illustration in the upper left corner; Figure 4 This is a schematic diagram of the connection between the support system and the load-bearing system provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the load-bearing system provided in an embodiment of the present invention; Figure 6 This is a schematic diagram of the support structure provided in an embodiment of the present invention; Figure 7 This is a schematic diagram of the support frame provided in an embodiment of the present invention; Figure 8 This is a schematic diagram of the wind-resistant system provided in an embodiment of the present invention; Figure 9 This is a schematic diagram of the connection between the support frame and the wind-resistant cable provided in an embodiment of the present invention; In the diagram: 1. Support system; 11. Tension-resistant foundation; 12. Compression-resistant foundation; 13. Support column; 14. Tie rod; 15. Intermediate support structure; 2. Load-bearing system; 21. Load-bearing cable; 22. Reinforcing cable; 221. First cable; 222. Second cable; 223. Bracket; 3. Wind-resistant system; 31. Wind-resistant cable; 32. Wind-resistant foundation; 4. Photovoltaic module; 5. Installation kit; 51. Pressure plate; 52. Pressure plate; Detailed Implementation It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0019] Terminology Explanation: A fish-belly structure refers to a load-bearing structure in which the upper and lower chord steel strands are distributed in an arc shape and connected by a support frame in the middle to form a shape similar to a fish belly.

[0020] Prestressing tensioning is the process of applying a pre-set tension to steel strands using mechanical means, causing them to undergo elastic deformation to withstand loads.

[0021] Flexible support is a photovoltaic support system that uses steel strands as the main load-bearing components and has a certain deformation capacity.

[0022] Example 1 This embodiment proposes a fish-belly-shaped flexible photovoltaic support system, which is mainly used for the construction of photovoltaic power stations in complex terrains such as mountains, gullies, and canyons, especially in scenarios requiring large spans of 30 to 40 meters without intermediate supports. The elevations on both sides of the gully may be inconsistent, and the slope of the mountain can reach less than 25 degrees.

[0023] like Figure 1 , Figure 2 As shown, the support system includes a support system 1 and a load-bearing system 2. The support system 1 includes a side support structure, which further includes a tensile foundation 11 and a compressive foundation 12, as shown. Figure 3 , Figure 4As shown, the tensile foundation 11 is located outside the compressive foundation 12. Support columns 13 are installed on the compressive foundation 12, and the tensile foundation 11 is connected to the support columns 13 via tie rods 14. The load-bearing system 2 is installed on the support columns 13 at both ends and includes a load-bearing cable 21 and a reinforcing cable 22. The photovoltaic module 4 is installed on the load-bearing cable 21. The reinforcing cable 22 has two cables arranged in a vertical direction and is located in the middle of the load-bearing cable 21 in the longitudinal direction.

[0024] The tensile foundation 11 and compressive foundation 12 are constructed using cast-in-place piles. When arranged on both sides of the ditch, two tensile foundations 11 and one compressive foundation 12 are installed on each side. The compressive foundation 12 has a depth of 2 meters, and the tensile foundation 11 has a depth of 3 meters, with a pile diameter of 300 mm. The support column 13 installed on the compressive foundation 12 is a triangular stabilizing structure welded from Q335B galvanized H-beams. The diagonal tie rod 14 connects the tensile foundation 11 and the support column 13, transferring horizontal loads and uplift forces to the tensile foundation 11.

[0025] The side support structures are located at both ends of the entire support system 1. Tensile foundations 11 are located on the outer side, and compressive foundations 12 are located on the inner side. Together with the support columns 13, they form a triangular load-bearing system via tie rods 14. When wind or snow loads are applied, the load-bearing chord 21 bears the vertical load, while the reinforcing chord 22 bears the reverse load and controls deformation. Because the reinforcing chord 22 has a vertically intersecting double-chord structure and is located in the middle of the load-bearing chord 21, it can provide intermediate elastic support for the load-bearing chord 21 under large span conditions, preventing excessive deflection.

[0026] First, traditional flexible support structures using a single row of steel strands suffer from excessive deflection over large spans, leading to mutual shading of photovoltaic modules 4 or insufficient ground clearance. This solution, by incorporating reinforcing chords 22 and crisscrossing double chords vertically to form a fish-belly-shaped load-bearing structure, can control the maximum deflection within 15 centimeters over a 30-meter span. Second, existing fish-belly-shaped structures have flawed foundation-steel strand connection designs, potentially leading to slippage under strong winds, snow accumulation, and other loads. This solution addresses this by using functionally separate tensile and compressive foundations 11 and 12, connected by tie rods 14, to distribute loads along different paths. The tensile foundation 11 specifically bears upward pulling forces, the compressive foundation 12 specifically bears compressive forces, and the tie rods 14 transmit horizontal forces, avoiding the slippage risk caused by a single pile bearing multiple loads simultaneously. Furthermore, the inner and outer foundation layout allows for flexible adaptation to elevation differences on both sides of the ditch, eliminating the need for excessive surface excavation.

[0027] In some further specific examples of this disclosure, there are two tensile foundations 11 and one compressive foundation 12, arranged in an isosceles triangle configuration. This triangular layout, with one in front and two behind, places the two tensile foundations 11 at the rear and the one compressive foundation 12 at the front. When the tie rod 14 connects from the support column 13 to the two tensile foundations 11, it forms two stable triangular supports. The isosceles triangular arrangement ensures uniform stress distribution on both sides of the tensile foundations 11, avoiding eccentric loading. Simultaneously, this layout occupies a small surface area, making it suitable for the limited construction space on both sides of mountainous terrain. Combined with RTK positioning technology, flexible site placement can be achieved, avoiding interference with existing pile foundations or obstacles.

[0028] In other specific examples of this disclosure, the edge support structures are located at both ends of the support system 1, and the support system 1 also includes a middle support structure 15 (such as...). Figure 6 As shown, the central support structure 15 is located in the middle of the two end support structures, and the load-bearing cable 21 and the reinforcing cable 22 are both installed on the central support structure 15.

[0029] For spans exceeding 40 meters, the end support structures alone may be insufficient to control deflection. A central support structure 15 is positioned in the middle of the end support structures, providing a central fulcrum for the load-bearing chord 21 and reinforcing chord 22. The number and location of the central support structures 15 need to be determined based on the actual span. The central support structure 15 also utilizes a cast-in-place pile foundation, with columns erected on top. The load-bearing chord 21 and reinforcing chord 22 pass through mounting holes in the columns or are connected via anchor heads. By combining the end support structures and the central support structure 15, larger spans can be achieved while maintaining deflection control precision.

[0030] In some specific examples of this disclosure, the reinforcing cable 22 includes a first cable 221 and a second cable 222. In the transverse direction, a portion of the first cable 221 is located above the second cable 222, and a portion of the second cable 222 is located above the first cable 221. This intersecting arrangement differs from the conventional stabilizing cables arranged in parallel vertically. The first cable 221 and the second cable 222 are not completely parallel in the vertical direction, but intersect in the transverse projection direction.

[0031] Specifically, in areas near the edge support structure, the first chord 221 is located above the second chord 222; in other areas, the second chord 222 is located above the first chord 221. This cross arrangement forms a truss-like spatial force-bearing system, enhancing the out-of-plane stiffness and torsional resistance of the reinforcing chord 22 itself. When wind loads act on the support system from different directions, the cross-arranged double chords can withstand loads in both directions, avoiding the limitation of a single chord only being able to withstand unidirectional forces.

[0032] In some further specific examples of this disclosure, there are two load-bearing cables 21, which are arranged in parallel, and the two load-bearing cables 21 and the two reinforcing cables 22 are arranged in a T-shape in the longitudinal section (e.g., Figure 5 (As shown).

[0033] The load-bearing chord 21 consists of two parallel steel strands used to mount the photovoltaic module 4. The reinforcing chord 22 includes a first chord 221 and a second chord 222, located below the load-bearing chord 21. In the longitudinal section, the two load-bearing chords 21 are located at the top, and the two reinforcing chords 22 are located in the middle and lower parts, forming an overall T-shaped distribution. This T-shaped layout lowers the center of gravity of the load-bearing system 2, improving its resistance to lateral deformation. Simultaneously, when the two load-bearing chords 21 are arranged in parallel, the four corners of the photovoltaic module 4 can be fixed separately by the mounting kit 5, forming four-point support and ensuring even stress distribution.

[0034] The load-bearing chord 21 is made of two 1860MPa grade φ15.2 galvanized steel strands with a PE layer (tensile strength 1860N / mm²); the reinforcing chord 22 is made of two steel strands of the same specification; the columns are made of Q335B galvanized H-beams welded into a triangular stable structure, and are arranged at equal intervals along the span direction.

[0035] In other specific examples of this disclosure, the load-bearing system 2 also includes a support 223, such as Figure 7 , Figure 9 As shown, the top of the support frame 223 is connected to the photovoltaic module 4, and the first chord 221 and the second chord 222 are respectively installed at different positions in the vertical direction of the support frame 223.

[0036] The support frame 223 is a key component connecting the load-bearing chord 21 and the reinforcing chord 22. It can be a triangular stable structure formed by bolting together galvanized or aluminum-magnesium-zinc steel plates. The first chord 221 and the second chord 222 are installed at different vertical positions on the support frame 223; that is, the first chord 221 is installed in the upper-middle or lower-middle part of the support frame 223, and the second chord 222 is installed at another height on the support frame 223. This different height installation method ensures that the first chord 221 and the second chord 222 are staggered vertically, achieving the desired cross arrangement. The support frames 223 are evenly distributed along the span direction, and the spacing between adjacent support frames 223 is determined according to design calculations. When the load-bearing chord 21 deforms downward under load, the support frame 223 transfers the load to the reinforcing chord 22. The reinforcing chord 22 provides an upward reaction force through prestressing, thereby controlling the deflection.

[0037] The existing support system lacks an effective linkage wind-resistant structure between individual spans. Under the action of mountain wind fields, the vibration of adjacent spans is asynchronous, which can easily lead to component microcracks and cable fatigue. In addition, the stress on the column stay cables is concentrated, and the foundation bears a large horizontal load, which increases the difficulty of construction in mountainous areas.

[0038] Based on this, some specific examples disclosed herein also include a wind-resistant system 3, such as... Figure 8 As shown, the wind-resistant system 3 includes a wind-resistant foundation 32 and a wind-resistant cable 31. The wind-resistant cable 31 is arranged longitudinally and perpendicular to the reinforcing chord 22. Both ends of the wind-resistant cable 31 are installed on the wind-resistant foundation 32, and the wind-resistant cable 31 is connected to the load-bearing chord 21 and / or the reinforcing chord 22.

[0039] The wind-resistant system 3 is a cross-array interconnected wind-resistant structure. Wind-resistant cables 31 are arranged longitudinally, along the arrangement direction of the photovoltaic array, and perpendicular to the horizontal projection of the reinforcing chords 22. Both ends of the wind-resistant cables 31 are anchored to wind-resistant foundations 32, which are located on the outer sides of both ends of the array. The wind-resistant cables 31 are connected to the load-bearing chords 21 via clamps, and also to the reinforcing chords 22 via clamps. When wind loads act on the support system, the vibration of a single span is transmitted to adjacent spans through the wind-resistant cables 31, achieving coordinated stress distribution across the entire area. The wind-resistant cables 31 disperse the horizontal wind force to multiple wind-resistant foundations 32, reducing the horizontal load borne by a single foundation.

[0040] In some other specific examples of this disclosure, the wind-resistant cable 31 is not directly connected to the load-bearing chord 21 or the reinforcing chord 22, but is connected to the support frame 223, such as... Figure 9 As shown. The support frame 223 is a rigid component connecting the load-bearing chord 21 and the reinforcing chord 22. Connecting the wind-resistant cable 31 to the support frame 223 allows the wind load to be directly transferred to the core node of the load-bearing system 2. Simultaneously, this connection method avoids setting too many connectors on the steel strands, reducing the impact on stress concentration points. The connection between the wind-resistant cable 31 and the support frame 223 can be achieved using clamps or bolts. In actual construction, connecting lugs can be installed on the side of the support frame 223, and the wind-resistant cable 31 passes through the lugs and is fixed by anchor heads.

[0041] In other specific examples of this disclosure, the carrying cable 21 is connected to the photovoltaic module 4 via the mounting kit 5, such as... Figure 9 As shown, the mounting kit 5 includes a pressure plate 51 and a pressure plate 52. The pressure plate 51 is clamped on the supporting string 21, and the pressure plate 52 is mounted on the pressure plate 51. The pressure plate 52 has two pieces, and the two pressure plates 52 are respectively pressed onto the structural parts of two adjacent photovoltaic modules 4.

[0042] The pressure plate 51 is a horizontally arranged plate-like component with an arc-shaped groove on its surface that matches the outer diameter of the supporting chord 21. The pressure plate 51 is pressed onto the supporting chord 21. Both ends of the pressure plate 51 are bent upwards or have mounting holes. The pressure sheet 52 is a sheet-like component installed at both ends of the pressure plate 51, with two pressure sheets 52 corresponding to each pressure plate 51. One end of the pressure sheet 52 is connected to the pressure plate 51, and the other end is pressed onto the aluminum frame or structural component of the photovoltaic module 4. Two adjacent photovoltaic modules 4 are respectively pressed and fixed by two pressure sheets 52. In this way, each mounting kit 5 simultaneously fixes two adjacent photovoltaic modules 4, reducing the number of connecting parts. The pressure plate 51 and the pressure sheet 52 are connected by M8×45 stainless steel bolts, allowing adjustment of the pressing force. A 20 mm gap is left between adjacent modules to avoid compression caused by thermal expansion and contraction.

[0043] It also includes a prestressed tensioning system: a portable, staged tensioning system suitable for mountainous terrain with limited power supply or confined spaces; lightweight hydraulic tensioning jacks (compatible with φ15.2 / φ12.7 steel strands) and a high-pressure manual oil pump, allowing for operation without external power; real-time acquisition of cable force and structural deformation during tensioning is achieved through oil pump pressure control; customized single-hole clamp-type anchor heads (anchor hole diameter of 15.2mm, compatible with main cable strands) are used, with clamps made of high-hardness alloy material, enhancing the gripping force with the steel strands and preventing slippage during tensioning and long-term service; the system has a preset staged tensioning program, compatible with the secondary staged tensioning process of this solution.

[0044] In summary, this application introduces a new stabilization system consisting of a longitudinally continuous wind-resistant cable 31 and inter-column diagonal bracing. The wind-resistant cable 31 is connected to the fish-belly-shaped reinforcing chord cable 22, forming a space-wide collaborative load-bearing structure. This integrates independent single spans into a unified load-bearing structure, reducing wind-induced vibrations and controlling the maximum deflection within 15cm for a 30m span; it also disperses horizontal forces, reducing foundation size and construction work, and minimizing vegetation damage; and it creates a redundant load-bearing structure, improving safety redundancy and durability.

[0045] This application uses Q335B fully galvanized steel triangular lattice columns, integrating a stable structure, multi-level elevation adjustment, and full corrosion protection design. It can be prefabricated in the factory and assembled on-site with bolts. It features improved out-of-plane stiffness; allows for precise elevation adjustment of ±500mm, avoiding component obstruction; hot-dip galvanizing provides corrosion protection, increasing service life by more than 2 times, simplifying construction and shortening the construction period.

[0046] This application adopts a multi-functional foundation system with front-side compressive resistance and rear-side dual tensile resistance to achieve load distribution along multiple paths. This multi-path distribution of compressive and tensile loads addresses the pain point of tensile failure; it optimizes foundation parameters, reduces material usage, and adapts to confined mountainous spaces; and it is equipped with RTK positioning for flexible placement, improving terrain adaptability.

[0047] This application employs a precast lifting + secondary staged tensioning process, equipped with specialized anchor heads, suitable for mountainous construction. Precasting on flat ground and overall lifting reduce safety risks and improve efficiency and forming accuracy; secondary tensioning eliminates prestress loss and enhances long-term stability.

[0048] Example 2 Traditional construction methods employ conventional high-altitude assembly and single-tensioning techniques, which not only pose high operational risks but also make it difficult to control the synchronization of cable tension, resulting in significant prestress loss during long-term service.

[0049] This embodiment provides a construction method for the aforementioned fish-belly-shaped flexible photovoltaic support system, which includes the following steps: On an open ground outside the construction site, the supporting chord 21, reinforcing chord 22, and multiple supports 223 are assembled into a fish-belly cable system according to the design drawings. The reinforcing chord 22 includes a first chord 221 and a second chord 222 arranged vertically in a cross pattern. The top of the supports 223 is connected to the supporting chord 21, and the lower part of the supports 223 is connected to the reinforcing chord 22. In traditional construction methods, the threading and tensioning of the steel strands must be carried out at a high altitude after the support column 13 is installed, which is risky and makes it difficult to control the synchronization of cable forces. This solution assembles the fish-belly cable system on an open ground outside the construction site, utilizing the flat ground conditions to precisely control the installation position of the supports 223, the intersection angle of the first chord 221 and the second chord 222, and the quality of each connection node. During assembly, the relative positions of each component are determined according to the design drawings to ensure forming accuracy. In practice, first lay out a large-scale drawing on the ground, place the supporting chord 21 and reinforcing chord 22 according to the large-scale drawing, and then install the support frame 223 between the chords at a predetermined interval.

[0050] The assembled fish-belly cable system is lifted as a whole between the two end support columns 13 of the installed support system 1. This step uses a whole-unit lifting process. The assembled fish-belly cable system is a spatial structure with a certain degree of flexibility, but its relative position is fixed. A winch or manual hoist is used as the lifting equipment. Lifting points are set at the top of the support columns 13, and the two ends and the middle of the fish-belly cable system are connected by steel wire ropes or slings for simultaneous lifting. During the whole-unit lifting process, the fish-belly cable system is kept straight or slightly curved to avoid excessive local stress.

[0051] The ends of the supporting chord 21 and the reinforcing chord 22 are passed through the mounting holes on the corresponding support columns 13, and springs are fitted onto each end before installing single-hole anchor heads. Mounting holes are pre-set on the support columns 13, with diameters adapted to the diameters of the supporting chord 21 and the reinforcing chord 22. After the fish-belly cable system is raised to the predetermined height, the ends of each chord are aligned with the mounting holes on the support columns 13 and passed through. Springs are fitted onto the ends after passing through; the springs provide elastic buffering after tensioning to prevent stress concentration caused by rigid connections. Then, single-hole anchor heads are installed. These are customized single-hole clamp-type anchor heads with an anchor hole diameter of 15.2 mm, adapted to the main cable strands. The clamps are made of high-hardness alloy material, providing high gripping force with the steel strands to prevent slippage.

[0052] The load-bearing chord 21 and the reinforcing chord 22 are initially tensioned to reach the first preset tension value, completing the structural formation. The initial tensioning employs a staged tensioning system, specifically a lightweight hydraulic tensioning jack and a matching high-pressure manual oil pump, requiring no external power supply. Tensioning is performed according to a preset staged procedure; for example, tensioning is first increased to 30% of the first preset tension value, and after checking for any abnormalities at each node and anchor head, tensioning continues to 60%, and finally to 100%. The cable force is controlled by the oil pump pressure, and structural deformation is simultaneously collected to ensure control of the tensioning process. After the initial tensioning, the fish-belly cable system transitions from a relaxed state to a stressed state, forming the designed fish-belly shape.

[0053] Photovoltaic modules 4 are installed on the supporting cables 21. After tensioning, the supporting cables 21 have sufficient stiffness and shape accuracy to install the photovoltaic modules 4. The aforementioned mounting kits 5 are used during installation, with each photovoltaic module 4 fixed to two supporting cables 21 by four mounting kits 5. The installation sequence is from one end of the array to the other, or from the middle to both ends, to avoid stress concentration caused by installation from both ends to the middle.

[0054] Secondary tensioning is applied to the supporting chord 21 and the reinforcing chord 22 to bring the cable force to the second preset tension value, thereby eliminating prestress loss. During the installation of the photovoltaic module 4, the self-weight of the module will generate an additional load on the supporting chord 21, causing elastic elongation of the chord and a decrease in cable force. At the same time, the creep of the steel strands themselves after the initial tensioning and the slight settlement of the foundation will also lead to prestress loss. The purpose of secondary tensioning is to eliminate these losses. Secondary tensioning also adopts a staged tensioning method to supplement the cable force to the second preset tension value. The second preset tension value is equal to the final cable force value required by the design, and the first preset tension value is slightly lower than the second preset tension value, reserving space for supplementary tensioning during secondary tensioning.

[0055] This method transforms high-altitude operations into ground-based operations through overall prefabrication and lifting, improving construction safety and enhancing the precision of cable system formation. It avoids issues like positional deviations of the support frame 223 and poor cable force synchronization that occur during high-altitude assembly. Secondly, the secondary tensioning process solves the problem of insufficient prestress loss after a single tensioning. The initial tensioning completes the structural formation, and a secondary tensioning after component installation precisely eliminates prestress losses caused by cable creep, foundation settlement, and component installation, ensuring long-term cable force stability. Thirdly, installing single-hole anchor heads after springs at the ends provides elastic buffering. When wind loads or temperature changes cause slight expansion and contraction of the steel strands, the springs absorb some deformation, avoiding rigid friction between the anchor head and the steel strands and reducing the risk of slippage. Furthermore, the simultaneous tensioning of the load-bearing chord 21 and the reinforcing chord 22 ensures cable force matching between the two chords in the fish-belly cable system.

[0056] Specific process: 1. Pile foundation construction.

[0057] The construction of pile foundations is crucial to the safety of the system. Therefore, it is essential to strictly control the location and construction quality of the pile foundations and to conduct pull-out force tests at each pile point after construction is completed.

[0058] For pile foundation layout, RTK instruments, theodolites, levels, steel tape measures (5 meters and 100 meters), ink markers, marker pens, and lime powder should be used.

[0059] Fish-belly type supports are used to span larger ditches; this system can span ditches of 30-40 meters. First, determine the approximate location based on the layout diagram. Then, determine the span of the support based on the installation of the fixed components on site. Simultaneously, one person stands on each side of the ditch to measure distances using a 100-meter measuring tape or laser rangefinder to determine the approximate area of ​​the pile points. At the same time, use RTK to measure the elevation, striving to ensure that the elevations on both sides are consistent. If the elevations are inconsistent, the elevation differences of pile points in the same array on the same side should be similar. After finding a suitable area, mark the pile points.

[0060] Depending on the site conditions, if it is feasible to open roads, an excavator can be used to create a 2-3 meter wide road on each side of the marked location to facilitate piling machine construction. After opening the roads, use a measuring tape to re-mark the installation positions. In the area where the piling machine can operate, install two pile foundations, one in front and one behind, with drilling diameters of 300 mm and depths of 2 meters and 3 meters respectively. In the sunlit areas (south, southwest, and southeast), the gap between modules in the array is 50mm. In the northern area, the array spacing is determined based on factors such as local latitude, module tilt angle, and module size to ensure that there is no obstruction between modules.

[0061] 2. Drilling holes at the pile locations.

[0062] Based on the marked locations, the foundation is first excavated to the required dimensions using handheld equipment. Then, holes are drilled using a down-the-hole drill. Where mechanical drilling is feasible, a pile driver is used for drilling. After completion, debris in the pit is removed to prepare for the next stage of grouting.

[0063] Construction sequence of cast-in-place piles: cleaning → placement and secondary binding of reinforcing cage → concrete mixing → concrete pouring → concrete vibration → repositioning of embedded parts → concrete leveling → concrete curing.

[0064] 2.1 Clean the foundation pit.

[0065] Cleaning the foundation pit involves removing surface loose soil and disturbed soil, ensuring no water accumulation. Leveling is performed to ensure the foundation bottom elevation meets design requirements; the foundation bottom elevation should be determined on the base surface before foundation construction.

[0066] The foundation of this project consists of cast-in-place piles and a pile cap. The drilling of the cast-in-place piles will be carried out first. After drilling is completed, the holes will be temporarily covered before the pile cap excavation begins. The pile cap will be an embedded type, and no formwork will be used. The pile cap pit will be excavated according to the dimensions. After completion, the pit will be cleaned, and the sealing materials from the cast-in-place pile holes will be removed to prepare for the next step: the construction of the reinforcing cage.

[0067] In areas with pure rock where it is impossible to excavate a platform, the next step is to proceed after setting up the formwork according to the design drawings.

[0068] 2.2 Reinforcement Engineering.

[0069] After the reinforcing cage is fabricated in the processing area, it is transported to the pile location. No ties are allowed in the reinforcing bar binding; the hook portion of the column insert must be bound at a 45° angle to the bottom slab reinforcement, and all connection points must be bound. The reinforcing cage of the cast-in-place pile is then securely bound or welded. After the embedded parts are positioned, they are securely bound to the adjacent reinforcing bars.

[0070] 2.3 Concrete mixing.

[0071] This project uses on-site self-mixed concrete, which will be mixed on-site according to the mix proportions. A mix proportion sign must be placed next to the mixer.

[0072] 2.4 Concrete pouring.

[0073] Concrete pouring should be carried out continuously in layers, with intervals not exceeding the initial setting time of the concrete, generally not exceeding 2 hours. To ensure the correct positioning of the reinforcing bars, a 5-10cm thick layer of concrete should be poured first to fix the reinforcing bars. During concrete pouring, the supports, reinforcing bars, bolts, reserved holes, and pipes should be frequently observed for any movement. If any deformation, movement, or displacement is found, pouring should be stopped immediately, and the formwork should be repaired and reinforced in a timely manner before continuing pouring.

[0074] 2.5 Concrete vibration.

[0075] Use an immersion vibrator, with an insertion spacing no greater than 1.25 times the length of the vibrator's effective section. Insert the upper vibrator rod 3-5 cm into the lower layer. Avoid collisions with embedded parts and bolts to prevent displacement of the embedded parts.

[0076] 2.6 Repositioning of embedded parts.

[0077] During the vibration process, it is necessary to frequently observe whether the position of the embedded parts has shifted. If there is any shift, vibration must be stopped immediately, the position of the embedded parts adjusted, and then vibration resumed.

[0078] 2.7 Concrete leveling.

[0079] After the concrete is poured, any large areas of concrete should be vibrated once with a plate vibrator, then leveled with a screed, and finally smoothed with a wooden trowel. Before finishing, the concrete surface elevation must be checked, and any areas that do not meet the requirements must be rectified immediately.

[0080] 2.8 Concrete curing.

[0081] Concrete that has been poured should be covered and watered approximately 12 hours after pouring. Curing at normal temperature should generally last no less than 7 days, and curing for special concrete should last no less than 14 days. A designated person should oversee and ensure the curing process is completed to prevent surface cracks due to delayed curing.

[0082] Pile foundation pull-out test: The pile foundation pull-out test is conducted according to the requirements of the testing unit.

[0083] 3. Steel structure installation.

[0084] The following steps will be performed sequentially for steel structure installation: Construction of edge support structure: After the steel columns arrive on site, they are assembled and welded a second time as required. Before welding, the galvanized layer at the welding location must be removed with an angle grinder. After welding, the weld slag is removed, the surface is ground, painted, and dried before being transported to the designated storage area. Then, a secondary handling device is used to transport the columns to their corresponding numbered locations and place them properly.

[0085] The embedded parts are welded to the columns. Before welding, the galvanized layer at the welding location and the rust layer on the embedded parts are removed using an angle grinder. The column height and diagonal brace length are adjusted according to the dimensions, and gas cutting is used for machining. After welding, the weld slag is removed, the surface is ground, and painted.

[0086] After installation, the steel beams in the area need to be made into a flat plane, or lower in the south and higher in the north, to prevent obstruction.

[0087] Construction of the central support structure 15: The single-layer cable-stayed flexible scaffolding includes a central column, which is a circular tube that is inserted into the circular tube pile foundation. It is not fixed temporarily before the cable tensioning is completed. The height of the central column is adjusted according to site conditions. After the upper steel strands are leveled, the column is fixed to the foundation steel pipe using through bolts.

[0088] 4. Steel strand construction Component installation cable construction: First, install the component installation cable, 12.7mm in diameter. Based on the span dimensions, cut the steel strands to the required dimensions in the open area, determining the quantity of steel strands; place the steel strands at one end of the column. Use a thin steel wire rope to pull it to another location, pass it through the installation holes in the steel beam, and then attach the specified size and number of springs before installing the single-hole anchor head. After both anchor heads are installed, tension the steel strands, using the design force.

[0089] Fish-belly type steel strand construction: According to the dimensions in the drawings, on an open ground, assemble the steel strands and support frame 223 into a fish-belly system. After tying steel wires to both ends of the crossbeam of support frame 223, lift the entire fish-belly system to the installation positions at both ends of the steel beam using a winch or manual hoist. Pass the ends of the steel strands through the installation holes, attach springs, and then perform tensioning, following the same steps as the previous one. While tensioning, observe the changes in the position of support frame 223; adjust promptly if any displacement occurs. The completed installation is shown in the following figure.

[0090] 5. Secondary tensioning of the steel strand.

[0091] After the overall flexible support structure is completed, secondary tensioning is required to ensure that the prestress of the steel strands reaches the design value. After tensioning, preparations will be made for component installation.

[0092] The construction method for the steel strands of the single-layer cable flexible support is the same as above, and the strands are tensioned to the specified tension according to the design value.

[0093] 6. Component installation.

[0094] The components should be installed sequentially from one end to the other, with the installation sequence chosen based on the project requirements. According to the component layout diagram, use hexagonal bolts and pressure plates 51 to secure the photovoltaic modules 4 to the steel strands.

[0095] When installing components on a fish-belly scaffold, a plank is erected on two adjacent load-bearing cables, and workers can then proceed to the site after the plank is secured.

[0096] If the chord height is too high to allow for construction below, pulleys or hooks can be installed to hang the component installation cable, with wooden boards placed below, allowing workers to sit on the boards and slide to carry out the construction.

[0097] Before working on the components, wooden templates or planks should be laid out, and personnel are strictly prohibited from standing directly on the components.

[0098] Points to note when installing components: When moving components, two people are required to move them; one person is not allowed to move components alone. The handling requirements of the component manufacturer must be followed.

[0099] Standing on the photovoltaic modules is strictly prohibited. If construction is required on the photovoltaic modules, wooden formwork must be laid. The formwork should be at least 10mm thick, and no steel nails or other iron objects are allowed on the formwork. Components should be installed sequentially from one end of the array toward the other and down the slope, or from the middle toward both ends; installation from both ends toward the middle is not permitted.

[0100] In summary, through the synergistic force-bearing of the fish-belly structure and the wind-resistant cable 31 system, it is possible to cross 30-40 meter ravines in mountainous photovoltaic high-wind scenarios without intermediate support. The maximum deflection under a 30-meter span can be controlled within 15 centimeters, significantly reducing the shading rate of the modules and increasing the annual power generation. The cross-array linkage wind-resistant cable 31 system achieves full-domain coordinated force, which greatly reduces the risk of wind-induced vibration and torsion under mountain turbulent wind fields, improves the wind resistance level of the structure, and forms a redundant force structure, which greatly improves the safety redundancy and long-term service durability. The multi-level elevation adjustment design of the fully galvanized triangular lattice column can perfectly adapt to the elevation difference on both sides of the slope of the mountain and the gully with a slope of less than 25°, and the tilt angle control accuracy of the component is greatly improved; the "one in front and two in the back" functional small diameter pile foundation reduces the amount of foundation construction, reduces the damage rate of surface vegetation, and meets the ecological and environmental protection requirements of mountain photovoltaic. The entire process design of factory prefabrication and on-site bolt assembly, combined with the overall prefabrication to improve construction technology, shortens the construction period in mountainous areas and significantly reduces the risks of high-altitude operations; at the same time, it reduces the amount of structural steel and foundation materials used, thereby reducing the overall construction cost of the project and the subsequent maintenance cost. The fully galvanized and corrosion-resistant design, along with the secondary graded tensioning process, can effectively solve the problems of prestress loss and structural deformation caused by cable creep and steel structure corrosion, and the designed service life can reach more than 25 years.

[0101] It can adapt to changes in slope angle, ensuring reasonable component tilt angle (component arrangement follows the slope, without excessively disturbing the ground surface to adapt to changes in slope angle, while the foundation elevation can be adjusted to control component tilt angle to ensure reasonable illumination angle) to improve power generation, optimize node connection structure, facilitate later maintenance and steel strand replacement, reduce damage to surface vegetation, meet ecological and environmental protection requirements, reduce equipment purchase and installation costs, and improve project economics.

[0102] While the specific embodiments of the present invention have been described above, they are not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A fish-belly-shaped flexible photovoltaic support system for installing photovoltaic modules, characterized in that, include: Support system and load-bearing system; The support system includes an edge support structure, which includes a tensile foundation and a compressive foundation. The tensile foundation is located outside the compressive foundation, and a support column is provided on the compressive foundation. The tensile foundation is connected to the support column by a tie rod. The load-bearing system is installed on the support columns at both ends and includes a load-bearing cable and a reinforcing cable. The photovoltaic module is installed on the load-bearing cable. The reinforcing cable has two cables that are arranged crosswise in the vertical direction and are located in the middle of the load-bearing cable in the longitudinal direction.

2. The fish-belly type flexible photovoltaic support system as described in claim 1, characterized in that, The tensile foundation has two parts and the compressive foundation has one part, which are arranged in an isosceles triangle.

3. The fish-belly type flexible photovoltaic support system as described in claim 1, characterized in that, The side support structures are located at both ends of the support system. The support system also includes a middle support structure, which is located in the middle of the two side support structures. The load-bearing cable and the reinforcing cable are both installed on the middle support structure.

4. The fish-belly type flexible photovoltaic support system as described in claim 1, characterized in that, The reinforcing string includes a first string and a second string. In the transverse direction, in some areas the first string is located above the second string, and in some areas the second string is located above the first string.

5. The fish-belly type flexible photovoltaic support system as described in claim 4, characterized in that, The load-bearing chord has two strands, which are arranged in parallel. The two load-bearing chords and the two reinforcing chords are arranged in a T-shape in the longitudinal section.

6. The fish-belly type flexible photovoltaic support system as described in claim 4, characterized in that, The load-bearing system also includes a support frame, the top of which is connected to the photovoltaic module, and the first and second cables are respectively installed at different vertical positions on the support frame.

7. The fish-belly type flexible photovoltaic support system as described in claim 1, characterized in that, It also includes a wind-resistant system, which includes a wind-resistant foundation and wind-resistant cables. The wind-resistant cables are arranged longitudinally and perpendicular to the reinforcing chords. Both ends of the wind-resistant cables are installed on the wind-resistant foundation, and the wind-resistant cables are connected to the load-bearing chords and / or reinforcing chords.

8. The fish-belly type flexible photovoltaic support system as described in claim 6, characterized in that, It also includes a wind-resistant system, which includes a wind-resistant foundation and wind-resistant cables. The wind-resistant cables are arranged longitudinally and perpendicular to the reinforcing chords. Both ends of the wind-resistant cables are installed on the wind-resistant foundation and connected to the support frame.

9. The fish-belly type flexible photovoltaic support system as described in claim 1, characterized in that, The load-bearing cable is connected to the photovoltaic module via an installation kit. The installation kit includes a pressure plate and a pressure plate. The pressure plate is clamped on the load-bearing cable, and the pressure plate is mounted on the pressure plate. The pressure plate has two pieces, and the two pressure plates are respectively pressed onto the structural components of two adjacent photovoltaic modules.

10. A construction method for a fish-belly type flexible photovoltaic support system, characterized in that, include: On the open ground outside the construction site, the load-bearing chords, reinforcing chords, and multiple supports are assembled into a fish-belly cable system according to the design drawings. The reinforcing chords include a first chord and a second chord arranged in a vertical direction. The top of the supports is connected to the load-bearing chords, and the bottom of the supports is connected to the reinforcing chords. The assembled fish-belly cable system is lifted as a whole between the two end support columns of the installed support system; Pass the end of the supporting chord and the end of the reinforcing chord through the mounting holes on the corresponding support column, and install a single-hole anchor head after fitting a spring on each end; The load-bearing and reinforcing cables are tensioned for the first time to bring the cable force to the first preset tension value, thus completing the structural forming. Install photovoltaic modules on the load-bearing cables; The load-bearing and reinforcing cables are tensioned a second time to bring the cable force to the second preset tension value in order to eliminate prestress loss.

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