Slope photovoltaic integrated system based on skeleton protection structure and design method thereof

Abstract

The application provides a slope photovoltaic integrated system based on a skeleton protection structure and a design method thereof, realizes the collaborative unification of slope stability protection and efficient utilization of photovoltaic load, and the system fixes the photovoltaic module at the skeleton node through a pre-embedded part, establishes a complete load transmission path from the photovoltaic module to the skeleton foundation and then to the slope body soil, and forms a slope protection-photovoltaic integrated stress structure; the design method adopts a strength reduction method to reduce the shear strength parameters of the slope body step by step, extracts the vertical displacement of the characteristic node at the top of the slope and draws a displacement-reduction coefficient curve, determines the integrated slope safety factor according to the displacement sudden change point, and respectively establishes control criteria for the horizontal displacement, horizontal strain, Mises equivalent stress and stress of the primary and secondary skeleton foundations in the limit equilibrium state, thereby forming a multi-dimensional collaborative control system.

Description

Technical Field

[0001] This application belongs to the field of road engineering technology and relates to slope photovoltaic integrated systems and their design methods. Background Technology

[0002] With the continuous advancement of highway construction in my country, the number and distribution of embankment slopes are enormous. To prevent slope erosion and localized shallow landslides, arched and rhomboid frameworks have become the main engineering forms for shallow slope protection. However, traditional framework protection structures are only used to bear the slope's own weight and surface soil load, and their structural bearing capacity has not been fully explored and utilized. Highway slopes possess continuous and wide slope resources, providing favorable conditions for large-scale deployment of photovoltaic modules. The integrated development model of slope protection and photovoltaics is gradually attracting widespread attention from academia and the engineering community. Developing an integrated system that balances slope stability protection and efficient utilization of clean energy has significant practical significance and application value.

[0003] However, existing technologies for integrating photovoltaic (PV) power generation modules into slope protection structures have the following prominent problems: 1. Unclear PV load transfer path: Existing solutions typically involve directly erecting PV supports on the slope surface without systematically studying how the load from PV modules is safely transferred to the foundation and further diffused into the slope under complex conditions such as wind load, snow load, and temperature changes. The load transfer mechanism lacks clear evidence. 2. Insufficient assessment of the overall slope stability impact: Existing research neglects the influence of PV additional loads on slope displacement, horizontal strain, and stress distribution, failing to determine whether the integrated structure alters the original slope stability. The stress and deformation patterns of slopes pose potential engineering risks that could lead to slope instability; third, the lack of evaluation methods for the safety factor of integrated structures: existing technologies lack systematic design and quantitative evaluation methods for integrated slope protection and photovoltaic structures, making it difficult to quantitatively assess the improvement effect of integrated structures on slope safety factor, resulting in insufficient design basis; fourth, unclear control indicators for graded skeleton foundations: there are significant differences in the load and stress distribution of the skeleton foundations of first-level and second-level slopes, but existing design methods lack clear provisions for the stress control standards of skeleton foundations of different slope levels, resulting in a lack of basis in engineering design and making it difficult to ensure the structural safety of graded skeleton foundations. Summary of the Invention

[0004] To address the issues raised in the background art regarding the unclear photovoltaic load transfer path, insufficient assessment of the overall slope stability impact, lack of evaluation methods for the safety factor of integrated structures, and unclear control indicators for graded frame foundations when photovoltaic power generation modules are integrated into slope protection structures, this application provides a slope photovoltaic integrated system based on a frame protection structure and its design method. This system does not alter the original overall distribution of displacement, strain, and stress of the slope, and the engineering modification has minimal impact on the original slope's mechanical behavior. It ensures the overall stability of the slope while effectively utilizing the frame protection structure to bear the photovoltaic load, achieving a unified approach to structural safety, deformation control, and stress optimization. It exhibits excellent structural compatibility and engineering adaptability.

[0005] The first aspect of this application provides a slope photovoltaic integrated system based on a skeleton protection structure, including a secondary slope of a fill roadbed, a skeleton protection structure, photovoltaic modules, and embedded parts; the skeleton protection structure covers the slope surface of the secondary slope of the fill roadbed; the embedded parts are pre-embedded at the node positions of the skeleton protection structure; the photovoltaic modules are fixed to the skeleton nodes through the embedded parts, forming a slope protection-photovoltaic integrated load-bearing structure; the external forces on the photovoltaic modules are transmitted to the skeleton foundation through the skeleton nodes and further diffused into the internal soil of the secondary slope of the fill roadbed.

[0006] Furthermore, the slope height of the secondary slope of the embankment is 16 m, the slope ratio of the primary slope is 1:1.5, the slope ratio of the secondary slope is 1:1.75, and the width of the graded platform is 2 m.

[0007] Furthermore, the frame protection structure adopts one or a combination of two of the following forms: arched frame or rhomboid frame, and the concrete strength grade is not lower than C30.

[0008] Furthermore, the embedded parts are made of galvanized steel, and the photovoltaic modules are fixed to the frame nodes at intervals of 3 m × 3 m; the photovoltaic modules are monocrystalline silicon photovoltaic panels with a single rated power of not less than 550 W.

[0009] Furthermore, under limit equilibrium conditions, the slope protection-photovoltaic integrated load-bearing structure has a slope safety factor of not less than 1.396; the maximum horizontal displacement does not exceed 0.13 m, and the magnitude of the horizontal displacement does not exceed 10 m. -2 m; maximum tensile strain not exceeding +1.44×10 -2 The absolute value of the maximum compressive strain does not exceed 1.90 × 10⁻⁶. -2 The maximum Mises equivalent stress on the slope does not exceed 1.38 × 10⁻⁶. 5 Pa.

[0010] The second aspect of this application provides a design method for the above-mentioned system, comprising the following steps: Step 1: Establish a numerical model. Use finite element software to establish a three-dimensional simulation model of the secondary slope of the fill roadbed. Input the physical and mechanical parameters of the soil, boundary conditions and initial stress field, simulate the connection method of the skeleton protection structure, photovoltaic modules and embedded parts, and define the contact conditions and load transfer path between the skeleton protection structure and the slope. Step 2: Using the strength reduction method, the shear strength parameters of the slope are reduced step by step, the vertical displacement of the characteristic nodes in the middle of the slope top is extracted, and the displacement-reduction coefficient curve is plotted. The reduction coefficient corresponding to the obvious abrupt change in the curve is used as the slope safety factor of the slope protection-photovoltaic integrated stress structure. Step 3: Extract the horizontal displacement contour map under the limit equilibrium state, and control the maximum horizontal displacement and its magnitude; Step 4: Extract the horizontal strain contour map under the limit equilibrium state, and control the maximum tensile strain and maximum compressive strain respectively; Step 5: Extract the Mises equivalent stress cloud map under the limit equilibrium state, and control the maximum Mises stress and the range of high stress region; Step 6: Extract the top reaction force cloud diagrams of the primary and secondary frame foundations respectively, and control the maximum Mises stress and stress concentration areas of the two frame foundations respectively.

[0011] Furthermore, in step one, the finite element software is ABAQUS; the slope soil constitutive model adopts the Mohr-Coulomb elastoplastic model, the element type is C3D8R three-dimensional stress analysis element, and the maximum mesh size is 0.3 m; the skeleton foundation adopts the linear elastic constitutive model, the element type is C3D8R three-dimensional stress analysis element, and the maximum mesh size is 0.085 m; the photovoltaic support adopts B31 two-node spatial linear beam element, and the maximum mesh size is 0.2 m; the photovoltaic panel adopts S4R four-node curved thin shell element, and the maximum mesh size is 0.2 m.

[0012] Furthermore, in step two, the initial value of the reduction coefficient of the strength reduction method is 1.0, the reduction step size is 0.02, and it is gradually increased until the vertical displacement of the characteristic node at the top of the slope changes abruptly; the safety factor of the slope protection-photovoltaic integrated load-bearing structure is not less than 1.30.

[0013] Furthermore, in step three, the maximum horizontal displacement under the limit equilibrium state does not exceed 0.13 m, and the magnitude of the horizontal displacement does not exceed 10. -2 The displacement distribution pattern shows that it is largest at the toe of the slope and decreases towards the inward direction; in step four, the maximum tensile strain does not exceed +1.44×10 m. -2 The maximum compressive strain is not less than -1.90×10 -2 The dependent variable level is 10 -2 Up to 10 -3The range shows a distribution pattern of concentrated tensile strain at the top of the slope and concentrated compressive strain at the toe; in step five, the maximum Mises equivalent stress does not exceed 1.38 × 10⁻⁶. 5 Pa, the high-stress area must not extend to the top of the slope or the graded platform area, and the stress distribution pattern is that it is high at the foot of the slope and low at the top of the slope.

[0014] Furthermore, in step six, the maximum Mises stress at the top of the primary frame foundation shall not exceed 5.40 × 10⁻⁶. 6 The stress is Pa, and the stress is evenly distributed along the foundation; the maximum Mises stress at the top of the secondary frame foundation does not exceed 6.04 × 10⁻⁶ Pa. 6 Pa, and the stress concentration area shall not extend to the edge of the foundation; when the stress of the primary or secondary skeleton foundation exceeds the above control index, the skeleton cross-sectional dimensions, node spacing or embedded part connection stiffness shall be adjusted until the control requirements are met.

[0015] Compared with the prior art, this application has the following advantages: (1) Constructing a slope protection-photovoltaic integrated stress structure with a clear and controllable load transfer path: By fixing the photovoltaic modules to the skeleton nodes through pre-embedded parts, a complete load transfer path of "photovoltaic modules → skeleton nodes → skeleton foundation → slope soil" is established, so that the external forces such as wind load, snow load and temperature load on the photovoltaic modules can be transferred and diffused into the interior of the slope in an orderly manner, which solves the problem of unclear photovoltaic load transfer path in the existing technology; (2) Significantly improved overall slope stability: The integrated stress-bearing structure formed by the frame and photovoltaic modules works together to constrain slope deformation and improve the stress distribution within the slope. Compared with the original slope without photovoltaic system, the safety factor of the integrated structure slope is significantly improved, and the overall slope stability is significantly improved; (3) Provide a safety factor quantitative evaluation method based on displacement mutation criterion: The shear strength parameters of the slope are reduced step by step by the strength reduction method, the vertical displacement of the characteristic nodes at the top of the slope is extracted and the displacement-reduction coefficient curve is plotted. The reduction coefficient when the curve shows obvious mutation is used as the safety factor of the integrated slope. This provides an objective and systematic safety evaluation method for the slope protection-photovoltaic integrated structure, filling the gap in the existing technology for safety factor evaluation methods of this type of structure. (4) Achieve multi-dimensional integrated control of displacement, strain and stress: Establish control criteria for horizontal displacement, horizontal strain and Mises equivalent stress respectively, form a multi-dimensional collaborative control system, and ensure that the deformation and stress state of the integrated structure under the limit equilibrium state are within the controllable range, systematically solving the problem of lack of overall stability assessment methods in the existing technology; (5) Establish a differentiated stress control system for graded skeleton foundations: extract top reaction cloud maps for primary and secondary skeleton foundations respectively, and control the Mises stress and stress concentration areas of each grade skeleton foundation respectively, clarifying the differentiated stress law of skeleton foundations of different slope levels, and providing a clear quantitative basis for the engineering design of graded skeleton foundations.

[0016] In summary, the slope photovoltaic integrated system of this invention fixes photovoltaic modules to the frame nodes through pre-embedded parts, establishing a complete load transfer path from the photovoltaic modules to the frame foundation and then to the slope soil, forming an integrated slope protection-photovoltaic stress structure. Its design method employs a strength reduction method to progressively reduce the slope's shear strength parameters, extracts the vertical displacement of characteristic nodes at the slope top, and plots a displacement-reduction coefficient curve. The safety factor of the integrated slope is determined by the displacement abrupt change point. Control criteria are established for horizontal displacement, horizontal strain, Mises equivalent stress, and the stress on the primary and secondary frame foundations under the limit equilibrium state, forming a multi-dimensional collaborative control system. Using this invention, the safety factor can be significantly improved, slope deformation and stress state are significantly improved, the stress on the graded frame foundations is clearly controllable, and the overall slope stability is significantly enhanced, achieving a synergistic unity between slope stability protection and efficient utilization of photovoltaic loads. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a photovoltaic integrated system for highway slopes based on a frame protection structure.

[0019] Figure 2 The curve shows the displacement-reduction coefficient of the slope top node under the action of the photovoltaic system in Example 1.

[0020] Figure 3 This is a cloud map of the plastic penetration zone of the slope under the action of the photovoltaic system in Example 1.

[0021] Figure 4 This is a cloud diagram of the horizontal displacement of the slope at the limit equilibrium under the action of the photovoltaic system in Example 1.

[0022] Figure 5 This is a horizontal strain cloud diagram of the slope under the ultimate equilibrium of the photovoltaic system in Example 1.

[0023] Figure 6 This is the Mises stress cloud diagram of the slope under the action of the photovoltaic system in Example 1 when it reaches ultimate equilibrium.

[0024] Figure 7 This is a cloud diagram of the top reaction force of the secondary skeleton foundation in Example 1.

[0025] Figure 8 This is a cloud diagram of the top reaction force of the primary skeleton foundation in Example 1. Detailed Implementation

[0026] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0027] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0028] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, 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 limitations on this application.

[0029] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0030] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0031] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0032] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0033] like Figure 1 As shown in the embodiment of this application, a slope photovoltaic integrated system based on a skeleton protection structure is provided, including a secondary slope of the fill roadbed, a skeleton protection structure, photovoltaic modules and embedded parts.

[0034] Specifically, the skeleton protection structure covers the slope surface of the secondary slope of the embankment; embedded parts are pre-embedded at the node positions of the skeleton protection structure; photovoltaic modules are fixed to the skeleton nodes through the embedded parts, forming an integrated slope protection-photovoltaic load-bearing structure. External forces such as wind load, snow load, and temperature load on the photovoltaic modules are transmitted to the skeleton foundation through the skeleton nodes and further diffused into the internal soil of the secondary slope of the embankment.

[0035] In one embodiment, the slope height of the secondary slope of the embankment is 16 m, the primary slope ratio is 1:1.5, the secondary slope ratio is 1:1.75, and the width of the graded platform is 2 m.

[0036] In one embodiment, the skeleton protection structure adopts one or a combination of two of the arched skeleton or rhomboid skeleton, and the concrete strength grade is not lower than C30.

[0037] In one embodiment, the embedded parts are made of galvanized steel, and the photovoltaic modules are fixed at the nodes of the frame with a node spacing of 3 m × 3 m; the photovoltaic modules are monocrystalline silicon photovoltaic panels with a single rated power of not less than 550 W.

[0038] In one embodiment, under limit equilibrium conditions, the slope protection-photovoltaic integrated load-bearing structure has a slope safety factor of not less than 1.396; the maximum horizontal displacement does not exceed 0.13 m, and the magnitude of the horizontal displacement does not exceed 10. -2 m; maximum tensile strain not exceeding +1.44×10 -2 The absolute value of the maximum compressive strain does not exceed 1.90 × 10⁻⁶. -2 The maximum Mises equivalent stress on the slope does not exceed 1.38 × 10⁻⁶. 5 Pa.

[0039] This application provides a design method for the above system, and the specific steps are as follows.

[0040] Step 1: Establish a numerical model. Use finite element software to establish a three-dimensional simulation model of the secondary slope of the fill roadbed. Input the physical and mechanical parameters of the soil, boundary conditions and initial stress field, simulate the connection method of the skeleton protection structure, photovoltaic modules and embedded parts, and define the contact conditions and load transfer path between the skeleton protection structure and the slope.

[0041] In one embodiment, the finite element software is ABAQUS; the slope soil constitutive model adopts the Mohr-Coulomb elastoplastic model, the element type is C3D8R three-dimensional stress analysis element, and the maximum mesh size is 0.3 m; the skeleton foundation adopts the linear elastic constitutive model, the element type is C3D8R three-dimensional stress analysis element, and the maximum mesh size is 0.085 m; the photovoltaic support adopts B31 two-node spatial linear beam element, and the maximum mesh size is 0.2 m; the photovoltaic panel adopts S4R four-node curved thin shell element, and the maximum mesh size is 0.2 m.

[0042] Step 2: Using the strength reduction method, the shear strength parameters of the slope are reduced step by step, the vertical displacement of the characteristic nodes in the middle of the slope top is extracted, and the displacement-reduction coefficient curve is plotted. The reduction coefficient corresponding to the obvious abrupt change in the curve is used as the slope safety factor of the slope protection-photovoltaic integrated stress structure.

[0043] In one embodiment, the initial value of the reduction coefficient of the strength reduction method is 1.0, the reduction step size is 0.02, and it is gradually increased until the vertical displacement of the characteristic node at the top of the slope changes abruptly; the safety factor of the slope protection-photovoltaic integrated load-bearing structure is not less than 1.30.

[0044] Step 3: Extract the horizontal displacement cloud map under the limit equilibrium state, and control the maximum horizontal displacement and its magnitude.

[0045] In one embodiment, the maximum horizontal displacement under the limiting equilibrium state does not exceed 0.13 m, and the magnitude of the horizontal displacement does not exceed 10. -2 The displacement is m, and the displacement distribution pattern shows that it is largest at the toe of the slope and decreases towards the inside of the slope.

[0046] Step 4: Extract the horizontal strain contour map under the limit equilibrium state, and control the maximum tensile strain and maximum compressive strain respectively.

[0047] In one embodiment, the maximum tensile strain does not exceed +1.44 × 10⁻⁶. -2 The maximum compressive strain is not less than -1.90×10 -2 The dependent variable level is 10 -2 Up to 10 -3The range shows that the tensile strain is concentrated at the top of the slope and the compressive strain is concentrated at the toe of the slope.

[0048] Step 5: Extract the Mises equivalent stress cloud map under the limit equilibrium state, and control the maximum Mises stress and the range of high stress areas.

[0049] In one embodiment, the maximum Mises equivalent stress does not exceed 1.38 × 10⁻⁶. 5 Pa, the high-stress area must not extend to the top of the slope or the graded platform area, and the stress distribution pattern is that it is high at the foot of the slope and low at the top of the slope.

[0050] Step 6: Extract the top reaction force cloud diagrams of the primary and secondary frame foundations respectively, and control the maximum Mises stress and stress concentration areas of the two frame foundations respectively.

[0051] In one embodiment, the maximum Mises stress at the top of the primary frame foundation does not exceed 5.40 × 10⁻⁶. 6 The stress is Pa, and the stress is evenly distributed along the foundation; the maximum Mises stress at the top of the secondary frame foundation does not exceed 6.04 × 10⁻⁶ Pa. 6 Pa, and the stress concentration area shall not extend to the edge of the foundation; when the stress of the primary or secondary skeleton foundation exceeds the above control index, the skeleton cross-sectional dimensions, node spacing or embedded part connection stiffness shall be adjusted until the control requirements are met.

[0052] Example 1 The slope photovoltaic integrated system described in this application was implemented on the embankment slope of a highway section from K45+320 to K45+680.

[0053] Slope parameters: slope height 16 m, first-level slope ratio 1:1.5, second-level slope ratio 1:1.75, grading platform width: 2 m.

[0054] Frame protection structure: arched frame or diamond frame combination, concrete strength grade C30.

[0055] Photovoltaic modules: monocrystalline silicon photovoltaic panels, each with a power of 550W, fixed to the frame nodes by pre-embedded galvanized steel parts, with a node spacing of 3 m × 3 m.

[0056] The design steps are as follows: The first step is to establish a three-dimensional finite element simulation model using ABAQUS. The constitutive model of the slope soil adopts the Mohr-Coulomb plastic model and the linear elastic constitutive model, and the element type adopts the C3D8R three-dimensional stress analysis element, with a maximum allowable mesh size of 0.3m. The pile foundation adopts the linear elastic model, the meshing strategy is the neutral axis algorithm, and the C3D8R three-dimensional stress analysis element is used, with a maximum allowable mesh size of 0.085m. The photovoltaic support adopts the B31 two-node spatial linear beam element, with a maximum allowable mesh size of 0.2m. The photovoltaic panel adopts the S4R four-node curved surface thin shell or thick shell, with a maximum allowable mesh size of 0.2m.

[0057] Step 2: Define soil parameters: cohesion c = 28 kPa, internal friction angle φ = 22∘, elastic modulus E = 25 MPa.

[0058] The third step is to use the strength reduction method to reduce the strength step by step, starting with a reduction coefficient of 1.0 and a step size of 0.02.

[0059] Step 4: Extract the vertical displacement of the mid-slope crest node and plot the displacement-reduction coefficient curve; the displacement-reduction coefficient curve of the slope crest node under the photovoltaic system is shown below. Figure 2 As shown, the horizontal axis represents the strength reduction factor, and the vertical axis represents the vertical displacement (m) at the top of the slope. By observing the curve characteristics, a significant displacement abrupt change occurs at the reduction factor of 1.396, thus determining the safety factor to be 1.396, which meets the requirement that the safety factor of the slope protection-photovoltaic integrated load-bearing structure is not less than 1.30.

[0060] Step 5: Verify horizontal displacement: Cloud map of the plastic penetration zone of the slope under the action of the photovoltaic system, as shown in the figure. Figure 3 As shown, the slope exhibits a circular plastic zone extending from the toe to the crest; the horizontal displacement contour map of the slope at its ultimate equilibrium under the action of the photovoltaic system is shown below. Figure 4 As shown, the maximum horizontal displacement is approximately 0.119 m, located at the toe of the slope, and the maximum horizontal displacement is 0.123 m ≤ 0.13 m.

[0061] Step 6: Strain Verification: The horizontal strain contour plot of the slope at its ultimate equilibrium under the action of the photovoltaic system is shown below. Figure 5 As shown in the figure, the slope crest is the region of concentrated tensile strain, and the slope toe is the region of concentrated compressive strain. The maximum tensile strain is 1.38 × 10⁻², and the maximum compressive strain is -1.85 × 10⁻². -2 The requirement is met: the maximum tensile strain does not exceed +1.44 × 10⁻⁶. -2 The maximum compressive strain is not less than -1.90×10 -2 .

[0062] Step 7: Verify Mises stress: The Mises stress contour diagram of the slope at limit equilibrium under the action of the photovoltaic system is shown below. Figure 6As shown in the figure, the maximum stress is 1.35 × 10⁻⁶. 5 Pa is concentrated in the lower part of the slope. The requirement is met: the maximum Mises equivalent stress does not exceed 1.38 × 10⁻⁶. 5 Pa Step 9: Verify the foundation framework: The reaction force cloud diagram at the top of the secondary foundation framework is shown below. Figure 7 As shown, the top reaction force cloud diagram of the primary skeleton foundation is as follows: Figure 8 As shown, the maximum stress of the secondary skeleton is 5.98 × 10⁻⁶. 6 Pa, the maximum stress of the first-level skeleton is 5.33 × 10⁻⁶. 6 Pa. The requirement is met: the maximum Mises stress at the top of the primary frame foundation does not exceed 5.40 × 10⁻⁶. 6 Pa, the maximum Mises stress at the top of the secondary frame foundation shall not exceed 6.04 × 10 Pa. 6 Pa.

[0063] All indicators meet the design requirements of this application, with no slope instability, frame cracking, or photovoltaic module detachment.

[0064] For the embankment slope of this application, the comparison table of various evaluation indicators of directly erecting photovoltaic supports on the slope surface and using the slope photovoltaic integrated system described in Embodiment 1 of this application is shown in Table 1.

[0065] Table 1 Comparison of Evaluation Indicators Table 1 shows that compared with directly erecting photovoltaic supports on the slope surface, the slope photovoltaic integrated system described in Embodiment 1 of this application increases the safety factor from 1.147 to 1.396, and reduces the horizontal displacement by 10. 0 Reduced to 10 -2 m, the peak strain was reduced by 98%, significantly improving slope stability and structural synergy.

[0066] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A slope photovoltaic integrated system based on a frame protection structure, characterized in that: The system includes a secondary slope of the earth-filled roadbed, a frame protection structure, photovoltaic modules, and embedded parts. The frame protection structure covers the slope surface of the secondary slope of the earth-filled roadbed. The embedded parts are pre-embedded at the node positions of the frame protection structure. The photovoltaic modules are fixed to the frame nodes through the embedded parts, forming an integrated slope protection-photovoltaic load-bearing structure. The external forces on the photovoltaic modules are transmitted to the frame foundation through the frame nodes and further diffused into the internal soil of the secondary slope of the earth-filled roadbed.

2. The system according to claim 1, characterized in that: The secondary slope of the embankment has a height of 16 m, a primary slope ratio of 1:1.5, a secondary slope ratio of 1:1.75, and a grading platform width of 2 m.

3. The system according to claim 1, characterized in that: The frame protection structure adopts one or a combination of two of the following forms: arched frame or rhomboid frame, and the concrete strength grade is not lower than C30.

4. The system according to claim 1, characterized in that: The embedded parts are made of galvanized steel, and the photovoltaic modules are fixed at the nodes of the frame with a node spacing of 3 m × 3 m; the photovoltaic modules are monocrystalline silicon photovoltaic panels with a single rated power of not less than 550 W.

5. The system according to claim 1, characterized in that: Under extreme equilibrium conditions, the slope protection-photovoltaic integrated load-bearing structure has a slope safety factor of not less than 1.396; the maximum horizontal displacement does not exceed 0.13 m, and the magnitude of the horizontal displacement does not exceed 10. -2 m; maximum tensile strain not exceeding +1.44×10 -2 The absolute value of the maximum compressive strain does not exceed 1.90 × 10⁻⁶. -2 The maximum Mises equivalent stress on the slope does not exceed 1.38 × 10⁻⁶. 5 Pa.

6. A design method based on the system according to any one of claims 1 to 5, characterized in that, Includes the following steps: Step 1: Establish a numerical model. Use finite element software to establish a three-dimensional simulation model of the secondary slope of the fill roadbed. Input the physical and mechanical parameters of the soil, boundary conditions and initial stress field, simulate the connection method of the skeleton protection structure, photovoltaic modules and embedded parts, and define the contact conditions and load transfer path between the skeleton protection structure and the slope. Step 2: Using the strength reduction method, the shear strength parameters of the slope are reduced step by step, the vertical displacement of the characteristic nodes in the middle of the slope top is extracted, and the displacement-reduction coefficient curve is plotted. The reduction coefficient corresponding to the obvious abrupt change in the curve is used as the slope safety factor of the slope protection-photovoltaic integrated stress structure. Step 3: Extract the horizontal displacement contour map under the limit equilibrium state, and control the maximum horizontal displacement and its magnitude; Step 4: Extract the horizontal strain contour map under the limit equilibrium state, and control the maximum tensile strain and maximum compressive strain respectively; Step 5: Extract the Mises equivalent stress cloud map under the limit equilibrium state, and control the maximum Mises stress and the range of high stress region; Step 6: Extract the top reaction force cloud diagrams of the primary and secondary frame foundations respectively, and control the maximum Mises stress and stress concentration areas of the two frame foundations respectively.

7. The method according to claim 6, characterized in that: In step one, the finite element software is ABAQUS; the slope soil constitutive model adopts the Mohr-Coulomb elastoplastic model, the element type adopts the C3D8R three-dimensional stress analysis element, and the maximum mesh size is 0.3 m; The skeleton foundation adopts a linear elastic constitutive model, and the element type is C3D8R three-dimensional stress analysis element with a maximum mesh size of 0.085 m; The photovoltaic support structure uses B31 two-node spatial linear beam elements with a maximum mesh size of 0.2m; the photovoltaic panels use S4R four-node curved thin-shell elements with a maximum mesh size of 0.2m.

8. The method according to claim 6, characterized in that: In step two, the initial value of the reduction coefficient of the strength reduction method is 1.0, the reduction step size is 0.02, and it is gradually increased until the vertical displacement of the characteristic node at the top of the slope changes abruptly; the safety factor of the slope protection-photovoltaic integrated load-bearing structure is not less than 1.

30.

9. The method according to claim 6, characterized in that: In step three, under the limit equilibrium state, the maximum horizontal displacement does not exceed 0.13 m, and the magnitude of the horizontal displacement does not exceed 10. -2 The displacement distribution pattern shows that it is largest at the toe of the slope and decreases towards the inward direction; in step four, the maximum tensile strain does not exceed +1.44×10 m. -2 The maximum compressive strain is not less than -1.90×10 -2 The dependent variable level is 10 -2 Up to 10 -3 The range shows a distribution pattern of concentrated tensile strain at the top of the slope and concentrated compressive strain at the toe; in step five, the maximum Mises equivalent stress does not exceed 1.38 × 10⁻⁶. 5 Pa, the high-stress area must not extend to the top of the slope or the graded platform area, and the stress distribution pattern is that it is high at the foot of the slope and low at the top of the slope.

10. The method according to claim 6, characterized in that: In step six, the maximum Mises stress at the top of the primary frame foundation shall not exceed 5.40 × 10⁻⁶. 6 The stress is Pa, and the stress is evenly distributed along the foundation; the maximum Mises stress at the top of the secondary frame foundation does not exceed 6.04 × 10⁻⁶ Pa. 6 Pa, and the stress concentration area shall not extend to the edge of the foundation; when the stress of the primary or secondary skeleton foundation exceeds the above control index, the skeleton cross-sectional dimensions, node spacing or embedded part connection stiffness shall be adjusted until the control requirements are met.

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