Flexible foundation photovoltaic support structure design method suitable for goaf

Abstract

The invention discloses a flexible foundation photovoltaic support structure design method suitable for a goaf, and particularly relates to the technical field of photovoltaic support structure design optimization. Aiming at the problems of complex geological conditions and uneven ground surface settlement of the goaf, the method comprises the following steps: obtaining settlement gradient distribution and foundation bearing capacity distribution, constructing a settlement response unit and an initial structure model, carrying out finite element simulation analysis, extracting displacement characteristic quantity and a stress state of a connection node, and establishing a response adaptability index system. And constructing an objective function based on the adjustable parameter set, iteratively updating parameters through a particle swarm optimization algorithm, and finally generating an optimal structure design scheme. According to the method, the dynamic adaptation of the structural parameters and the geological response is realized, the adaptability and the stability of the photovoltaic bracket in the non-uniform settlement area are improved, and the method has good engineering implementability.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic support structure design optimization technology, specifically to a flexible foundation photovoltaic support structure design method applicable to mining subsidence areas. Background Technology

[0002] Currently, with the advancement of the "dual-carbon" strategy and the increasing prominence of land resource scarcity, land in mining subsidence areas is gradually being developed and utilized for photovoltaic power station construction due to its vast area. However, as underground voids left after coal or mineral resource extraction, mining subsidence areas have typical problems such as uneven surface subsidence, foundation disturbance, and poor structural stability, leading to numerous challenges for traditional rigid photovoltaic supports in practical applications.

[0003] Specifically, traditional photovoltaic (PV) support structures often use rigid foundations (such as independent concrete foundations or pile foundations) directly anchored to the ground surface. This makes them unable to effectively absorb and adapt to geological deformations such as slow or sudden settlement and horizontal displacement caused by mining subsidence. This can easily lead to warping, tilting, or even complete collapse of the support structure, severely impacting the power generation efficiency and lifespan of the PV array. Especially when there is "nonlinear uneven settlement" (i.e., different support foundations experience settlement displacement of varying amplitude and direction per unit time), the overall structure struggles to respond in a coordinated manner, becoming a common cause of support failure.

[0004] Furthermore, due to the complexity of the geological structure of goaf areas and the significant differences in settlement mechanisms across different regions, there is currently a lack of a design method that possesses structural flexibility, can dynamically respond to settlement, and can be optimized by adjusting parameters according to different goaf conditions. Existing technologies often rely on empirical formulas for pre-setting, lacking data-driven analysis and feedback optimization mechanisms, and cannot collaboratively design the relationship between foundation form, connection structures, and geological settlement parameters from a system perspective.

[0005] Therefore, how to propose a design method based on geological settlement response parameters for analysis and modeling, and combined with flexible connection and structural adjustment mechanisms to achieve intelligent optimization of support foundation design parameters has become a key technical problem that urgently needs to be solved. Summary of the Invention

[0006] The purpose of this invention is to provide a design method for a flexible foundation photovoltaic support structure suitable for mining subsidence areas, so as to overcome the shortcomings of the prior art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a design method for a flexible foundation photovoltaic support structure suitable for goaf areas, comprising: S100: Obtain geological parameter information of the target goaf, including settlement gradient distribution and foundation bearing capacity distribution; S200: Based on the obtained settlement gradient distribution and foundation bearing capacity distribution, establish the initial design model of the flexible foundation photovoltaic support structure in the goaf area; S300: Perform finite element simulation calculations on the initial design model to simulate the structural response under preset settlement loads, wind loads, and snow loads, and obtain the displacement characteristic quantity V of key parts of the structure and the stress state M of the connection nodes. S400: Based on the displacement characteristic quantity V and the stress state of the connection node M, a response and adaptability index system W for flexible foundation structures is constructed. S500: Conduct correlation analysis between the response adaptability index system W and the set of structural adjustable parameters P to establish the objective function F; S600: An iterative optimization algorithm is used to update the set of adjustable structural parameters P to obtain the optimal set of flexible foundation design parameters. To maximize the objective function F; S700: Based on A final flexible foundation photovoltaic support structure design scheme suitable for the geological conditions of the goaf area is generated for actual construction deployment.

[0008] Preferably, the set of adjustable structural parameters P includes the height difference adjustment range of the support, the stiffness coefficient of the flexible node, and the foundation spacing.

[0009] Preferably, the initial design model for establishing a flexible foundation photovoltaic support structure in the goaf includes the following steps: S201, based on the settlement gradient distribution, divide the goaf into several settlement response units, and determine the corresponding allowable foundation displacement range for each settlement response unit. S202, Based on the distribution of foundation bearing capacity corresponding to each settlement response unit, determine the arrangement spacing and foundation bearing parameters of the flexible foundation, and use the foundation bearing parameters as the boundary constraint conditions of the initial design model; S203, under the boundary constraints, construct a three-dimensional structural model including flexible columns, flexible connection nodes and basic contact surfaces; S204. The three-dimensional structural model is associated with the spatial positional relationship of each settlement response unit to form an initial design model.

[0010] Preferably, the finite element simulation calculation of the initial design model includes the following steps: S301, Import the initial design model into the finite element analysis platform, and set the nonlinear foundation spring element according to the geological parameters of each settlement response unit to simulate the foundation contact boundary conditions; S302, apply a combination of multiple load conditions including uneven settlement load, regional wind load and equivalent snow load, and solve the initial design model using static loading method; S303, record the vertical and lateral displacements of the top of each flexible column in the initial design model, calculate the displacement characteristic quantity V of the key parts of the structure, and determine whether it exceeds the preset displacement tolerance. S304, extract the internal force response of each flexible connection node under the maximum deformation condition, and generate the force state M of the connection node.

[0011] Preferably, the response adaptability index system W for constructing a flexible infrastructure includes the following steps: S401, statistical normalization is performed on the displacement characteristics of key parts of the structure, and the maximum displacement difference, average displacement and standard deviation are extracted as deformation indicators. S402, the stress amplitude is normalized for the stress state of all flexible connection nodes, and the maximum bending moment, maximum shear force and maximum axial force are extracted as connection strength indicators; S403, Based on the extracted connection strength index, construct a two-dimensional response adaptability index vector containing deformation index and connection strength index; S404, compare the two-dimensional response adaptability index vector with the structural safety threshold, and denote it as the response adaptability index system W.

[0012] Preferably, the correlation analysis between the response adaptability index system W and the set of structural adjustable parameters P includes the following steps: S501, set the set of adjustable structural parameters P, including the adjustment range of the height difference of the support, the stiffness coefficient of the flexible connection node and the arrangement spacing of the flexible foundation, denoted as P1, P2 and P3 respectively. S502, based on the structural finite element simulation results, constructs the functional mapping relationship between P1, P2, P3 and each index component in the response adaptability index system; S503 uses the weighted sum of squares of the differences between each indicator and its corresponding safety threshold as the expression for the objective function F.

[0013] Preferably, updating the set of adjustable structural parameters P using an iterative optimization algorithm includes the following steps: S601, Select the initial set of adjustable structural parameters P and substitute it into the objective function F to calculate the adaptive performance; S602, Based on the particle swarm optimization algorithm, the parameters of P are perturbed to generate a set of candidate solutions, and the objective function value corresponding to each candidate solution is calculated; S603 selects the optimal parameter solution based on the principle of minimum objective function value, and iteratively generates a new round of candidate parameters based on the parameter set; S604, when the objective function value converges to the range of a preset threshold during continuous iteration, the current parameter set is determined as the optimal flexible foundation structure design parameter set P*.

[0014] The technical effects and advantages provided by the present invention in the above technical solution are as follows: 1. This invention overcomes the technical bottlenecks of traditional photovoltaic support structures in goaf geological conditions, such as poor adaptability to uneven settlement, excessive connection rigidity, and easy structural instability, by introducing geological zoning modeling, response feature extraction, and parametric design optimization. By establishing a settlement response unit and a spatial model of foundation bearing capacity, the invention achieves coupled design of flexible foundation support structures with complex geological data, providing a precise parameter basis for subsequent structural simulation and performance optimization, and effectively improving the adaptability and scientific design of photovoltaic supports in goaf environments.

[0015] 2. This invention constructs a response adaptability index system and objective function, and uses a particle swarm optimization algorithm to iteratively update the adjustable parameters of the structure in multiple rounds to obtain the optimal set of flexible foundation design parameters. This further improves the overall stability and operational reliability of the structure under the combined effects of settlement, wind load, and snow load. This method not only possesses high repeatability and scalability, but can also be flexibly adjusted according to different geological conditions in goaf areas, enabling engineering-level customized design of flexible photovoltaic support structures, and has significant engineering application value. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0017] Figure 1 This is a flowchart of the method of the present invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] For examples, please refer to Figure 1 As shown in this embodiment, a flexible foundation photovoltaic support structure design method suitable for goaf areas includes: S100: Obtain geological parameter information of the target goaf, including the distribution of settlement gradient and foundation bearing capacity.

[0020] In the flexible foundation photovoltaic support structure design method applicable to goaf areas described in this invention, step S100 is first executed, which involves obtaining geological parameter information of the target goaf area, mainly including the settlement gradient distribution and the foundation bearing capacity distribution. This step provides basic data support for subsequent structural model construction and response analysis, and its specific implementation is as follows: First, select several representative monitoring points on the surface of the target mined-out area for on-site drilling and geological exploration. The following basic data need to be obtained from each monitoring point: Soil type and depth; soil compression modulus (in megapascals); vertical settlement rate of the ground surface (in millimeters per year); standard value of bearing capacity of the foundation (in kilopascals); location and depth of cavities (in meters); depth of groundwater level (in meters).

[0021] The spacing between each measuring point should be set according to the scale of the goaf and the geological differences, usually between 20 and 50 meters. Data from all exploration points are spatially mapped using two-dimensional coordinate positioning to generate a geological information spatial model.

[0022] The coordinates of all surface settlement monitoring points are denoted as Pi(xi,yi), and the corresponding annual average settlement rate is denoted as vi, where i=1,2,…,n. A surface settlement rate distribution map of the goaf is constructed using the triangular mesh interpolation method (TIN method). Then, for each pair of adjacent monitoring points, the ratio of the difference in settlement rate to the horizontal distance is calculated as the local settlement gradient Gij, expressed as: Local Settlement Gradient. , where dij represents the horizontal distance between point i and point j (in meters).

[0023] All Gij values ​​are projected onto the 2D terrain grid to generate a global settlement gradient distribution map of the goaf. This map is used to identify high deformation areas and provide constraint boundaries for subsequent flexible support design.

[0024] To determine whether a region belongs to a high settlement deformation area, a threshold value Gth is introduced, which is determined based on the maximum allowable tilt angle of the structure. For example, if the maximum allowable tilt angle of the photovoltaic support is 5 degrees, then when the support span is 5 meters, the corresponding maximum settlement difference is 0.44 meters. Therefore, the corresponding settlement gradient threshold is: Gth = 0.44 / 5 = 0.088 (unit: mm / m). If the settlement gradient of a certain area is greater than this threshold, it is determined to be a settlement-sensitive area.

[0025] Obtain the standard value of the foundation bearing capacity qi at each measuring point, in kilopascals. Perform Kriging interpolation based on the geographical coordinates of each measuring point to generate a two-dimensional continuous function model q(x,y), which is the foundation bearing capacity distribution function.

[0026] Meanwhile, set the minimum foundation bearing capacity threshold \(q_{min}\), whose value is determined based on the lower limit of the unit foundation load of the support structure. If \(q(x,y) \lt q_{min}\) in a certain area, it is determined as a soft foundation area, and the high-bearing capacity adjustment support method should be preferentially considered in the flexible foundation design.

[0027] Perform a spatial overlay analysis on the above settlement gradient distribution map and the foundation bearing capacity distribution map to generate a comprehensive geological risk zoning map. Divide the risk levels according to the following rules: High-risk area: settlement gradient \(\gt G_{th}\), and foundation bearing capacity \(\lt q_{min}\); Medium-risk area: satisfy one of the following; Low-risk area: both satisfy the safety threshold.

[0028] This map provides a spatial guidance basis for the subsequent support foundation layout strategy and parameter optimization.

[0029] S200: According to the obtained settlement gradient distribution and foundation bearing capacity distribution, establish an initial design model of the flexible foundation photovoltaic support structure in the goaf.

[0030] In the present invention, after obtaining the settlement gradient distribution and foundation bearing capacity distribution of the goaf, it is necessary to further establish an initial design model of the flexible foundation photovoltaic support structure. This part realizes the engineering structure adaptation design for the complex goaf geological conditions by constructing spatial partitions, setting parameter constraints, and generating a three-dimensional model of the structure. The specific implementation methods are as follows: Step S201: First, based on the settlement gradient distribution map, divide the entire goaf into several regions with geological consistency and settlement similarity, called settlement response units. Specifically, it is realized by using a zoning algorithm based on the settlement gradient threshold: Set the settlement gradient critical threshold \(G_{lim}\), in units of millimeters per meter, whose value is obtained by back-calculating based on the maximum allowable inclination of the structure design; centered on each sampling measurement point, expand to the surrounding areas, and any area where the settlement gradient is continuously less than \(G_{lim}\) is classified into one settlement response unit; if the settlement gradient between any two measurement points is greater than \(G_{lim}\), they are classified into different response units.

[0031] After the division, for each settlement response unit, count the annual maximum settlement difference \(\Delta h\) and the average support span \(L\) inside it, and calculate the maximum displacement tolerance \(V_{max}\) of the foundation per unit span, and its calculation method is: the allowable foundation displacement range \(V_{max}=\Delta h / L\), in units of millimeters per meter. This displacement range is used to guide the stiffness design of the subsequent flexible connection nodes.

[0032] Step S202: For each settlement response unit, read the foundation bearing capacity distribution function q(x,y) of its corresponding region. Based on the spatial variation law of bearing capacity values, determine the layout spacing and bearing parameters of the flexible foundation using the following method: If the bearing capacity of a certain area is less than qmin, the foundation spacing shall be reduced to the minimum design spacing dmin in order to increase the effective bearing area of ​​the foundation. If the bearing capacity is greater than qmin, the foundations shall be laid out according to the standard spacing dstd to reduce the amount of material used; Simultaneously, the minimum bearing capacity qmin, maximum settlement difference Δh, and maximum settlement gradient Gmax within the region are used as boundary conditions and imported into the initial design model to constrain the structural modeling range and response objectives. The aforementioned spacing and bearing parameters will be directly used to generate the flexible foundation location nodes in the three-dimensional structural model.

[0033] Step S203: Under the established boundary constraints, construct a 3D structural model containing the following elements using architectural structural modeling software (such as Revit, SolidWorks, or Tekla): Flexible column unit: To adapt to uneven foundation settlement, the column adopts a circular tube structure and is equipped with a telescopic sleeve. The total height of the column is determined according to the local maximum snow load, and the adjustable range of the bottom nested section is set to be no less than 400 mm; Flexible connection nodes: The support beams and columns are connected via connection nodes equipped with hinged ball joints or sliding groove structures. The node stiffness parameter Kj is set according to the foundation displacement tolerance Vmax of each response unit to ensure that it does not suffer rigid failure within the maximum settlement difference range; Basic contact surface modeling: The contact surface between the foundation and the ground is modeled as an elastic contact surface. The contact stiffness value is calculated based on the soil modulus and the contact area, and the unit is kN / m. 3 The contact type is set to non-linear compression to accurately reflect changes in load.

[0034] All components in the model are parametrically defined for subsequent optimization and simulation input.

[0035] Step S204: Spatially associate the positions of each basic node in the completed 3D structural model with the corresponding settlement response units using a matching method based on 2D coordinate mapping. Assign coordinate labels (xi, yi) to each basic node in the structural model; According to the boundary division rules of the settlement response unit, determine whether the coordinates (xi,yi) fall into the unit; If a match is successful, an index relationship is established between the node and the geological parameters Vmax, qmin, and Gmax in the settlement response unit for subsequent simulation and design parameter optimization.

[0036] After this step is completed, an initial structural design model closely coupled with geological settlement data is formed, laying the foundation for subsequent finite element analysis and optimization design.

[0037] By constructing spatial response units and refining structural parameters, this step achieves high-precision adaptive modeling of photovoltaic support foundation structures in complex goaf environments. Compared to traditional uniform assumption design methods, this step enables the model to possess realistic geological feedback capabilities, significantly improving the reliability of structural simulation analysis and the engineering applicability of the design output.

[0038] S300: Perform finite element simulation calculations on the initial design model to simulate the structural response under preset settlement loads, wind loads, and snow loads, and obtain the displacement characteristic quantity V of key parts of the structure and the stress state M of the connection nodes.

[0039] After establishing the initial design model of the flexible foundation photovoltaic support structure, finite element simulation analysis is required to evaluate the stress response and deformation behavior of the model under actual geological conditions in a goaf area. By simulating the structural response under the combined effects of non-uniform settlement, wind load, and snow load, the displacement characteristics of key structural components and the stress state of connection nodes are obtained. The specific technical implementation method is as follows: Step S301: Import the established initial design model into the finite element analysis platform. It is preferable to use general-purpose finite element analysis software with the ability to model complex boundary conditions, such as ABAQUS or ANSYS.

[0040] In the model, nonlinear foundation spring elements are introduced into the contact area at the bottom of all foundations. These spring elements are used to simulate the interaction between the flexible foundation and the ground. The spring stiffness is set based on the compression modulus and contact area of ​​the corresponding soil layer for each settlement response element, specifically: Spring stiffness K = E × A / H; where E is the compression modulus of the soil layer corresponding to the response element (in kPa), A is the contact area at the bottom of the foundation (in square meters), and H is the depth of influence (in meters), which is generally taken as twice the width of the foundation bottom.

[0041] In addition, the spring unit is set to only allow operation in the compression direction, i.e., it does not bear tensile force, to simulate the real foundation response behavior during settlement.

[0042] Step S302: In the simulation model, set the following three types of load conditions and apply them as a combined load: Uneven settlement load: Based on the settlement gradient distribution obtained in S100, simulated foundation displacement boundaries are applied to different foundation nodes, and the displacement values ​​are set according to the predicted settlement values ​​of the settlement response units to which each node belongs. Regional wind load: Based on the basic wind pressure set according to the national "Code for Design of Building Structures", and combined with the support height and orientation, the equivalent wind load force applied to the surface of the photovoltaic module is calculated and mapped to the support members; Equivalent snow load: Calculate the uniformly distributed vertical load applied to the top of the support based on the maximum design snow thickness.

[0043] All loads are solved by superimposing static loads, and the simulation solution uses an incremental iterative method until the structure reaches a stable equilibrium state.

[0044] Step S303: After the simulation calculation is completed, read the total displacement values ​​of the top nodes of each flexible column in the vertical (Z direction) and lateral (X-Y direction) directions, and record them as Vz(i) and Vxy(i), where i represents the structural unit number.

[0045] Select representative key locations in the structure to form a displacement feature vector V={V1,V2,...,Vn}, and compare it with the maximum allowable displacement tolerance Vlim of the structural design: If there exists any Vi > Vlim, then the initial design structure is considered not to meet the allowable deformation condition under the current working conditions, and structural parameters need to be adjusted in subsequent steps.

[0046] The maximum allowable displacement tolerance Vlim is set based on the limit of the electrical connection stretch length and tilt angle adjustment tolerance of the photovoltaic module, and is usually in the range of 40 to 60 mm.

[0047] Step S304: In the simulation model, extract the force response data of all flexible connection nodes (i.e., the movable joints between the support beam and the column) under the maximum deformation condition, including: shear force (in kilonewtons); bending moment (in kilonewton-meters); node angle rotation (in degrees); tensile and compressive axial forces (in kilonewtons).

[0048] The above data are summarized to form the force state matrix M=[mij] of the connection nodes, where each row corresponds to a node and each column represents the internal force value in different directions. This matrix serves as the basis for evaluating the connection strength and flexible adjustment capability of the structure under maximum load, and provides the parameter input basis for subsequent optimization design steps.

[0049] S400: Based on the displacement characteristic quantity V and the stress state of the connection node M, a response and adaptability index system W for flexible foundation structures is constructed.

[0050] After completing the finite element simulation calculation of the flexible foundation photovoltaic support structure and obtaining the displacement characteristics of key structural components and the stress state of connection nodes, this invention further constructs a response adaptability index system for the flexible foundation structure to achieve a quantitative assessment of the structure's adaptability. This index system is used to characterize the structure's adaptability under multiple load conditions, providing an evaluation basis for subsequent design parameter optimization. The specific technical steps are as follows: Step S401: In step S303, the set of displacement characteristic quantities of each key part of the structure has been obtained, denoted as V={V1,V2,...,Vi,...,Vn}, where each element Vi represents the total displacement value of the i-th measuring point, in millimeters.

[0051] To construct a highly comparable deformation index system, the following statistical processing was performed on the set of displacement characteristic quantities: Maximum displacement difference: Calculate the difference between the maximum and minimum displacements at all measuring points, which is taken as the maximum deformation of the overall structure; Average displacement: The arithmetic mean of all displacement values ​​in V represents the average deformation level of the entire structure; Displacement standard deviation: used to measure the dispersion of structural displacement distribution, reflecting the uniformity of the structure affected by settlement.

[0052] The three statistical values ​​mentioned above together constitute a subset of deformation indexes, denoted as D={D1,D2,D3}, where: D1 is the maximum displacement difference (unit: mm); D2 is the average displacement (unit: mm); and D3 is the standard deviation of displacement (unit: mm).

[0053] To improve the consistency of subsequent indicators, each indicator is normalized by its maximum value so that each value falls within the range of 0 to 1.

[0054] Step S402: Based on the force state matrix M=[mij] of the connection nodes obtained in step S304, extract the typical internal force data of all flexible connection nodes, including bending moment, shear force and axial force.

[0055] To ensure that the indicators have a uniform measurement standard, the following processing is performed on each type of internal force data: Extract the maximum bending moment Mmax, maximum shear force Qmax, and maximum axial force Nmax from all nodes respectively; set the structural ultimate bearing values ​​of each internal force index, denoted as Mlim, Qlim, and Nlim, which are determined based on the construction materials, cross-sectional dimensions, and code limits of the connection nodes. Perform normalization processing and calculate the following values ​​separately: normalized bending moment M′=Mmax / Mlim; normalized shear force Q′=Qmax / Qlim; normalized axial force N′=Nmax / Nlim.

[0056] The normalized results form a subset of connection strength indices S={S1,S2,S3}, where: S1=M′, S2=Q′, S3=N′, and the values ​​of the three are in the range of 0 to 1. The closer to 1, the closer to the structural limit.

[0057] Step S403: Merge the deformation index subset D={D1,D2,D3} obtained in step S401 with the connection strength index subset S={S1,S2,S3} obtained in step S402 to construct a two-dimensional response adaptability index vector W={W1,W2,...,W6}, where: W1=D1, W2=D2, W3=D3; W4=S1, W5=S2, W6=S3. This index vector comprehensively describes the deformation performance and connection strength status of the structure under settlement and load, and has good engineering judgment significance.

[0058] Step S404: Set the structural response safety threshold vector T = {T1, T2, ..., T6}, the values ​​of which are set according to engineering specifications and actual construction requirements. For example: Deformation thresholds T1=0.8, T2=0.6, T3=0.5; The intensity index thresholds are T4=0.9, T5=0.9, and T6=0.9.

[0059] Each indicator Wi is compared with its corresponding threshold Ti. If any Wi > Ti, it is determined that the current structural design has the risk of overload or overdeformation under the corresponding indicator.

[0060] All comparison results are compiled into a response adaptability index system, denoted as the response adaptability index system W. This index system can not only quantify the structural adaptability of the current design model under goaf conditions, but also serve as the objective function input for subsequent design parameter optimization.

[0061] S500: The response adaptability index system W is correlated with the set of structural adjustable parameters P to establish the objective function F.

[0062] To optimize the response performance of flexible-foundation photovoltaic support structures under subsidence conditions in goaf areas, this invention constructs an optimization objective function based on the relationship between a response adaptability index system and adjustable structural parameters. This objective function guides subsequent design parameter updates and adaptive structural optimization. The specific technical steps are as follows: Step S501: Based on the structural characteristics and stress adjustment capability requirements of the initial structural design model, determine the set of adjustable structural parameters P = {P1, P2, P3}, where: Parameter P1: The height difference adjustment range of the support frame, in millimeters, represents the maximum allowable height difference adjustment range between the support columns, used to adapt to different foundation settlement conditions; Parameter P2: Stiffness coefficient of flexible connection node, in kilonewton-meters per degree, representing the stiffness of the node against angular changes. The smaller the value, the higher the flexibility of the node and the better it can buffer angular deformation caused by settlement. Parameter P3: Spacing of flexible foundations, in meters, represents the horizontal distance between adjacent foundations, which directly affects the distribution of the total bearing capacity and deformation coordination of the foundation.

[0063] The above three parameters are the main controllable and adjustable variables in the design and optimization process of the structure, which can significantly affect the structural deformation and the stress state of the connection.

[0064] Step S502: After completing the finite element simulation calculations under multiple parameter combinations, for the response adaptability index vector W={W1,W2,...,W6} extracted from the simulation output results corresponding to each group P1, P2, and P3, establish a functional mapping relationship between parameters and response. The relationship is as follows: Wj=fj(P1,P2,P3), where j=1 to 6, corresponding to various indices of deformation and connection strength, respectively.

[0065] The function fj can be constructed using a multiple linear regression model, a support vector regression model, or a gradient boosting-based regression tree model, depending on the number of data samples and the distribution characteristics of the indicators. To enhance the model's fit, all input parameters P1, P2, P3 and the response indicator Wj are normalized before modeling to ensure their values ​​are uniformly within the range of [0,1].

[0066] After training, each function fj expresses the response trend of the j-th response fitness index as the structural parameters change, providing a data foundation for constructing the objective function.

[0067] Step S503: To comprehensively evaluate the structural response performance, an objective function, denoted as F, is constructed, which measures the deviation between each response adaptability index Wj and its corresponding structural safety threshold Tj. The objective function is constructed using a weighted squared difference form and is expressed as follows: Where: Wj is the value of the j-th structural response index; Tj is the safety threshold of the index (in normalized value); ωj is the weight coefficient of the corresponding index, reflecting the importance of the index to the overall structural performance.

[0068] By adjusting the values ​​of each component in the parameter set P to minimize the objective function F, the optimal matching of the overall structure's response performance under given geological conditions can be achieved.

[0069] The objective function F serves as the basis for solving subsequent parameter optimization algorithms. Its mathematical expression and physical meaning are clear, and it can comprehensively measure the structure's response and adaptability in terms of deformation and stress state.

[0070] This step establishes a functional mapping relationship between structural response indices and adjustable parameters, and uses the minimization of weighted deviation as the optimization objective. This achieves an effective connection between response adaptability quantification and structural parameter controllability, breaking through the limitations of traditional photovoltaic support design in terms of the lack of dynamic evaluation and adjustment mechanisms for adaptability to uneven settlement. It provides a scientific and efficient optimization method for the adaptive design of flexible foundation structures.

[0071] S600: An iterative optimization algorithm is used to update the set of adjustable structural parameters P to obtain the optimal set of flexible foundation design parameters. To maximize the objective function F.

[0072] After constructing the objective function, to achieve the globally optimal configuration of the structural parameters of the flexible foundation photovoltaic support, this invention introduces a particle swarm optimization algorithm in step S600 to iteratively update the set of adjustable structural parameters, ultimately obtaining the optimal set of flexible foundation structural design parameters. The specific optimization process is as follows: Step S601: First, set the initial value of the set of adjustable structural parameters P(0) = {P1(0), P2(0), P3(0)}, where: Parameter P1(0): Initial value of the height difference adjustment range of the support; Parameter P2(0): Initial value of stiffness coefficient of flexible connection node; Parameter P3(0): Initial value of flexible foundation layout spacing.

[0073] Substitute the initial parameter set P(0) into the constructed objective function F, calculate the corresponding structural response adaptive objective function value F(0), and use it to evaluate the performance of the current parameter set.

[0074] Step S602: In each iteration, the parameter set P is updated with perturbation using the particle swarm optimization algorithm. Specific steps include: In the three-dimensional parameter space, a particle position vector P(k) = {P1(k), P2(k), P3(k)} is defined; each particle corresponds to a combination of structure parameters, and its velocity and position are updated in the search space. The update formula is: Particle velocity update: Particle position update: P(k+1) = P(k) + v(k+1); where: ω is the inertia weight coefficient, usually taken as 0.5 to 0.9; c1, c2 are learning factors, usually taken as 2; r1, r2 are random numbers in the range [0,1]; Pbest is the current particle's historical best position; Gbest is the population's global best position. For all candidate solution particles, calculate their corresponding objective function value F(k), which is used to compare the optimal parameter positions.

[0075] Step S603: After each iteration of the particle swarm optimization, select the position of the particle with the smallest objective function value. The optimal set of structural parameters for the current round: like Then let The optimal particle will be used to update the velocity and position of all particles in the next round, serving as a global guiding direction to continue searching for a better solution in the parameter space. Through continuous iteration, the particle swarm gradually converges towards the optimal region.

[0076] Step S604: Set the convergence threshold ε of the objective function, in the form of a dimensionless normalized value, typically set to 0.001–0.005. The optimal objective function value should change within a series of iterations if the following condition is met: If the number of consecutive convergences exceeds the set number of iterations to stabilize, for example, 10 iterations, then the algorithm is considered to have reached convergence.

[0077] At this point, the corresponding parameter group The optimal set of flexible foundation design parameters is recorded, and this set of parameters can be directly used to generate the final construction design scheme.

[0078] By introducing the particle swarm optimization algorithm, global search and optimal solution convergence are achieved in the multidimensional design parameter space, which significantly improves the ability of structural design parameters to match settlement response performance.

[0079] S700: Generates a flexible foundation photovoltaic support structure design scheme based on P*, which is ultimately suitable for the geological conditions of the goaf area, and is used for actual construction deployment.

[0080] After completing the optimization calculation of the design parameters for the flexible foundation photovoltaic support structure, in order to realize the engineering application of the design results, in step S700 of this invention, based on the determined optimal flexible foundation structure design parameter set... This process generates a final flexible-foundation photovoltaic support structure design scheme suitable for the geological conditions of the target goaf area. The specific implementation process is as follows: The structural parameter set obtained by iterative optimization The three parameters are converted into specific engineering design values: The height difference adjustment range of the bracket : This refers to the design length of the adjustable section at the bottom of the column, in millimeters, used to address ground elevation differences in different foundation settlement areas; Stiffness coefficient of flexible connection node : Connecting node components used to select specific models or custom structures, whose mechanical properties should meet the corresponding stiffness values ​​to ensure that they are rotatable and do not fail within the angle changes caused by settlement; Basic layout spacing Used to develop the construction layout diagram of the support foundation, ensuring that a reasonable foundation layout density is selected in different settlement response units, thereby enhancing the stability and adaptability of the overall structure.

[0081] With parameter group As input, all component parameters in the initial design model are updated, adjusting the length of the flexible columns, connection node types, and foundation spacing to generate a final 3D structural design model that meets construction requirements. The model includes: a distribution diagram of flexible foundation components; settlement response unit identifiers for each support foundation node; all connection node numbers and corresponding stiffness parameters; and the adjustable height range of supports in different areas. The model output is a Building Information Modeling (BIM) file (such as IFC or Revit format) for use by construction companies.

[0082] Based on the updated 3D design model, export the engineering construction drawings and layout plan, including: Construction site layout plan: Marks the location of different settlement response units and foundation layouts within the goaf area; Foundation construction details: based on Specify the foundation spacing and adjust the foundation type (such as pile foundation, embedded foundation, etc.) according to geological conditions. Connection node layout diagram and numbering table: according to All connection nodes are selected and numbered to ensure accurate matching during later installation; Schematic diagram of support column adjustment: based on Set the height difference adjustment range for each set of supports to assist in precise on-site positioning.

[0083] During the construction deployment phase, the above design results will be used as the basis for foundation pre-embedding and support installation; at the same time, based on the settlement monitoring data of the goaf area, adjustment redundancy will be reserved at the structural height difference adjustment section and flexible connection node.

[0084] For areas with a strong tendency for settlement, monitoring points are set up and their locations are marked on the construction drawings. After construction, the structure is adjusted regularly through adjustable points to achieve dynamic matching between the structure and the settlement, ensuring the stability of the photovoltaic array operation and the power generation efficiency.

[0085] By constructing a complete engineering design model and construction drawings based on parameter optimization results, a high degree of unity between structural performance optimization and actual engineering deployment is achieved, ensuring that the flexible foundation photovoltaic support has good adaptability and construction operability under complex settlement geological conditions, and effectively improving the long-term operational safety of photovoltaic power stations in mining subsidence areas.

[0086] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A design method for a flexible foundation photovoltaic support structure suitable for goaf areas, characterized in that: include: S100: Obtain geological parameter information of the target goaf, including settlement gradient distribution and foundation bearing capacity distribution; S200: Based on the obtained settlement gradient distribution and foundation bearing capacity distribution, establish the initial design model of the flexible foundation photovoltaic support structure in the goaf area; S300: Perform finite element simulation calculations on the initial design model to simulate the structural response under preset settlement loads, wind loads, and snow loads, and obtain the displacement characteristic quantity V of key parts of the structure and the stress state M of the connection nodes. S400: Based on the displacement characteristic quantity V and the stress state of the connection node M, a response and adaptability index system W for flexible foundation structures is constructed. S5 00: Conduct correlation analysis between the response adaptability index system W and the set of structurally adjustable parameters P to establish the objective function F; S600: An iterative optimization algorithm is used to update the set of adjustable structural parameters P to obtain the optimal set of flexible foundation design parameters. To maximize the objective function F; S700: Based on A final flexible foundation photovoltaic support structure design scheme suitable for the geological conditions of the goaf area is generated for actual construction deployment.

2. The design method for a flexible foundation photovoltaic support structure suitable for goaf areas according to claim 1, characterized in that: The set of adjustable parameters P of the structure includes the adjustment range of the height difference of the support, the stiffness coefficient of the flexible node, and the foundation spacing.

3. The design method for a flexible foundation photovoltaic support structure suitable for goaf areas according to claim 1, characterized in that: The initial design model for establishing a flexible foundation photovoltaic support structure in the goaf includes the following steps: S201, based on the settlement gradient distribution, divide the goaf into several settlement response units, and determine the corresponding allowable foundation displacement range for each settlement response unit. S202, Based on the distribution of foundation bearing capacity corresponding to each settlement response unit, determine the arrangement spacing and foundation bearing parameters of the flexible foundation, and use the foundation bearing parameters as the boundary constraint conditions of the initial design model; S203, under the boundary constraints, construct a three-dimensional structural model including flexible columns, flexible connection nodes and basic contact surfaces; S204. The three-dimensional structural model is associated with the spatial positional relationship of each settlement response unit to form an initial design model.

4. The design method for a flexible foundation photovoltaic support structure suitable for goaf areas according to claim 1, characterized in that: The finite element simulation calculation of the initial design model includes the following steps: S301, import the initial design model into the finite element analysis platform, and set nonlinear foundation spring elements according to the geological parameters of each settlement response unit to simulate the foundation contact boundary conditions; S302, apply a combination of multiple load conditions including uneven settlement load, regional wind load and equivalent snow load, and solve the initial design model using static loading method; S303, record the vertical and lateral displacements of the top of each flexible column in the initial design model, calculate the displacement characteristic quantity V of the key parts of the structure, and determine whether it exceeds the preset displacement tolerance. S304, extract the internal force response of each flexible connection node under the maximum deformation condition, and generate the force state M of the connection node.

5. The design method for a flexible foundation photovoltaic support structure suitable for goaf areas according to claim 1, characterized in that: The aforementioned response and adaptability index system W for constructing a flexible infrastructure includes the following steps: S401, statistical normalization is performed on the displacement characteristics of key parts of the structure, and the maximum displacement difference, average displacement and standard deviation are extracted as deformation indicators. S402, the stress amplitude is normalized for the stress state of all flexible connection nodes, and the maximum bending moment, maximum shear force and maximum axial force are extracted as connection strength indicators; S403, Based on the extracted connection strength index, construct a two-dimensional response adaptability index vector containing deformation index and connection strength index; S404, compare the two-dimensional response adaptability index vector with the structural safety threshold, and denote it as the response adaptability index system W.

6. The design method for a flexible foundation photovoltaic support structure suitable for goaf areas according to claim 2, characterized in that: The correlation analysis between the response adaptability index system W and the set of structural adjustable parameters P includes the following steps: S501, set the set of adjustable structural parameters P, including the adjustment range of the height difference of the support, the stiffness coefficient of the flexible connection node and the arrangement spacing of the flexible foundation, denoted as P1, P2 and P3 respectively. S502, based on the structural finite element simulation results, constructs the functional mapping relationship between P1, P2, P3 and each index component in the response adaptability index system; S503 uses the weighted sum of squares of the differences between each indicator and its corresponding safety threshold as the expression for the objective function F.

7. The design method for a flexible foundation photovoltaic support structure suitable for goaf areas according to claim 1, characterized in that: The method of updating the set of adjustable structural parameters P using an iterative optimization algorithm includes the following steps: S601, Select the initial set of adjustable structural parameters P and substitute it into the objective function F to calculate the adaptive performance; S602, Based on the particle swarm optimization algorithm, the parameters of P are perturbed to generate a set of candidate solutions, and the objective function value corresponding to each candidate solution is calculated; S603 selects the optimal parameter solution based on the principle of minimum objective function value, and iteratively generates a new round of candidate parameters based on the parameter set; S604, When the objective function value converges to a preset threshold range during continuous iterations, the current parameter set is determined as the optimal flexible foundation structure design parameter set. .

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