A method for calculating earthwork volume for leveling desert photovoltaic field sites

Abstract

This invention discloses a method for earthwork calculation in desert photovoltaic field leveling, comprising: extracting the original topographic elevation points of a selected area in the desert to form original topographic elevation data; performing a first smoothing process on the original topographic elevation data, specifically including: dividing the selected area into a regular grid structure on a plan view from a top-down perspective, obtaining the three-dimensional average points of all grids within the selected area, forming design surface elevation data; performing a second smoothing process on the design surface elevation data; and importing the second-smoothed design surface elevation data into earthwork calculation software for earthwork calculation to obtain calculation results and drawings. The calculations of this invention conform to the actual site conditions, providing a more accurate basis for investment estimates; the calculation results are smooth surfaces, without steps, which is more conducive to the use of photovoltaic sites; it eliminates the need for manual zoning calculations, allowing for rapid earthwork calculations for the entire site, significantly improving work efficiency.

Description

Technical Field

[0001] This invention belongs to the field of earthwork engineering quantity calculation technology, specifically relating to an earthwork calculation method for leveling desert photovoltaic field areas. Background Technology

[0002] The state has repeatedly proposed accelerating the construction of large-scale wind and solar power bases in desert, Gobi, and arid regions. A major challenge in constructing solar projects in the desert is site leveling. Current technology cannot accurately calculate and design desert site leveling. The best current approach is to divide the solar field into several sub-regions, assuming each sub-region is a plane or slope, and calculating earthwork volume separately for each region. This method has the following drawbacks: 1. It cannot accurately simulate the original site, as even within a small area, the site cannot be simply assumed to be a plane or slope; 2. Steps of varying heights appear between sub-regions, which is undesirable for on-site construction and operation; 3. The workload is large, increasing with smaller site divisions. These drawbacks arise because site leveling in large desert areas is a new problem, and there are currently no effective and targeted earthwork calculation methods. Summary of the Invention

[0003] The technical problem to be solved by this invention is to provide an earthwork calculation method for leveling desert photovoltaic field areas, which solves the problem that existing earthwork calculation methods are difficult to apply to site leveling in large desert areas, fills the gap in the existing technology, and achieves beneficial technical effects such as calculation conforming to the actual site conditions, calculation results being smooth curved surfaces, and the ability to quickly generate earthwork calculation result maps.

[0004] According to the technical solution of the present invention, the present invention provides a method for calculating earthwork for leveling desert photovoltaic field areas, comprising the following steps: Step S1: Extract the original terrain elevation points of the selected area in the desert to form original terrain elevation data; the original terrain elevation data contains the three-dimensional coordinate values ​​corresponding to all original terrain elevation points. Step S2 involves performing a first smoothing process on the original terrain elevation data, specifically including: Step S21: Divide the selected site area into a regular grid structure on the plan view from the top viewpoint, where each grid contains several original terrain elevation points. Step S22: For each grid, the average values ​​of the x-coordinate, y-coordinate, and y-coordinate of the original terrain elevation points within the grid are taken to obtain a three-dimensional average point within the grid. Step S23: Obtain the three-dimensional average points of all grids within the selected area through step S22 to form the design surface elevation data; the design surface elevation data includes the three-dimensional coordinate values ​​corresponding to the three-dimensional average points of all grids; the three-dimensional average points of all grids are distributed in a grid pattern; Step S3 involves a second smoothing process on the design surface elevation data, specifically including: Step S31: Calculate the slope value of the line connecting all adjacent three-dimensional average points in the design surface elevation data, and obtain the maximum slope value among them. Step S32: Compare the maximum slope value obtained in step S31 with the set slope specification value. If the maximum slope value is less than or equal to the slope specification value, it indicates that all slopes meet the requirements, and continue to step S4; if the maximum slope value is greater than the slope specification value, it indicates that the maximum slope value does not meet the requirements. Adjust the vertical coordinate values ​​of the two three-dimensional average points corresponding to the maximum slope value so that the slope value of the line connecting the two three-dimensional average points is equal to the slope specification value, and return to step S31 to repeat until step S32 determines that the maximum slope value is less than or equal to the slope specification value. Step S4: Import the design surface elevation data after the second smoothing process into the earthwork calculation software to perform earthwork calculations and obtain the calculation results and drawings.

[0005] In some implementations, in step S32, the method of adjusting the vertical coordinate values ​​of the two three-dimensional average points corresponding to the maximum slope value is to simultaneously adjust the vertical coordinate values ​​of the two three-dimensional average points in a centrally symmetrical manner, with the center point of the line connecting the two three-dimensional average points as a reference, such that the vertical coordinate value of one three-dimensional average point is increased and the vertical coordinate value of the other three-dimensional average point is decreased.

[0006] In some implementations, in step S21, several horizontal lines and several vertical lines are formed on a plan view of the selected field area from a top-down perspective. The horizontal and vertical lines intersect perpendicularly, and the spacing between the horizontal and vertical lines is the same, thus forming a grid structure.

[0007] In some implementations, in step S31, adjacent three-dimensional average points include adjacent three-dimensional average points in the horizontal length direction and adjacent three-dimensional average points in the vertical length direction.

[0008] In some implementations, during step S4, when performing earthwork calculations, the excavation and filling volumes for each grid are calculated separately.

[0009] Compared with the prior art, the beneficial technical effects of the present invention are as follows: The earthwork calculation method for leveling desert photovoltaic sites of this invention simplifies and smooths the original topographic map to obtain a design surface. By comparing the design surface with the original topography, earthwork calculations are performed to obtain a quantifiable and map-ready earthwork calculation result that conforms to the actual site conditions, thus providing a basis for budget estimation and on-site construction. This method's calculations are consistent with the actual site conditions and fit the topographic characteristics of desert areas, resulting in more accurate calculations and a more precise basis for investment budget estimation. The calculated result is a smooth surface, without steps, making the site smoother and more conducive to the use of photovoltaic sites. Furthermore, because manual zoning calculations are no longer required, earthwork calculations for the entire site can be performed quickly and in one go, greatly saving calculation time and significantly improving work efficiency. Attached Figure Description

[0010] Figure 1 This is a flowchart of the method of the present invention.

[0011] Figure 2 This is a schematic diagram of the grid structure and the three-dimensional average points therein of the present invention.

[0012] Figure 3 yes Figure 2 A schematic diagram of the original terrain elevation point and the three-dimensional average point at one of the grids.

[0013] Figure 4 yes Figure 2 A schematic diagram of a three-dimensional average point network structure.

[0014] Figure 5 yes Figure 4 A schematic diagram of the cross-sectional structure at one of the connecting lines.

[0015] Figure 6 This is a partial plan view of the calculation results of an embodiment of the present invention.

[0016] Figure 7 This is a cross-sectional view (partial) of the calculation results of an embodiment of the present invention.

[0017] Figure 8 This is a flowchart of the second smoothing process in this invention. Detailed Implementation

[0018] This invention provides a method for earthwork calculation for leveling desert photovoltaic field sites, and more specifically, a method for calculating and generating earthwork volume and drawings when leveling sites for building photovoltaic power stations in desert areas. It solves the problem that existing earthwork calculation methods are difficult to apply to site leveling in large desert areas, fills the gap in existing technology, and achieves beneficial technical effects such as calculation conforming to the actual site conditions, calculation results being smooth curved surfaces, and the ability to quickly generate earthwork calculation result maps.

[0019] Please see Figure 1 The present invention provides a method for calculating earthwork for leveling desert photovoltaic field areas, comprising the following steps: Step S1: Extract the original terrain elevation points of the selected area in the desert to form original terrain elevation data; the original terrain elevation data contains the three-dimensional coordinate values ​​corresponding to all original terrain elevation points. Step S2 involves performing a first smoothing process on the original terrain elevation data, specifically including: Step S21: Divide the selected site area into a regular grid structure on the plan view from the top viewpoint, where each grid contains several original terrain elevation points. Step S22: For each grid, the average values ​​of the x-coordinate, y-coordinate, and y-coordinate of the original terrain elevation points within the grid are taken to obtain a three-dimensional average point within the grid. Step S23: Obtain the three-dimensional average points of all grids within the selected area through step S22 to form the design surface elevation data; the design surface elevation data includes the three-dimensional coordinate values ​​corresponding to the three-dimensional average points of all grids; the three-dimensional average points of all grids are distributed in a grid pattern; Step S3 involves a second smoothing process on the design surface elevation data, specifically including: Step S31: Calculate the slope value of the line connecting all adjacent three-dimensional average points in the design surface elevation data, and obtain the maximum slope value among them. Step S32: Compare the maximum slope value obtained in step S31 with the set slope specification value. If the maximum slope value is less than or equal to the slope specification value, it indicates that all slopes meet the requirements, and continue to step S4; if the maximum slope value is greater than the slope specification value, it indicates that the maximum slope value does not meet the requirements. Adjust the vertical coordinate values ​​of the two three-dimensional average points corresponding to the maximum slope value so that the slope value of the line connecting the two three-dimensional average points is equal to the slope specification value, and return to step S31 to repeat until step S32 determines that the maximum slope value is less than or equal to the slope specification value. Step S4: Import the design surface elevation data after the second smoothing process into the earthwork calculation software to perform earthwork calculations and obtain the calculation results and drawings.

[0020] More specifically, in step S1, a large number of original topographic elevation points are obtained in the selected area. These original topographic elevation points are generally evenly distributed, and the number of points meets the accuracy requirements. As a supplementary explanation, existing technologies offer multiple ways to obtain the original topographic map of the desired area, and this method can process data based on the original topographic map. The original topographic elevation data is generated, for example, into a txt file, where the three-dimensional coordinates of each original topographic elevation point are in the format "x,y,z", where x represents the horizontal coordinate, y represents the vertical coordinate, and z represents the vertical coordinate (height). Since the original topographic map consists of numerous feature points, the coordinate values ​​of these feature points can be easily extracted using programs such as AutoCAD Lisp and stored in a txt file.

[0021] Step S2 uses a smoothing algorithm to smooth the original terrain and obtain the control points of the designed surface; specifically, for example, using Python or Excel VBA to read the data from the txt file and perform regional average calculation.

[0022] Please see Figure 2 , Figure 3 , Figure 6 Preferably, in step S21, several horizontal and vertical lines are formed on a plan view of the selected site from a top-down perspective. The horizontal and vertical lines intersect perpendicularly, and the spacing between the horizontal and vertical lines is the same, thus forming a grid structure. The grid consists of square cells (at the edge of the selected site, it is an incomplete grid formed by cutting the square cells along the edge line). The side length S of the square cells is the spacing between the horizontal and vertical lines. The side length S is a smoothing parameter that can be controlled and selected by the designer. The aforementioned horizontal and vertical lines are only used as calculation reference lines for grid division and do not need to be actually drawn.

[0023] The value of the side length S determines the accuracy of the first smoothing process. A smaller S value results in a lower smoothing degree and less earthwork, but more areas on the site that do not meet the slope requirements. Conversely, a larger S value results in a higher smoothing degree, more earthwork, but fewer areas with substandard slopes. The S value can be determined through trial and error: initially, a value of 80m is manually determined. If, after the first smoothing, the area of ​​areas not meeting the slope requirements is too large, then the S value is too small and should be appropriately increased; conversely, if the area is too small, then the S value should be increased. Through several rounds of trial calculations, a more reasonable S value can be determined, ensuring that most areas of the site meet the slope requirements. Based on engineering experience, for terrain similar to the Kubuqi Desert in my country, an S value of around 100m is ideal. It is particularly important to note that the selection of S does not need to be overly precise, because even if a large area still exists that does not meet the slope requirements after the first smoothing, the site can be gradually adjusted to the design requirements through multiple iterations during the second smoothing process. Therefore, the S value does not need to be over-optimized.

[0024] As a supplementary explanation, the grid can also be selected in other shapes such as triangles, hexagons, etc., but square grids are preferred as they are easier to process and can simplify the process. Each grid will contain several original terrain elevation points. There is no restriction on the order of steps S21 and S1. For example, the grid structure can be formed first, and then the original terrain elevation points can be selected in each grid. Alternatively, all the original terrain elevation points can be selected first, and then the grid structure can be formed. If an original terrain elevation point happens to be located on a grid line, that point can be discarded, and only the points inside the grid can be used to calculate the three-dimensional average point.

[0025] Step S22, obtaining a three-dimensional average point within the grid, involves assuming there are n original terrain elevation points within a grid, namely P1(x1, y1, z1), P2(x2, y2, z2), P3(x3, y3, z3), ..., P n (x) n y n , z n Based on this, the corresponding three-dimensional average points are calculated. The formula for calculating the three-dimensional coordinates (average x-coordinate, average y-coordinate, and average y-coordinate) of a three-dimensional average point is as follows: .

[0026] The three-dimensional average point represents the average design elevation within the grid. After calculating the three-dimensional average points of all grids in the field area using this method, the three-dimensional average points become the control points of the smoothed design surface, forming the design surface elevation data in step S23. The control point (three-dimensional average point) data consists of a grid of three-dimensional points.

[0027] Step S3 further performs secondary smoothing on the site to achieve the maximum slope I. max Less than or equal to the specified slope value I d (To be determined according to layout requirements). Specifically, the second smoothing process is performed on the surface after the first smoothing process. By traversing the slope values ​​between adjacent points, local areas that do not meet the set values ​​are identified, and targeted smoothing is performed on these areas. The flowchart for the second smoothing process is as follows: Figure 8 As shown.

[0028] In the aforementioned scheme using a square grid, step S31 includes adjacent three-dimensional average points in the horizontal length direction (east-west direction in the embodiment) and adjacent three-dimensional average points in the vertical length direction (north-south direction in the embodiment); for example... Figure 4As shown, the connecting lines will form a quadrilateral network structure. In this scheme, only the slope values ​​between adjacent points in the horizontal and vertical directions are considered, simplifying the data processing process and ensuring that the accuracy meets the requirements for earthwork calculation. In step S31, these slope values ​​are traversed to obtain the maximum slope value.

[0029] Preferably, in step S32, the method for adjusting the vertical coordinate values ​​of the two three-dimensional average points (i.e., the two endpoints) corresponding to the maximum slope value is as follows: taking the center point of the line connecting the two three-dimensional average points as a reference, the vertical coordinate values ​​of the two three-dimensional average points are adjusted simultaneously in a centrally symmetrical manner, with the vertical coordinate value of one three-dimensional average point increasing and the vertical coordinate value of the other three-dimensional average point decreasing by the same amount; for example... Figure 5 As shown, the horizontal axis represents the horizontal distance corresponding to a certain line, and the vertical axis represents the height. The solid line in the graph represents the slope before adjustment, and the dashed line represents the slope after adjustment. The middle section of the graph corresponds to the maximum slope value. By symmetrically adjusting its two ends, the slope is reduced to the specified slope value I. d At the same time, the adjacent slopes will also change, so it is necessary to recalculate (at least recalculate the slope of the line connecting the adjusted endpoints, so as to...) Figure 4 For example, the thickened line segment located slightly to the right of the center corresponds to the line with the maximum slope value. After adjustment, the slope of a total of 7 lines changed.

[0030] The design surface elevation data after the second smoothing process forms the design ground line (design surface diagram, such as a surface with sharp edges obtained by directly connecting the points, or a smoother surface obtained through fitting) calculated by this method. Construction will be carried out on the selected site based on this data to make the site more level than its natural state before construction, meeting the needs of photovoltaic construction. Step S4 involves earthwork calculation, specifically calculating the excavation and filling volumes. For example, the design ground line (design surface diagram) can be compared (subtracted) with the original ground line (original topographic map). This process can be completed using existing software. Specifically, the smoothed surface generated after the second smoothing process can be imported into earthwork calculation software, such as Feishida software, and conventional earthwork calculation operations can be performed to obtain the excavation and filling volumes for the entire site, with the two being nearly balanced. If necessary, the surface elevation can be fine-tuned to achieve precise earthwork balance. Then, based on the calculation results, subsequent site leveling work, etc., will be carried out. Preferably, in step S4, when performing earthwork calculations, the excavation and filling volumes for each grid are calculated separately.

[0031] Figure 6 This is a plan view (top view) showing the results of calculations performed on a certain project using a preferred embodiment of the present invention. Figure 6The image shows only a local area near the edge of the selected site. It contains the three-dimensional coordinate values ​​of each grid (the three-dimensional average point after a second smoothing process) and the earthwork volume of each grid (divided into positive and negative values ​​based on cut and fill). By summing these values, the earthwork volume of any desired area and the overall earthwork volume can be obtained.

[0032] Figure 7 The image shows a partial cross-sectional view of the results calculated for a certain project using a preferred embodiment of the present invention. The horizontal axis represents the distance along the length of the selected cross-section, and the vertical axis represents the height. This image shows the difference between the designed ground line obtained by this method and the original ground line, as well as the flatness effect.

[0033] It should be noted that this method is designed for the specific terrain and geological conditions of desert photovoltaic projects and is not applicable to other types of industrial projects. Desert photovoltaic power stations, as a newly emerging industry in recent years, often cover sites of thousands of hectares. The placement of photovoltaic modules requires specific slope conditions, yet they do not require precise point-to-point elevation control as in precision engineering. These characteristics make traditional earthwork calculation methods unsuitable—existing point-to-point precise elevation control methods are typically designed for general industrial projects, artificially dividing the site into several plots, each treated as a plane or single-slope surface, relying on earthwork software for point-to-point elevation calculation or preset slope calculation. Applying this method to desert photovoltaic projects is not only time-consuming but also disrupts the essential characteristics of the macroscopic continuity and microscopic fluctuations inherent in desert photovoltaic sites.

[0034] This invention abandons the traditional "block calculation and manual assembly" model, and instead treats the vast site as an organic whole: by acquiring terrain data through point sampling, and through two optimization solutions, it directly generates a globally continuous ideal design surface with a slope that meets the design requirements, and finally imports it into conventional earthwork software to complete the engineering quantity calculation. This method includes two smoothing calculations: the first smoothing uses a grid averaging algorithm to perform indiscriminate smoothing of terrain fluctuations across the entire site to eliminate random undulations. Because this algorithm indiscriminately processes terrain features, areas with severe terrain undulations are prone to having substandard slopes after processing. Therefore, the second smoothing focuses on these areas that do not meet the slope requirements, carrying out targeted secondary smoothing optimization, ultimately ensuring that the processed terrain fully meets the preset slope requirements.

[0035] In summary, the earthwork calculation method for leveling desert photovoltaic sites of the present invention simplifies and smooths the original topographic map to obtain a design surface. Each feature point on the surface is checked individually, and the elevation of adjacent points is optimized to ensure that the slope of each point on the surface meets the specified requirements. Earthwork calculations are performed by comparing the design surface with the original topography, ultimately yielding a quantifiable and map-ready earthwork calculation result that conforms to the actual site conditions, thus providing a basis for preliminary cost estimates and on-site construction. This method's calculations are consistent with the actual site conditions and fit the topographical characteristics of desert areas, resulting in more accurate calculations and providing a more accurate basis for investment cost estimates. The calculated result is a smooth surface, without steps, making the site smoother and more conducive to the use of photovoltaic sites. Furthermore, because manual zoning calculations are no longer required, earthwork calculations for the entire site can be performed quickly and in one go, greatly saving calculation time and significantly improving work efficiency.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; obviously, the described embodiments are some embodiments of the present invention, but 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; in the absence of conflict, the embodiments and features in the embodiments of the present invention can be combined with each other; modifications to the technical solutions described in the foregoing embodiments, or equivalent substitutions for some of the technical features, 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 the present invention.

Claims

1. A method for calculating earthwork volume for leveling desert photovoltaic field areas, characterized in that, Includes the following steps: Step S1: Extract the original terrain elevation points of the selected area in the desert to form original terrain elevation data; the original terrain elevation data contains the three-dimensional coordinate values ​​corresponding to all original terrain elevation points. Step S2 involves performing a first smoothing process on the original terrain elevation data, specifically including: Step S21: Divide the selected site area into a regular grid structure on the plan view from the top viewpoint, where each grid contains several original terrain elevation points. Step S22: For each grid, the average values ​​of the x-coordinate, y-coordinate, and y-coordinate of the original terrain elevation points within the grid are taken to obtain a three-dimensional average point within the grid. Step S23: Obtain the three-dimensional average points of all grids within the selected area through step S22 to form the design surface elevation data; the design surface elevation data includes the three-dimensional coordinate values ​​corresponding to the three-dimensional average points of all grids; the three-dimensional average points of all grids are distributed in a grid pattern; Step S3 involves a second smoothing process on the design surface elevation data, specifically including: Step S31: Calculate the slope value of the line connecting all adjacent three-dimensional average points in the design surface elevation data, and obtain the maximum slope value among them. Step S32: Compare the maximum slope value obtained in step S31 with the set slope specification value. If the maximum slope value is less than or equal to the slope specification value, it indicates that all slopes meet the requirements, and continue to step S4; if the maximum slope value is greater than the slope specification value, it indicates that the maximum slope value does not meet the requirements. Adjust the vertical coordinate values ​​of the two three-dimensional average points corresponding to the maximum slope value so that the slope value of the line connecting the two three-dimensional average points is equal to the slope specification value, and return to step S31 to repeat until step S32 determines that the maximum slope value is less than or equal to the slope specification value. Step S4: Import the design surface elevation data after the second smoothing process into the earthwork calculation software to perform earthwork calculations and obtain the calculation results and drawings.

2. The earthwork calculation method for leveling desert photovoltaic field areas according to claim 1, characterized in that, In step S32, the method for adjusting the vertical coordinate values ​​of the two three-dimensional average points corresponding to the maximum slope value is to simultaneously adjust the vertical coordinate values ​​of the two three-dimensional average points in a centrally symmetrical manner, with the center point of the line connecting the two three-dimensional average points as the reference, increasing the vertical coordinate value of one three-dimensional average point and decreasing the vertical coordinate value of the other three-dimensional average point.

3. The earthwork calculation method for leveling desert photovoltaic field areas according to claim 1, characterized in that, In step S21, several horizontal lines and several vertical lines are formed on the plan view of the selected field area from a top-down perspective. The horizontal and vertical lines intersect perpendicularly, and the spacing between the horizontal and vertical lines is the same, thus forming a grid structure.

4. The earthwork calculation method for leveling desert photovoltaic field areas according to claim 3, characterized in that, In step S31, adjacent three-dimensional average points include adjacent three-dimensional average points in the horizontal length direction and adjacent three-dimensional average points in the vertical length direction.

5. The earthwork calculation method for leveling desert photovoltaic field areas according to any one of claims 1 to 4, characterized in that, In step S4, when performing earthwork calculations, the excavation and filling volumes for each grid are calculated separately.

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