Intelligent Planning and Topographic Data Application Methods for Surveying Tasks in Bridge Design

Abstract

This invention discloses an intelligent planning method for surveying tasks and the application of topographic data for bridge design, belonging to the field of bridge engineering design technology. The method includes the following steps: First, longitudinal and cross-sectional information is automatically extracted from CAD topographic maps; then, by combining an automatic topographic undulation recognition algorithm with cross-sectional quantitative evaluation, key sections requiring on-site measurement are intelligently selected to form a precise surveying task book; subsequently, based on standardized measured data provided by surveying professionals, the pier height and abutment top elevation are automatically optimized and determined with the core objective of minimizing the total earthwork volume at a single pier location; finally, automated bridge design and engineering quantity calculation are completed. This invention achieves intelligent and objective surveying task planning, efficient collaboration between bridge and surveying professionals, and automatic optimization of design schemes, effectively overcoming the drawbacks of traditional methods such as reliance on experience, poor collaboration, and large earthwork volumes, significantly improving design efficiency and economy.

Description

Technical Field

[0001] This invention belongs to the field of bridge engineering design technology, specifically relating to an intelligent planning method for surveying tasks and the application of terrain data for bridge design. Background Technology

[0002] In bridge engineering, especially in the design of railway bridges in mountainous areas, accurately obtaining topographic data of the bridge site is fundamental for pier layout, pier height determination, and engineering quantity calculation. Traditional workflows typically rely on topographic maps with limited accuracy (e.g., 1:2000 aerial survey maps), with designers making preliminary judgments and designs based on personal experience. This process has the following main limitations:

[0003] 1. Insufficient objectivity and efficiency in survey task planning: The layout of cross-section measurement points relies heavily on the designer's subjective interpretation of topographic maps, lacking unified and quantifiable selection criteria. This easily leads to two disadvantages: first, the omission of key cross-sections with drastic topographic changes, resulting in insufficient basis for subsequent design; second, the establishment of too many unnecessary measurement cross-sections in areas with gentle terrain, thereby increasing unnecessary survey costs and time.

[0004] 2. Low efficiency in interdisciplinary collaboration and data flow: There is a lack of standardized data request reporting and feedback mechanisms between bridge engineering and surveying. Measurement tasks are often communicated through unstructured methods, which may lead to misunderstandings, inconsistent data formats, and consequently, repeated communication or secondary surveys, seriously affecting the overall progress of the early design phase.

[0005] 3. Poor design fit with terrain and lack of economy: When determining the pier elevation, traditional methods typically rely only on finite elevation points along the longitudinal profile of the bridge centerline, failing to fully consider the pier cap projection area and the three-dimensional topographic undulations of the surrounding area. This simplified approach often results in the pier foundation design failing to achieve an "adaptive" match with the original terrain, ultimately leading to a significant increase in earthwork excavation and backfilling, which not only drives up project costs but also increases disturbance to the original surface.

[0006] In summary, existing technologies suffer from drawbacks such as subjective inefficiency in surveying and planning, poor interdisciplinary collaboration, and suboptimal economic efficiency in design schemes. Therefore, there is an urgent need in this field for a bridge design method that enables intelligent planning of surveying tasks, efficient collaboration of professional data, and automatic optimization of the design based on accurate topographic data to minimize engineering workload. Summary of the Invention

[0007] To address the problems in the existing technology, this invention aims to provide an intelligent planning method for surveying tasks and the application of topographic data for bridge design. This method aims to achieve intelligent planning of surveying tasks, standardized and efficient collaboration between bridge engineering and surveying disciplines, and ultimately, automated bridge design with the optimization of earthwork engineering as its objective.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A method for intelligent planning of survey tasks and application of topographic data for bridge design includes the following steps:

[0010] A. Topographic map section extraction and intelligent planning: Extract the elevation of longitudinal ground points in the bridge site area from the CAD topographic map, determine the terrain change area and lay out cross sections based on the terrain undulation automatic identification algorithm, and automatically generate the cross section task book that needs to be measured on site by calculating the terrain quantitative index of each cross section and comparing it with the preset threshold.

[0011] B. Collaborative Measurement and Data Acquisition: The surveying professionals conduct on-site measurements based on the surveying task book generated in step A to obtain standardized longitudinal and cross-sectional datasets containing mileage and elevation.

[0012] C. Longitudinal design of bridge: Based on the standardized cross-section data obtained in step B, with the earthwork excavation and filling balance at the pier location as the main optimization objective, the elevation of the pier cap and the height of the pier body of each pier are automatically determined.

[0013] D. Bridge transverse design and engineering quantity calculation: Based on the pier location and elevation determined in step C, the cross-sectional design of the pier and abutment and the slope design are automatically completed, and the quantity of slope protection works is calculated.

[0014] Preferably, step A specifically includes:

[0015] From the CAD topographic map, extract the elevation of longitudinal ground points in the bridge site area at preset intervals along the centerline of the bridge route;

[0016] Using an automatic terrain undulation recognition algorithm, areas with drastic terrain changes were initially identified.

[0017] Automatically cut a series of cross sections along the bridge site. The cross sections include points determined by an automatic terrain undulation recognition algorithm, and cross section points supplemented according to the principle of equal spacing when the spacing between the above points is greater than the preset maximum value.

[0018] By calculating the topographic quantification index of each cross section and comparing it with the preset threshold, the system automatically determines and generates a task list for cross sections that need to be measured on-site.

[0019] Preferably, in step A, the method for extracting the longitudinal ground point elevation of the bridge site area from the CAD topographic map is as follows: taking the target point as the center, delineate all contour lines and elevation points within a preset radius around it; analyze the spatial positional relationship between the target point and the topographic features within the delineated area; and calculate the ground elevation of the target point based on a specific positional relationship model and interpolation algorithm.

[0020] Preferably, in step A, the automatic terrain undulation recognition algorithm includes:

[0021] Calculate the slope at each point along the bridge alignment;

[0022] Calculate the rate of change of slope;

[0023] When the absolute value of the slope change rate is greater than the preset threshold, the system automatically sets up a cross-sectional measurement task at that mileage location.

[0024] Preferably, the preset threshold for the slope change rate is 0.15.

[0025] Preferably, in step A, the terrain quantification indicators include cross-sectional elevation difference ΔH, cross-sectional average slope percentage SAvg, and terrain undulation coefficient K. A cross-section is marked as requiring actual measurement when any of the following conditions are met:

[0026] Condition 1: ΔH > 5m;

[0027] Condition 2: SAvg > 15%;

[0028] Condition 3: K>2.

[0029] Preferably, the method for calculating the cross-sectional elevation difference ΔH is as follows: a 20m long sliding window is used on the cross-section, the maximum elevation difference in each window is calculated, and the maximum value among all the calculation results is taken as the ΔH value.

[0030] Preferably, the terrain undulation coefficient K is calculated as follows: a 10m long sliding window is used on the cross section, and the mean of the square of the difference between the elevation of the sampling point and the elevation of the trend line in each window is calculated. The maximum value among all the calculation results of all windows is taken as the K value.

[0031] Preferably, in step C, the method for automatically determining the top elevation of the pier cap of each bridge pier includes:

[0032] For each pier, obtain the elevation of all ground points within the area formed by the projection range of its pier cap and extending it outward by a certain distance.

[0033] Under the condition of meeting the structural requirements of minimum foundation burial depth, a series of alternative design elevation schemes for the top of the foundation are generated;

[0034] For each alternative scheme, design the cross-section slope of the pier;

[0035] The total excavation and filling volumes for each scheme are calculated and compared. The optimal design elevation of the pier top is automatically selected with the earthwork excavation and filling balance at the location of a single pier as the main optimization objective.

[0036] Preferably, the slope design of the pier cross section is implemented based on the algorithm disclosed in the paper "Intelligent Bridge Design Based on Mountainous Railway Terrain".

[0037] Preferably, in step D, the bridge transverse design and engineering quantity calculation automatically completes the pier cross-section design by decomposing the three-dimensional engineering entity into multiple transverse key sections, and then calculates the cumulative engineering quantity of slope trimming and slope protection.

[0038] Compared with the prior art, the present invention has the following significant advantages:

[0039] Intelligent and objective survey planning: By automatically identifying key measurement areas through quantitative algorithms, the subjectivity and uncertainty of human experience are avoided, making the layout of survey tasks more scientific and effectively reducing unnecessary field measurement workload while ensuring data quality.

[0040] Professional collaboration and efficiency: Standardized data processes and interfaces have been established, reducing repeated communication between bridge and surveying professionals and significantly improving the efficiency of early-stage design work.

[0041] Design optimization: By closely integrating the determination of pier height with specific and accurate cross-sectional topography and earthwork calculations, the direct goal of achieving "earthwork balance at pier location" can be achieved. This can significantly reduce the total amount of earthwork, thereby reducing project costs and environmental impact, resulting in significant economic and environmental benefits.

[0042] Design process automation: It has achieved full or semi-automation of the entire process from terrain data analysis and pier height optimization to engineering quantity calculation, which has greatly improved design efficiency and consistency of output quality. Attached Figure Description

[0043] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0044] Figure 1 This is the overall flowchart of the method of the present invention;

[0045] Figure 2 It is a topographic map with bridge alignments according to the method of this invention;

[0046] Figure 3 yes Figure 2 A schematic diagram of the automatically laid-out cross-section positions corresponding to the topographic map in the image;

[0047] Figure 4 This is a schematic diagram of the cross-section at mileage DK130+850.00 in the method of the present invention;

[0048] Figure 5 This is a schematic diagram of the cross-section at mileage DK131+070.00 in the method of this invention;

[0049] Figure 6 This is a calculation diagram of earthwork balance optimization in the pier cap area according to the method of the present invention. Detailed Implementation

[0050] Exemplary embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the invention to those skilled in the art. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0051] Example

[0052] A method for intelligent planning of survey tasks and application of topographic data for bridge design, such as Figure 1 As shown, this method is implemented based on the determined bridge alignment and digital topographic map of the bridge site area (usually in CAD format, with a scale of no less than 1:2000). The implementation system needs to have the ability to process CAD graphics, perform spatial analysis, conduct numerical calculations, and perform automated modeling. This embodiment takes a railway bridge design project in a mountainous area as an example, with the bridge mileage ranging from DK124+780.00 to DK131+570.00.

[0053] The specific implementation steps are as follows:

[0054] Step A: Topographic map section extraction and intelligent planning:

[0055] The goal of this step is to intelligently and quantitatively identify the locations of key cross-sections that must be measured in the field, based on existing topographic maps, and generate accurate survey task sheets.

[0056] Step B: Collaborative Measurement and Data Acquisition

[0057] The surveying professionals conduct fieldwork based on the precise task sheet generated in step A. Using surveying equipment such as GPS-RTK and total stations, they perform in-situ intensive measurements on each cross-section listed in the task sheet, accurately recording the coordinates (mileage, offset, elevation) of measurement points at regular intervals (e.g., 2 meters) along the cross-section line. After the measurements are completed, the data is organized into a standardized format (e.g., a text file or database table with a specific column order), containing a complete and accurate dataset of longitudinal sections and all measured cross-sections, which is then delivered to the bridge design professionals. This process avoids blind measurements and repeated communication, achieving efficient and accurate data collaboration between different disciplines.

[0058] Step C: Longitudinal Design of Bridge – Optimization of Pier Height and Abutment Elevation:

[0059] The core of this step is to utilize precise, measured 3D terrain data, with the primary optimization objective being the balance of earthwork excavation and filling at the location of each bridge pier, to optimize and determine the top elevation of the pier cap and the height of the pier body for each bridge pier; taking pier No. 206 (mileage DK131+496.10) as an example:

[0060] Terrain data acquisition: The system acquires the planar projection range of the bridge pier abutment and extends it by a certain safety distance (2.5 meters in this embodiment) to form an optimized calculation area; the system extracts the elevation data of all measured ground points in the area, and obtains that the maximum ground elevation of the area is 192.432 meters and the minimum is 190.225 meters.

[0061] Generate alternative solutions: Under the structural requirement of meeting the minimum foundation burial depth (e.g., 0.3 meters), based on the range of ground elevation changes, generate a series of feasible alternative solutions for the design elevation of the top of the pier with a fixed step size (e.g., 0.5 meters, while considering that the pier height should be an integer multiple of 0.5 meters); in this example, 4 solutions were generated.

[0062] Automatic slope design and earthwork calculation: For each pier top elevation scheme, the system automatically calls the algorithm published in the paper "Intelligent Bridge Design Based on Mountain Railway Terrain" (Liao Lijian. Intelligent Bridge Design Based on Mountain Railway Terrain [J]. Journal of Railway Engineering, 2018, 35(12):20-25.) to perform detailed cross-sectional slope design at the pier location (determine the geometry of excavation and slope); based on the designed three-dimensional cut and fill body, the system accurately calculates the total excavation volume and total fill volume under this scheme.

[0063] Scheme Comparison and Optimization: The system calculates the total earthwork volume (excavation volume + fill volume) for each scheme; for example... Figure 6 As shown:

[0064] When the top elevation of the foundation is set at 191.660 meters, the excavation volume is 6.09 m. 3 The fill volume is -24.20m. 3 Therefore

[0065] Total earthwork volume = |excavation + fill| = 18.11m 3 ;

[0066] When the top elevation of the foundation is set at 191.160 meters, the excavation volume is 26.28 m. 3 The fill volume is -10.39m. 3 Therefore

[0067] Total earthwork volume = |excavation + fill| = 15.89m 3 ;

[0068] When the top elevation of the foundation is set at 190.660 meters, the excavation volume is 55.38 m. 3 The fill volume is -3.04m. 3 Therefore

[0069] Total earthwork volume = |excavation + fill| = 52.34 m³ 3 ;

[0070] When the top elevation of the foundation is set at 190.160 meters, the excavation volume is 86.91 meters. 3 The fill volume is 0m. 3 Therefore

[0071] Total earthwork volume = |excavation + fill| = 86.91m 3 .

[0072] After calculation and comparison, when the top elevation of the pier cap is set at 191.160 meters, the total earthwork volume is the smallest (15.89 cubic meters), and the engineering rationality requirement of excavation exceeding filling is met. Therefore, the system automatically selects this elevation as the optimal solution and calculates the pier height based on the design elevation of the bridge longitudinal section.

[0073] By repeating this optimization process for all piers, the longitudinal design of the entire bridge can be completed.

[0074] Step D: Transverse design and quantity calculation of the bridge:

[0075] Based on the optimal locations and elevations of all bridge piers determined in step C, the system automatically completes the subsequent detailed design:

[0076] Detailed cross-section design: Based on design specifications and standard drawings, the system automatically generates a complete cross-section design drawing for each pier, including the cap, pile foundation, pier body, and slope shape.

[0077] Automatic quantity summary: The system decomposes the three-dimensional design model of all piers and abutments of the entire bridge into continuous transverse calculation sections, accumulates the area changes of all sections, automatically summarizes the quantities of excavation, filling, and slope protection area (such as arch frame and hydroseeding) of the entire bridge, and generates a detailed bill of quantities.

[0078] Step A specifically includes the following sub-steps:

[0079] Sub-step 1: Extraction of ground point elevations from longitudinal profile:

[0080] The system reads a CAD topographic map containing the bridge alignment (e.g., the centerline of the left line); based on the algorithm published in "Method for Extracting Ground Point Elevation of Bridge Site Area along Railway Line in Aerial Survey Plan Map" (Liao Lijian, Wang Yuquan, Jiang Peng. Method for Extracting Ground Point Elevation of Bridge Site Area along Railway Line in Aerial Survey Plan Map [J]. China Railway Science, 2012, 33(B8):76-79.), target points are set up at preset intervals (e.g., 5 meters) along the centerline of the bridge line; for each target point, the system searches for all contour lines and elevation points and other topographic features within a circular area with a preset radius (e.g., 30 meters) centered on that target point; by analyzing the relative positional relationship between the target point and these topographic features (e.g., between which two contour lines it is located), the system uses linear or surface interpolation algorithms to accurately calculate the ground elevation of the target point; finally, a preliminary digital longitudinal profile of the bridge site area containing mileage and elevation is generated.

[0081] Sub-step 2: Initial screening of key sections based on the automatic terrain undulation identification algorithm:

[0082] The system performs an automatic terrain undulation recognition algorithm on the above preliminary longitudinal profile data to capture abrupt changes in terrain curvature along the route. These locations are usually sensitive areas of cross-sectional terrain changes.

[0083] Calculating the slope: For the i-th point on the longitudinal profile, the slope (i) is calculated using the following formula:

[0084] Slope(i) = [Elevation(i+1) - Elevation(i)] / [Mileage(i+1) - Mileage(i)];

[0085] Calculation of slope change rate (curvature): The formula for calculating the slope change rate (i) is:

[0086] The rate of change of slope (i) = [slope (i+1) - slope (i)] / [mileage (i+1) - mileage (i)];

[0087] Key point identification: The system sets a slope change rate threshold, which is 0.15 in this embodiment. This value is an empirical value obtained after statistical analysis of a large amount of actual longitudinal profile data of mountain railways. Engineering practice shows that when this value exceeds 0.15, the corresponding ground point is highly likely to be located on a terrain feature line (such as a ridgeline or valley line) or a slope inflection point, which has a decisive influence on the cross-sectional topographic morphology. Therefore, cross-sections need to be set up at this location for control. When the absolute value of the slope change rate at a certain point is greater than this threshold, the system determines that the terrain change at that mileage is drastic and automatically sets up a cross-section measurement task at this location. In this embodiment, a total of 226 such key points were identified throughout the entire route. The topographic map of the bridge alignment within the range of DK130+500.00 to DK131+500.00 is shown below. Figure 2 As shown, the automatically deployed cross-sectional positions are as follows: Figure 3 As shown, these cross sections are mostly located where the slope changes significantly.

[0088] Sub-step 3: Ensuring cross-sectional layout density:

[0089] Check the mileage interval between all cross-section points automatically deployed by the algorithm; the system sets a maximum allowable spacing (10 meters in this embodiment); if the spacing between any two adjacent key points exceeds this maximum value, the system will automatically supplement the cross-section points in that interval according to the principle of equal spacing of 10 meters to ensure the basic density of cross-section deployment in the entire bridge site area.

[0090] Sub-step 4: Extraction and quantitative evaluation of cross-sectional topographic information:

[0091] Along the bridge site line, at each deployment point (including algorithm-identified points and equally spaced supplementary points), the system automatically cuts a cross-sectional line of a certain width (e.g., 50 meters on each side) perpendicular to the bridge site direction, and extracts the ground elevation sequence on the cross-sectional line from the CAD topographic map.

[0092] For each cross section, the system calculates three core topographic quantification indicators:

[0093] Cross-sectional elevation difference ΔH: On the cross-section line, a 20-meter-long sliding window is used to traverse the entire cross-section; the elevation difference between the highest and lowest ground points within each window is calculated; the maximum value among all window calculation results is taken as the ΔH of the cross-section;

[0094] Cross-sectional average slope percentage SAvg: Fits discrete elevation points of the cross-sectional ground line to a straight line (trend line) and calculates the slope percentage of the trend line.

[0095] Topographic relief coefficient K: On the cross-section line, a 10-meter-long sliding window is used; within each window, a local trend line is fitted to the ground points in the window, and the square of the difference between the elevation of each sampling point in the window and the corresponding elevation of the local trend line is calculated. Then, the average of these squared values ​​is calculated. The larger the value, the more severe the topographic relief and the more uneven the terrain within the window. After traversing all windows, the maximum value in the calculation results is taken as the K value of the cross section.

[0096] Sub-step 5: Intelligent judgment and task list generation:

[0097] The system compares the quantitative indicators of each cross-section with preset thresholds. In this embodiment, the thresholds are set as follows: ΔH > 5 meters, or SAvg > 15%, or K > 2. As long as any one of these conditions is met, the cross-section is marked as "must be measured". The thresholds ΔH > 5 meters, SAvg > 15%, and K > 2 are set based on the following criteria: ΔH > 5 meters is used to identify terrain with significant absolute elevation differences (such as steep slopes or deep valleys); SAvg > 15% is used to identify cross-sections on obvious slopes (in engineering, a slope greater than 15% is generally considered an obvious slope); and K > 2 is used to identify cross-sections with dramatic local undulations and complex shapes (such as "V" shaped valleys). These three thresholds constitute a complementary combination of criteria, aiming to accurately screen cross-sections with complex terrain that require precise data acquisition through actual measurement from different dimensions (scale, slope, and shape).

[0098] like Figure 4 As shown, at section DK130+850.00, ΔH=2.66m, SAvg=0.68%, and K=0.878, all within the limits, and are marked as "no actual measurement required"; Figure 5 As shown, at section DK131+070.00, ΔH=5.42m, SAvg=16.6%, K=1.74, triggering both elevation difference and slope criteria simultaneously, and is marked as "must be measured".

[0099] The system compiles all cross-sectional mileage and location information marked as "must be measured" and automatically generates a standard format "Bridge Site Cross-Section Field Measurement Task Sheet", which clearly specifies the specific locations that need to be measured.

Claims

1. A method for intelligent planning and topographic data application in surveying tasks for bridge design, characterized in that, Includes the following steps: A. Topographic map section extraction and intelligent planning: Extract the elevation of longitudinal ground points in the bridge site area from the CAD topographic map, determine the terrain change area and lay out cross sections based on the terrain undulation automatic identification algorithm, and automatically generate the cross section task book that needs to be measured on site by calculating the terrain quantitative index of each cross section and comparing it with the preset threshold. B. Collaborative Measurement and Data Acquisition: The surveying professionals conduct on-site measurements based on the surveying task book generated in step A to obtain standardized longitudinal and cross-sectional datasets containing mileage and elevation. C. Longitudinal design of bridge: Based on the standardized cross-section data obtained in step B, with the earthwork excavation and filling balance at the pier location as the main optimization objective, the elevation of the pier cap and the height of the pier body of each pier are automatically determined. D. Bridge transverse design and engineering quantity calculation: Based on the pier location and elevation determined in step C, the cross-sectional design of the pier and abutment and the slope design are automatically completed, and the quantity of slope protection works is calculated.

2. The intelligent planning and topographic data application method for surveying tasks oriented towards bridge design according to claim 1, characterized in that, Step A specifically includes: From the CAD topographic map, extract the elevation of longitudinal ground points in the bridge site area at preset intervals along the centerline of the bridge route; Using an automatic terrain undulation recognition algorithm, areas with drastic terrain changes were initially identified. Automatically cut a series of cross sections along the bridge site. The cross sections include points determined by an automatic terrain undulation recognition algorithm, and cross section points supplemented according to the principle of equal spacing when the spacing between the above points is greater than the preset maximum value. By calculating the topographic quantification index of each cross section and comparing it with the preset threshold, the system automatically determines and generates a task list for cross sections that need to be measured on-site.

3. The intelligent planning and topographic data application method for surveying tasks in bridge design according to claim 1, characterized in that, In step A, the method for extracting the elevation of longitudinal ground points in the bridge site area from the CAD topographic map is as follows: taking the target point as the center, delineate all contour lines and elevation points within a preset radius around it; analyze the spatial positional relationship between the target point and the topographic features within the delineated area; and calculate the ground elevation of the target point based on a specific positional relationship model and interpolation algorithm.

4. The intelligent planning and topographic data application method for surveying tasks in bridge design according to claim 1, characterized in that, In step A, the automatic terrain undulation recognition algorithm includes: Calculate the slope at each point along the bridge alignment; Calculate the rate of change of slope; When the absolute value of the slope change rate is greater than the preset threshold, the system automatically sets up a cross-sectional measurement task at that mileage location.

5. The intelligent planning and topographic data application method for surveying tasks in bridge design according to claim 4, characterized in that, The preset threshold for the slope change rate is 0.

15.

6. The intelligent planning and terrain data application method for surveying tasks oriented towards bridge design according to claim 1, characterized in that, In step A, the topographic quantification indicators include cross-sectional elevation difference ΔH, cross-sectional average slope percentage SAvg, and topographic relief coefficient K. A cross-section is marked as requiring measurement when any of the following conditions are met: Condition 1: ΔH > 5m; Condition 2: SAvg > 15%; Condition 3: K>2.

7. The intelligent planning and topographic data application method for surveying tasks in bridge design according to claim 6, characterized in that, The method for calculating the cross-sectional elevation difference ΔH is as follows: a 20m long sliding window is used on the cross-section, the maximum elevation difference in each window is calculated, and the maximum value among all the calculation results is taken as the ΔH value.

8. The intelligent planning and terrain data application method for surveying tasks in bridge design according to claim 6, characterized in that, The terrain undulation coefficient K is calculated as follows: a 10m long sliding window is used on the cross section. The mean of the square of the difference between the elevation of the sampling point and the elevation of the trend line in each window is calculated. The maximum value among all the calculation results is taken as the K value.

9. The intelligent planning and topographic data application method for surveying tasks in bridge design according to claim 1, characterized in that, In step C, the method for automatically determining the top elevation of the pier cap of each bridge pier includes: For each pier, obtain the elevation of all ground points within the area formed by the projection range of its pier cap and extending it outward by a certain distance. Under the condition of meeting the structural requirements of minimum foundation burial depth, a series of alternative design elevation schemes for the top of the foundation are generated; For each alternative scheme, design the cross-section slope of the pier; The total excavation and filling volumes for each scheme are calculated and compared. The optimal design elevation of the pier top is automatically selected with the earthwork excavation and filling balance at the location of a single pier as the main optimization objective.

10. The intelligent planning and terrain data application method for surveying tasks oriented towards bridge design according to claim 1, characterized in that, In step D, the bridge transverse design and engineering quantity calculation automatically completes the pier cross-section design by decomposing the three-dimensional engineering entity into multiple transverse key sections, and then calculates the cumulative engineering quantity of slope trimming and slope protection.

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