River and lake management project earthwork calculation method and system based on dynamic BIM

Abstract

The application belongs to the technical field of river and lake management, and particularly relates to a river and lake management engineering earthwork volume calculation method and system based on dynamic BIM. The method comprises the following steps: marking the area between adjacent turning nodes as an evaluation subdivision area; calculating the total offset amount in each evaluation subdivision area, and marking it as a digging area or a filling area according to the positive and negative of the total offset amount; projecting the filling surface and the digging surface in the engineering planning scheme to each evaluation subdivision area to construct a digging model and a filling model; and calculating the digging volume and the filling volume in each evaluation subdivision area based on the digging model and the filling model, and calculating the total earthwork volume. The application can effectively identify and correct data anomalies, provide a region basis conforming to the actual topographic features, and improve the rationality of earthwork volume allocation.

Description

Technical Field

[0001] This invention belongs to the field of river and lake management technology, specifically relating to a method and system for calculating earthwork volume in river and lake management projects based on dynamic BIM. Background Technology

[0002] River and lake management projects are primarily used to ensure water resource security and improve the quality of the ecological environment. Through the effective implementation of these projects, regional ecological balance is maintained, and the quality of the living environment is enhanced. Accurate calculation of earthwork volume is a fundamental task in the planning, design, and construction of river and lake management projects, mainly used to ensure project quality, control project costs, and optimize resource allocation.

[0003] Traditional earthwork calculation methods rely heavily on manual surveying and two-dimensional drawing analysis. Their accuracy is limited by surveying tools, personnel experience, and data processing capabilities, resulting in significant errors and failing to meet the demands of high-precision engineering. Furthermore, traditional methods lack real-time interactive capabilities. The long feedback cycle between the design scheme and actual terrain data hinders dynamic adjustments and optimizations during construction, extending project cycles and significantly increasing the investment of manpower and resources.

[0004] To address the aforementioned issues, this invention proposes a method and system for calculating earthwork volume in river and lake management projects based on dynamic BIM. Summary of the Invention

[0005] To achieve the above-mentioned objectives, the technical solution adopted by the present invention is as follows: The method for calculating earthwork volume in river and lake management projects based on dynamic BIM executes the following when an earthwork volume calculation instruction for the target project area is received: Based on the original survey data of the target project area, multiple assessment sub-regions within the target project area are identified, and the cut-fill attributes of each assessment sub-region are determined. Specifically, this includes: calibrating the original survey data to generate calibrated assessment data; identifying the turning points used to define the assessment sub-regions based on the offset trends in the calibrated assessment data; calculating the total offset within each assessment sub-region, and labeling the assessment sub-region as an excavation area or a fill area according to the sign of the total offset. Based on the cut and fill attributes and engineering planning schemes of each assessment sub-region, an excavation model or filling model is constructed to calculate the earthwork volume, and the total earthwork volume of the target engineering area is calculated.

[0006] Preferably, calibrating the original survey data to generate calibrated evaluation data includes: Based on a preset interference threshold, data points in the original survey data are labeled as valid data or verification data. The calibration data is compared with the baseline data in the offset database to determine the calibration offset corresponding to the calibration data, thereby generating calibrated evaluation data.

[0007] Preferably, based on the cut and fill attributes and engineering planning scheme of each assessment sub-region, an excavation model or filling model is constructed to calculate the earthwork volume, and the total earthwork volume of the target engineering area is calculated, including: Based on the filling and excavation surfaces in the engineering planning scheme, the filling and excavation surfaces are projected onto the assessment subdivision areas that are identified as filling and excavation areas, respectively, to construct filling and excavation models. Based on the excavation and filling models, the excavation volume and filling volume in each assessment subdivision area are calculated, and the sum of the excavation volume and filling volume is taken as the total earthwork volume.

[0008] Preferably, the method further includes: Before calculating the excavation volume, the excavation area is further divided into a main excavation area and a secondary excavation area based on the threshold for dividing the main and secondary excavation areas. When the sum of the excavation volumes of the main excavation area and the secondary excavation area is less than the preset minimum excavation volume, the main excavation area and the secondary excavation area are merged into a single excavation area, and the excavation volume is recalculated based on the single excavation area.

[0009] Preferably, the method further includes: after calculating the total earthwork volume, calculating the difference between the excavation volume and the filling volume to obtain a balance term; and based on the balance term, determining the matching level between the excavation area and the filling area.

[0010] This invention also discloses a dynamic BIM-based earthwork volume calculation system for river and lake management projects, comprising: The data calibration module is used to process raw survey data to generate calibrated evaluation data; The earthwork volume analysis module is configured to respond to the calibrated evaluation data generated by the data calibration module to perform: Based on the calibrated evaluation data, multiple assessment sub-regions within the target engineering area are identified, the cut and fill attributes of each assessment sub-region are determined, and an excavation model or filling model is constructed based on the cut and fill attributes and the engineering planning scheme, and the total earthwork volume is calculated. Additionally, a cut-fill balance assessment module is configured to respond to the excavation and filling volumes calculated by the earthwork volume analysis module to calculate balance terms and calibrate the matching level between the excavation and filling areas.

[0011] Preferably, the data calibration module is configured as follows: Based on a preset interference threshold, data points in the original survey data are labeled as valid data or verification data. Additionally, the calibration data is compared with the baseline data in the offset database to determine the calibration offset corresponding to the calibration data, thereby generating calibrated evaluation data.

[0012] Preferably, the earthwork volume analysis module is configured as follows when identifying and evaluating subdivided areas: Based on the offset trend in the calibrated evaluation data, the turning points used to define the evaluation sub-regions are identified.

[0013] Preferably, before calculating the excavation volume, the excavation area is further divided into a main excavation area and a secondary excavation area based on the threshold for dividing the main and secondary excavation areas; when the sum of the excavation volumes of the main excavation area and the secondary excavation area is less than the preset minimum excavation volume, the main excavation area and the secondary excavation area are merged into a single excavation area, and the excavation volume is recalculated based on the single excavation area.

[0014] Preferably, based on the filling surface and excavation surface in the engineering planning scheme, the filling surface and excavation surface are projected onto the assessment subdivision areas that are determined as filling areas and excavation areas, respectively, to construct filling models and excavation models; based on the excavation models and filling models, the excavation volume and filling volume in each assessment subdivision area are calculated respectively, and the sum of the excavation volume and filling volume is taken as the total earthwork volume.

[0015] Beneficial effects

[0016] 1. This invention, by calling the original survey data, performs data quality judgment, calibration offset acquisition and calibration on the original survey data, and generates calibrated evaluation data, effectively identifying and correcting anomalies and deviations in the original survey data, ensuring the accuracy and reliability of the data basis for subsequent calculations.

[0017] 2. After obtaining the calibrated evaluation data, this invention extracts the offset trend of adjacent data points based on the calibrated evaluation data, determines whether the current data segment is an upward segment or a downward segment, and marks data points with opposite directions of change as turning points, which are then converted into turning nodes. The area between adjacent turning nodes is marked as the evaluation subdivision area. Thus, the evaluation subdivision area is dynamically and finely divided according to the actual trend of terrain change, avoiding the problems of blurred boundaries and inaccurate calculations that may be caused by traditional fixed area division methods.

[0018] 3. After determining the evaluation sub-regions, this invention calculates the total offset within each evaluation sub-region and, based on the sign of the total offset, marks the evaluation sub-regions as excavation areas, filling areas, or equivalent replacement areas. If the total offset is zero, the evaluation sub-region is marked as an equivalent replacement area, thus avoiding unnecessary calculations and resource waste, thereby improving the rationality of earthwork allocation and the efficiency of engineering planning.

[0019] 4. After completing the allocation of cut and fill areas, this invention projects the cut and fill surfaces and excavation surfaces in the engineering planning scheme onto each evaluation sub-area, respectively. Based on the corresponding point layout results, excavation models and cut and fill models are constructed. Then, based on the excavation models and cut and fill models, the excavation volume and cut and fill volume in each evaluation sub-area are calculated, and the total earthwork volume is calculated. This closely integrates the planning intention with the actual terrain changes, and achieves accurate quantification of earthwork volume. Attached Figure Description

[0020] Figure 1 This is a flowchart of the method of the present invention; Figure 2 This is a system module diagram of the present invention. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are merely for explaining the invention and are not intended to limit the scope of protection of the invention.

[0022] Example 1 Please refer to Figure 1 This embodiment provides a method for calculating earthwork volume in river and lake management projects based on dynamic BIM, including the following steps: The process involves accessing raw engineering survey data acquired through technologies such as satellite remote sensing, 3D laser scanning, or UAV photogrammetry. This data contains a large set of geospatial coordinate points describing the terrain and landforms—i.e., data points. The raw survey data undergoes data quality assessment and calibration to ensure the accuracy of subsequent calculations. The specific calibration process includes: Set a preset interference threshold, traverse all data points, and analyze the trend of elevation or position changes between adjacent data points. If the trend of a data point exceeds the preset interference threshold, for example, if its elevation shows a sharp protrusion or depression that does not conform to the natural landform pattern compared with the surrounding points, then the data point is marked as verification data; if the trend is within the preset interference threshold range, then it is marked as valid data. It should be noted that the interference threshold is a preset numerical range, preferably an absolute value of the elevation change rate not exceeding 0.5, that is, for every 1 meter of horizontal distance, the elevation change does not exceed 0.5 meters.

[0023] This interference threshold is used to define the reasonableness of the trend of elevation or location change of data points. When the elevation or location change between adjacent data points exceeds this threshold, it indicates that the data point may have measurement errors or abnormal terrain features and needs to be verified. For data points marked as verification data, the spatial difference between them is calculated by comparing them with the reference data. This difference is defined as the calibration offset of the data point. This calibration offset is associated with the corresponding data point and stored together in the offset database as the basis for subsequent corrections.

[0024] After completing the above steps, calibrated evaluation data is generated, which includes all original data points and the corresponding calibration offset for each data point.

[0025] The baseline data is reference data used to compare with the calibration data to determine its calibration offset. It can be a preset theoretical value or a reference value calculated by interpolation, fitting or other methods based on the valid data adjacent to the calibration data.

[0026] Based on the calibrated assessment data, terrain feature identification and regional division are performed to segment continuous terrain data into multiple sub-regions with independent terrain trends, as detailed below: The data points in the calibrated assessment data are processed sequentially, and the local upward or downward displacement trend of the terrain is determined by calculating the elevation difference between every two adjacent data points. When the direction of the offset trend reverses, for example, from a continuous upward offset trend to a downward offset trend or vice versa, and the magnitude of the change in the offset trend exceeds the inflection value, the data point where the offset trend reverses is marked as an inflection point. This is to filter out unimportant minor topographic fluctuations. These inflection points usually correspond to key landform features such as ridgelines and valley lines.

[0027] The turning point value is a preset threshold for identifying significant terrain changes.

[0028] These marked turning points are established as turning nodes in the data structure, and the entire assessment area is divided into multiple independent assessment sub-regions based on the virtual boundary lines connecting adjacent turning nodes. This ensures that the terrain change and offset trends within each assessment sub-region are consistent, providing logically clear and geographically reasonable units for subsequent zoning calculations of cut and fill volumes.

[0029] After completing the regional subdivision, the earthwork engineering attributes of each subdivision need to be determined. The specific process is as follows: Calculate the sum of the calibration offsets of all data points in each evaluation subdivision area to obtain the total offset of that area, based on the preset engineering design elevation datum. If the total offset is positive, it means that the average terrain of the area is lower than the design elevation in the engineering plan, and earthwork filling is required. Therefore, it is marked as a filling area. If the total offset is negative, it means that the average terrain of the area is higher than the design elevation in the engineering plan, and earthwork excavation is required. Therefore, it is marked as an excavation area. If the total offset is close to zero within the allowable error range, it indicates that the earthwork in the area is basically balanced and can be designated as an equivalent replacement area.

[0030] Furthermore, a threshold for dividing primary and secondary excavation zones is set to differentiate the intensity of excavation operations. Within the marked excavation area, sub-regions with absolute values ​​of marked offsets greater than the threshold for dividing primary and secondary excavation zones are identified and marked as primary excavation zones. These areas are the focus of earthwork excavation. The remaining area is designated as the secondary excavation area. To ensure the economy of construction, if the sum of the calculated excavation volumes of the main excavation area and the secondary excavation area is less than the preset minimum excavation volume, the two will be merged into a single excavation area, and the total offset after merging will be recalculated to avoid independent operations on scattered small plots that do not have economies of scale.

[0031] The preferred threshold for dividing the primary and secondary excavation areas is 1.5 meters.

[0032] Based on the design elevations determined in the engineering plan, infill and excavation surfaces are generated for volume calculation. For each identified infill and excavation area, a three-dimensional geometry is constructed for accurate earthwork volume calculation. Specifically: For the filled area, the corresponding filled geometry is a three-dimensional space formed by using the calibrated terrain surface in the area as the bottom surface, the filled surface of the engineering planning scheme as the top surface, and the boundary of the evaluation subdivision area as the lateral constraint. Similarly, for the excavation area, the corresponding excavation geometry is a three-dimensional space formed by the excavation surface of the engineering planning scheme as the bottom surface, the calibrated terrain surface in the area as the top surface, and the boundary of the evaluation subdivision area as the lateral constraint. These three-dimensional geometries are accurately constructed in the dynamic building information model environment, and their volume directly corresponds to the amount of earthwork that needs to be filled or excavated.

[0033] Based on the constructed excavation and infill geometries, the excavation and infill volumes within each evaluation sub-region are accurately calculated. The calculation process is as follows: Numerical integration methods are applied to each three-dimensional geometry. For example, by superimposing a high-density virtual mesh on its bottom surface, the geometry is discretized into a large number of tiny prismatic elements. The volume of each tiny prismatic element is calculated, which is the area of ​​the mesh element multiplied by its average height at that location. Finally, the volumes of all the tiny prismatic elements are summed to obtain the total volume of the geometry. The excavation volumes of all excavated areas are added together to obtain the total excavation volume of the project. The filling volumes of all filled areas are added together to obtain the total filling volume of the project. The sum of the two is the total earthwork volume of the river and lake management project.

[0034] Furthermore, to optimize the allocation of earthwork, the difference between the total excavation volume and the total filling volume is calculated. This difference is designated as a balance term. If the balance term is positive, its value represents the remaining excavation volume that needs to be transported off-site; if it is negative, its absolute value represents the remaining filling volume that needs to be purchased off-site. Based on the size of the balance term and the geographical proximity of each filling and excavation area, a matching level assessment standard is set to classify the earthwork allocation schemes of the excavation area and the filling area into levels such as highly matched, moderately matched, or mismatched. This provides the construction party with intuitive and quantitative decision support to minimize earthwork transportation costs and environmental impact.

[0035] Matching grade evaluation criteria are used to assess the quality of earthwork allocation schemes between excavation and filling areas. They typically consider factors such as the size of the balance term and geographical proximity, and classify allocation schemes into different grades.

[0036] Example 2 Please see Figure 2 As shown, this embodiment provides a dynamic BIM-based earthwork volume calculation system for river and lake management projects, including the following modules: Data calibration module: configured to receive raw survey data and calibrate it to generate calibrated evaluation data.

[0037] When a command to calculate the earthwork volume for the target engineering area is received, the data calibration module analyzes each data point in the original survey data based on a preset interference threshold. If a data point exceeds the preset interference threshold, it is calibrated as verification data; otherwise, it is calibrated as valid data. The preset interference threshold is a preset numerical range or statistical standard used to determine whether data points are subject to abnormal interference.

[0038] For data points that are calibrated as verification data, the data calibration module compares them with the reference data in the offset database. The offset database pre-stores correction parameters or reference values ​​corresponding to different types of interference such as sensor drift, environmental noise, and measurement error.

[0039] By comparison, the data calibration module determines the calibration offset corresponding to the verification data. Specifically, if the verification data is caused by sensor drift, the data calibration module will look up the correction value for this type of drift in the offset database.

[0040] The data calibration module applies the calibration offset to the verification data and combines it with the valid data to generate calibrated evaluation data. The calibrated evaluation data is a dataset that has been cleaned and corrected to more accurately reflect the original topography of the target engineering area.

[0041] Earthwork volume analysis module: Configured to respond to the calibrated assessment data generated by the data calibration module to perform identification and assessment of subdivided areas, determine cut and fill attributes, construct excavation or fill models, and calculate the total earthwork volume.

[0042] When the calibrated assessment data is received, the earthwork volume analysis module first identifies the turning points used to define the subdivision of the assessment area based on the offset trend in the calibrated assessment data. The turning points represent data points where the direction or rate of change of terrain elevation changes significantly. The turning points naturally divide the target engineering area into different assessment subdivisions.

[0043] The offset trend can be obtained by performing topographic profile analysis, elevation change rate calculation, or curvature analysis on the calibrated assessment data.

[0044] The earthwork volume analysis module calculates the total offset within each assessment sub-region. The total offset can be obtained by comparing the calibrated assessment data within the assessment sub-region with the design elevation in the engineering planning scheme and accumulating the elevation difference. For example, the grid method or triangular mesh method can be used to calculate the volume difference of each grid or triangular region and then accumulate them. Depending on the sign of the total offset, the earthwork volume analysis module will label the assessment sub-region as an excavation area or a filling area.

[0045] The earthwork volume analysis module constructs an excavation model or filling model for calculating earthwork volume based on the cut and fill attributes of each assessment sub-region and the engineering planning scheme. Specifically, according to the filling surface and excavation surface in the engineering planning scheme, the earthwork volume analysis module projects the filling surface onto the assessment sub-region that is identified as the filling region to construct the filling model; at the same time, it projects the excavation surface onto the assessment sub-region that is identified as the excavation region to construct the excavation model. The excavation model and the filling model can be three-dimensional digital models, such as surface models based on dynamic building information models or geographic information systems.

[0046] After constructing the excavation model, before calculating the excavation volume, the earthwork volume analysis module further divides the excavation area into main excavation area and secondary excavation area based on the primary and secondary excavation area division threshold. The primary and secondary excavation area division threshold can be a preset volume or area threshold, used to distinguish between main earthwork operation areas and sporadic earthwork operation areas. For example, areas with a volume greater than the primary and secondary excavation area division threshold are classified as primary excavation areas, and areas with a volume less than the primary and secondary excavation area division threshold are classified as secondary excavation areas.

[0047] The module determines whether the sum of the excavation volumes of the main excavation area and the secondary excavation area is less than the preset minimum excavation volume. The preset minimum excavation volume is the minimum excavation volume that is considered economically reasonable in engineering practice. If it is less than the preset minimum excavation volume, the earthwork analysis module will merge the main excavation area and the secondary excavation area into a single excavation area and recalculate the excavation volume based on the single excavation area to avoid scattered operations and improve construction efficiency.

[0048] Based on the excavation model and the filling model, the excavation volume and the filling volume in each evaluation sub-area are calculated respectively. For example, the volume difference between the surface of the excavation model and the filling model and the original terrain surface is calculated, and the sum of the excavation volume and the filling volume is taken as the total earthwork volume of the target engineering area.

[0049] Cut-fill balance assessment module: Configured to respond to the excavation and filling volumes calculated by the earthwork analysis module, in order to calculate the balance term and determine the matching level between the excavation and filling areas, specifically: After the total earthwork volume is calculated, the cut-fill balance assessment module calculates the difference between the excavation volume and the filling volume to obtain the balance item, which reflects the surplus or deficit of earthwork volume in the project area. The cut-fill balance assessment module determines the matching level between the excavation area and the filling area based on the balance items. The matching level can be classified according to the absolute value of the balance items or their proportion to the total earthwork volume.

[0050] Furthermore, a balance term close to zero indicates a high matching level, meaning the earthwork is basically balanced, while a large balance term indicates a low matching level, meaning the earthwork is severely unbalanced and requires external transportation or purchase of earthwork.

[0051] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for calculating earthwork volume in river and lake management projects based on dynamic BIM, characterized in that, When an instruction to calculate the earthwork volume for the target project area is received, execute: Based on the original survey data of the target project area, multiple assessment sub-regions within the target project area are identified, and the cut-fill attributes of each assessment sub-region are determined. Specifically, this includes: calibrating the original survey data to generate calibrated assessment data; identifying the turning points used to define the assessment sub-regions based on the offset trends in the calibrated assessment data; calculating the total offset within each assessment sub-region, and labeling the assessment sub-region as an excavation area or a fill area according to the sign of the total offset. Based on the cut and fill attributes and engineering planning schemes of each assessment sub-region, an excavation model or filling model is constructed to calculate the earthwork volume, and the total earthwork volume of the target engineering area is calculated. The calibration of the original survey data to generate calibrated evaluation data includes: Based on a preset interference threshold, data points in the original survey data are labeled as valid data or verification data. The calibration data is compared with the baseline data in the offset database to determine the calibration offset corresponding to the calibration data, thereby generating calibrated evaluation data. Based on the cut and fill attributes and engineering planning schemes of each assessment sub-region, an excavation model or filling model is constructed to calculate the earthwork volume, and the total earthwork volume of the target engineering area is calculated, including: Based on the filling and excavation surfaces in the engineering planning scheme, the filling and excavation surfaces are projected onto the assessment subdivision areas that are identified as filling and excavation areas, respectively, to construct filling and excavation models. Based on the excavation and filling models, the excavation volume and filling volume in each assessment subdivision area are calculated, and the sum of the excavation volume and filling volume is taken as the total earthwork volume. The method further includes: after calculating the total earthwork volume, calculating the difference between the excavation volume and the filling volume to obtain a balance term; and based on the balance term, determining the matching level between the excavation area and the filling area.

2. The method for calculating earthwork volume in river and lake management projects based on dynamic BIM according to claim 1, characterized in that, The method further includes: Before calculating the excavation volume, the excavation area is further divided into a main excavation area and a secondary excavation area based on the threshold for dividing the main and secondary excavation areas. When the sum of the excavation volumes of the main excavation area and the secondary excavation area is less than the preset minimum excavation volume, the main excavation area and the secondary excavation area are merged into a single excavation area, and the excavation volume is recalculated based on the single excavation area.

3. A dynamic BIM-based earthwork volume calculation system for river and lake management projects, characterized in that, include: The data calibration module is used to process raw survey data to generate calibrated evaluation data; The earthwork volume analysis module is configured to respond to the calibrated evaluation data generated by the data calibration module to perform: Based on the calibrated evaluation data, multiple assessment sub-regions within the target engineering area are identified, the cut and fill attributes of each assessment sub-region are determined, and an excavation model or filling model is constructed based on the cut and fill attributes and the engineering planning scheme, and the total earthwork volume is calculated. In addition, a cut-fill balance assessment module is configured to respond to the excavation and filling volumes calculated by the earthwork volume analysis module to calculate balance terms and calibrate the matching level between the excavation and filling areas. The data calibration module is configured as follows: Based on a preset interference threshold, data points in the original survey data are labeled as valid data or verification data. Additionally, the calibration data is compared with the baseline data in the offset database to determine the calibration offset corresponding to the calibration data, thereby generating calibrated evaluation data; Based on the filling and excavation surfaces in the engineering planning scheme, the filling and excavation surfaces are projected onto the assessment subdivision areas that are identified as filling and excavation areas, respectively, to construct filling and excavation models. Based on the excavation and filling models, the excavation volume and filling volume in each assessment subdivision area are calculated, and the sum of the excavation volume and filling volume is taken as the total earthwork volume. When identifying and evaluating subdivided areas, the earthwork volume analysis module is configured to identify the turning points used to define the subdivided areas based on the offset trends in the calibrated evaluation data.

4. The earthwork calculation system for river and lake management projects based on dynamic BIM according to claim 3, characterized in that, Before calculating the excavation volume, the excavation area is divided into a main excavation area and a secondary excavation area based on the threshold for dividing the main and secondary excavation areas. When the sum of the excavation volumes of the main excavation area and the secondary excavation area is less than the preset minimum excavation volume, the main excavation area and the secondary excavation area are merged into a single excavation area, and the excavation volume is recalculated based on the single excavation area.

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