BIM-based low-carbon construction drawing review method and system for house building project

Abstract

The application relates to the technical field of BIM construction drawing, in particular to a BIM-based low-carbon construction drawing review method and system for a house building project, which comprises the following steps: reading a BIM model, performing collision detection on mechanical and electrical pipelines and structural walls in the model, extracting interference areas where physical collisions occur, and obtaining effective interference points; evaluating the carbon emission of in-situ excavation waste generated by in-situ oblique slotting through walls; iteratively solving optimal wall-penetrating points, calculating the space congestion degree representing the degree of limitation of the construction environment; calculating the newly-added carbon emission of the pipeline foundation generated by additional translation, evaluating the carbon emission generated by detouring and avoiding, and comparing the carbon emission of in-situ excavation waste and the carbon emission generated by detouring and avoiding, to generate differentiated drawing review instructions for drawing review modification. The application effectively avoids the false low-carbon drawing review decision caused by the blind elimination of BIM geometric collision, which leads to the rapid increase of the actual project carbon footprint.

Description

Technical Field

[0001] This application relates to the field of BIM construction drawing technology, specifically to a BIM-based method and system for reviewing low-carbon construction drawings for building construction projects. Background Technology

[0002] In the field of detailed design of MEP (Mechanical, Electrical, and Piping) systems using Building Information Modeling (BIM), 3D geometric collision detection is a crucial step in the design review process to ensure smooth construction. However, in specific situations where existing building MEP system renovation projects or new construction projects require on-site secondary excavation to remedy omissions in the masonry structure for pre-reserved sleeves, the existing design review optimization logic has significant blind spots.

[0003] When existing BIM drawing review software handles collisions caused by pipelines tilting and penetrating walls, it typically issues a direct, mandatory drawing modification order, requiring designers to relocate and detour to eliminate geometric interference. However, in densely populated utility tunnels or shaft areas, relocating pipelines outwards often forces them to intrude into narrow gaps between components, severely hindering the erection of scaffolding and the operation of lifting platforms on site, significantly increasing machinery operating time, and consequently generating extremely high carbon emissions from construction operations.

[0004] Current technology can only calculate the difference in pipe length before and after pipeline relocation, lacking a quantitative calculation mechanism to convert spatial topological congestion into construction inefficiency costs. This makes it impossible for design reviewers to determine whether the "increased carbon emissions from pipe material + reduced carbon emissions from construction inefficiency" incurred by relocation is lower than the carbon emissions from waste generated by retaining the original design and implementing in-situ trenching repairs. Due to the lack of a unified quantitative benchmark for carbon emissions comparison, blindly relocating pipelines often leads to an increase in the actual total carbon emissions of the building, contrary to the original intention of low-carbon optimization. Summary of the Invention

[0005] To address the aforementioned technical issues, a BIM-based method and system for reviewing low-carbon construction drawings for building projects is provided to resolve existing problems.

[0006] The solution to the technical problem proposed in this application is to provide a BIM-based method and system for reviewing low-carbon construction drawings for building projects, including the following steps: In a first aspect, embodiments of this application provide a method for reviewing low-carbon construction drawings for building construction projects based on BIM. This method includes the following steps: Read the BIM model, perform collision detection on the electromechanical pipelines and structural walls in the model, extract the interference area where physical collision occurs, and analyze the tilt angle between the electromechanical pipelines and structural walls that collide within the interference area to filter the interference area and obtain effective interference points. For each effective interference point, based on the geometric characteristics of the pipeline passing through the wall and the material of the structural wall, assess the carbon emissions of in-situ excavation waste generated by maintaining the in-situ oblique groove through the wall. A two-dimensional virtual projection plane parallel to the wall surface is constructed with the effective interference point as the geometric origin. The solid components around the effective interference point are projected onto this projection plane to generate component interference avoidance boundaries. Within this projection plane, the repulsion cost of avoiding all component interference avoidance boundaries and the convergence cost of approaching the effective interference point are simulated to iteratively solve for the optimal wall penetration point. Based on the repulsion cost of the optimal wall penetration point during iterative convergence, the spatial congestion degree characterizing the degree of restriction of the construction environment is calculated. The additional carbon emissions generated by the pipeline due to the translation are calculated based on the translation distance between the optimal wall penetration point and the effective interference point and the reversal path after the vertical wall penetration. Combined with the spatial congestion, the carbon emissions from detours caused by the translation are evaluated. The carbon emissions from in-situ excavation waste and detours are compared, and differentiated drawing review instructions are generated based on the comparison results for drawing review modification.

[0007] Preferably, the step of screening interference regions to obtain effective interference points includes: for each interference region, obtaining the axial vector of the colliding electromechanical pipeline and the surface normal vector of the outer surface of the colliding structural wall, calculating the acute angle between the two vectors as the pipe wall tilt angle; selecting interference regions where the pipe wall tilt angle is less than or equal to the preset maximum allowable wall penetration tilt angle, defining them as effective interference regions; and defining the centroid of each effective interference region as an effective interference point.

[0008] Preferably, the calculation process for the carbon emissions of the in-situ excavation waste is as follows: Obtain the normal thickness of the structural wall and the cross-sectional radius of the electromechanical pipeline in the two collision components that constitute each effective interference point; The sum of the cross-sectional radius of the electromechanical pipeline in the two colliding components, the preset pipeline installation clearance, and the preset pipeline additional layer thickness is taken as the effective opening radius, and the slot cross-sectional area is calculated based on the effective opening radius. The ratio of the normal thickness to the cosine of the pipe wall inclination angle is taken as the oblique penetration length; the product of the groove cross-sectional area and the oblique penetration length is taken as the oblique groove repair volume. The product of the oblique groove repair volume and the preset waste destruction carbon emission coefficient is used as the in-situ excavation waste carbon emission amount corresponding to each effective interference point.

[0009] Preferably, the method for obtaining the component interference avoidance boundary is as follows: taking the geometric origin as the center point, a local spatial bounding box of a preset size is extracted. After performing a three-dimensional solid truncation operation on the remaining solid components within the local spatial bounding box except for the two collision components that constitute the effective interference point, the components are vertically projected onto a two-dimensional virtual projection plane along the opposite direction of the surface normal vector of the structural wall to form multiple two-dimensional projection contours. An expansion operation is performed on each two-dimensional projection contour outward, and its expansion width is equal to the effective opening radius. The boundary of the expanded contour is defined as the component interference avoidance boundary.

[0010] Preferably, the iterative solution process for the optimal wall penetration point is as follows: Using the geometric origin in the two-dimensional virtual projection plane as the target point for the regression gravity. And establish a virtual cursor, initially placing the virtual cursor at the return gravity target point; then the virtual cursor at the th... The position coordinates at the next iteration are recorded as the test coordinates. Solution from point to The direction vector is multiplied by the preset gravity gain coefficient and used as the convergence cost gradient. calculate The minimum vertical distance to each component interference avoidance boundary in the two-dimensional virtual projection plane is used to filter out all component interference avoidance boundaries that satisfy the minimum vertical distance being less than a preset distance limit. These are then considered as effective repulsion boundaries, and a repulsion force component is generated for each effective repulsion boundary. The direction of this repulsion force component is set to be perpendicular from the boundary to the test coordinate point. The magnitude of the repulsive force component is the negative mapping result of the minimum vertical distance corresponding to the effective repulsive boundary; The repulsive force components of all effective repulsive boundaries are vector-summed to obtain the repulsive cost gradient. This gradient is then vector-summed with the convergence cost gradient to obtain the total cost gradient. Starting from the point indicated by the total cost gradient, extend the distance corresponding to the product of the magnitude of the total cost gradient and the preset constant update step size, and use this distance as the virtual cursor at the _th ... Test coordinates at the next iteration By continuously iterating, the interval between test coordinates of two adjacent iterations is calculated. When the interval is less than or equal to a preset convergence threshold or the maximum number of iterations is reached, the iteration stops and the test coordinates of the last iteration are taken as the optimal wall-penetrating point.

[0011] Preferably, the calculation process of the spatial congestion is as follows: calculate the minimum vertical distance between the optimal wall penetration point and the interference avoidance boundary of each component in the two-dimensional virtual projection plane, and select the minimum value from all minimum vertical distances. If the minimum value is less than the preset safety threshold, the spatial congestion is assigned a preset penalty value; otherwise, the spatial congestion is the magnitude of the repulsion cost gradient at the last iteration.

[0012] Preferably, the calculation process for the basic increase in carbon emissions is as follows: Calculate the straight-line distance between the optimal wall-penetrating point and the geometric origin in the two-dimensional virtual projection plane, and record it as the vertical wall-penetrating translation distance. Double this distance as the increased pipe length of the parallel segment. Calculate the difference between the oblique wall-penetrating length and the normal thickness as the saved pipe length. The difference between the increased pipe length of the parallel segment and the saved pipe length is taken as the length difference. If the length difference is less than 0, the net pipeline growth rate is assigned to 0; otherwise, the net pipeline growth rate is the length difference. Based on the vertical wall penetration translation distance and the cross-sectional radius of the electromechanical pipeline, the preset engineering pipe fitting matching rule library is searched to obtain the required dynamic pipe fitting combination equivalent; Calculate the product of the net increase in pipeline length and the preset unit carbon emission equivalent of pipe manufacturing, calculate the product of the dynamic pipe fitting combination equivalent and the preset unit carbon emission equivalent of pipe fitting manufacturing, and use the sum of the two products as the basic increase in carbon emissions.

[0013] Preferably, the calculation process of the detour and avoidance carbon emissions is as follows: the spatial congestion degree and the preset congestion dimension scaling factor are positively integrated as the congestion inefficiency carbon emission multiplier; the product of the basic new carbon emissions and the congestion inefficiency carbon emission multiplier is used as the detour and avoidance carbon emissions corresponding to each effective intervention point.

[0014] Preferably, the generation of differentiated drawing review instructions includes: for each effective interference point, if the carbon emission from detouring is less than the carbon emission from in-situ excavation waste, a mandatory rerouting drawing review instruction is generated; otherwise, an original drawing exemption drawing review instruction is generated.

[0015] Secondly, embodiments of this application also provide a BIM-based low-carbon construction drawing review system for building construction projects, including a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, it implements the steps of any of the above-described BIM-based low-carbon construction drawing review methods for building construction projects.

[0016] This application has at least the following beneficial effects: This application uses collision detection to identify and filter effective interference points whose wall penetration angles conform to conventional construction conditions, while excluding invalid collisions where pipelines are almost parallel to the wall surface. It calculates the carbon emissions of in-situ excavation waste, which benefits from considering multi-dimensional geometric elements, making the trench volume calculation closer to actual construction conditions. This transforms the demolition action into a calculable carbon emission equivalent, quantifying the bottom-line carbon emission cost of the "preserving the original design" option. Furthermore, it constructs a two-dimensional virtual projection plane and generates component interference avoidance boundaries, iteratively solving for the optimal wall penetration point. This benefits from translating complex obstacle avoidance problems in three-dimensional space into more comprehensive solutions. The problem is reduced to a two-dimensional plane, which greatly improves the optimization efficiency of the iterative algorithm. Through the force field game of convergence cost and repulsion cost, it can automatically find the absolute optimal wall-penetrating point with the shortest translation distance and no physical collision. The calculation of spatial congestion degree, which represents the degree of restriction of the construction environment, has the beneficial effect of innovatively using the repulsion cost during optimization convergence to represent spatial congestion degree. It successfully maps the topological environmental tension in the virtual algorithm to a quantitative characteristic index of the obstruction of workers' operation by the restricted space in real construction, so as to reflect the difficulty of scaffolding erection and the degree of restriction of mechanical operation faced by construction workers in actual operation. The calculation of the basic increase in carbon emissions, combined with the determination of detour carbon emissions based on space congestion, has the advantage of quantifying the material increase of the relocation plan into the basic increase in carbon emissions, realizing the carbon emission conversion of material consumption, and using space congestion to penalize the reduction in construction efficiency, objectively restoring the true cost of the combined carbon emissions from the increase in pipe materials and the combined labor / mechanical energy consumption. By comparing the carbon emissions of in-situ excavation waste and detour carbon emissions, differentiated drawing review instructions are generated based on the comparison results for drawing review modifications. Its advantage lies in realizing the quantitative basis of drawing review decisions by directly comparing the carbon emissions of the two schemes. The system integrates simplification and automation. When detours result in lower carbon emissions, a forced rerouting command is output, guiding designers to change inclined wall penetrations to vertical wall penetrations and to move around to the optimal penetration point. When in-situ excavation results in lower or equal carbon emissions, an original drawing exemption command is output, guiding designers to retain the original inclined layout design, avoiding unnecessary waste of pipe materials and reduced construction efficiency. This comprehensive quantitative comparison mechanism, which considers both material consumption and construction environmental resistance, ensures that the final adopted solution is a truly low-carbon solution. It effectively avoids pseudo-low-carbon drawing review decisions that lead to a surge in the actual engineering carbon footprint due to blindly eliminating BIM geometric collisions. Attached Figure Description

[0017] Figure 1 A flowchart illustrating the steps of a BIM-based low-carbon construction drawing review method for building construction projects provided in this application embodiment; Figure 2 A flowchart illustrating the steps of the method for obtaining carbon emissions from in-situ excavation waste provided in this application embodiment. Detailed Implementation

[0018] The following, in conjunction with the accompanying drawings and embodiments, provides a more detailed description of the BIM-based low-carbon construction drawing review method and system for building construction projects proposed in this application.

[0019] Please see Figure 1 This document illustrates a flowchart of a BIM-based low-carbon construction drawing review method for building construction projects, provided in one embodiment of this application. The method includes the following steps: Step 1: Read the BIM model, perform collision detection on the MEP pipelines and structural walls in the model, extract the interference areas where physical collisions occur, and analyze the tilt angle between the MEP pipelines and structural walls within the interference area to filter the interference areas and obtain effective interference points; for each effective interference point, based on the geometric features of the pipelines penetrating the wall and the material of the structural wall, evaluate the carbon emissions of in-situ excavation waste generated by maintaining the in-situ oblique groove through the wall.

[0020] During the review of construction drawings for building projects, spatial conflicts between pipelines and structural walls are one of the main causes of on-site rework, excavation and damage, and additional carbon emissions. By quantifying the carbon emission impact of different design schemes, the optimal low-carbon decision can be made between in-situ demolition and relocation to avoid rerouting.

[0021] This embodiment applies to engineering scenarios such as the renovation of existing building electromechanical pipelines, or special situations in new construction projects where secondary excavation is necessary to remedy the situation due to the omission of pre-installed sleeves during structural construction. In such specific scenarios, if the original construction drawings are retained, directly creating openings in the solid wall using mechanical equipment involves in-situ excavation, which is a real and objective construction action. Conversely, if the drawings are modified to adjust the pipeline to pass vertically through the wall or to move it horizontally, additional material consumption and reduced mechanical efficiency due to construction in confined spaces will be incurred, resulting in carbon emissions. The two solutions correspond to different carbon emission costs: the former is reflected in the carbon emissions from waste disposal caused by wall damage, while the latter is reflected in the total carbon emissions caused by the increased pipeline relocation. This solution uses the carbon emissions from in-situ excavation as the evaluation benchmark, quantifies the carbon emission equivalent of the two solutions using a BIM model, and decides whether to force a rerouting based on the comparison results.

[0022] Based on the above analysis, global parameters are read from external building construction cost standards databases and carbon emission standards databases, specifically including: The waste destruction carbon emission coefficient is used to characterize the carbon emission equivalent generated per unit volume of a structural wall of a specific material using mechanical crushing. This value is determined according to the calculation method in the national standard "Standard for Calculation of Building Carbon Emissions". In this embodiment, for ordinary unreinforced concrete walls, the range of the waste destruction carbon emission coefficient is set as follows: For reinforced concrete walls, the carbon emission coefficient for waste destruction is set as follows: The specific value can be determined according to the construction machinery shift quota, electricity carbon emission factor and waste transportation distance in the project location, and in accordance with the calculation method specified in the national standard "Building Carbon Emission Calculation Standard". The pipeline installation clearance is used to characterize the extra width of the standard holes reserved around the pipe wall to meet the needs of on-site pipe installation operations. The value of the pipeline installation clearance ranges from 20mm to 50mm. In this embodiment, the pipeline installation clearance is set to 20mm for pipe diameters of DN50 and below, 30mm for pipe diameters above DN50 and below DN100, and 50mm for pipe diameters of DN100 and above. As for other implementation methods, the implementer can set it according to the actual situation. The congestion metric scaling factor, used as an empirical alignment parameter, limits the excessive expansion of subsequent efficiency degradation indicators. The value ranges from 0.01 to 0.05. In this embodiment, the congestion metric scaling factor is set to 0.02. As for other implementation methods, the implementer can set it according to the actual situation. Additional layer thickness for pipelines is used to characterize the conventional thickness of the insulation layer, fireproof layer, or non-body accessories such as connecting flanges that wrap the outside of electromechanical pipelines. Depending on the pipeline's purpose and design specifications, the insulation layer thickness ranges from 20mm to 50mm for air conditioning hot and cold water pipes and heating pipes; for fire protection pipelines, when fireproof wrapping is used, the fireproof layer thickness is usually 10mm to 30mm; when only considering protruding parts such as flanges, the additional layer thickness can be 15mm to 25mm; as other implementation methods, implementers can set it according to the actual situation. The maximum permissible wall penetration angle, serving as a limiting threshold constant to prevent division-by-zero collapse boundaries generated in geometric calculations, is typically set to [value missing] in engineering practice. As other implementation methods, implementers can set them according to the actual situation; Read the building information model (BIM), call the 3D geometric collision detection operator to perform collision detection on the electromechanical pipelines and structural walls in the model, and define all the spatial areas where physical collisions occur as interference areas; In this embodiment, a three-dimensional geometric Boolean intersection detection operator is used for collision detection. The three-dimensional geometric Boolean intersection detection operator is a well-known technology and will not be described in detail here. The grid cells located on the electromechanical pipeline components and the grid cells located on the structural walls can be obtained from the building information model. By calling the three-dimensional geometric Boolean intersection detection operator, the spatial region contained in the grid cells that are occupied by each other is found, that is, the Boolean intersection of the two components. The corresponding axis-aligned bounding box is defined as the interference region. The axis-aligned bounding box is a well-known technology and will not be described in detail here.

[0023] For the two colliding components constituting each interference region, namely the electromechanical pipeline that collides and the structural wall that collides, the axial vector of the electromechanical pipeline that collides and the surface normal vector of the outer surface of the structural wall that collides are obtained, and the acute angle value of the angle between the two vectors is calculated as the pipe wall tilt angle. In this embodiment, the surface normal vector of the outer surface of the structural wall is extracted from the wall structure, and the axial vector of the electromechanical pipeline is extracted from the pipeline. The direction of the axial vector is from the center of the pipeline to the external space. The surface normal vector and the axial vector are multiplied by a vector dot product, and the pipe wall tilt angle between the two is calculated by the inverse cosine function.

[0024] The interference area with a pipe wall tilt angle less than or equal to the preset maximum allowable wall tilt angle is defined as the effective interference area; It should be noted that when the pipe wall tilt angle is greater than the maximum allowable wall penetration tilt angle, it indicates that the pipeline layout direction is extremely parallel to the wall surface, which is not a normal wall penetration condition. In this case, the subsequent calculation process for the interference area should be stopped directly. Conversely, it indicates that the interference area is a valid tilted wall penetration behavior, and subsequent calculations should be performed.

[0025] The centroid of each effective interference region is defined as the effective interference point; The calculation of the center of gravity is a well-known technique and will not be elaborated upon here.

[0026] Furthermore, since the construction drawings do not directly indicate the actual dimensions of the irregularly shaped holes, algebraic deduction is required based on the cross-sectional radius of the electromechanical pipelines, the thickness of the pipeline additional layer, and the tilt orientation to reconstruct the actual trenching damage volume. This volume is then uniformly converted into a carbon emission equivalent standard to calculate the carbon emission of the in-situ excavation waste. The flowchart of the method for obtaining the carbon emission of in-situ excavation waste provided in this application embodiment is shown below. Figure 2 As shown, it specifically includes: Obtain the normal thickness of the structural wall and the cross-sectional radius of the electromechanical pipeline in the two collision components that constitute each effective interference point; In this embodiment, the normal thickness refers to the thickness in the direction perpendicular to the wall surface.

[0027] For each effective interference point, the sum of the cross-sectional radius of the electromechanical pipeline, the preset pipeline installation clearance, and the preset pipeline additional layer thickness is taken as the effective opening radius, and the slot cross-sectional area is calculated based on the effective opening radius. The ratio of the normal thickness to the cosine of the pipe wall inclination angle is taken as the oblique penetration length; the product of the groove cross-sectional area and the oblique penetration length is taken as the oblique groove repair volume. In this embodiment, the formula for calculating the volume of the oblique groove repair is: in, To repair the volume by cutting grooves at an angle, For the effective opening radius, Normal thickness The angle of inclination of the pipe wall; secondly, The length of the wall penetration at an angle. This represents the cross-sectional area of ​​the slot.

[0028] It should be noted that the volume of the oblique groove repair is used to realistically represent the physical volume of the wall that on-site construction workers would actually need to damage and remove using machinery if the original construction drawings' oblique design were retained; among which, This indicates the amplification effect of the oblique wall penetration length caused by the inclined posture of the pipeline. The larger the diameter, the more inclined the pipeline, the greater the length of the oblique penetration through the wall, and the larger the volume of damage.

[0029] The product of the oblique groove repair volume and the preset waste destruction carbon emission coefficient is used as the in-situ excavation waste carbon emission amount corresponding to each effective interference point. It should be noted that the carbon emissions from in-situ excavation waste are used to characterize the baseline carbon emission cost of directly drilling holes in the wall while retaining the original construction drawings. The higher the value, the higher the carbon emission cost of drilling holes in the wall.

[0030] Thus, the carbon emissions from in-situ excavation waste corresponding to each effective interference point are obtained.

[0031] Step 2: Construct a two-dimensional virtual projection plane parallel to the wall surface with the effective interference point as the geometric origin. Project the solid components around the effective interference point onto this projection plane to generate component interference avoidance boundaries. Within this projection plane, simulate the repulsion cost of avoiding all component interference avoidance boundaries and the convergence cost of approaching the effective interference point. Iterate to find the optimal wall penetration point. Calculate the spatial congestion degree, which characterizes the degree of restriction of the construction environment, based on the repulsion cost of the optimal wall penetration point during iterative convergence.

[0032] Furthermore, a two-dimensional virtual projection plane parallel to the wall surface is established, reducing the three-dimensional interference avoidance problem to a planar topological problem. By deploying a two-dimensional iterative algorithm incorporating a zero-reduction prevention mechanism and deadlock escape logic, a perforation location is found within the projection plane that both avoids obstacles and is as close as possible to the original position. Specifically: Using each effective interference point as the geometric origin and the surface normal vector of the structural wall as the normal direction, construct an infinitely large two-dimensional virtual projection plane that is parallel to the outer surface of the wall. Using the geometric origin as the center point, a local bounding box of a preset size is extracted; It should be noted that the length and width of the local space enclosure box are both 10 times the cross-sectional diameter of the electromechanical pipeline, which is used to delineate the range of obstacles that need to be avoided. As another implementation method, the implementer can set it according to the actual situation.

[0033] To prevent other extremely tilted or even parallel long strip components in the space from being infinitely stretched during projection, thus causing distortion of the two-dimensional boundary, the six physical boundary surfaces of the local space bounding box are first used to perform a three-dimensional solid truncation operation on all other solid components inside the bounding box, except for the two collision structures that constitute the effective interference point, such as beams, columns, walls, and adjacent pipelines. After removing the redundant volume part that exceeds the bounding box range, the truncated solid components are vertically projected onto the two-dimensional virtual projection plane along the opposite direction of the surface normal vector to form multiple two-dimensional projection contours. The effective opening radius is used as the safe expansion span; an expansion operation is performed on each two-dimensional projected profile, and the expansion width is equal to the safe expansion span. The boundary of the expanded profile is defined as the component interference avoidance boundary. Using the geometric origin in the two-dimensional virtual projection plane as the target point for the regression gravity. And create a virtual cursor, and initially place the virtual cursor at the return gravity target point; The virtual cursor at the second The position coordinates at the next iteration are recorded as the test coordinates. ; Solving from test coordinates Pointing to the target point of gravity for return The direction vector is multiplied by the preset gravity gain coefficient and used as the convergence cost gradient. In this embodiment, the preset gravity gain coefficient is used to control the backtracking tendency, and its value ranges from 0.5 to 1.0. The value is 0.7. As for other implementation methods, the implementer can set it according to the actual situation.

[0034] It should be noted that each effective interference point is the preset wall penetration point of the pipeline and the wall in the original design. Using it as the target point of the regression gravity reflects that the iterative algorithm prioritizes following the original design intention and minimizes the amount of pipeline modification during the obstacle avoidance solution process. The convergence cost gradient represents the magnitude and direction of the pulling force that pulls the virtual cursor back to the target point. The existence of this gradient ensures that in open areas without obstacles or with obstacles far away, the optimal wall penetration point obtained in the end is as close as possible to the original design scheme, thereby controlling the minimization of pipeline material increment.

[0035] Calculate test coordinate points The minimum vertical distance to each component interference avoidance boundary in the two-dimensional virtual projection plane is used to filter out all component interference avoidance boundaries that satisfy the minimum vertical distance being less than the preset distance limit, which are then used as effective rejection boundaries. In this embodiment, the preset distance limit is used to control the influence limit of the obstacle perception range, and its value ranges from 500mm to 1000mm. The value is 500mm. In other implementation methods, the implementer can set it according to the actual situation.

[0036] For each valid repulsion boundary, a repulsion component is generated, wherein the direction of the repulsion component is set to be perpendicular to the boundary and pointing to the test coordinate point. The magnitude of the repulsive force component is the negative mapping result of the minimum vertical distance; In this embodiment, the negative mapping process is as follows: the reciprocal of the square of the minimum vertical distance is multiplied by a preset repulsion gain coefficient to obtain the negative mapping result. To avoid a denominator of 0 when calculating the reciprocal, a parameter tuning factor is added to the denominator. In this embodiment, the parameter tuning factor is set to 0.01. In other implementations, the implementer can set it according to the actual situation. The preset repulsion gain coefficient is set to 10. 6 cubic millimeters, as another implementation method, can be set by the implementer according to the actual situation.

[0037] The repulsive force components of all effective repulsive boundaries are vector-accumulated to form the repulsion cost gradient; The convergence cost gradient and the repulsion cost gradient are vectored together to obtain the total cost gradient. Test coordinates Starting from the point indicated by the total cost gradient, extend the distance corresponding to the product of the magnitude of the total cost gradient and the preset constant update step size, and use this distance as the virtual cursor at the _th ... Test coordinates at the next iteration ; In this embodiment, the constant update step size for each cursor position update ranges from 10mm to 30mm. Therefore, the preset constant update step size is 10mm. In other implementations, the implementer can set it according to the actual situation.

[0038] By continuously iterating, the interval between test coordinates of two adjacent iterations is calculated. When the interval is less than or equal to a preset convergence threshold or the maximum number of iterations is reached, the iteration stops and the test coordinates of the last iteration is taken as the optimal wall-penetrating point. In this embodiment, the preset convergence threshold is set to a range of 2mm to 5mm, and the value is 3mm; the maximum number of iterations is set to 500 times. As other implementation methods, the implementer can set it according to the actual situation; secondly, the interval distance is measured by calculating the Euclidean distance between the test coordinate points of two adjacent iterations. Euclidean distance is a well-known technique and will not be described in detail here.

[0039] It should be noted that the repulsive force component represents the force that pushes the cursor away from the obstacle, and the repulsion cost gradient represents the overall pressure exerted by the surrounding obstacles on the current position of the virtual cursor. The total cost gradient reflects the combined effect of the "return to original position" pull and the "move away from the obstacle" push that the virtual cursor is currently experiencing. When the interval distance is less than or equal to the preset convergence threshold, it means that the cursor can no longer move significantly under the counteracting force of attraction and repulsion, that is, the cursor has reached a static state of force equilibrium, and the iteration loop is terminated at this time.

[0040] Furthermore, since such gradient-based iterative algorithms may erroneously stop at a dead end between multiple obstacles, i.e., get trapped in a local minimum deadlock, directly punching through the optimal wall-penetrating point still results in hard interference. Therefore, a deadlock escape safety check must be performed after terminating the loop, specifically: Calculate the minimum vertical distance between the optimal wall penetration point and the interference avoidance boundary of each component in the two-dimensional virtual projection plane, and select the minimum value from all minimum vertical distances. If the minimum value is less than the preset safety threshold, the space crowding degree is assigned a preset penalty value; otherwise, the space crowding degree is the magnitude of the repulsion cost gradient at the last iteration. In this embodiment, the preset safety threshold is set as the sum of the safe expansion span and the preset construction tolerance, wherein the construction tolerance is set to 50mm. In other implementation methods, the implementer can set it according to the actual situation. Secondly, the preset penalty value is set to a very large value. In this embodiment, the value is set to 9999. This mechanism ensures that when the space is extremely congested and the rerouting is impossible, the abnormal state can be identified and eliminated in the subsequent subtraction comparison, thus avoiding deadlock failure.

[0041] It should be noted that when the minimum value is less than the preset safety threshold, it means that the optimal wall-penetrating point has fallen into the local minimum deadlock collision zone, indicating that this solution has no reasonable obstacle avoidance space. At this time, the optimal wall-penetrating point is rejected as the optimal solution. Conversely, it means that the optimal wall-penetrating point is in a compliant and spacious area. In this case, the modulus of the rejection cost gradient objectively reflects the degree of spatial confinement imposed on the on-site workers due to the intrusion of surrounding components. Therefore, the greater the spatial congestion, the smaller the operating space faced by the construction workers and the more difficult the operation of erecting scaffolding.

[0042] Thus, the optimal wall penetration point and its corresponding spatial congestion level are obtained.

[0043] Step 3: Calculate the additional carbon emissions generated by the pipeline due to the translation based on the translation distance between the optimal wall penetration point and the effective interference point and the return path after vertical wall penetration. Combined with the space congestion, assess the carbon emissions from detours caused by the translation relocation. Compare the carbon emissions from in-situ excavation waste with the carbon emissions from detours, and generate differentiated drawing review instructions based on the comparison results for drawing review modification.

[0044] Furthermore, based on the optimal wall penetration point, the change in physical length caused by the straightening of the pipeline trajectory is calculated, specifically as follows: Calculate the straight-line distance between the optimal wall-penetrating point and the geometric origin in the two-dimensional virtual projection plane, and denot it as the vertical wall-penetrating translation distance; take twice the vertical wall-penetrating translation distance as the additional pipe length for the parallel segment. It should be noted that the vertical wall penetration distance reflects the horizontal offset that the penetration point needs to make on the wall surface to avoid obstacles. It directly determines the extent of pipeline detour. The larger the value, the more additional pipe material is required. The additional pipe length in the parallel section means that the pipeline is led out from the original inclined wall penetration position, horizontally shifted along a direction parallel to the wall surface to the optimal wall penetration point, and then turned back to the original pipeline design axis. This additional pipe length reflects the additional pipe material consumption that has to be increased due to the horizontal offset.

[0045] Calculate the difference between the diagonal wall penetration length and the normal thickness to save pipe length; It should be noted that the pipe length saving reflects the length of pipe saved inside the wall due to the change to vertical perforation. This value reflects the amount of pipe material saved inside the wall by the rerouting scheme.

[0046] The difference between increasing the pipe length and saving the pipe length in the parallel section is taken as the length difference; In certain special spatial arrangements, such as when the normal thickness of the structural walls is extremely thick and the translation distance is extremely short, this length difference may mathematically result in a negative value. To avoid ultimately deriving a negative carbon emission value that violates physical laws and leads to a logical deadlock, a negative value reset check is performed here, specifically: When the length difference is less than 0, the net pipeline growth rate is assigned a value of 0; otherwise, the net pipeline growth rate is the length difference. It should be noted that the greater the net increase in pipeline length, the more additional pipe material is required due to the pipeline relocation, and the higher the corresponding carbon emissions from material production.

[0047] Based on the vertical wall penetration translation distance and the cross-sectional radius of the electromechanical pipeline, the preset engineering pipe fitting matching rule library is searched to obtain the required dynamic pipe fitting combination equivalent; It should be noted that the pipe fitting matching rule library for this project includes national building standard design drawings and conventional construction process requirements, defining the standard pipe fitting combinations corresponding to different detour distances, such as pipe fitting combinations with two 45-degree elbows or four 90-degree right-angle elbows.

[0048] Calculate the product of the net increase in pipeline and the preset unit carbon emission equivalent of pipe manufacturing, calculate the product of the dynamic pipe fitting combination equivalent and the preset unit carbon emission equivalent of pipe fitting manufacturing, and use the sum of the two products as the basic new carbon emission amount. It should be noted that the preset unit carbon emission equivalent for pipe manufacturing represents the carbon emissions generated by producing a unit length of electromechanical pipeline of a specific material and specification, while the preset unit carbon emission equivalent for pipe fitting manufacturing represents the carbon emissions generated by producing a set of standard pipe fittings. These two unit carbon emission equivalents are extracted from the building construction carbon emission standard database. For DN100 galvanized steel pipes, the range of values ​​for the unit carbon emission equivalent of pipe manufacturing is as follows: For DN100 PVC pipes, the range of values ​​for the unit carbon emission equivalent of pipe manufacturing is as follows: For DN100 ductile iron pipes, the range of values ​​for the unit carbon emission equivalent in pipe manufacturing is as follows: Secondly, for a set of Z-bend pipe fittings made of ordinary carbon steel (including two 90° elbows and connecting short pipes), the range of values ​​for the unit carbon emission equivalent of the pipe fittings is as follows: For similar PVC pipe fitting combinations, the range of values ​​for the unit carbon emission equivalent of the pipe fitting manufacturing is as follows: As an alternative implementation method, the implementer may set the parameters according to the actual situation; the basic additional carbon emissions represent the carbon emissions corresponding to the additional physical material consumption caused by the line modification.

[0049] Furthermore, while the carbon emissions of pipes are constant during the production stage, construction workers encounter extremely congested spaces when handling and installing these pipes on-site, such as being close to other rows of pipes and columns. This drastically increases the difficulty of setting up scaffolding and operating lifting machinery, resulting in double the energy consumption of machinery being stuck and personnel operating shifts for the same amount of work.

[0050] The spatial congestion level and the preset congestion scale coefficient are positively integrated as a congestion efficiency reduction carbon emission multiplier. It should be noted that the specific representation of positive fusion is a multiplicative relationship, an additive relationship, etc. In this embodiment, the calculation formula for the congestion-induced carbon emission multiplier is: in, The carbon emission multiplier caused by congestion reduces efficiency. This is a preset scaling factor for the congestion measurement units. For space congestion, It is a logarithmic function with the natural constant as the base; It should be noted that the carbon emission multiplier for congestion reduction is always a real number greater than or equal to 1, used to characterize the amplification factor of construction energy consumption caused by scaffolding and machinery operation restrictions on site; spatial congestion objectively reflects the topological pressure felt by the proximity of components; the congestion dimensional scaling factor is an engineering experience-aligned parameter, and its unit configuration is consistent with... The units of measurement are reciprocals of each other; through and Multiply, The negative geometric spatial dimensions carried are completely canceled out, transformed into a pure algebraic proportional value, and then incremented by 1, ensuring that even in an absolutely open ideal space, i.e. When the value is 0, the argument of the logarithmic function is at its minimum of 1; secondly, by smoothing and suppressing through logarithmic operations, the potential algebraic exponential explosion caused by directly deriving from the reciprocal of distance is effectively prevented, thus constraining the output of the logarithmic function within the range of the actual reduction in labor-hour efficiency in construction engineering, making the final output multiplier... This aligns with common sense regarding normal engineering increments; the congestion-induced efficiency reduction and carbon emission multiplier represents the severity of the construction environment. The larger the value, the more cramped the on-site construction space, the denser the surrounding obstacles, the higher the difficulty for construction workers to erect scaffolding and operate lifting machinery, and the greater the energy consumption of machinery stagnation and personnel shift operation.

[0051] The product of the basic new carbon emissions and the congestion-induced inefficiency carbon emissions is used as the detour carbon emissions corresponding to each effective intervention point. It should be noted that by directly amplifying the penalty multiplier of environmental factors and applying it to the carbon emission base of the basic materials, the carbon emission of detours reflects the double penalty effect of the absolute consumption of materials and the harsh on-site construction environment. The absolute consumption of materials is caused by the increase in pipeline length and fittings due to the relocation, while the harsh on-site construction environment is caused by the extreme congestion of surrounding components, resulting in obstructed work, difficulty in scaffolding erection, and doubled energy consumption of machinery. Therefore, the larger this value is, the higher the comprehensive carbon emission cost of adopting the pipeline relocation and detour scheme. It indicates that forcibly changing the route in this narrow and confined space violates the principle of low carbon, and retaining the original design of the construction drawings and carrying out in-situ demolition is a more reasonable choice.

[0052] Furthermore, to determine whether requiring designers to alter pipeline trajectories truly aligns with the engineering objective of reducing overall carbon emissions during construction, it is necessary to quantitatively compare two mutually exclusive solutions—direct in-situ drilling and outward relocation—under the same benchmark. By comparing the carbon emissions from relocation versus the carbon emissions from in-situ excavation waste, the construction drawings can be evaluated. Specifically: For each effective intervention point, if the carbon emissions from detouring are less than the carbon emissions from excavating waste at the original site, a mandatory rerouting drawing review order will be generated; otherwise, an original drawing exemption drawing review order will be generated. The mandatory relocation drawing review instruction calls the BIM application programming interface (API) to write a data identifier with the value "Mandatory_Revision" into the status attribute dictionary of the electromechanical pipelines in the two colliding components that constitute this effective interference point, and renders the surface material of the electromechanical pipeline as pure red to warn the designer that the relocation operation must be performed. The original drawing exemption instruction is as follows: write a data identifier with the value "Exempted" into the state attribute dictionary of the electromechanical pipelines in the two colliding components that constitute this effective interference point, and simultaneously render the surface material of the electromechanical pipelines as pure green to indicate that the electromechanical pipelines are constructed according to the original design and do not need to be modified. It should be noted that when the carbon emissions from detouring are less than the carbon emissions from excavating waste material in the original location, it means that the total carbon emissions from the additional pipes caused by modifying the construction drawings and the reduced efficiency per shift due to space constraints are still lower than the baseline carbon emissions from the waste wall material incurred by directly enlarging the hole and demolishing the wall while retaining the original design. This means that relocating the route outward has objective and credible low-carbon benefits. When the carbon emissions from detouring are greater than or equal to the carbon emissions from excavating waste material in the original location, it means that relocating the route outward will not only lead to a large waste of pipes, but the extremely narrow environment around the new location will also force a significant increase in construction time. The overall carbon emission cost has exceeded the carbon emission cost of enlarging the trench in the original location. This means that maintaining the original inclined wall penetration route on the drawings is a more rational low-carbon choice.

[0053] Secondly, in order to eliminate hard collision errors at the BIM level and ensure that subsequent quantity calculation software will not fail due to physical interference, the system will never simply retain the error status when executing exemption instructions.

[0054] Based on the pipe wall inclination angle and the effective opening radius, a virtual reserved hole component is generated at the corresponding spatial position of the structural wall to enclose the pipeline trajectory. After generating the hole component, the API is called to perform a Boolean difference operation. This pre-reserved hole component is used to deduct the volume of the structural wall. Through this deduction operation, hard interference errors between pipelines and walls are completely eliminated at the physical level of the BIM model, while legally preserving the original inclined layout trajectory of the pipelines. The Boolean difference operation is a well-known technique and will not be elaborated upon here. After traversing all valid interference points, the drawing review process ends.

[0055] Based on the same inventive concept as the above methods, this application also provides a BIM-based low-carbon construction drawing review system for building construction projects, including a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, it implements the steps of any one of the above-described BIM-based low-carbon construction drawing review methods for building construction projects.

Claims

1. A BIM-based method for reviewing low-carbon construction drawings for building projects, characterized in that: The method includes the following steps: Read the BIM model, perform collision detection on the electromechanical pipelines and structural walls in the model, extract the interference area where physical collision occurs, and analyze the tilt angle between the electromechanical pipelines and structural walls that collide within the interference area to filter the interference area and obtain effective interference points. For each effective interference point, based on the geometric characteristics of the pipeline passing through the wall and the material of the structural wall, assess the carbon emissions of in-situ excavation waste generated by maintaining the in-situ oblique groove through the wall. A two-dimensional virtual projection plane parallel to the wall surface is constructed with the effective interference point as the geometric origin. The solid components around the effective interference point are projected onto this projection plane to generate component interference avoidance boundaries. Within this projection plane, the repulsion cost of avoiding all component interference avoidance boundaries and the convergence cost of approaching the effective interference point are simulated to iteratively solve for the optimal wall penetration point. Based on the repulsion cost of the optimal wall penetration point during iterative convergence, the spatial congestion degree characterizing the degree of restriction of the construction environment is calculated. The additional carbon emissions generated by the pipeline due to the translation are calculated based on the translation distance between the optimal wall penetration point and the effective interference point and the reversal path after the vertical wall penetration. Combined with the spatial congestion, the carbon emissions from detours caused by the translation are evaluated. The carbon emissions from in-situ excavation waste and detours are compared, and differentiated drawing review instructions are generated based on the comparison results for drawing review modification.

2. The method for reviewing low-carbon construction drawings for building construction projects based on BIM as described in claim 1, characterized in that, The process of selecting interference regions to obtain effective interference points includes: for each interference region, obtaining the axial vector of the colliding electromechanical pipeline and the surface normal vector of the outer surface of the colliding structural wall, calculating the acute angle between the two vectors as the pipe wall tilt angle; selecting interference regions where the pipe wall tilt angle is less than or equal to the preset maximum allowable wall inclination angle, defining them as effective interference regions; and defining the centroid of each effective interference region as an effective interference point.

3. The method for reviewing low-carbon construction drawings for building construction projects based on BIM as described in claim 2, characterized in that, The calculation process for the carbon emissions from the in-situ excavation waste is as follows: Obtain the normal thickness of the structural wall and the cross-sectional radius of the electromechanical pipeline in the two collision components that constitute each effective interference point; The sum of the cross-sectional radius of the electromechanical pipeline in the two colliding components, the preset pipeline installation clearance, and the preset pipeline additional layer thickness is taken as the effective opening radius, and the slot cross-sectional area is calculated based on the effective opening radius. The ratio of the normal thickness to the cosine of the pipe wall inclination angle is taken as the oblique penetration length; the product of the groove cross-sectional area and the oblique penetration length is taken as the oblique groove repair volume. The product of the oblique groove repair volume and the preset waste destruction carbon emission coefficient is used as the in-situ excavation waste carbon emission amount corresponding to each effective interference point.

4. The BIM-based low-carbon construction drawing review method for building construction projects as described in claim 3, characterized in that, The method for obtaining the component interference avoidance boundary is as follows: taking the geometric origin as the center point, a local spatial bounding box of a preset size is extracted. After performing a three-dimensional solid truncation operation on the remaining solid components within the local spatial bounding box except for the two collision components that constitute the effective interference point, the components are vertically projected onto a two-dimensional virtual projection plane along the opposite direction of the surface normal vector of the structural wall to form multiple two-dimensional projection contours. An expansion operation is performed on each two-dimensional projection contour outward, and its expansion width is equal to the effective opening radius. The boundary of the expanded contour is defined as the component interference avoidance boundary.

5. The BIM-based low-carbon construction drawing review method for building construction projects as described in claim 4, characterized in that, The iterative solution process for the optimal wall penetration point is as follows: Using the geometric origin in the two-dimensional virtual projection plane as the target point for the regression gravity. And establish a virtual cursor, initially placing the virtual cursor at the return gravity target point; then the virtual cursor at the th... The position coordinates at the next iteration are recorded as the test coordinates. Solution from point to The direction vector is multiplied by the preset gravity gain coefficient and used as the convergence cost gradient. calculate The minimum vertical distance to each component interference avoidance boundary in the two-dimensional virtual projection plane is used to filter out all component interference avoidance boundaries that satisfy the minimum vertical distance being less than a preset distance limit. These are then considered as effective repulsion boundaries, and a repulsion force component is generated for each effective repulsion boundary. The direction of this repulsion force component is set to be perpendicular from the boundary to the test coordinate point. The magnitude of the repulsive force component is the negative mapping result of the minimum vertical distance corresponding to the effective repulsive boundary; The repulsive force components of all effective repulsive boundaries are vector-summed to obtain the repulsive cost gradient. This gradient is then vector-summed with the convergence cost gradient to obtain the total cost gradient. Starting from the point indicated by the total cost gradient, extend the distance corresponding to the product of the magnitude of the total cost gradient and the preset constant update step size, and use this distance as the virtual cursor at the _th ... Test coordinates at the next iteration By continuously iterating, the interval between test coordinates of two adjacent iterations is calculated. When the interval is less than or equal to a preset convergence threshold or the maximum number of iterations is reached, the iteration stops and the test coordinates of the last iteration are taken as the optimal wall-penetrating point.

6. The BIM-based low-carbon construction drawing review method for building construction projects as described in claim 5, characterized in that, The calculation process of the spatial congestion is as follows: calculate the minimum vertical distance between the optimal wall penetration point and the interference avoidance boundary of each component in the two-dimensional virtual projection plane, and select the minimum value from all minimum vertical distances. If the minimum value is less than the preset safety threshold, the spatial congestion is assigned a preset penalty value; otherwise, the spatial congestion is the magnitude of the repulsion cost gradient at the last iteration.

7. The BIM-based low-carbon construction drawing review method for building construction projects as described in claim 6, characterized in that, The calculation process for the basic increase in carbon emissions is as follows: Calculate the straight-line distance between the optimal wall-penetrating point and the geometric origin in the two-dimensional virtual projection plane, and record it as the vertical wall-penetrating translation distance. Double this distance and use it as the increase in pipe length for the parallel segment. Calculate the difference between the oblique wall-penetrating length and the normal thickness, and use it as the saved pipe length. Use the difference between the increased pipe length and the saved pipe length for the parallel segment as the length difference. If the length difference is less than 0, the net pipeline growth rate is assigned a value of 0; otherwise, the net pipeline growth rate is the length difference. Based on the vertical wall penetration translation distance and the cross-sectional radius of the electromechanical pipeline, the preset engineering pipe fitting matching rule library is searched to obtain the required dynamic pipe fitting combination equivalent; Calculate the product of the net increase in pipeline size and the preset unit carbon emission equivalent of pipe manufacturing, calculate the product of the dynamic pipe fitting combination equivalent and the preset unit carbon emission equivalent of pipe fitting manufacturing, and use the sum of the two products as the basic increase in carbon emissions.

8. The method for reviewing low-carbon construction drawings for building construction projects based on BIM as described in claim 1, characterized in that, The calculation process for the detour and avoidance carbon emissions is as follows: the spatial congestion degree and the preset congestion dimension scaling factor are positively integrated as the congestion-induced efficiency reduction carbon emission multiplier; the product of the basic new carbon emissions and the congestion-induced efficiency reduction carbon emission multiplier is used as the detour and avoidance carbon emissions corresponding to each effective intervention point.

9. The BIM-based low-carbon construction drawing review method for building construction projects as described in claim 1, characterized in that, The generation of differentiated drawing review instructions includes: for each effective interference point, if the carbon emission from detouring is less than the carbon emission from in-situ excavation waste, a mandatory rerouting drawing review instruction is generated; otherwise, an original drawing exemption drawing review instruction is generated.

10. A BIM-based low-carbon construction drawing review system for building construction projects, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the BIM-based low-carbon construction drawing review method for building construction projects as described in any one of claims 1-9.

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