A method and system for constructing a spatial three-curved steel box girder model based on BIM technology

Abstract

The application discloses a kind of space three curved steel box girder model construction methods based on BIM technology, comprising: step 1, obtain the two-dimensional drawing data of bridge, generate route space curve;Step 2, according to the ellipse equation in two-dimensional drawing data, generate the corresponding semicircular arc part profile of roof, bottom plate, web plate and rib plate in bridge, and form parameterized profile family with corresponding straight line part profile;Step 3, with the obtained route space curve as reference, generate the corresponding steel box girder frame entity of bridge;Step 4, according to the diaphragm parameter of bridge section in two-dimensional drawing data, generate diaphragm entity;Step 5, with route space curve reference, the generated diaphragm entity is imported into steel box girder frame entity, and the corresponding three curved steel box girder model is output.The application further provides a kind of space three curved steel box girder model construction system.The method of the application can solve the technical problems of three curved steel box girder fine lofting and deepening design.

Description

A method and system for constructing spatial triple-curved steel box girder models based on BIM technology Technical Field

[0001] This invention belongs to the field of bridge BIM modeling technology, specifically relating to a method and system for constructing a spatial three-curved steel box girder model based on BIM technology. Background Technology

[0002] Compared to traditional reinforced concrete bridges, steel structure bridges have been widely used due to their advantages such as lower self-weight, better seismic performance, ease of automated production, high durability, and recyclability. While meeting engineering requirements, they are also gradually evolving towards spatial design, improving space utilization and enhancing the aesthetics of cities. Curved steel box girder bridges are aesthetically pleasing and highly adaptable to different regions, making them extremely popular in long-span curved viaducts in cities. However, most are two-dimensional horizontal curve bridges or vertical curve variable cross-section bridges, such as the Daxie Second Bridge and the Shenzhen Bay Bridge. "Spatial triple-curved bridges" composed of horizontal curves, vertical curves, and cross-sectional changing curves are extremely rare.

[0003] Due to the complex spatial alignment of curved steel box girder bridges, detailed construction drawings and fabrication are challenging. Traditional two-dimensional wireframe-based planar representations are insufficient for in-depth design and steel plate layout in steel structure factories, making it difficult to achieve the required alignment control precision for segmental assembly. To meet the alignment control precision requirements for each segment's positioning, layout, and assembly, it is necessary to integrate BIM technology for refined layout and detailed design of tri-curved steel box girder bridges.

[0004] Because Revit has certain limitations in handling complex curves and surfaces, it cannot obtain the intersection point of the offset semi-elliptical arc and the shear line. In addition to manually visually determining the intersection point, which can lead to significant drafting errors, it is also impossible to annotate the offset semi-elliptical arc and make corresponding parametric settings, thus making parametric modeling impossible.

[0005] Patent document CN114065357A discloses a Revit-based method and system for modeling segmental bridges. The method includes: creating a bridge centerline coordinate table and a segment data table; creating an adaptive metric conventional model of the segmental beams and loading it into a new project; running a DYNAMO plugin to create a three-dimensional bridge spatial curve; and arranging the adaptive metric conventional model of the segmental beams according to the three-dimensional bridge spatial curve to generate an overall model of the segmental bridge. This method only proposes that the modeling dimensions can be dynamically adjusted using the Revit model, but the curves of actual bridges are very complex, leading to errors when directly using the model.

[0006] Patent document CN 112651061A discloses a method for establishing a BIM model of a multi-span bridge superstructure using Dynamo, mainly including the following steps: (1) organizing the data of the bridge centerline coordinates and component parameters in the design drawings and storing them as an Excel file; (2) establishing a parametric family of the bridge superstructure; (3) Dynamo reads the Excel data and automatically places the parametric family of the bridge superstructure; (4) Dynamo reads the Excel data and automatically changes the family parameters of the parametric family of the bridge superstructure. This method only aims to solve the problem of quickly building a bridge model, but does not consider that the curved surface part during the bridge construction process cannot be parametrically controlled in a conventional way. Summary of the Invention

[0007] To address the problems existing in the prior art, this invention provides a spatial triple-curved steel box girder model construction and layout system based on BIM technology. This system can realize the modeling and layout of triple-curved steel box girders with complex spatial linearity, solving the technical challenges of refined layout and detailed design of triple-curved steel box girders.

[0008] To achieve the above objectives, this invention provides a method for constructing a spatial three-curved steel box girder model based on BIM technology, comprising:

[0009] Step 1: Obtain the two-dimensional drawing data of the bridge and generate the route space curve corresponding to the center line of the bridge road. The two-dimensional drawing data includes the horizontal curve development diagram, the longitudinal curve development diagram, the cross-sectional diagram of the bridge, and the ellipse equation corresponding to each two-dimensional drawing.

[0010] Step 2: Based on the ellipse equation in the 2D drawing data, generate the semi-circular arc contours corresponding to the top plate, bottom plate, web plate and rib plate of the bridge, and form a parametric contour family with the corresponding straight line contours.

[0011] Step 3: Using the route space curve obtained in Step 1 as a reference, import the parametric contour family obtained in Step 2 into the three-dimensional space to generate the steel box girder frame entity corresponding to the bridge.

[0012] Step 4: Generate the diaphragm entity based on the diaphragm parameters in the bridge cross-section data of the two-dimensional drawing.

[0013] Step 5: Using the route space curve obtained in Step 1 as a reference, import the generated diaphragm entity into the steel box girder frame entity and output the corresponding three-curved steel box girder model.

[0014] Specifically, in step 1, the process of generating the route space curve is as follows:

[0015] Step 1-1: Based on the information of the horizontal curve development diagram and the vertical curve development diagram of the bridge, construct the corresponding piecewise function with the horizontal and vertical curve alignment as the reference. The piecewise function includes the horizontal curve function and the vertical curve development function.

[0016] Steps 1-2: Import the horizontal curve function and the vertical curve expansion function into Revit software using Dynamo:

[0017] Based on the fact that the length of the x-coordinate on the longitudinal curve development graph is equal to the arc length on the horizontal curve, after taking points in the longitudinal curve development graph at equal intervals with x-coordinates in each segment, the corresponding y-coordinate is obtained as the spatial z-coordinate through the longitudinal curve development function.

[0018] Based on the development of the horizontal curve, the coordinates of the corresponding points are obtained as the spatial x-coordinate and spatial y-coordinate using the equal arc length method.

[0019] Steps 1-3: Obtain the route space curve by fitting all the spatial coordinates obtained in Step 1-2.

[0020] Specifically, in step 2, after the semi-circular arc portion of the outline generates the curve corresponding to the ellipse equation through the Revit metric conventional model, Dynamo is used to perform the translation and shearing of the curve, and the execution result is re-imported into the Revit metric conventional model in the form of modelCurve.

[0021] Specifically, the shearing process requires determining the shearing points before and after translation, and the specific process is as follows:

[0022] Based on the 2D construction drawing, obtain the specific coordinates, use the Point.ByCoordinates command and the Line.ByStartPointEndPoint command to generate the corresponding shear line, use the Geometry.Insert command twice to obtain the intersection point of the shear line with the curve before and after offset, use the Code Block to retrieve the first point in the obtained Geometry[] table (i.e. the intersection point of the shear line and the curve after offset), and call the Curve.ParameterAtPoint command to obtain the value of the arc length from the start point of the curve to the first point as a ratio of the total arc length of the curve.

[0023] Based on the position parameters of the first point, the Curve.NormalAtParameter command is called to obtain the normal vector of the curve at the first point, and the intersection of the perpendicular line of the normal vector and the curve before offset is taken as the shear point.

[0024] Specifically, in step 3, the process of generating the steel box girder frame entity is as follows:

[0025] Step 3-1: Import the parametric profile families of the top plate, bottom plate, web plate, and ribs into the Revit metric conventional model;

[0026] Step 3-2: Directly measure the coordinates of the connection points of the corresponding parts of the parametric contour family in the two-dimensional three-view drawing to obtain the spatial coordinates of the parametric contour family.

[0027] Step 3-3: Using Dynamo, based on the route space curve and the parametric contour family space coordinates obtained in Step 3-2, arrange the contours of the top plate, bottom plate, web plate and rib plate in the corresponding positions in three-dimensional space.

[0028] Steps 3-4: Perform lofting and fusion on the completed 3D space to generate the corresponding steel box girder frame entity.

[0029] Specifically, in step 4, the diaphragm entity is generated by drawing the diaphragm outline corresponding to the diaphragm parameters using Dynamo and then performing an extrusion operation and Boolean operations.

[0030] Specifically, the stretching operation and Boolean operation are performed as follows:

[0031] The `List Create` command is used to input the outlines as items to form a list. Then, the `PolyCurve.ByJoinedCurves` command is used to combine the individual outlines into a closed polyline. Finally, the `Curve.ExtrudeAsSolid` command is used to input the closed polyline and the extrusion length to generate a solid diaphragm without holes. Similarly, the above operations can be used to generate the solid with the holes in the middle, and then the `Solid.Difference` Boolean operation is used to remove the holes from the diaphragm, generating the final diaphragm solid.

[0032] This invention also provides a spatial triple-curved steel box girder model construction system, and a BIM-based spatial triple-curved steel box girder model construction method for performing modeling, including:

[0033] The route space curve generation unit generates the corresponding route space curve based on the input two-dimensional drawing data;

[0034] The parametric box girder profile family generation unit generates parametric profile families of top plate, bottom plate, web plate, rib plate and diaphragm plate based on the ellipse equation in the input two-dimensional drawing and the diaphragm parameters in the bridge section drawing.

[0035] The model building unit outputs a three-curved steel box girder model corresponding to the two-dimensional drawing data, based on the data generated by the route space curve generation unit and the parameterized box girder profile family generation unit.

[0036] The model unfolding unit outputs the surface unfolding diagram of the three-curved steel box girder model based on the model building unit, and then lays it out.

[0037] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0038] 1) The spatial triple-curved steel box girder bridge is a spatial combination of horizontal curves, vertical curves, and cross-sectional change curves, with complex structural forms, high requirements for stress analysis, numerous irregular components, and high connection precision. This invention is based on the Revit platform and uses the visual programming language Dynamo to assist in modeling, which can generate spatial triple-curved steel box girder BIM models relatively quickly and accurately, better describing spatial irregular shapes that are difficult to intuitively represent in two-dimensional drawings;

[0039] 2) The spatial three-curved steel box girder BIM model established based on the present invention can help to achieve more accurate three-dimensional layout, better determine the size of the plate, and the visualization layout of the three-dimensional model can also achieve more reasonable layout, make the size of each unit accurate, and improve the processing and on-site assembly accuracy of the steel box girder. Attached Figure Description

[0040] Figure 1 is a flowchart of a spatial triple-curved steel box girder model construction method based on BIM technology provided in this embodiment;

[0041] Figure 2 is a flowchart for generating the corresponding route space curve;

[0042] Figure 3 is a flowchart for generating the corresponding steel box girder frame entity;

[0043] Figure 4 is a flowchart of a spatial triple-curved steel box girder model construction system provided in this embodiment;

[0044] Figure 5 shows the generated model of the bridge's three-curved steel box girder. Detailed Implementation

[0045] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0046] As shown in Figure 1, a method for constructing a spatial triple-curved steel box girder model includes:

[0047] Step 1: Obtain the two-dimensional drawing data of the bridge and generate the route space curve corresponding to the center line of the bridge road. The two-dimensional drawing data includes the horizontal curve development diagram, the longitudinal curve development diagram, the cross-sectional diagram of the bridge, and the ellipse equation corresponding to each two-dimensional drawing.

[0048] Furthermore, Figure 2 illustrates the specific process of generating the route space curve:

[0049] Step 1-1: Based on the information from the horizontal and vertical curve development diagrams of the bridge, construct corresponding piecewise functions using the horizontal and vertical curve alignments as a reference. The piecewise functions include horizontal curve functions and vertical curve development functions.

[0050] Steps 1-2: Import the horizontal curve function and the vertical curve expansion function into Revit software using Dynamo:

[0051] Based on the fact that the length of the x-coordinate on the longitudinal curve development graph is equal to the arc length on the horizontal curve, after taking points in the longitudinal curve development graph at equal intervals with x-coordinates in each segment, the corresponding y-coordinate is obtained as the spatial z-coordinate through the longitudinal curve development function.

[0052] Based on the horizontal curve function, the coordinates of the corresponding points are obtained as spatial x-coordinates and spatial y-coordinates using the equal arc length method.

[0053] Steps 1-3: Obtain the route space curve by fitting all the spatial coordinates obtained in Step 1-2.

[0054] Step 2: Based on the ellipse equation in the 2D drawing data, generate the semi-circular arc contours corresponding to the top plate, bottom plate, web plate and rib plate of the bridge, and form a parametric contour family with the corresponding straight line contours.

[0055] Furthermore, after the semi-circular arc portion of the outline generates the curve corresponding to the ellipse equation through the Revit metric conventional model, the curve is translated and sheared using Dynamo, and the execution result is re-imported into the Revit metric conventional model in the form of modelCurve.

[0056] The shearing process requires determining the shearing points before and after translation. The specific process is as follows:

[0057] Based on the 2D construction drawing, specific coordinates are obtained. The Point.ByCoordinates and Line.ByStartPointEndPoint commands are used to generate the corresponding shear line. The Geometry.Insert command is used twice to obtain the intersection points of the shear line with the curve before and after offset. Then, the first point in the obtained Geometry[] table (i.e., the intersection point of the shear line and the curve after offset) is retrieved using the Code Block. The Curve.ParameterAtPoint command is called to obtain the ratio of the arc length from the curve start point to the first point to the total arc length of the curve.

[0058] Based on the position parameters of the first point, the Curve.NormalAtParameter command is called to obtain the normal vector of the curve at the first point, and the intersection of the perpendicular line of the normal vector and the curve before offset is taken as the shear point.

[0059] Step 3: Using the route space curve obtained in Step 1 as a reference, import the parametric contour family obtained in Step 2 into the three-dimensional space to generate the steel box girder frame entity corresponding to the bridge.

[0060] As shown in Figure 3, the process of generating the steel box girder frame entity is as follows:

[0061] Step 3-1: Import the parametric profile families of the top plate, bottom plate, web plate, and ribs into the Revit metric conventional model;

[0062] Step 3-2: Directly measure the coordinates of the connection points of the corresponding parts of the parametric contour family in the two-dimensional three-view drawing to obtain the spatial coordinates of the parametric contour family.

[0063] Step 3-3: Using Dynamo, based on the route space curve and the parametric contour family space coordinates obtained in Step 3-2, arrange the contours of the top plate, bottom plate, web plate and rib plate in the corresponding positions in three-dimensional space.

[0064] Steps 3-4: Perform lofting and fusion on the completed 3D space to generate the corresponding steel box girder frame entity.

[0065] Step 4: Generate the diaphragm entity based on the diaphragm parameters of the bridge cross section in the 2D drawing data;

[0066] Furthermore, the diaphragm entity is generated by stretching and Boolean operations after the diaphragm outline corresponding to the diaphragm parameters is drawn using Dynamo.

[0067] Furthermore, the specific operations of the stretching operation and Boolean operation are as follows:

[0068] The `List Create` command is used to input the outlines as items to form a list. Then, the `PolyCurve.ByJoinedCurves` command is used to combine the individual outlines into a closed polyline. Finally, the `Curve.ExtrudeAsSolid` command is used to input the closed polyline and the extrusion length to generate a solid diaphragm without holes. Similarly, the above operations can be used to generate the solid with the holes in the middle, and then the `Solid.Difference` Boolean operation is used to remove the holes from the diaphragm, generating the final diaphragm solid.

[0069] Step 5: Using the route space curve obtained in Step 1 as a reference, import the generated diaphragm entity into the steel box girder frame entity and output the corresponding three-curved steel box girder model.

[0070] As shown in Figure 4, this embodiment also provides a spatial triple-curved steel box girder model construction system, which is implemented based on the spatial triple-curved steel box girder model construction method proposed in the above embodiments, including:

[0071] The route space curve generation unit generates the corresponding route space curve based on the input two-dimensional drawing data;

[0072] The parametric box girder profile family generation unit generates parametric profile families of top plate, bottom plate, web plate, rib plate and diaphragm plate based on the ellipse equation in the input two-dimensional drawing and the diaphragm parameters in the bridge section drawing.

[0073] The model building unit outputs a three-curved steel box girder model corresponding to the two-dimensional drawing data, based on the data generated by the route space curve generation unit and the parameterized box girder profile family generation unit.

[0074] The model unfolding unit outputs the surface unfolding diagram of the three-curved steel box girder model based on the model building unit, and then lays it out.

[0075] In actual use, the two-dimensional CAD drawing of the three-curved steel box girder is input into the three-curved steel box girder model building system in this space to output the three-curved steel box girder model as shown in Figure 5.

Claims

1. A method for constructing a spatial triple-curved steel box girder model based on BIM technology, characterized in that, include: Step 1: Obtain the 2D drawing data of the bridge and generate the route space curve corresponding to the bridge's road centerline. The 2D drawing data includes the horizontal curve development diagram, vertical curve development diagram, cross-sectional view, and the ellipse equation corresponding to each 2D drawing. The specific process of generating the route space curve is as follows: Step 1-1: Based on the information of the horizontal curve development diagram and the vertical curve development diagram, construct the corresponding piecewise function based on the horizontal and vertical curve line types. The piecewise function includes the horizontal curve function and the vertical curve development function; Step 1-2: Import the horizontal curve function and the vertical curve development function into Revit software using Dynamo: Based on the fact that the x-coordinate length on the vertical curve development diagram is equal to the arc length on the horizontal curve, after taking points in the vertical curve development diagram at equal intervals using the x-coordinate in each segment, obtain the corresponding y-coordinate as the spatial z-coordinate through the vertical curve development function; Based on the horizontal curve development diagram, obtain the corresponding point coordinates as the spatial x-coordinate and spatial y-coordinate using the equal arc length method; Step 1-3: By fitting all spatial coordinates obtained in steps 1-2, the route spatial curve is obtained; Step 2: Based on the ellipse equation in the 2D drawing data, the semi-circular arc contours corresponding to the top plate, bottom plate, web plate, and rib plate of the bridge are generated, and these are combined with the corresponding straight line contours to form a parametric contour family. After the semi-circular arc contours are generated as curves corresponding to the ellipse equations using the Revit metric conventional model, the curves are translated and sheared using Dynamo, and the results are re-imported into the Revit metric conventional model in the form of modelCurve. The shearing process requires determining the shearing point, and the specific process is as follows: Based on the 2D drawing data, specific coordinates are obtained, and the corresponding shearing lines are generated using the Point.ByCoordinates command and the Line.ByStartPointEndPoint command. The intersection points of the shearing lines with the curves before and after offset are obtained using the Geometry.Insert command twice, and then the Code is used... The Block code takes out the first point from the Geometry[] table and calls the Curve.ParameterAtPoint command to get the ratio of the arc length from the curve start point to the first point to the total arc length of the curve; based on the position parameter of the first point, it calls the Curve.NormalAtParameter command to get the normal vector of the curve at the first point, and takes the intersection of the perpendicular line of the normal vector and the curve before offset as the shear point; Step 3: Based on the route space curve obtained in Step 1, the parameterized contour family obtained in Step 2 is segmented and imported into the three-dimensional space to generate the steel box girder frame entity corresponding to the bridge; Step 4: According to the transverse diaphragm parameters of the bridge section in the two-dimensional drawing data, the transverse diaphragm entity is generated; Step 5: Based on the route space curve obtained in Step 1, the generated transverse diaphragm entity is imported into the steel box girder frame entity, and the corresponding three-curved steel box girder model is output.

2. The method for constructing a spatial triple-curved steel box girder model based on BIM technology according to claim 1, characterized in that, In step 3, the specific process of generating the steel box girder frame entity is as follows: Step 3-1, import the parametric contour families of the top plate, bottom plate, web plate and rib plate into the Revit metric conventional model; Step 3-2, directly measure the coordinates of the connection points of the corresponding parts of the parametric contour families in the two-dimensional three views to obtain the spatial coordinates of the parametric contour families; Step 3-3, use Dynamo to arrange the contours of the top plate, bottom plate, web plate and rib plate in the corresponding positions in the three-dimensional space according to the route space curve and the spatial coordinates of the parametric contour families obtained in step 3-2; Step 3-4, perform lofting and fusion on the three-dimensional space after the arrangement is completed to generate the corresponding steel box girder frame entity.

3. The method for constructing a spatial triple-curved steel box girder model based on BIM technology according to claim 1, characterized in that, In step 4, the diaphragm entity is generated by drawing the diaphragm outline corresponding to the diaphragm parameters using Dynamo and then performing an extrusion operation and Boolean operations.

4. The method for constructing a spatial triple-curved steel box girder model based on BIM technology according to claim 3, characterized in that, The specific operations of the stretching operation and Boolean operation are as follows: The outline lines are input as items to form a list using the List Create command. Then, the PolyCurve.ByJoinedCurves command is called to combine the individual outline lines into a closed polyline. Finally, the Curve.ExtrudeAsSolid command is used to input the closed polyline and the stretching length to generate a solid diaphragm without holes. Similarly, the solid with holes in the middle is generated, and the Solid.Difference Boolean operation is used to remove the holes from the diaphragm to generate the final diaphragm solid.

5. A spatial triple-curved steel box girder model construction system, which performs modeling using the BIM-based spatial triple-curved steel box girder model construction method as described in any one of claims 1 to 4, characterized in that, include: The route space curve generation unit generates the corresponding route space curve based on the input two-dimensional drawing data; The parametric box girder profile family generation unit generates parametric profile families of the top plate, bottom plate, web plate, rib plate, and diaphragm based on the ellipse equation and diaphragm parameters in the bridge section diagram from the input 2D drawings; the model building unit outputs a three-curved steel box girder model corresponding to the 2D drawing data based on the data generated by the route space curve generation unit and the parametric box girder profile family generation unit; the model unfolding unit outputs a surface unfolding diagram for layout and lofting based on the three-curved steel box girder model output by the model building unit.

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