An accurate simulation method for longitudinal prestressed steel bars of a long-span cable-stayed bridge with a large longitudinal slope

Abstract

An accurate simulation method for longitudinal prestressed steel bars of a long-span cable-stayed bridge with a large longitudinal slope, comprising the following steps: Step 1, modeling the main bridge structure; Step 2, performing two-dimensional spline PL modeling on the flat-curved prestressed steel bars; Step 3, segmenting the vertical-curved prestressed steel bars; Step 4, generating two-dimensional splines SL1 and SL1' for the tensioning sections on both sides of the vertical-curved prestressed steel bars; Step 5, generating a two-dimensional spline SL2 for the middle section of the vertical-curved prestressed steel bars; Step 6, synthesizing the vertical-curved two-dimensional spline SL; Step 7, generating the longitudinal prestressed three-dimensional space curve YL; Step 8, generating a single longitudinal prestressed steel bar; Step 9, batch generating longitudinal prestressed steel bars. The present invention solves the technical problems that the results simulated by the traditional method for prestressed construction are quite different from the actual construction, and it is impossible to batch create the prestress model, so that accurate cutting cannot be carried out according to the prestress model.

Description

Technical Field

[0001] The invention belongs to the technical field of building engineering construction, and particularly relates to an accurate simulation method for longitudinal prestressed steel bars of a large longitudinal slope and large span cable-stayed bridge. Background Art

[0002] In the construction of prestressed bridges, the design drawings provide the steel bar layout drawings of the longitudinal prestress, which include the vertical bend and flat bend drawings corresponding to the prestress with the number. The vertical bend drawings only give the distance between the top surface of the box girder and the prestressed vertical bend. For the box girder structure with longitudinal slope, the design drawings give the slope ratio, but in actual construction, the elevation of the top surface of the box girder at the highest slope change point of the vertical curve changes slowly. Far away from the slope change point, the elevation of the top surface of the box girder changes proportionally, which is a fixed slope. The distance from the prestressed vertical bend to the top surface of the box girder is a fixed value, which means that the prestressed vertical bend changes with the change of the elevation of the top surface of the box girder. As a result, the longitudinal prestressed vertical bend is not a straight line segment provided in the design drawings, that is, the flat bend and vertical bend layout drawings provided in the design drawings are only theoretical data and cannot be directly used as a basis for construction.

[0003] In addition, when implementing prestressed collision checks through 3D modeling, the current common technical basis is to use the stretching function of the Revit software to stretch the flat bends and vertical bends into entities according to the design drawings (according to the theoretical values ​​of the design drawings, the flat bends are closed into closed curves, and along this curve they can be stretched into a solid model. The vertical bends are stretched into a solid model in the same way.) Then the two solid models are put together and intersected to form an edge line, which is used as the layout path for the vertical prestress to form a single longitudinal prestress. Repeat the above steps to complete the prestressing of the entire bridge. The prestress created by the above method is still a theoretical value model created according to the design drawings. The results of the construction simulation are quite different from the actual construction, and it cannot be created in batches. The prestressed model has inaccurate prestressed length and position, and cannot be accurately cut according to the prestressed model. Summary of the invention

[0004] The purpose of the present invention is to provide a precise simulation method for the longitudinal prestressed steel bars of a large-span cable-stayed bridge with a large longitudinal slope, so as to solve the technical problem that the prestress created by the traditional method is still a theoretical value model created according to the design drawings, the result of the construction simulation is quite different from the actual construction, and it is impossible to create in batches, and the prestressed model has inaccurate prestressed length and prestressed position, resulting in the collision detection structure between the prestressed steel bundles and between the prestressed steel and the steel bars not being consistent with the actual construction site, thereby making it impossible to accurately cut materials according to the prestressed model.

[0005] To achieve the above purpose, the present invention adopts the following technical solution.

[0006] A precise simulation method for longitudinal prestressed steel bars of a large longitudinal slope and large span cable-stayed bridge comprises the following steps.

[0007] Step 1: Modeling of the main structure of the bridge: Divide the main structure of the bridge into sections according to the construction sections. According to the elevation of the control points of the bridge and the pre-camber table, use Revit to model the main structure of the bridge in stages according to the construction sections through the structural framework. At the same time, it is necessary to adjust the elevation of the main structure of the bridge in the model in combination with the bridge elevation control table to complete the accurate modeling of the main structure of the bridge.

[0008] Step 2: Use Revit to perform two-dimensional spline PL modeling on the flat-bent prestressed steel bars: According to the layout drawing of the longitudinal prestressed steel bars, first use the Revit model line to complete the drawing of the two-dimensional curve of the flat-bent prestressed steel bars, and then convert the two-dimensional curve model line of the flat-bent prestressed steel bars into a two-dimensional spline PL that can be recognized by the visual programming software.

[0009] Step three, divide the vertical prestressed steel bars into sections. The vertical prestressed steel bars are divided into tensioning sections on both sides and a middle section that changes with the height of the bridge.

[0010] Step 4: Use Revit to generate two-dimensional spline lines SL1 and SL1' for the tensioning sections on both sides of the vertical prestressed steel bars: According to the layout drawing of the longitudinal prestressed steel bars, first use the Revit model line to complete the drawing of the two-dimensional curve of the tensioning section, and then convert the two-dimensional curve of the tensioning section into two-dimensional spline lines SL1 and SL1' that can be recognized by the visual programming software.

[0011] Step five: Use Revit to generate the two-dimensional spline SL2 for the middle section of the vertical prestressed steel bars.

[0012] Step six: synthesis of vertical curved two-dimensional spline SL.

[0013] Step 7, generation of the longitudinal prestressed three-dimensional space curve YL: use the programming node Curve.Extrude to stretch SL along the specified distance and direction to form the surface Surface; use the programming node Curve.Project to project the two-dimensional spline PL onto the surface Surface, and you can get the longitudinal prestressed three-dimensional space curve YL that is consistent with the actual project.

[0014] Step 8: Generation of single longitudinal prestressed steel bar in the prestressed steel strand.

[0015] Step nine, batch generation of longitudinal prestressed steel bars: batch modeling of longitudinal prestressed steel bars is completed by modifying the longitudinal prestressed steel bar data, and accurate simulation and precise cutting of longitudinal prestressed steel bars are performed based on the completed longitudinal prestressed steel bar model.

[0016] Preferably, when the flat-bend two-dimensional curve is created in step 2, the accuracy is consistent with the design drawing, and the flat-bend two-dimensional curve is converted into a Polycurve recognizable by the programming software using the visual programming nodes Select Model Elements, Element.Geometry and PolyCurve.ByJoinedCurves; the specific steps are as follows:

[0017] Step 1: Use the Select Model Elements node to select the flat-bend 2D curve element from the model.

[0018] Step 2: Pass the selected 2D curve element to the Element.Geometry node to extract its geometric information; this node will output the geometric representation of the curve.

[0019] Step 3. Pass the curve output by Element.Geometry as input to the PolyCurve.ByJoinedCurves node. The PolyCurve.ByJoinedCurves node will connect multiple curve segments into a Polycurve.

[0020] Preferably, in step three, the length of the tensioning section is 321 mm to 398 mm; the length of the middle section is 15000 mm to 16000 mm.

[0021] Preferably, the specific method of dividing the center line of the top surface of the main structure of the bridge into a plurality of single Polycurves is as follows.

[0022] Step 1: Use the visual programming node Select Model Elements to select the center line of the top surface of the bridge main structure.

[0023] Step 2: Pass the selected centerline element to the Element.Geometry node to extract the centerline geometry information. The Element.Geometry node will output the geometry information of the curve.

[0024] Step 3, use the Curve.Explode node to decompose the center line into multiple independent curve segments.

[0025] Step 4, select at least two points from each curve, and then shift these points a fixed distance along the top surface of the box girder.

[0026] Step 5: Continue until all points on the curve are shifted, and then string all the points together through the NurbsCurve.ByPoint node to form a complete curve, which is the two-dimensional spline SL2.

[0027] Preferably, if the centerline is a multi-segment curve, the Curve.Explode node will decompose it into multiple separate curves, and the decomposed nodes are the turning points of two adjacent curve segments.

[0028] Preferably, the number of segments is determined according to the accuracy of the corresponding longitudinal prestressed steel bar simulation. The more segments there are, the more accurate the longitudinal prestressed steel bar path is, and the length of each segment is less than 1m, which can improve the operating efficiency and model accuracy.

[0029] Preferably, the programming nodes Curve.StartPoint and Curve.EndPoint respectively obtain the end point of the two-dimensional spline SL1, the starting point of the two-dimensional spline SL2 and the starting point of the two-dimensional spline SL1', and take the end point of the two-dimensional spline SL1 as the reference point to coincide the starting point of the two-dimensional spline SL2 with the end point of the two-dimensional spline SL1, and take the end point of the two-dimensional spline SL2 as the reference point to coincide the starting point of the two-dimensional spline SL1' with the end point of the two-dimensional spline SL2, so as to complete the modeling of the two-dimensional spline SL of the vertical bending prestressed steel bar in the programming environment.

[0030] Preferably, in step eight, the specific method for generating a single longitudinal prestressed steel bar in the prestressed steel bundle is: using Revit to create a two-dimensional cross-sectional profile of the longitudinal prestressed steel bar, using the programming node Select Model Element to obtain the contour line of the cross section, and converting the contour line into a spline recognizable by the visual programming software; then obtaining the starting point of the longitudinal prestressed three-dimensional space curve YL, placing the spline on the starting point of the three-dimensional space curve YL and completing the direction rotation, so that the rotated cross-sectional profile spline is perpendicular to the tangent direction at the starting point of the longitudinal prestressed three-dimensional space curve YL, and the programming node Curve.SweepAsSolid uses the longitudinal prestressed three-dimensional space curve YL as a path, and uses the rotated profile cross section to sweep the longitudinal prestressed steel bar three-dimensional model.

[0031] Preferably, in step eight, when using the programming node Curve.SweepAsSolid to use the longitudinal prestressed three-dimensional space curve YL as a path and sweeping the rotated contour cross section into a prestressed steel bar three-dimensional model, the contour cross section is always perpendicular to the tangent direction at the corresponding position on the longitudinal prestressed three-dimensional space curve YL.

[0032] Compared with the prior art, the present invention has the following characteristics and beneficial effects.

[0033] 1. The core of this patent is to solve the modeling of the two-dimensional spline SL of the vertical bending prestressed steel bar to achieve the establishment of the three-dimensional space curve of the longitudinal prestressed steel bar, and then use the programming software to evolve the vertical bending curve into a surface, and project the flat bending curve onto the vertical bending surface to solve the problem that the traditional prestressed steel bundle modeling is difficult to form a three-dimensional curve in space. In addition, the method of the present invention also effectively solves two difficult problems in the current prestressed bridge construction, one is the collision between prestressed steel bundles, and the other is the technical problem that the longitudinal prestressed model cannot be generated in batches and the material cannot be accurately cut according to the prestressed model.

[0034] 2. The present invention realizes accurate simulation of prestressed steel strands through programming functions, solves the core problem of prestress collision in bridge prestressing construction, and accurately simulates the position of prestressed steel strands through prestressing, and can complete the optimization and adjustment of prestressed steel strands in advance through three-dimensional visualization models. Secondly, by accurately simulating prestressed steel strands, the cutting length of prestress can be accurately calculated, reducing costs and increasing efficiency.

[0035] 3. During the bridge construction process, the bridge structure is complex, with a large number of steel bars, many types, a large number of embedded parts, a large number of prestressed parts, and a three-dimensional spatial irregular structure. During construction, collisions between steel bars and prestressed parts are likely to occur, and even damage to multiple pipelines may be caused, leading to leakage problems. In serious cases, if the prestressed position during construction is inaccurate due to collision problems, safety accidents may occur during prestressing tensioning and subsequent bridge use. Therefore, before construction, the patented technology is used to accurately simulate the installation position of prestressed bars, optimize the relative positions of prestressed bars and embedded parts, steel bars and other components, and ensure accurate construction of prestressed bars, which plays a vital role in the quality of the project.

[0036] 4. When using BIM technology to solve the problem of prestress visualization, the conventional Revit modeling software has considerable difficulty in modeling prestress. The currently commonly used technical method is to use the Revit family (component) function to first create a closed curve entity model of the flat bend, and then create a closed curve entity model of the vertical bend. The intersection of the two entity components is the three-dimensional path curve of the prestressed steel strand. This method has three disadvantages: First, the vertical bend flat curve directly created by Revit is a design theoretical value, which cannot adapt to the changes in the bridge structure and is not authentic; second, when the conventional method creates prestress, each prestress must be created manually and then moved to the corresponding bridge position, which is inefficient in modeling; third, the prestressed steel strand created by the conventional method does not have a length attribute, and the length cannot be counted, and it is impossible to cut materials according to BIM data. In view of the above disadvantages, the use of visual programming software based on Revit software can not only solve the above problems, but also adapt to the audience of Revit software. DETAILED DESCRIPTION

[0037] In this embodiment, the long-span cable-stayed bridge is a box-beam bridge, and the longitudinal prestressed steel bars are arranged in two rows in the long-span cable-stayed bridge. The two rows of longitudinal prestressed steel bars are arranged at intervals at the top and bottom surfaces of the long-span cable-stayed bridge respectively; each longitudinal prestressed steel bar is a three-dimensional solid structure. Before simulating the three-dimensional longitudinal prestressed steel bars, the longitudinal prestressed steel bars are decomposed into two-dimensional flat-bent prestressed steel bars and vertical-bent prestressed steel bars.

[0038] The precise simulation method of the longitudinal prestressed steel bars of the large longitudinal slope and large span cable-stayed bridge specifically includes the following steps:

[0039] Step 1: Modeling of the main structure of the bridge: Divide the main structure of the bridge into sections according to the construction sections. According to the elevation of the control points of the bridge and the pre-camber table, use Revit to model the main structure of the bridge in stages according to the construction sections through the structural framework. At the same time, it is necessary to adjust the elevation of the main structure of the bridge in the model in combination with the bridge elevation control table to complete the accurate modeling of the main structure of the bridge.

[0040] Step 2: Use Revit to perform two-dimensional spline PL modeling on the flat-bent prestressed steel bars: According to the layout drawing of the longitudinal prestressed steel bars, first use the Revit model line to complete the drawing of the two-dimensional curve of the flat-bent prestressed steel bars, and then convert the two-dimensional curve model line of the flat-bent prestressed steel bars into a two-dimensional spline PL that can be recognized by the visual programming software.

[0041] Step three, divide the vertical prestressed steel bars into sections. The vertical prestressed steel bars are divided into tensioning sections on both sides and a middle section that changes with the height of the bridge.

[0042] Step 4: Use Revit to generate two-dimensional spline lines SL1 and SL1' for the tensioning sections on both sides of the vertical prestressed steel bars: According to the layout drawing of the longitudinal prestressed steel bars, first use the Revit model line to complete the drawing of the two-dimensional curve of the tensioning section, and then convert the two-dimensional curve of the tensioning section into two-dimensional spline lines SL1 and SL1' that can be recognized by the visual programming software.

[0043] Step five: Use Revit to generate the two-dimensional spline SL2 for the middle section of the vertical prestressed steel bars.

[0044] Step six, synthesis of the vertical bent two-dimensional spline SL: the programming nodes Curve.StartPoint and Curve.EndPoint respectively obtain the end point of the two-dimensional spline SL1, the starting point of the two-dimensional spline SL2 and the starting point of the two-dimensional spline SL1', take the end point of the two-dimensional spline SL1 as the reference point, coincide the starting point of the two-dimensional spline SL2 with the end point of the two-dimensional spline SL1, take the end point of the two-dimensional spline SL2 as the reference point, coincide the starting point of the two-dimensional spline SL1' with the end point of the two-dimensional spline SL2, and complete the modeling of the vertical bent prestressed steel bar two-dimensional spline SL in the programming environment.

[0045] Step 7, generation of the longitudinal prestressed three-dimensional space curve YL: use the programming node Curve.Extrude to stretch SL along the specified distance and direction to form the surface Surface; use the programming node Curve.Project to project the two-dimensional spline PL onto the surface Surface, and you can get the longitudinal prestressed three-dimensional space curve YL that is consistent with the actual project.

[0046] Step 8. Generation of a single longitudinal prestressed steel bar in the prestressed steel bundle: Use Revit to create a two-dimensional cross-sectional profile of the longitudinal prestressed steel bar, and the two-dimensional cross-sectional profile is a circle; use the programming node Select Model Element to obtain the profile of the cross section, and convert the profile into a spline that can be recognized by the visual programming software; then obtain the starting point of the longitudinal prestressed three-dimensional space curve YL, place the spline on the starting point of the three-dimensional space curve YL and complete the direction rotation, so that the rotated cross-sectional profile spline is perpendicular to the tangent direction at the starting point of the longitudinal prestressed three-dimensional space curve YL, and the programming node Curve.SweepAsSolid uses the longitudinal prestressed three-dimensional space curve YL as the path, and uses the rotated profile cross section to sweep the three-dimensional model of the longitudinal prestressed steel bar.

[0047] Step nine, batch generation of longitudinal prestressed steel bars: For the longitudinal prestressed steel bars at other locations in the main structure of the bridge, batch modeling of the longitudinal prestressed steel bars is completed by modifying the longitudinal prestressed steel bar data, and the longitudinal prestressed steel bars are accurately simulated and cut based on the completed longitudinal prestressed steel bar model.

[0048] In this embodiment, when the flat-bend two-dimensional curve is created in step 2, the accuracy is consistent with the design drawing, and the flat-bend two-dimensional curve is converted into a Polycurve recognizable by the programming software using the visual programming nodes Select Model Elements, Element.Geometry and PolyCurve.ByJoinedCurves. Polycurve is a complex curve formed by connecting multiple curve segments (which can be straight lines, arcs or other types of curves); the specific steps are as follows.

[0049] Step 1: Use the Select Model Elements node to select the flat-bend 2D curve element from the model.

[0050] Step 2: Pass the selected 2D curve element to the Element.Geometry node to extract its geometric information; this node will output the geometric representation of the curve.

[0051] Step 3. Pass the curve output by Element.Geometry as input to the PolyCurve.ByJoinedCurves node. The PolyCurve.ByJoinedCurves node will connect multiple curve segments into a Polycurve.

[0052] In this embodiment, the length of the tensioning section in step three is 321 mm to 398 mm; the length of the middle section is 15000 mm to 16000 mm.

[0053] In this embodiment, in step 5, the specific method of dividing the center line of the top surface of the main structure of the bridge into a number of single Polycurves is:

[0054] Step 1: Use the visual programming node Select Model Elements to select the center line of the top surface of the bridge main structure;

[0055] Step 2: Pass the selected centerline element to the Element.Geometry node to extract the centerline geometry information. The Element.Geometry node will output the geometry information of the curve.

[0056] Step 3, use the Curve.Explode node to decompose the center line into multiple independent curve segments;

[0057] Step 4, select at least two points from each curve, and then shift these points along the top surface of the box girder by a fixed distance;

[0058] Step 5: Continue until all points on the curve are shifted, and then string all the points together through the NurbsCurve.ByPoint node to form a complete curve, which is the two-dimensional spline SL2.

[0059] In this embodiment, if the center line is a multi-segment curve, the Curve.Explode node will decompose it into multiple separate curves, and the decomposed nodes are the turning points of two adjacent curve segments.

[0060] In this embodiment, the number of segments is determined according to the accuracy of the corresponding longitudinal prestressed steel bar simulation. The more segments there are, the more accurate the longitudinal prestressed steel bar path is. The length of each segment is less than 1m, which can improve the operating efficiency and model accuracy.

[0061] In this embodiment, in step eight, when the programming node Curve.SweepAsSolid is used to take the longitudinal prestressed three-dimensional space curve YL as the path and the rotated contour cross section is used to sweep the prestressed steel bar three-dimensional model, the contour cross section is always perpendicular to the tangent direction at the corresponding position on the longitudinal prestressed three-dimensional space curve YL.

[0062] In this embodiment, in step nine, after drawing a longitudinal prestressed steel bar, there are multiple steel bars on the top of the box beam, and there is a specified distance between the steel bars. These data can be sorted out through Excel, and the batch processing function of the programming software can be used to complete the modeling in batches. The longitudinal prestressed steel bar data is the same as the data on the top of the box beam, which is also the distance between the prestressed steel bars, and is used for the data of the longitudinal prestressed steel bar positioning (position).

Claims

1. An accurate simulation method for longitudinal prestressed steel bars of a large-span cable-stayed bridge with a large longitudinal slope, characterized in that: The steps include: Step 1: Modeling of the main structure of the bridge: Divide the main structure of the bridge into sections according to the construction segments. According to the control point elevation and pre-camber table of the bridge, use Revit to model the main structure of the bridge in stages according to the construction segments through the structural framework. At the same time, it is necessary to adjust the elevation of the main structure of the bridge in the model in combination with the bridge elevation control table, so as to complete the accurate modeling of the main structure of the bridge. Step 2: Use Revit to perform two-dimensional spline PL modeling on the flat-bent prestressed steel bars: According to the layout drawing of the longitudinal prestressed steel bars, first use the Revit model line to complete the drawing of the two-dimensional curve of the flat-bent prestressed steel bars, and then convert the two-dimensional curve model line of the flat-bent prestressed steel bars into a two-dimensional spline PL that can be recognized by the visual programming software; When creating a flat-bend 2D curve, the accuracy is consistent with the design drawing, and the flat-bend 2D curve is converted into a Polycurve that can be recognized by the programming software using the visual programming nodes Select Model Elements, Element.Geometry, and PolyCurve.ByJoinedCurves; the specific steps are as follows: Step 1: Use the Select Model Elements node to select the flat curved 2D curve element from the model. Step 2, pass the selected 2D curve element to the Element.Geometry node to extract its geometric information; this node will output the geometric representation of the curve; Step 3: Pass the curve output by Element.Geometry as input to the PolyCurve.ByJoinedCurves node. The PolyCurve.ByJoinedCurves node will connect multiple curve segments into a Polycurve. Step 3: Segment the vertical prestressed steel bars. The vertical prestressed steel bars are divided into tensioning segments on both sides and a middle segment that changes with the height of the bridge. The length of the tensioning segment is 321mm~398mm; the length of the middle segment is 15000mm~16000mm. Step 4: Use Revit to generate two-dimensional spline lines SL1 and SL1' for the tensioning sections on both sides of the vertical bending prestressed steel bars: According to the layout drawing of the longitudinal prestressed steel bars, first use the Revit model line to complete the drawing of the two-dimensional curves of the tensioning sections on both sides, and then convert the two-dimensional curves of the tensioning sections into two-dimensional spline lines SL1 and SL1' that can be recognized by the visual programming software; Step 5: Use Revit to generate a two-dimensional spline SL2 for the middle section of the vertical bending prestressed steel bar; Step 6: Synthesis of vertical curved two-dimensional spline SL; Step 7, generation of the longitudinal prestressed three-dimensional space curve YL: use the programming node Curve.Extrude to stretch SL along the specified distance and direction to form the surface Surface; use the programming node Curve.Project to project the two-dimensional spline PL onto the surface Surface, and you can get the longitudinal prestressed three-dimensional space curve YL that is consistent with the actual project; Step 8: Generation of a single longitudinal prestressed steel bar in the prestressed steel strand: Step nine, batch generation of longitudinal prestressed steel bars: batch modeling of longitudinal prestressed steel bars is completed by modifying the longitudinal prestressed steel bar data, and accurate simulation and precise cutting of longitudinal prestressed steel bars are performed based on the completed longitudinal prestressed steel bar model.

2. The accurate simulation method of longitudinal prestressed steel bars of a large-span cable-stayed bridge with a large longitudinal slope according to claim 1 is characterized by: In step 5, the specific method of dividing the center line of the top surface of the main structure of the bridge into several single Polycurves is: Step 1: Use the visual programming node Select Model Elements to select the center line of the top surface of the bridge main structure; Step 2: Pass the selected centerline element to the Element.Geometry node to extract the centerline geometry information. The Element.Geometry node will output the geometry information of the curve. Step 3, use the Curve.Explode node to decompose the center line into multiple independent curve segments; Step 4, select at least two points from each curve, and then shift these points along the top surface of the box girder by a fixed distance; Step 5: Continue until all points on the curve are shifted, and then string all the points together through the NurbsCurve.ByPoint node to form a complete curve, which is the two-dimensional spline SL2.

3. The accurate simulation method of longitudinal prestressed steel bars of a large-span cable-stayed bridge with a large longitudinal slope according to claim 2 is characterized by: If the centerline is a multi-segment curve, the Curve.Explode node will decompose it into multiple separate curves, and the decomposed nodes are the turning points of two adjacent curves.

4. The accurate simulation method of longitudinal prestressed steel bars of a large-span cable-stayed bridge with a large longitudinal slope according to claim 1 is characterized by: In step six, the specific method for synthesizing the vertical bending two-dimensional spline SL is: programming nodes Curve.StartPoint and Curve.EndPoint respectively obtain the end point of the two-dimensional spline SL1, the starting point of the two-dimensional spline SL2 and the starting point of the two-dimensional spline SL1', taking the end point of the two-dimensional spline SL1 as the reference point, coinciding the starting point of the two-dimensional spline SL2 with the end point of the two-dimensional spline SL1, taking the end point of the two-dimensional spline SL2 as the reference point, coinciding the starting point of the two-dimensional spline SL1' with the end point of the two-dimensional spline SL2, and completing the modeling of the vertical bending prestressed steel bar two-dimensional spline SL in the programming environment.

5. The accurate simulation method of longitudinal prestressed steel bars of a large-span cable-stayed bridge with a large longitudinal slope according to claim 2 is characterized by: The number of segments is determined according to the accuracy of the corresponding longitudinal prestressed steel bar simulation. The more segments there are, the more accurate the longitudinal prestressed steel bar path is. The length of each segment is less than 1m, which can improve the operating efficiency and model accuracy.

6. The accurate simulation method of longitudinal prestressed steel bars of a large-span cable-stayed bridge with a large longitudinal slope according to claim 1 is characterized by: In step eight, the specific method for generating a single longitudinal prestressed steel bar in the prestressed steel bundle is as follows: using Revit to create a two-dimensional cross-sectional profile of the longitudinal prestressed steel bar, using the programming node Select Model Element to obtain the contour line of the cross section, and converting the contour line into a spline recognizable by the visual programming software; then obtaining the starting point of the longitudinal prestressed three-dimensional space curve YL, placing the spline on the starting point of the three-dimensional space curve YL and completing the direction rotation, so that the rotated cross-sectional profile spline is perpendicular to the tangent direction at the starting point of the longitudinal prestressed three-dimensional space curve YL, and the programming node Curve.SweepAsSolid uses the longitudinal prestressed three-dimensional space curve YL as a path, and uses the rotated profile cross section to sweep the longitudinal prestressed steel bar three-dimensional model.

7. The accurate simulation method of longitudinal prestressed steel bars of a large-span cable-stayed bridge with a large longitudinal slope according to claim 6 is characterized by: In step eight, when the programming node Curve.SweepAsSolid is used to sweep the prestressed steel bar three-dimensional model with the rotated contour cross section using the longitudinal prestressed three-dimensional space curve YL as the path, the contour cross section is always perpendicular to the tangent direction at the corresponding position on the longitudinal prestressed three-dimensional space curve YL.