A BIM forward design method applied to super-kilometer cable-stayed bridge

Abstract

The application discloses a BIM forward design method applied to super-kilometer cable-stayed bridges, relates to the technical field of bridge engineering design, and discloses the following technical scheme: through the modeling mode combining from top to bottom with from bottom to top, first, inputting a horizontal curve and a vertical curve element table, calling an Inventor API function by using a C# programming language to create a bridge design center line, establishing an overall model of the cable-stayed bridge according to overall information such as a bridge span, a bridge width, a tower height and a cable spacing, simultaneously, performing component division on a main beam, a tower, a cable and a foundation of the cable-stayed bridge, forming a component position and size parameter table, then, using Inventor software to establish a parameterized model of different types of components, and forming a component library, finally, generating an instantiated component from the component library through the component position and size parameter table and automatically assembling the instantiated component to form a full-bridge BIM model. The whole method adopts the Inventor+C# secondary development mode, achieves the purpose of the BIM forward design of the super-kilometer cable-stayed bridge, and solves the pain point problem that traditional modeling is first two-dimensional design and then "model conversion".

Description

Technical Field

[0001] This invention relates to the field of bridge engineering design technology, specifically to a BIM forward design method applied to cable-stayed bridges exceeding 1,000 meters in length. Background Technology

[0002] With the rapid development of transportation infrastructure construction, cable-stayed bridges exceeding 1,000 meters in length, as an important form of long-span bridge, have been widely used in the construction of cross-river and cross-sea passages due to their advantages such as strong spanning capacity, reasonable structural stress, and good aesthetic effects. However, cable-stayed bridges exceeding 1,000 meters in length are characterized by complex structures, a large number of components, complex spatial relationships, and high design precision requirements. Traditional two-dimensional design methods are no longer sufficient to meet their design needs, revealing many problems that urgently need to be solved.

[0003] Traditional two-dimensional design methods are based on CAD software, which express design intentions by drawing two-dimensional drawings such as plans, elevations, and cross-sections. In the design of cable-stayed bridges exceeding 1,000 meters in length, this method has the following significant drawbacks: First, low design accuracy. Since the components of cable-stayed bridges exceeding 1,000 meters in length are mostly spatially irregular structures, two-dimensional drawings cannot accurately express the spatial shape and positional relationships of the components, easily leading to problems such as dimensional deviations and coordinate misalignments, which in turn cause potential hazards such as component collisions and installation difficulties during the construction phase. Second, low design efficiency. Traditional two-dimensional design requires designers to manually draw a large number of drawings, and the drawings of each discipline are independent of each other. When design parameters change, it is necessary to modify the relevant drawings one by one, resulting in a huge workload, a long modification cycle, and a high risk of incorrect or missed modifications. Third, poor collaboration. The design of cable-stayed bridges exceeding 1,000 meters in length involves multiple disciplines such as bridge engineering, structure, geotechnical engineering, and electromechanical engineering. In traditional two-dimensional design, the information transmission between the drawings of each discipline is not timely or accurate, easily leading to design conflicts between disciplines and high coordination costs. Fourth, difficulty in reusing design data. The information in traditional two-dimensional drawings is fragmented and cannot form a unified digital model. The design data is difficult to directly apply to subsequent construction simulation, operation and maintenance management, etc., resulting in a disconnect between design and subsequent stages, affecting the efficiency of the entire life cycle management of the project.

[0004] To address the shortcomings of traditional two-dimensional design methods, BIM (Building Information Modeling) technology is increasingly being applied to bridge design. BIM technology, with its core three-dimensional digital model, integrates relevant information throughout the entire building lifecycle, enabling collaborative management of design, construction, and operation. However, currently, the application of BIM technology in the design of cable-stayed bridges exceeding 1,000 meters in length largely follows a "two-dimensional model conversion" approach. This involves first completing the two-dimensional design and then converting the two-dimensional drawings into a three-dimensional model. This approach does not fully leverage the advantages of BIM technology and still suffers from problems such as low design efficiency, a disconnect between the model and design logic, and low parametric levels.

[0005] In existing technologies, some bridge BIM design methods attempt to use parametric modeling technology, but these are mostly applicable to small and medium-span bridges. There is a lack of dedicated parametric component libraries for cable-stayed bridges with spans exceeding 1,000 meters, which cannot meet the design requirements of complex components for cable-stayed bridges with spans exceeding 1,000 meters. At the same time, existing methods rely heavily on manual adjustments in the component assembly stage and fail to achieve automatic assembly based on route data, resulting in design efficiency and accuracy still needing improvement.

[0006] Therefore, in view of the structural characteristics of cable-stayed bridges over 1,000 meters long, it is of great practical significance and engineering value to develop a BIM forward design method based on a parametric component library to realize the rapid instantiation and automatic assembly of components, improve design accuracy and efficiency, and realize the full life cycle reuse of design data. Summary of the Invention

[0007] To address the shortcomings of existing design methods for cable-stayed bridges exceeding 1,000 meters in length, such as low accuracy, poor efficiency, and difficulty in data reuse, this invention aims to provide a BIM-based forward design method for such bridges. This method, by constructing a dedicated parametric component library and parsing route information data to achieve automatic component assembly, significantly improves design accuracy and efficiency, enables the full lifecycle flow of design data, and provides technical support for the full lifecycle management of cable-stayed bridges exceeding 1,000 meters in length.

[0008] To further achieve the above objectives, the technical solution adopted by the present invention is as follows: A BIM-based forward design method for cable-stayed bridges exceeding 1,000 meters in length includes the following steps: S1. Construct a parametric component library for cable-stayed bridges of over 1,000 meters in length. The parametric component library includes a main tower component family, a main beam component family, a cable stay component family, a foundation component family, and an auxiliary component family. Each component family has a preset editable parameter set. S2. Obtain route information data for cable-stayed bridges exceeding 1,000 meters in length, including horizontal curve elements, vertical curve elements, cross-sectional elements, and route control coordinates; S3. Analyze the route information data and calculate the three-dimensional positioning coordinates and deflection angles of each component; S4. Determine the component type and specification parameters according to the design requirements, search for matching component families from the parametric component library, and combine the positioning parameters and deflection angle obtained in step S3 to complete the rapid instantiation of the component. S5. Assemble all the generated instantiated components according to their three-dimensional positional relationships to form a complete BIM model of the super-kilometer-level cable-stayed bridge; S6. Perform collision detection and accuracy verification on the assembled BIM model. If there is a collision or accuracy deviation, return to step S3 or S4 to adjust the parameters until the model meets the design requirements.

[0009] Optionally, the specific implementation process of step S1 includes: S11. The component types of cable-stayed bridges with a length of over 1,000 meters are sorted out and divided into three categories according to structural function: standard components, family templates and general components. Standard components include main towers, main beams, cable stays, piers and foundations; family templates include steel box girders, composite beams, steel shell towers and steel anchor boxes; and general components include high-strength bolts, shear studs, steel sections, plate ribs and U-ribs. S12. Define parameters for each type of component, and determine core parameters and extended parameters. Core parameters include geometric dimension parameters and material performance parameters, while extended parameters include construction process parameters and operation and maintenance management parameters. S13. Create parametric part files for each component, establish the association mapping relationship between parameters and component geometry, and realize the dynamic adjustment of component shape driven by parameters; S14. Utilize the local folder-based parametric component library management system to classify and store parametric part files, manage versions, optimize retrieval, and control access permissions, supporting quick retrieval by component name, component type, specifications, and application scenario.

[0010] Furthermore, in step S13, the correlation mapping relationship between parameters and component geometry is achieved through Inventor parametric modeling. Specifically, it defines the geometric constraint relationship between parameters and component vertices, edges, and faces. When the parameters are adjusted, the component geometry is automatically updated according to the constraint relationship.

[0011] Optionally, in step S2, the route information data is acquired by reading the horizontal curve, vertical curve, and cross-sectional element data of the route from the sdb project file of the JSL route expert system software. The horizontal curve elements include the coordinates of the starting point, the coordinates of the intersection point, the curve radius, the length of the transition curve, and the curve turning angle; the vertical curve elements include the coordinates of the vertical curve slope change point, the slope, the slope length, and the vertical curve radius; and the cross-sectional elements include the cross-sectional width, the number of lanes, the width of the sidewalk, the width of the curb, the superelevation value, and the cross slope.

[0012] Optionally, the specific implementation process of step S3 includes: S31. Data preprocessing: Data cleaning algorithms are used to remove invalid and duplicate data, and unstructured data is transformed into standardized structured data. S32. Calculation of three-dimensional positioning coordinates: Based on horizontal and vertical curve elements, a curve fitting algorithm is used to calculate the plane coordinates of the component installation reference point, and the vertical coordinates are calculated by combining the cross-sectional elevation data to obtain the three-dimensional positioning coordinates of the component. S33. Deflection angle calculation: Based on the tangent direction of the horizontal curve, the slope direction of the vertical curve, and the superelevation direction of the cross section, the spatial vector operation method is used to calculate the horizontal deflection angle, vertical deflection angle, and cross section deflection angle of the component.

[0013] Furthermore, in step S32, the curve fitting algorithm adopts a cubic spline interpolation algorithm. By interpolating and fitting discrete points of the horizontal and vertical curves of the route, a continuous route centerline is obtained. Then, based on the relative positional relationship between the component and the route centerline, the three-dimensional positioning coordinates of the component installation reference point are determined.

[0014] Optionally, the specific implementation process of step S4 includes: S41. Based on the overall design scheme of the super-long-stayed bridge, input the component names, specifications, and installation location requirements in an Excel spreadsheet; S42. Match the optimal component family from the parametric component library based on component name, type, and specification parameters; S43. An Inventor plugin program developed in C# instantiates a component family based on the input parameters.

[0015] Optionally, the specific implementation process of step S5 includes: S51. Preset component assembly priority and connection constraint rules. The assembly priority from high to low is as follows: foundation components → pier components → main tower components → main beam components → cable-stayed components → connecting components → auxiliary components. S52. Based on the component's positioning parameters, type information, and preset assembly rules, automatically identify the connection relationship between adjacent components and complete the assembly of components sequentially according to assembly priority.

[0016] Furthermore, in step S51, the foundation components and pier components are rigidly connected to constrain the coordinates of the bottom of the pier and the top of the foundation to coincide and the axis to align; the main tower components and main beam components are connected by supports to constrain the installation position and posture of the supports; the stay cable components are connected to the main tower and main beam by anchors to constrain the coordinates of the anchor points at both ends of the stay cable to coincide with the coordinates of the anchor points of the main tower and main beam.

[0017] Optionally, the method also includes step S7: exporting the verified BIM model into a standardized data format, including IFC, FBX, and GLTF, for subsequent finite element analysis, construction simulation, and operation and maintenance management, thereby realizing the full lifecycle flow of design data.

[0018] Compared with the prior art, the present invention has the following significant advantages: 1. Improved design accuracy and reduced design risks. This invention constructs a dedicated parametric component library for cable-stayed bridges exceeding 1,000 meters in length, enabling parametric-driven design of components. This avoids problems such as dimensional deviations and coordinate misalignments caused by manual drawing in traditional 2D design. Simultaneously, based on precise analysis of route information data, it achieves automatic assembly of components and precise control of their spatial attitude, significantly improving the design accuracy of the model. Through collision detection and accuracy verification, potential collision hazards and accuracy deviations in the design can be identified in advance, allowing for timely optimization and adjustments, thus reducing design risks during the construction phase.

[0019] 2. Improved design efficiency and shortened design cycle. The parametric component library of this invention supports rapid component instantiation. Designers can generate components of different specifications simply by adjusting parameters, eliminating the need for repetitive modeling. The automatic assembly function based on route data replaces the tedious manual adjustment of component positions and orientations in traditional design, significantly reducing the design workload. Furthermore, the reusability of the component library and the multi-disciplinary collaborative design function further improve design efficiency and shorten the design cycle. Practice shows that using the method of this invention, the design cycle of cable-stayed bridges exceeding 1,000 meters can be shortened by more than 30%.

[0020] 3. Achieving full lifecycle reuse of design data and reducing overall project costs. The standardized BIM model derived from this invention can be directly applied to subsequent finite element analysis, construction simulation, and operation and maintenance management, realizing the full lifecycle flow of design data. In finite element analysis, geometric and material parameters of components can be directly extracted from the BIM model without remodeling. In construction simulation, construction progress simulation and construction process optimization can be performed based on the BIM model, reducing construction costs. In operation and maintenance management, the BIM model can serve as the basic data for the operation and maintenance management platform, enabling full lifecycle monitoring and maintenance of components. By reusing design data throughout its entire lifecycle, the amount of repetitive work in each stage of the project is reduced, information loss is minimized, and thus the overall project cost is lowered.

[0021] 4. Excellent versatility and scalability. The parametric component library constructed in this invention adopts a standardized parameter system and family file format, which can adjust parameters and expand components according to the design requirements of different super-kilometer-class cable-stayed bridges. It is applicable to the design of super-kilometer-class cable-stayed bridges with various spans and structural forms. At the same time, this method supports data interaction with mainstream BIM software, route design software, finite element analysis software, etc., and has good compatibility and scalability. Attached Figure Description

[0022] Figure 1 This is a flowchart of the BIM forward design method of the present invention applied to cable-stayed bridges with a length of over 1,000 meters; Figure 2 This is a schematic diagram illustrating the structure of the parameterized component library of the present invention; Figure 3 This is a logic diagram illustrating the automatic assembly of components according to the present invention; Figure 4 This is a schematic diagram of the BIM model of a cable-stayed bridge with a length of over 1,000 meters, as shown in Example 1. Detailed Implementation

[0023] The present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the described embodiments are intended only to facilitate understanding of the invention and are not intended to limit it in any way.

[0024] A BIM-based forward design method for cable-stayed bridges exceeding 1,000 meters in length includes the following steps: S1: Construct a parametric component library for cable-stayed bridges exceeding 1,000 meters in length. This library includes main tower component families, main girder component families, stay cable component families, foundation component families, and auxiliary component families. Each component family has a pre-set editable parameter set. The implementation process of step S1 includes: S11: Component Classification and Analysis. Based on the structural characteristics and functional requirements of a super-long-distance cable-stayed bridge, all bridge components are classified into three main categories according to their structural function: core standard components, family templates, and general components. Standard components are the main load-bearing components of a super-long-distance cable-stayed bridge, including the superstructure, substructure, cable system, and bridge deck system. Family templates are used for the parametric assembly of standard components and include steel shell segments, steel box girder segments, and steel anchor boxes. General components provide the basic parts for family templates and include high-strength bolts, shear studs, and U-ribs. This classification and analysis clarifies the structural characteristics and design requirements of each type of component, laying the foundation for subsequent parametric design.

[0025] S12: Parameter System Definition. For each type of component, establish a comprehensive parameter system, including core parameters and extended parameters. Core parameters are key parameters that determine the component's geometry and basic performance, including geometric dimensions (such as main tower height, main beam cross-sectional dimensions, stay cable length and diameter, foundation diameter, etc.) and material performance parameters (such as concrete strength grade, steel grade, modulus of elasticity, compressive strength, etc.). Extended parameters are parameters that assist in design, construction, and operation and maintenance, including construction process parameters (such as component prefabrication accuracy requirements, installation tolerances, welding process parameters, etc.) and operation and maintenance management parameters (such as component service life, maintenance cycle, monitoring point location, etc.). The establishment of the parameter system must follow the principles of standardization and normalization to ensure the parameters' universality and scalability.

[0026] S13: Parametric Family Creation. Inventor software is used to create parametric parts or components as family files for each component. During family creation, Inventor parametric modeling establishes a mapping relationship between parameters and component geometry. Specifically, during modeling, geometric constraints between parameters and component vertices, edges, and faces are defined. When the user adjusts parameter values, the component's geometry automatically updates according to these constraints, achieving parametric-driven component operation. For example, for the main tower component family, by defining parameters such as tower height, tower base cross-sectional dimensions, tower top cross-sectional dimensions, and wall thickness, constraints are established between these parameters and the main tower's outline and cross-sectional shape. When the tower height parameter is adjusted, the overall height of the main tower automatically changes, while the cross-sectional dimensions adjust proportionally.

[0027] S14: Component Library Management Platform Setup. Establish a parameterized component library management system based on local folders to categorize, store, version-manage, optimize retrieval, and control access to created parameterized family files. The management platform supports multi-dimensional searching by component name, component type, specifications, application scenarios, etc., allowing users to quickly locate the required component families. Simultaneously, the platform has version control functionality, recording the modification history of component families and supporting version rollback to avoid design errors caused by parameter modifications.

[0028] S2: Obtain route information data for the super-long-distance cable-stayed bridge. This route information data includes horizontal curve elements, vertical curve elements, cross-sectional elements, and route control coordinates. Route information data is fundamental for the positioning and assembly of components in super-long-distance cable-stayed bridges. It is primarily obtained by reading horizontal curve, vertical curve, and cross-sectional element data from the sdb project file of the JSL route expert system software. Horizontal curve elements include the coordinates of the starting point (X0, Y0), intersection coordinates (JD1, JD2, ..., JDn), curve radius (R), transition curve length (Ls), and curve turning angle (α). Vertical curve elements include the coordinates of the vertical curve slope change point (Xp, Yp, Zp), slope (i1, i2), slope length (L), and vertical curve radius (Rv). Cross-sectional elements include cross-sectional width, number of lanes, sidewalk width, curb width, superelevation (h), and cross slope (i).

[0029] S3: Analyze the route information data to calculate the three-dimensional positioning coordinates (X, Y, Z) and deflection angles (α, β, γ) of each component. This step is the core of achieving automatic component assembly, and the specific implementation process includes: S31: Data Preprocessing. First, data cleaning algorithms are used to remove invalid data (such as data whose coordinates are outside the reasonable range) and duplicate data, and to fill in missing data (for a small number of missing data such as the length of transition curves and slope, interpolation is used to fill in the missing data). Second, the data is standardized to unify all coordinates to the same coordinate system (such as the geodetic coordinate system) to ensure data consistency.

[0030] S32: Calculation of 3D Positioning Coordinates. Based on the preprocessed horizontal and vertical curve elements, the 3D positioning coordinates of the component installation reference points are calculated using a cubic spline interpolation algorithm. Specifically, firstly, based on the horizontal curve elements, a curve fitting method is used to generate the route's plane centerline. Then, the discrete points of the plane centerline are interpolated using a cubic spline interpolation algorithm to obtain the continuous plane centerline equation y=f(x). Next, based on the vertical curve elements, the route's longitudinal profile centerline is generated, and the longitudinal profile elevation equation z=g(x) is obtained through interpolation. Finally, based on the relative positional relationship between the component and the route centerline (e.g., the main beam centerline coincides with the route centerline, and the piers are located at specific distances on either side of the route centerline), the plane coordinates (X, Y) of the component installation reference points are determined. Combined with the longitudinal profile elevation equation, the vertical coordinates (Z) are calculated, ultimately obtaining the component's 3D positioning coordinates (X, Y, Z). For example, for the main beam component, its installation reference point is the midpoint of the main beam centerline. The three-dimensional coordinates of the reference point can be directly calculated based on the equation of the route centerline and the equation of the longitudinal section elevation. For the pier component, the plane coordinates of the pier installation reference point are calculated based on the coordinates of the route centerline and the lateral offset distance (d) of the pier. The vertical coordinates are then obtained by combining the longitudinal section elevation of the corresponding position.

[0031] S33: Deflection Angle Calculation. The deflection angles of a component include the horizontal deflection angle α, the vertical deflection angle β, and the cross-sectional deflection angle γ, used to determine the component's attitude in space. The horizontal deflection angle α is the angle between the component's axis and the tangent direction of the route's centerline, calculated using spatial vector operations based on the tangent direction of the horizontal curve and the component's installation direction. The vertical deflection angle β is the angle between the component's axis and the tangent direction of the route's longitudinal section centerline, calculated based on the slope direction of the vertical curve and the component's installation direction. The cross-sectional deflection angle γ is the angle between the component's cross section and the cross-sectional reference plane, calculated based on the cross-sectional superelevation and cross slope. Specifically, the deflection angles are calculated by extracting the tangent vector and normal vector of the route's centerline at the component's installation reference point, combining them with the component's installation direction vector, and using vector dot product and cross product operations.

[0032] S4: Determine the component type and specifications based on design requirements, search for matching component families in the parametric component library, and combine the positioning parameters and deflection angles obtained in step S3 to quickly instantiate the component. The specific implementation process includes: S41: Design Requirements Input. Based on the overall design scheme of the cable-stayed bridge exceeding 1,000 meters in length, the bridge designer inputs the design requirements for each component in an Excel spreadsheet, including component type (such as main tower, main beam, stay cables, etc.), specifications (such as main tower height, main beam cross-sectional dimensions, etc.), and installation location range.

[0033] S42: Component Family Matching and Retrieval. After receiving design requirements, the component library management platform activates the retrieval algorithm to match the optimal component family from the parameterized component library based on keywords such as component name, type, and specifications. The retrieval algorithm combines fuzzy matching and exact matching. For components with clearly defined specifications, exact matching is used to directly locate the corresponding component family; for components with specifications that have range requirements, fuzzy matching is used to filter out component families that meet the requirements for designers to choose from.

[0034] S43: Component Instantiation Generation. An Inventor plugin developed in C# instantiates component families based on input parameters.

[0035] S5: Using the 3D positioning coordinates (X, Y, Z) and deflection angles (α, β, γ) obtained in step S3, an Inventor plugin developed in C# is used to automatically assemble the instantiated components, forming a complete BIM model of the super-kilometer-class cable-stayed bridge. The structural assembly logic of the super-kilometer-class cable-stayed bridge follows the principle of "from bottom to top, from core to auxiliary," and the specific implementation process includes: S51: Assembly Rule Definition. Preset component assembly priority and connection constraint rules. Assembly priority from highest to lowest is: foundation components → pier components → main tower components → main beam components → stay cable components → connecting components → auxiliary components. Connection constraint rules clarify the connection methods and geometric constraint relationships between adjacent components. For example, a rigid connection is used between foundation components and pier components, constraining the coordinates of the bottom of the pier and the top of the foundation to coincide and the axis to align; the main tower components and main beam components are connected through supports, constraining the installation position and attitude of the supports; stay cable components are connected to the main tower and main beam through anchorages, constraining the coordinates of the anchor points at both ends of the stay cable to coincide with the anchor point coordinates of the main tower and main beam.

[0036] S52: Automated Assembly Execution. An Inventor plugin program developed in C# automatically identifies the connection relationships between adjacent components based on their positioning parameters, type information, and preset assembly rules, and assembles the components sequentially according to their assembly priority. Specifically, it first reads the positioning parameters and type information of all instantiated components to establish a component association table; then, starting with the basic components, it installs them to their designated positions according to assembly priority, followed by the piers, main towers, and main beams, ensuring the alignment and secure connection of each core load-bearing component; next, it installs the stay cable components, automatically adjusting the length and orientation of the stay cables based on the anchor point coordinates of the main towers and main beams to achieve precise connections between the stay cables and the main towers and main beams; finally, it installs connecting components and auxiliary components to complete the assembly of the entire bridge BIM model.

[0037] S6: Perform collision detection and accuracy verification on the assembled BIM model. If there is a collision or accuracy deviation, return to step S3 or S4 to adjust the parameters until the model meets the design requirements.

[0038] S7: Export the validated BIM model into a standardized data format for subsequent finite element analysis, construction simulation, and operation and maintenance management. Supported standardized data formats include IFC (Industry Foundation Classes), FBX, and GLTF. These formats have good compatibility and can be recognized and used by mainstream finite element analysis software, construction simulation software, and operation and maintenance management platforms. Standardizing the data format enables the full lifecycle flow of design data, avoiding data redundancy and information loss, and improving the efficiency of project lifecycle management.

[0039] like Figure 1 As shown, the core process of this invention is illustrated, including steps such as constructing a parametric component library, acquiring and parsing route information data, instantiating components, automatically assembling components, collision detection and accuracy verification, and exporting models. Each step is interconnected through data flow, forming a complete positive design closed loop.

[0040] like Figure 2 As shown, the parametric component library has a three-level structure. The first level is classified into standard components, family templates, and general components. The second level is classified into specific component types under each first level (such as core load-bearing components including main towers, main beams, and stay cables). The third level is classified into parametric family files corresponding to each component type, and each family file is associated with a corresponding parameter set.

[0041] like Figure 3As shown, the logical flow of automatic component assembly is demonstrated. After parsing the route information data, the three-dimensional positioning coordinates and deflection angle of the component are obtained. The component library management platform matches the component family according to the design requirements, inputs the positioning parameters and deflection angle into the component family to generate component instances, and the assembly script completes the automatic assembly of components according to the preset assembly rules and component association relationships, based on priority.

[0042] Taking a cable-stayed bridge with a main span of 1160 meters as an example, the application process of the present invention will be explained in detail.

[0043] Step 1: Construct a parametric component library for cable-stayed bridges exceeding 1,000 meters in length. S11: Component Classification and Analysis. Based on the structural characteristics of this super-long-distance cable-stayed bridge, the components are divided into three main categories: core load-bearing components (main tower, main beam, stay cables, piers, foundations), connecting components (anchors, supports, steel connectors), and auxiliary components (guardrails, drainage system, lighting system).

[0044] S12: Parameter System Definition. A parameter system is defined for various components: Core parameters for the main tower include tower height (262m), base cross-sectional dimensions (17m × 11.5m), top cross-sectional dimensions (11m × 8.25m), wall thickness (1.4~2.8m), and concrete strength grade (C60); core parameters for the main beam include cross-sectional dimensions (34.5m × 4m), concrete strength grade (C50), and steel grade (Q355); core parameters for the stay cable components include length (128~610m), diameter (0.3m), and steel strength grade (1860MPa); core parameters for the foundation include diameter (3.2m), depth (76~105m), and concrete strength grade (C40). Extended parameters include construction process parameters (e.g., main tower prefabrication accuracy ±0.3mm, stay cable installation tolerance ±1mm) and operation and maintenance management parameters (e.g., main tower monitoring point location, stay cable maintenance cycle 25 years).

[0045] S13: Parametric Family Creation. Inventor software is used to create parametric family files for each component, linking the family parameters to an Excel spreadsheet. For example, the script for the main tower component family defines the constraints between the tower height, base cross-sectional dimensions, top cross-sectional dimensions, and the main tower's geometry. When the tower height parameter is adjusted, the main tower's outline automatically scales proportionally. The script for the stay cable component family defines the relationship between length, diameter, and the stay cable's geometry, supporting the automatic generation of the stay cable's curve shape.

[0046] S14: Component Library Management Platform Setup. Establish a component library management system based on local folders to categorize and store completed component family files such as main towers, main beams, and stay cables. Support for searching by parameters such as component name, tower height, and cross-sectional dimensions. Set permissions for different roles such as designers and reviewers to ensure secure management of the component library.

[0047] Step 2: Obtain route information data The route information data for this super-long-distance cable-stayed bridge was retrieved from the JSL route expert system software. The data included: coordinates of the starting point of the horizontal curve (X0=518737.718m, Y0=3331435.735m) and the ending point (X0=520482.685m, Y0=3332070.399m); coordinates of the vertical curve slope change point (station K17+709.404, elevation 72.330m), slope (i1=1.8%, i2=-1.8%), vertical curve radius (Rv=35000m); cross section width (34.5m) and cross slope (i=2%).

[0048] Step 3: Route Information Data Analysis S31: Data Preprocessing. Convert the route data in sdb format to JSON format, remove invalid data (such as duplicate intersection coordinates), fill in the missing transition curve length data using linear interpolation, and unify all coordinates to the geodetic coordinate system.

[0049] S32: Calculation of 3D positioning coordinates. A cubic spline interpolation algorithm is used to interpolate the horizontal curve elements, generating the route's plane centerline equation y=f(x); and to interpolate the vertical curve elements, generating the longitudinal profile elevation equation z=g(x). Taking the main beam component as an example, its installation reference point is the midpoint of the main beam's centerline. The plane coordinates of this reference point are calculated based on the plane centerline equation (X=520425.922m, Y=3332049.754m), and the vertical coordinates are calculated using the longitudinal profile elevation equation (Z=63.528m). Therefore, the 3D positioning coordinates of the main beam component are (520425.922, 3332049.754, 63.528). For the main tower component, its installation reference point is the center of the tower base. Based on the coordinates of the route centerline and the lateral offset distance of the main tower (d=33.850m), the plane coordinates (X=519058.127m, Y=3331574.085m) are calculated. Combined with the longitudinal section elevation of the corresponding position, the vertical coordinates (Z=33.500m) are obtained. That is, the three-dimensional positioning coordinates of the main tower component are (519058.127, 3331574.085, 33.500).

[0050] S33: Deflection Angle Calculation. Extract the tangent vector (1,0,0.02) of the route centerline at the main beam installation reference point. The installation direction vector of the main beam component is consistent with the tangent vector; therefore, the horizontal deflection angle α = 0°, and the vertical deflection angle β = arctan(0.02) = 1.146°. The installation direction of the main tower component is perpendicular to the route centerline; therefore, the horizontal deflection angle α = 90°, the vertical deflection angle β = 0°, and the cross-sectional deflection angle γ = 0°.

[0051] Step 4: Quick Instantiation of Components S41: Design Requirements Input. Input the component type as "Main Beam", the specifications as "Cross-section size 33.5m × 4m, Concrete strength grade C50", and the installation location range as the route section from K17+779.404 to K18+129.404.

[0052] S42: Component Family Matching and Retrieval. The component library management platform accurately matches the corresponding main beam component family from the parametric component library based on keywords such as "main beam" and "section size 33.5m×4m".

[0053] S43: Component Instantiation Generation. The three-dimensional positioning coordinates of the main beam component (520425.922,3332049.754,63.528), horizontal deflection angle of 0°, vertical deflection angle of 1.146°, and cross-sectional deflection angle of 0.955° are used as instantiation parameters and input into the main beam component family. The main beam instance is generated through the developed Inventor plugin program.

[0054] S44: Instantiation parameter verification. The cross-sectional dimensions of the generated main beam instance are 33.5m × 4m, with a deviation of 0 from the design dimensions; the three-dimensional coordinates are (520425.922, 3332049.754, 63.528), with a deviation of 0 from the theoretical coordinates; the deflection angle meets the design requirements, and the verification is qualified.

[0055] The same method is used to instantiate the main tower, stay cables, foundation, connecting components, and auxiliary components.

[0056] Step 5: Automatic assembly of components S51: Assembly Rule Definition. The preset assembly priority is: Foundation → Pier → Main Tower → Main Girder → Stay Cables → Anchorages / Supports → Guardrails / Drainage System. Connection Constraint Rules: For a rigid connection between the foundation and pier, the coordinates of the bottom of the pier and the top of the caisson are constrained to coincide; for a rigid connection between the main tower and pier, the coordinates of the bottom of the main tower and the top of the pier are constrained to coincide; for a connection between the main girder and main tower via supports, the coordinates of the support installation position are constrained to coincide with the coordinates of the connection point between the main tower and main girder; for a connection between the stay cable and the main tower / main girder via anchorages, the coordinates of the anchor points at both ends of the stay cable are constrained to coincide with the anchor point coordinates of the main tower / main girder.

[0057] S52: Automated Assembly Execution. The developed Inventor plugin reads the positioning parameters and type information of all instantiated components, and installs the caisson foundation, piers, main tower, and main beam components in sequence according to assembly priority. Then, the stay cable components are installed, and the length and posture of the stay cables are adjusted to ensure that the anchor points at both ends are precisely connected to the anchor points of the main tower and main beam. Finally, the anchorages, supports, guardrails, drainage system, and other components are installed to complete the assembly of the entire bridge BIM model.

[0058] Step 6: Collision Detection and Accuracy Verification S61: Collision Detection. Collision detection was performed on the assembled BIM model using Navisworks software. The detection revealed two hard collisions between the stay cable and the guardrail of the main beam, with the collision points located at segment K18+129.

[0059] S62: Accuracy Verification. The actual height of the main tower is 262.000m, with a deviation of 0 from the design height; the actual cross-sectional dimensions of the main beam are 33.5m × 4m, with a deviation of 0; the actual coordinates of the main tower are (519058.127, 3331574.085, 33.500), with a deviation of 0, and the accuracy meets the requirements.

[0060] S63: Parameter Adjustment and Model Optimization. The collision was analyzed to be caused by the installation position deviation of the guardrail. Returning to step S4, the instantiation parameters of the guardrail components were adjusted, changing the lateral offset distance from 16.5m to 16.75m. The guardrail instance was regenerated and assembled. Collision detection was performed again; no collision points were found, and the model verification was successful.

[0061] Step 7: Model Export and Subsequent Applications The verified BIM model is exported in IFC format for subsequent finite element analysis and construction simulation. In the finite element analysis, the geometric and material parameters of the main tower, main beam, and stay cables are directly extracted from the IFC model and imported into the finite element analysis software for structural stress analysis. In the construction simulation, the IFC model is imported into Navisworks software for construction progress simulation and construction process optimization, thereby improving construction efficiency.

[0062] like Figure 4 As shown in the figure, the numbers represent 1. Main tower; 2. Steel main beam; 3. Concrete main beam; 4. Pier; 5. Stay cable; 6. Pile foundation; 7. Auxiliary pier; 8. Support; 9. Crash guardrail; 10. Transition pier. Figure 4 The complete BIM model of a cable-stayed bridge with a length of over 1,000 meters shown in Example 1 is presented, including the main tower, main beam, stay cables, foundation, and auxiliary components. The model clearly presents the spatial form and connection relationship of each component, which can be used for subsequent analysis and application.

[0063] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A BIM-based forward design method for cable-stayed bridges exceeding 1,000 meters in length, characterized in that, Includes the following steps: S1. Construct a parametric component library for cable-stayed bridges of over 1,000 meters in length. The parametric component library includes a main tower component family, a main beam component family, a cable stay component family, a foundation component family, and an auxiliary component family. Each component family has a preset editable parameter set. S2. Obtain route information data for cable-stayed bridges exceeding 1,000 meters in length, including horizontal curve elements, vertical curve elements, cross-sectional elements, and route control coordinates; S3. Analyze the route information data and calculate the three-dimensional positioning coordinates and deflection angles of each component; S4. Determine the component type and specification parameters according to the design requirements, search for matching component families from the parametric component library, and combine the positioning parameters and deflection angle obtained in step S3 to complete the rapid instantiation of the component. S5. Assemble all the generated instantiated components according to their three-dimensional positional relationships to form a complete BIM model of the super-kilometer-level cable-stayed bridge; S6. Perform collision detection and accuracy verification on the assembled BIM model. If there is a collision or accuracy deviation, return to step S3 or S4 to adjust the parameters until the model meets the design requirements.

2. The method according to claim 1, characterized in that, The specific implementation process of step S1 includes: S11. The component types of cable-stayed bridges with a length of over 1,000 meters are sorted out and divided into three categories according to structural function: standard components, family templates and general components. Standard components include main towers, main beams, cable stays, piers and foundations; family templates include steel box girders, composite beams, steel shell towers and steel anchor boxes; and general components include high-strength bolts, shear studs, steel sections, plate ribs and U-ribs. S12. Define parameters for each type of component, and determine core parameters and extended parameters. Core parameters include geometric dimension parameters and material performance parameters, while extended parameters include construction process parameters and operation and maintenance management parameters. S13. Create parametric part files for each component, establish the association mapping relationship between parameters and component geometry, and realize the dynamic adjustment of component shape driven by parameters; S14. Utilize the local folder-based parametric component library management system to classify and store parametric part files, manage versions, optimize retrieval, and control access permissions, supporting quick retrieval by component name, component type, specifications, and application scenario.

3. The method according to claim 2, characterized in that, In step S13, the mapping relationship between parameters and component geometry is achieved through Inventor parametric modeling. Specifically, it defines the geometric constraint relationship between parameters and component vertices, edges, and faces. When the parameters are adjusted, the component geometry is automatically updated according to the constraint relationship.

4. The method according to claim 1, characterized in that, In step S2, the route information data is acquired by reading the horizontal curve, vertical curve, and cross-sectional element data from the sdb project file of the JSL route expert system software. The horizontal curve elements include the coordinates of the starting point, intersection point, curve radius, transition curve length, and curve turning angle; the vertical curve elements include the coordinates of the vertical curve slope change point, slope, slope length, and vertical curve radius; and the cross-sectional elements include the cross-sectional width, number of lanes, sidewalk width, curb width, superelevation, and cross slope.

5. The method according to claim 1, characterized in that, The specific implementation process of step S3 includes: S31. Data preprocessing: Data cleaning algorithms are used to remove invalid and duplicate data, and unstructured data is transformed into standardized structured data. S32. Calculation of three-dimensional positioning coordinates: Based on horizontal and vertical curve elements, a curve fitting algorithm is used to calculate the plane coordinates of the component installation reference point, and the vertical coordinates are calculated by combining the cross-sectional elevation data to obtain the three-dimensional positioning coordinates of the component. S33. Deflection angle calculation: Based on the tangent direction of the horizontal curve, the slope direction of the vertical curve, and the superelevation direction of the cross section, the spatial vector operation method is used to calculate the horizontal deflection angle, vertical deflection angle, and cross section deflection angle of the component.

6. The method according to claim 5, characterized in that, In step S32, the curve fitting algorithm uses a cubic spline interpolation algorithm. By interpolating and fitting discrete points of the horizontal and vertical curves of the route, a continuous route centerline is obtained. Then, based on the relative positional relationship between the component and the route centerline, the three-dimensional positioning coordinates of the component installation reference point are determined.

7. The method according to claim 1, characterized in that, The specific implementation process of step S4 includes: S41. Based on the overall design scheme of the super-long-stayed bridge, input the component names, specifications, and installation location requirements in an Excel spreadsheet; S42. Match the optimal component family from the parametric component library based on component name, type, and specification parameters; S43. An Inventor plugin program developed in C# instantiates a component family based on the input parameters.

8. The method according to claim 1, characterized in that, The specific implementation process of step S5 includes: S51. Preset component assembly priority and connection constraint rules. The assembly priority from high to low is as follows: foundation components → pier components → main tower components → main beam components → cable-stayed components → connecting components → auxiliary components. S52. Based on the component's positioning parameters, type information, and preset assembly rules, automatically identify the connection relationship between adjacent components and complete the assembly of components sequentially according to assembly priority.

9. The method according to claim 1, characterized in that, In step S51, the foundation components and pier components are rigidly connected to constrain the coordinates of the bottom of the pier and the top of the foundation to coincide and the axis to align; the main tower components and main beam components are connected by supports to constrain the installation position and posture of the supports; the stay cable components are connected to the main tower and main beam by anchors to constrain the coordinates of the anchor points at both ends of the stay cable to coincide with the coordinates of the anchor points of the main tower and main beam.

10. The method according to claim 1, characterized in that, It also includes step S7: exporting the verified BIM model into a standardized data format, including IFC, FBX, and GLTF.

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