How does BIM technology establish a model in the architectural design stage?

At present, the traditional two-dimensional design can no longer meet the actual needs of the architectural field, and it is difficult to deal with the problems in architectural design. Based on this background, a newly designed 3D simulation software is developed. Through this software, a technical platform for collaborative design can be built for all majors, so that the building system can get ideal technical support when creating bim model, which is more scientific and efficient. The application of modern BIM technology in building structure design is expounded in detail, and it is systematically discussed and analyzed from the following three aspects: a deep understanding of BIM theory and technology; Introduce the modeling software based on BIM technology; Taking a complex building as the research object, the BIM model of the main body of the building is constructed by using Revit software.

1 and the theoretical knowledge of BIM

Building information modeling (BIM) uses contemporary three-dimensional digital technology to optimize all links in project construction, improve the quality of project construction and shorten the time-consuming of project construction. At the same time, this technology covers the data model of data information of various departments in the building system, and it is a process of engineering data processing and operation from planning scheme to demolition. BIM has obvious advantages, for example, it can make operators perform more convenient visual operations, and it can support Concord simulation, thus significantly improving production efficiency, reducing obstacles encountered by all parties involved in the project in communication, and further optimizing the quality of work projects.

In the past, CAD design usually used a two-dimensional platform for corresponding operations, and interacted with data and information through various design drawings. The brand-new BIM technology can support visual operation. Like 3D design, it can build virtual entity images and support staff's project analysis and research. For example, the overall wiring and pipeline layout in building engineering can be verified by visualization function, so that the limited space in the building can be used more fully and scientifically, and the conflict between professional pipelines can be avoided, thus significantly improving the synergy of various professional departments. At the same time, it can also help staff to find hidden problems in engineering matters in a short time, so that engineering drawings are not easy to make mistakes when submitted by various professional departments.

2. Modeling software based on BIM technology

Modeling software reasonably uses contemporary computer technology to complete the construction of engineering project structure model. At the same time, the whole system is integrated through the same data structure, and then with the help of more scientific and efficient parameterization technology, the information interaction between various construction engineers is better, thus promoting the establishment of engineering project information model. BIM technology is constantly updated and developed, and its application fields are constantly expanding. At present, there are four software developers for BIM technology, which have a good reputation all over the world. They are: Autodesk's Revit series software; Bentley's Bentley architecture series; ArchiCADGraphisoft company; Nemetschek's ALLPLAN software. The software they developed is shown in figure 1, among which Revit software is the most representative.

2.1introduction to Revit software revit company developed a software called RevitStructure on 1997, which was written and developed by Pro/E company. When Revit first came out, even though it could exchange data and programs with AutoCAD software, the program structure of the software itself was different from AutoCAD. Generally speaking, Revit software can be understood as a brand-new technology, which represents the pioneering nature of new technology. Revit software was a relatively mature software at that time, emphasizing the application of BIM technology, which could complete the good connection between the design life cycle of engineering projects and the transmission of data and information.

For the construction industry, Revit has achieved BIM ideally. With the help of relational database, a more scientific and reasonable three-dimensional building model can be established, and two-dimensional graphics can be established to deal with many non-graphical building engineering data. The basic elements of drawing have changed significantly, from the previous elements such as points and lines to objects such as walls and window beams. Essentially, the whole building structure is described by modeling language, which is a program specially written for project engineering inspection. The whole application is based on BIM Revit software. It can perfectly display the index and graphic structure of buildings and structures, and can be analyzed and observed in many ways, so that the information and structure of buildings can present more accurate data.

2.2 application of BIM technology in office building design

This paper takes a comprehensive office building as the research object, and uses Revit software to model the main body of the building. Design the main body of the building, and do not study the information such as reinforcement ratio and load in structural design for the time being, so as to prepare for the collaborative design of architecture and water supply and drainage specialty in the future.

2.2. 1 Project When preparing to create other projects in Revit software, any project will take the project template as the basis of programming, and write different building parameters and relevant information in the template file. In addition, the suffix name corresponding to this file should be changed to ". rte”。 In Revit software, template files must be used for core projects. The template file contains the initial project parameters set by the system, including the default measurement unit, height information, floor number setting information, display setting, line type setting, etc. In Revit software, an appropriate project template can reduce the setting and adjustment in the later modeling process and improve the efficiency of project design.

Using the Project Browser, you can switch between views and provide powerful and easy-to-use view manipulation tools to zoom, pan and rotate views. At the same time, the software can also display the attribute list of the operation content in real time, which helps designers to define the attributes of the design content during design, as shown in Figure 2 and Figure 3. In the process of modeling, it is inevitable to edit and modify the primitives used in the process to meet the actual needs of designers. Therefore, the software also covers many editing tools, so as to edit a series of primitives. You can access these modification and editing tools through the Modify tab, as shown in Figure 4.

2.2.2 As a complex design system engineering, the construction project of establishing working set is generally completed by multiple professions, but in the process of collaborative design among professions, BIM design of multiple professions cannot be carried out at the same time. Therefore, in the overall design process of the project, each major can establish multiple working sets according to the design needs of the major.

In the collaborative design process of architecture and water supply and drainage specialty in this paper, architecture specialty can establish its own working set according to the requirements of architectural design, and at the same time set the permissions of the working set and designate relevant designers to view the working set. Similarly, water supply and drainage majors can usually set up special working sets, or they can set up different working sets according to the required projects. For example, the water supply and drainage specialty can be divided into water supply, drainage, hot water, fire fighting, reclaimed water and other subsystems according to the detailed design, and each subsystem can set a working set, which is convenient for designers to manage the design content more accurately, as shown in Figure 5.

2.2.3 Creating a facade and a grid is an important spatial positioning information in architectural design. Revit locates the relative spatial relationship of each component element participating in model construction through elevation and grid. In fact, elevation and grid are the basis and premise of realizing three-dimensional collaborative design of architecture, structure and equipment on Revit platform. When designing a project with Revit software, it is necessary to measure the elevation and grid first, and then build building models such as doors and windows according to the relevant information of the elevation and grid. This method conforms to the design process of most domestic architectural design institutes. Before Revit starts modeling, we should plan the height and elevation information of the project as a whole.

When building a model, Revit determines the height information and spatial position of building components in the model through the elevation. Furthermore, in Revit, a mesh object is similar to an elevation object, which is a set of "mesh surfaces" perpendicular to the elevation plane. Designers can locate the engineering entity according to the grid in the engineering plan, and finally determine the specific spatial position of the component in the model with the elevation information. In the process of drawing the elevation and grid, use the "elevation" and "grid" commands in the Datum panel of the Home tab in Revit to build a two-dimensional plan as a program template, and draw the elevation and grid information of the project, while paying attention to labeling related labels and numbers, as shown in Figures 6 and 7.

2.2.4 loading family file family is the foundation of RevitArchitecture project, and model elements and annotation elements are composed of various component families. There are two types of families in RevitArchitecture: system families and loadable families. The system family has been predefined in RevitArchitecture, and the related information of the system family is saved in the template and the project, which is used to create the basic elements of the project, such as walls, floors, ceilings, stairs and so on. Loadable families can be defined and created by users themselves, or they can be obtained through communication between designers and then saved as family files in ". Rfa "format is independent of software. RevitArchitecture does not allow users to create, copy, modify or delete system families, but can copy and modify types in system families, so that users can create custom system family types according to the specific needs of the project.

The model category family of residential buildings is divided into independent single family and subject-based family. Generally speaking, an independent single family refers to a program structure that is not based on other subjects, such as furniture and structural columns. A host-based family refers to a component that cannot exist independently but must depend on the host. For example, elements such as doors and windows must exist with walls as the main body. Host-based families can be attached to walls, ceilings, floors, roofs, lines and faces. RevitArchitecture provides family template files based on these host entities. RevitArchitecture needs to define various types of parameters of the family. When using this family in a project, you can adjust the parameters defined in all families in the Type Properties dialog box, or you can create a family type similar to this family through the Copy function. For example, you can adopt a new family type with an external wall of 300mm in the system family. 240mm family type, create external walls by copying and modifying parameters, as shown in Figure 8.

3. Construction of the model

At this time, Revit is mainly used to design the main body and structural walls, beams and columns of this project, and to construct the BIM model of the building main body. Based on this BIM model, the collaborative design between water supply and drainage specialties is completed, and a BIM model integrating the design information of buildings, structures and water supply and drainage specialties is constructed.

3. 1 Create the main wall of the project

In Revit software, walls can be divided into system families, and system families can be transformed into brand-new 3D wall models according to the corresponding wall structure data. The software not only has wall tools, but also facilitates model drawing and wall object generation. When creating a wall in Revit, you need to define the type of the wall, including its thickness, method, material, function, etc. , and then make the plane position and height of the wall and other parameters. Based on the two-dimensional plan, the main components of the project, such as walls, constructional columns and structural beams, are set out. In the design process, two-dimensional CAD drawings are imported, and the drawings are adjusted to correspond to the grid, and then the walls and structural columns of the project are drawn on this basis. The corresponding plan view and perspective view are shown in Figure 9 and Figure 10.

After the wall and constructional column of this project are arranged, structural members such as structural beams and structural floors will be laid, and these structural members will participate in pipeline synthesis and collision inspection when cooperating with water supply and drainage specialty. The function of constructional column is to support the whole building. Structural walls and beams are also important load-bearing members. Although there are no operations such as steel bar arrangement and load analysis for structural members, structural members must be considered when cooperating with water supply and drainage specialty. Revit provides a series of structural tools to create basic structural components, such as structural walls, columns and beams.

3.2 Add other components required by the project

After the construction of the main wall of the project is completed, the lofting of other components needed in the building model will be carried out. Components include doors, windows, stairs, railings, floors and roofs. Revit software provides family file templates for various components, which can be directly loaded and used in the software. The properties of commonly used components are shown in table 1. Taking the drawing of stairs as an example, this paper introduces the creation method of basic components in the process of model construction. First, the type of stairs is defined. Based on the original system family type of the software, the type of stairs needed for creating the project is copied, and the properties of stairs such as function, step depth and material are set, as shown in figure 1 1.

After the property setting is completed, the layout and modification of stairs are completed by combining the reference plane and 3D view drawn in the plane, as shown in Figure 12 and Figure 13. At the same time, the three-dimensional design of architecture based on BIM emphasizes the visual design of "what you see is what you get", and designers can accurately and clearly understand the design effect of the interior of the building through the three-dimensional view of BIM model. In order to further optimize the final design effect of the building, the target wall and its components can be rendered with the help of corresponding rendering functions, making it more sensory and fully embodying the humanized design of the software. The BIM model of the main building of the project finally constructed by using Revit software is shown in figure 14.

4. Conclusion

Based on the related achievements and applications of BIM technology theory, this paper analyzes the application prospect of BIM technology in the future and the current architectural model structure from a macro perspective. The main body of the office building project is modeled by using the three-dimensional simulation software Revit. The difficulties encountered in modeling and drawing are expounded in detail, and the software is further required to have the ability to deal with two-dimensional plans.

For more information about project/service/procurement bidding, and to improve the winning rate, please click on the bottom of official website Customer Service for free consultation:/#/? source=bdzd