Experiencing Interoperability of BIM in a Stadium Project in China

Transcription

1 Experiencing Interoperability of BIM in a Stadium Project in China Cheng Zhang 1, Bo Liu 2, Guobin Gong 3 1) Lecturer, Department of Civil Engineering, Xi an Jiaotong-Liverpool University, Suzhou, Jiangsu, China. cheng.zhang@xjtlu.edu.cn 2) BIMEngineer, Xi an Jiuhe Construction Consultation Co. Ltd., Xi an, Shanxi, China 3) Lecturer, Department of Civil Engineering, Xi an Jiaotong-Liverpool University, Suzhou, Jiangsu, China. guobin.gong@xjtlu.edu.cn Abstract: As the main advantage of using BIM, interoperability aspects are experienced in various projects not only from different stakeholders, but also at different stages of the building life cycle. A shortcoming of current BIM method is the discrepancy between design and construction, which means that the BIM model provided by the designer cannot be directly used for construction. In an extreme case, the general contractor has to rebuild the BIM model for construction purpose. Moreover, the complexity of the project requires the designer or the constructor to use BIM tools creatively and take the full advantages of available functionalities. In this paper, a BIM-based work procedure is developed to replace paper-based method so as to facilitate conceptual design, integrated design, detail design and tailored manufactory. The model created by the designer is used for construction by incorporating data from the manufacturer, so that an accurate model can be used for bidding, project delivery, and structural engineering. Two BIM software packages are used to model the architecture and the structural components. An IFC-based data exchange is developed to transfer information between the two software packages so as to take full advantage of the two and create a combined BIM model. A case study of a stadium project is presented in the paper to show the effectiveness of the BIM-based work procedure. The parametric modeling of the steel structure is described in detail as well as the integration of structural analysis, visualization, and material scheduling. The BIM-based work procedure enables a smooth data flow through design, manufactory and construction. Efficiency of the work has been improved by taking the advantage of interoperability. Keywords: Interoperability, Building information modelling, parametric modelling. 1. INTRODUCTION Building Information Modeling (BIM) is a new approach to design, construction, and facilities management in which a digital representation of the building process is used to facilitate the exchange and interoperability of information in a digital format (Eastman et al., 2011). Research in the building construction industry reveals that BIM has not been popularly used to take the advantages of the new technology due to several reasons. Lack of knowledge and personnel that familiar with the technology are the major issues. Using BIM is also changing the manner of constructing buildings in the construction industry. The model stores costs, element quantities, process data and all possible information for the whole project participants. It can provide the 4D model which is the combination of 3D geometry and schedule quality control (3D + time) (Gilligan & Kunz, 2007). To automate information processing, standardized and qualified data is necessary for efficient working processes. Compared with the traditional CAD technology, BIM is capable of re-storing both geometric and rich semantic information of building models, as well as their relationships, to support lifecycle data sharing. A growing trend is found in the usability of the data produced by BIM that is produced by many different tools, but the data format is mostly proprietary due its commercial nature (Vanlande et al. 2008). However, some models contain non-propriety building data such as Industry Foundation Class (IFC). IFC was developed by International Alliance for Interoperability (IAI) and is currently known as BuildingSmart.BIM is accepted as a process and corresponding technology to improve the efficiency and effectiveness of delivering a project from inception to operation/maintenance. A number of case studies have been published that show useful BIM implementations on actual construction projects including use of proposed use of 3D/4D models for design review from the perspective of constructability, design of a BIM-based game for fire evacuation simulations, 4D visualization technology for safety (Zhou et. al. 2013). Reusability of the information has always been the prime concern for all information modeling systems; however different software solutions have a unique approach towards data processing and management. BIM from its very initiation has shown a tendency to collect all the information on a single platform that can be used, reused and improved along the lifecycle of the project. Revit and Tekla are the two most popular BIM software packages that used in design and construction. Both software packages have their own different import-export

2 procedures that are based on IFC, which provides a possibility of data transferring from design to construction. 2. METHOD 2.1Parametric modelling of steel joints Due to huge amount of joints in a steel structure, it is not efficient to create joints individually. Therefore, an automatic batch creation for nodes in modelling a steel structure is developed, by using the database and developed plug-ins. Figure 1 shows the parameters defined for a bolted spherical joint, which consists of all the nominal dimensions of the joints. These nodes are then assembled together with steel members, forming a detailed BIM model for the steel structure. One of the benefits of parametric modelling of steel joints is that the total amount of steel consumption can be easily obtained when any changes happen to one specific type of joints. All the changes can be reflected in the model quickly and accurately. Thus re-work and errors can be avoided. Figure 1. Parametric modeling of a bolted spherical joint 2.2Interoperability A work process is developed during the project to enhance the interoperability through BIM. Starting from the scheme design, all stakeholders retrieved related information from the same model, which consists of architectural data, geometric information of the main structural components, and building functional data, spatial relationship between different components, loading information, etc. During the architectural design and structural design stage, the owner, designers, general contractor, and constructors can access the same BIM platform to integrate designs from different domains. Workspaces are assigned to different working groups to work on an integrated model. Each group has a local copy of an updated model and all the local works will be uploaded to the integrated model regularly. Clash detection and other checks will be done to the integrated model and send back to different groups. The work efficiency is enhanced in this way. In the engineering stage, details of traditional structural components, e.g., pile, wall, support, are designed in 3D. Other complex structure, such as bolted spherical joints, rebar, are also designed in detail using parametric modelling, which enabled a quick modeling of similar structural components and saved time and labor. Moreover, the detailed design of the steel structure is used for manufactory to get accurate dimension information in detail. 3. CASE STUDY The case study is about a stadium project in Guangdong province of China.The HoujieStadium is located in Dongguan, Guangdong, China, with a capital investment of 120,000,000 RMB, covering a land of around 11 hectares, as shown in Figure 2(a). It is designed as a complex stadium with the main functions for indoor sports like basketball, tennis, etc., supplemented by entertainment activities.the total gross floor area is about m 2, and the basement area is about m 2. Asuspendome steel structure is designed for the roof while, while a reinforced concrete frameis for the rest of the main body structure.

3 (b) (a) (c) Figure 2.The HoujieStadium in China The plan of the suspendome roof is an ellipse, with long axis of m and short axis of 93m,in which the net span along the long axis and the short axis are 100m and 80m, respectively. It is surrounded by cantilever structures along the circumferential direction. The rise of vault for the elliptic top reticulate shells 9.4m, with a rise/span ratio of 1/8.5 along the short axis direction. 3.1 Structural Analysis In the design of the steel roof structure of the stadium, two numerical models (Figures 2(b) and 2(c)) are prepared and the results are compared.the part between the steel roof structure and the lower stand is globally modelled with concrete columns and beams. A global structural analysis is carried out to consider the effects of the concrete sub-structure on the roof by using MIDAS Gen7.8 and 3D3S9.0. While an individual model for the steel roof structure is prepared by using the same method (Figure 2(c)). By comparing the result from the two models, considering that the lower structure and roof are working together, except the max stress ratio of the top steel members, the indexes such as max support reaction and max vertical displacement are relatively smaller for the first model; therefore, the calculations based on the second model are conservative and used for the final design. In the detailing of the steel structure, by visualizing each components of the frame, the design team found that the curve ratio is bigger when reaching the bottom support. Meanwhile, the calculation also shows that the corresponding inertial forces and the curvature become larger. Considering that the superstructure and the substructure work together, the structure of the frame net is revised to solve the constructability problem that may be encountered in the original design. 3.2 Parametric Modeling of the Steel Structure TeklaStructure is selected to build the structural model of the stadium due to its capability of prefabricated concrete module, which is suitable for prefabricated construction management. Another advantage is that parametric joint design is feasible in TeklaStructure, which improves the efficiency of modelling. As shown in Figure 3, a model of joint is built to analyze stress under the most unfavorable load combination.

4 (a) Members (b) Solid model (c) Mesh and boundary (d) Stress contour (e) Stress contour (top) (f) Stress contour (bottom) 3.3 IFC-based Data Exchange Figure 3.Joint design details Since the architectural model is built in Revit, IFC is used to export the structural data from TeklaStructure to Revit to form the complete BIM model of the project. As shown in Figure 4(a), a plug-in embedded in Tekla is used for data transportation from Tekla to Revit. This plug-in is developed by Tekla to fulfil a seamless transmission of data from Tekla to Revit. By clicking on the button, model designed in Tekla is exported to an IFC-based file, which can be imported to Revit for integration. Figures 4(b) and 4(c) show the architectural and the structural models of the project. Since there are some parts of the data missing due to the capability of the plug-in, a manual checking is done in Revit to ensure all the structural data are integrated into the architectural model. Embedded Plug-in from Tekla (a) (b) (c) Figure 4.Architectural and Structural Models of the project 3.3 Steel Structure Manufacturing For prefabrication purpose, the DSTV file is exported to manufactory to precisely describe the size and dimension of all the components of the steel structure. The fabricated components therefore can be assembled without any mismatching or errors. Figure 5 shows the data exported from Revit as DSTV files.

5 Figure 5. Data export to DSTV files Figure 6. Steel Components with Detailed Dimensions Figure 6 shows an example of the designed steel structure components with detailed dimension information. Figure 7 shows the working procedure of fabrication of the steel components following the schedule, which enables a lean construction to save time and cost for the whole project.

6 Figure 7. Working Procedure of Steel Fabrication 3.4 Constructability Constructability issues are reduced by visualizing the BIM model for construction. For example, in the connection parts of beams and columns, where the density of the rebar should be increased, usually, the constructability of those reinforcement stirrups will be a big issue if the construction method is not properly applied. In the project, an automated creation of components tag is developed to guide how to pre-construct the reinforcement stirrup, thus the efficiency of reinforcement work is improved. As shown in Figure 8, the reinforcement stirrups are installed to the column before connecting to the beam, followed by the side formwork installation. Figure 8.Reinforcement Stirrups Installation at the Connection between Columns and Beams 3.5Quantity Takeoff Materials that used in the project can be calculated accurately compared with traditional estimation, which is based on the total weight of the steel from analysis plus 5% to 15% for the joints. Since all the steel structural joints are detailed in the model, the quantity of the total steel consumption is easily obtained, as can be seen in Figure 9.

7 Figure 9. Quantity Take Off 3.6 Construction Progress Simulation A simulation of construction is developed to show the sequence of steel structure assembly as shown in Figure 10. By attaching schedule to each components in Navisworks, components constructed at different time will be shown sequentially. Equipment, such as tower cranes, trucks are also shown in the simulation to help analyze the site layout and spatial congestion. 4. DISCUSSION Figure 10. Construction Progress Simulation By using BIM method in this stadium project, one essential factor is realized to be collaboration between different stakeholders. Team work is essential during the project that using BIM technology. A BIM team consists of staff from different areas. A team manager should lead BIM engineers in different domains working together and efficiently. The team manager is responsible for the plan for BIM applications, task assignment,

8 coordination and model integration. The BIM engineers are responsible for modeling of the specific domain, such as architectural, structural, MEP, etc. and need to communicate frequently with the team manager. A reasonable team structure and clear task assignment are essential for a successful project. One of the major problems that encountered while applying BIM in the project was the localization of international BIM software packages, which should be tailored to match the Chinese construction traditions and construction methods. 5. CONCLUSIONS This paper introduces the experiences gained from a stadium project that uses BIM method through the design, construction, and manufactory phases. By taking the advantages of interoperability either between different BIM software packages or the working procedures for design, construction and fabrication, the efficiency of the construction has been improved and the new method is proved to be applicable although a lot of improvement needs to be taken. ACKNOWLEDGMENTS The author of this paper would like to thank the support from Qiguang Group to provide us the case study and technical support. REFERENCES Eastman, C., Teicholz, P., Sacks, R., and Liston, K. (2011).BIM Handbook: A Guide to Building Information Modeling for Owners, Managers, Designers, Engineers, and Contractors (2 nd ed.). John Wiley & Sons. Gilligan, B. and Kunz, J VCD use in 2007: Significant value, dramatic growth, and apparent business opportunity, Stanford,CA: CIFE Technical rep. #TR171, Stanford University. Vanlande R., Nicolle C. and Cruz C., 2008, IFC and building lifecycle management. Journal of Automation in Construction, Vol. 18(1), pp Zhou, Y., Ding, L.Y., Chen, L.J Application of 4D visualization technology for safety management in metro construction. Autom. Constr. 34,