Dynamic Management and Schedule Risk in Rail Transit Projects based on 4D-BIM

Rail transit project is system engineering with long construction period which involves different specialties and numerous departments. Project management and schedule control have a great impact on economic interests and social benefits. In this paper, project management model with comprehensive application of 4D-CAD and BIM technology is set for 4D-BIM rail transit project. Then, the risk earlywarning model is proposed which is built on visual dynamic and integrating project management model. These provide a new method to improve management level and progress controlling ability of rail transit project. KEYWORD: BIM; 4D-CAD; Rail Transit; schedule risk early warning International Conference on Industrial Technology and Management Science (ITMS 2015) © 2015. The authors Published by Atlantis Press 1344 property information of component material, mechanics performance, construction resources and so on. Using BIM as a platform of communication, the participants of the project can share data on the same platform. Thus it can decrease the number of requests for information between the more professions and shorten the response time for information. Especially for rail transit project which is huge, complex and has many functions, it is particularly important that applying BIM to implement coordination management between all professions [5-6]. The integrated use of 4DBIM technology has more advantages than previous management methods which are based on 2D drawing and paper documents [7]. First of all, it solves the problem of information communication. Because of using a single engineering data source, BIM ensure that the engineering data is accuracy and consistency. It also can coordinate the design problem about architecture, structure, equipment and so on which is often appeared in the process of the construction. Second, it can simulate the actual construction. [8] The 4D simulation according to the schedule can guide the construction to determine the reasonable construction scheme. [9] 3 THE RESEARCH OF INFORMATION MODEL OF RAIL TRANSIT PROJECTS BASED ON 4D-BIM According to the application requirement of rail transit project, comprehensive model must meet the following three characteristics: (1) The integrity of the model information. According to the application purpose, the scope and the detail of the expression of information should be determined so that to avoid redundant or missing of information. In general component should contain 3D geometry information, such as location, shape, etc. It also should include the engineering attribute information, such as type of component, component of material, type of structure, performance of project, etc. And schedule, technique, quality, labor, cost, materials, resources and so on should be included. (2) The correlation of model information. The participants of the project share information each other. Document’s submitting, reviewing, approving and using can be completed through network. Due to the parametric design, BIM make the design changes between different units to get fast delivery. If an object of the model has been changed or an engineering program has been modified, it can update automatically all object associated with it. (3) The unity of model information. Because the application of BIM requires a series of software, the unified modeling tools and the same information interoperability standards are needed. Such model’s information is unity. And the same information don’t need input repeatedly. 3.1 BIM Modeling Technology BIM model is different from the CAD drawings of 2D representation. It is also different from general 3D renderings. It’s 3D drawing with lots of engineering properties. The main integrated model (As shown in Figure 1) should be set up according drawing first. And then the construction model should be established according to BIM application goal and needs. (1) The main integrated model. The BIM model consists of building model, structure model, pipeline model and mechanical model. Different models which are established according to BIM application goal can express model’s components and their properties. The 3D building model which integrated the design, construction and management information realize the parametric create and display of 3D model, correlation, view, edit, and extension of building components and information of material, schedule, cost, quality, safety and so on. (2) The construction model. The construction model is needed after the main integrated model was established, so that for followup collision detection. Horizontal transportation tools such as excavator, payload, for example, the mechanical arm can rotation within a certain radius. So the entity of the three-dimensional shape description at a certain moment does not reflect the space requirements of the work. So we should ascertain its space requirements according to its movement characteristics and the whole model with its rotating parts. Figure 1. The composition of the 3D integrated model 3.2 4D Virtual Construction Technology Combined BIM model and schedule, the progress of the model can be displayed dynamically according the schedule. We can fix up the construction site, stack materials and preview the machinery route in advance. Simulation the whole construction progress makes all parties involved in the project to have a more intuitive understanding of the schedule. So the