Research On GIS Modeling Method For Railway Construction Organization

Geographic information system (GIS) is a strong tool to visualize and to analyze a variety of spatial information. Digital railway information systems combine geographical information, global positioning and remote sensing technologies together. They provide efficient management and visual representation of system resources, such as railway infrastructure, equipment and environment. They have been playing more and more important roles in the railway design, construction, and daily maintenance. The natural terrain, artificial structures and construction sites along the railway constitute a complex and integrated system. It usually takes many years of time from the railway planning to design, construction and operation, therefore the spatial-temporal information concerned digital modeling and visualization method of the railway system is an important research area of railway informational construction.The topic of this paper is from a project of China Road and Bridge Corporation. Taking Kenya Mombasa-Nairobi railway project as the application background, our work mainly focused on some key technologies about data modeling and visualization of spatial-temporal information and implementation of three-dimensional railway GIS module. This paper studies:Parametric modeling method of railway construction sites for railway construction management. We use static CAD drawings to build three-dimensional GIS models, which can also show the construction progress. The modeling system takes railway design data, location coordinates and construction progress as parameters. We position and assemble the geometry models from the building coordinate system to WGS-84 in the railway system. Moreover, we use construction progress to change the appearance of railway GIS models. We implement the real-time visualization of construction daily progress of the railway bridges, subgrades and tunnels using the re-development interface.Multi-source data visualization method of the railway construction progress. It applies to the big screen monitoring in the railway construction headquarters. The Railway GIS Unit (RGU) maps the spatial-temporal data of railway construction to the terrain, images,3D models, vector graphics and labels. We can use RGUs to organize the ordered list of construction sites. The visualization module renders the appropriate GIS elements with the current viewpoint and date in real-time by GIS scene tree.Using the three-dimensional railway modeling method in this paper, we can generate Kenya Mombasa-Nairobi railway models automatically. The system loads these models with Mombasa-Nairobi topography along the railway line, forming a good environment to monitor the construction status and assist work progress tracking and visual display. We make complete, real-time presentation of the construction progress of railway project using these railway models. They provide great help to the implementation of the railway information system. With further standardization, this method helps to customize quickly for other railway construction management GIS system.