Engineering CAD For Tunnel's Vertical Section Design Of Railway In Mountain

As the cross-science of tunnel engineering and computer software, the tunnel CAD technology focused on lining referenced drawing design and portal design currently. However, the tunnel vertical section design is one of the most critical components in the tunnel design, only few research literatures and achievements about it can be found. In this paper, the application of CAD technology on the tunnel vertical section design is studied. According to the design process of the tunnel vertical section, it consists of processing the topography and geological information, the stave design, and the statistics of the tunnel project.The topography information process is a significant part of the topography and geological information process above mentioned. In the topographic drawing of the mountain, the topographic lines of vertical section and transect have their special graphic information respectively. Through the analysis of the graphic information of the topographic lines, a three-step approach of extracting terrain data of the mountain is proposed. It contains the three steps: grouping graphic elements, merging them and transferring. Dispatch algorithm and Find-tail algorithm are two of the algorithm for grouping. It is more efficient for the find-tail algorithm to apply for the CAD system than the dispatch algorithm.Stave design is a major part of the design of tunnel vertical section. Firstly, it defines several entities of the stave: wall rock, lining, construction technology, parallel chunnel, transverse chunnel, tunnel silo, tunnel cave, and so on. The custom entities of them can be described and edited based on ObjectARX technique. The design of wall rock, lining and construction technology, and the design of ground elevation and mileage tags, there are some design logic about them. Based on that logic, the automatically design strategy of the stave is studied.To some extent, the statistic tables of the tunnel project have form characters. Through the common technology analysis of the form of table, data processing and statistics output, the generation technology of common statistic table based on table template is proposed.Finally, based on the research results, an engineering CAD system for tunnel's vertical section design of railway in mountain is developed. The CAD system records all the design data in the whole design process of tunnel's vertical section, by a unitive database. The project database ensures the unity and integrity of the data. An example validates that the CAD system is advanced and practical.