Research And Construction Of Geological Knowledge Database For Railway 3D Location

With the development and application of spatial information technology of remote sensing, geographic information systems, digital photogrammetry and virtual reality technology, digital railway line selection technology has matured. The key to achieve a practical level for digital design of railway location is the digital geological line selection technology of complicated geological area. In China’s railway location, there are some problems in complex mountain area and complicated engineering geological condition area. Such as complicated geological problems, wide study area, numerous long tunnels, large human factors, complicated related data and so on. Engineering-geological route selection plays an important role in the railway location. Sometimes it plays a decisive role. It is critical to do a good job of engineering-geological route selection to ensure the quality of engineering survey and design. How to analyze and apply geological information to provide service for the route location better has become an urgent problem to achieve railway geological route location in mountain area. How to choose a reasonable route according to geological conditions, whether by passing bad geology or not, the line through which part of the geological object and how to through the line. It not only depends on the line selection design code but also engineers’ experience which plays an important role. It can provide normative knowledge and experience knowledge for designers to set up geological route selection database to solve the shortage of experience. This paper mainly includes the following several aspects of the work.(1)According to the characteristics of the geological knowledge of selected lines,the paper studied the geological knowledge representation of line selection. Object-oriented representation is used in the selection case knowledge and object-oriented binding with production representation is used in the rule knowledge. The paper has also studied external visualization of knowledge.(2)In terms of knowledge acquisition, according to the characteristics and requirements of the railway 3D location environment, the paper studied the acquisition method of 3D spatial information based on GIS and storage method based on mesh generation.(3)This paper established library geological route selection case base and rule base. It achieved the reasoning applications for line selection knowledge of combined knowledge base in different geological conditions using forward reasoning method.(4) This article studied the space conflict analysis of lines and geological objects. According to block grid storage method of geological object, the paper constructed AABB axial bounding box and OBB directed bounding box algorithm for line entity and geological entities and achieved rough rejection rapidly and the fine test of space conflict between line entity and geological entity.(5) This paper developed geological knowledge base management system of line selection to achieve many functions, such as, the acquisition, query, deletion, modification and preservation of knowledge and knowledge base maintenance, and so on. Finally, this paper provided application examples of the system.