Study Of Key Techniques On The Integration Of Digital Underground Space And Engineering (DUSE) And Numerical Analysis

With the exploitation of underground space and the development of information visualization in geotechnical engineering, the primitive complex geological condition and strata information are shown in digitized way in order to serve for the construction of underground engineering. Aiming at the situation, the Digital Underground Space and Engineering (DUSE) is established and it is in process of research. Numerical analysis is an important simulation method in the field of geotechnical engineering. However, the lack of visualization model is the difficulty to implement mechanical analysis and current numerical simulations are difficult in geological modeling. It is ultimately necessary to integrate calculation function into the digitalization system and it is a great challenge to how to perfectly implement it.In full consideration of the characteristics of digital modeling and numerical analysis, a new idea is presented, which realizes the integration of digitalization and numerical analysis based on the DUSE system. Taking the thinking as masterstroke, this thesis carries through a completely, systemically research on the key techniques of integration. The primary contents are as follows:1. DUSE system is roundly introduced, and its framework and functional module are analyzed. The main functions, including data management, 3D modeling, visualization, spatial analysis and special application, are discussed respectively.2. The preprocessing of FEM numerical analysis is analyzed. According to the flowchart of finite element analysis, the data, processing mode, modeling regulation and method are studied in detail. The mesh generation method of the complex model in the underground engineering is explored.3. The thought of the integration of digitalization and numerical analysis based on DUSES is presented. The coupling mode is determined to adopt a new composite structure of loose coupling and embedded coupling. And the coupling contents are discussed from three aspects of data, function and technique. The organizational structure is built from two aspects of DUSE system and numerical analysis system. The implementation frame and procedure of the integration system is established.4. The key technique of the integration is investigated. In the view of two kinds of different models, a method, called CRM geologic model transforming method, is presented to realize the model coupling by using the techniques of region cutting, model reconstruction and automatic generation of FEM mesh sequentially. The algorithm of region cutting is fulfilled with the intersection calculation of plane and polygon. It is highly efficient and can avoid to product the redundant data. By region cutting, the construction process can be simulated conveniently and the geologic model can be used repeatedly. Based on the Delaunay triangulation, the algorithm of the surface model reconstruction and FEM triangle meshing in space plane are performed. A multiple TIN region method is presented to generate automatically FEM mesh of the geologic surface model. Then, some man-machine interaction operations can be avoided, such as seeking manually the closed region and discretizing the boundaries one by one. In the process of FEM solid meshing, the conceptions of Single Space Region (SSR) and Multiple Space Region (MSR) are presented, and the thought of the blocking by strata attribute is applied in the MSR method. The manual construction for the SSR and the geometry inspection can be avoided before solid meshing. The efficiency of the whole modeling is improved thoroughly.5. A platform of the integration system is exploited. Using ACCESS for data storage and OpenGL for image processing, the 3D visualization interface and the FEM analysis module are exploited by VC++. So the data coupling and the function coupling are realized. Then, several defects of the integration system are indicated.6. The new analysis method presented in this thesis are applied into a real project of 2010 Expo power station in Shanghai. Excavation process of the foundation is simulated and analyzed. The procedure and the superiority of the integration system are shown sufficiently.