Research On Three-dimensional Geological Modeling Based On Planar Geological Map

Planar geological map is a complex of results of geological investigation outdoors and geological expert knowledge, which reveals regional information, such as rock, strata and geological structure. It is the most attainable and direct data resource for people to understand regional geology. Research of this thesis is able to solve problems of three-dimensional geological modeling and simulation in bedrock area which are short of drillings and sections. At present, modeling directly based on planar geological map is of many problems, including sparse distribution of occurrence information and difficulty in manual interactive intervention of modeling results. In order to overcome those problems, this thesis put forward a modeling method which uses cutting profile as intermediate data to model three-dimension geological body based on planar geological map.Cutting profile map is an important kind of geological section map, the data of which mainly comes from planar geological map and mixes together abundant expert knowledge as well. Three-dimension concept of geological structure can be acquired by combining cutting profiles and planar geological map, which reflect spatial correlations and geological evolutionary relations of geological body and geological structure. Therefore, building three-dimension geological body model with planar geological map and cutting profiles has merits of abundant data volume and extensive coverage areas.The main research results and achievements of this thesis are as follows:a) In this paper, detailed analysis of the drawings information in planar geological map, the geometric relationships of elements and the symbolic representation of geological object are proposed. On the basis of this analysis, the corresponding data model and storage structure is built to express the abundant information contained in the geological plane figure. All of these lay the foundation for the generation of cutting profile.b) By analyzing the production process of manual cutting profile, the characteristics of data and demands, the data model and data structure for the cutting profile is built. Then the cutting profile automatic generation algorithm is designed in view of the representation of the features in cutting profile. It achieved in the automatic acquisition of cutting profile in any direction and any density interactively. Hence, the solution for the automatic generation of fault and drape is proposed. c) In this paper, the domestic and oversea research status is reviewed firstly. Then the characteristics of the existing three-dimensional spatial data model and the three-dimensional geological modeling method is summed and concluded. Considering the characteristics of cutting profile, an algorithm for three-dimensional geological model based on inerratic voxels is designed. It makes the space search more efficiency, the model more suitable for geometric feature calculation, boolean operation and Quick Displaying that organizing the body-mode data by linear octree in this algorithm.In this paper, the automatic generation of computer-based cutting profile is accomplished. It improves the generation efficiency and utilization value of planar geological map. Meanwhile, effectively and adequately information excavation of the planar geological map by cutting profile figure is shown which gives the three-dimensional geological modeling data support and enhance the controllability of modeling. This method provides a new idea for solving the problems like the lack of data, low degree of automation, low precision existing in the current modeling. And it expands the available data sources of three-dimensional geological modeling. Meanwhile, a top-down superficial strata model in macroscopic scale is constructed. Furthermore, it provides guidance for other micro-fine modeling and lays the foundation for model optimization and stepwise refinement for fusing multiple source data(drilling, section, geophysical exploration, etc).