Research On Three-Dimensional Data Models Of Geological Objects In Mine

Three-dimensional data model of geology in mine is the foundation of mining 3D GIS, and also the keystone and difficulty in the studies of GIS. Based on making use of research fruits from domestic and overseas, a series of studies were made such as the spatial characteristics, the topological relationships, the data models and the modeling methods of geological objects in mine. The main fruits of study are showed as follow:1. Based on the theory of 3D sptial data models, the issues for spatial objects in mine were systematic analyzed such as the compositions, types, the characteristic, the description methods of its spatial status, the data sources and data acquired method. The expression ways of the spatial character, property character and relationships of 3D geological objects were summarized.2. Aimed at the problem that it is difficult to express the border elaborately arised from the complicated geological bodies and the rare data were obtained from prospecting, the border virtual boreholes were introduced to control the border shape of the complicated geological bodies. On the basis of analyzing the suitable conditions for border virtual borehole, taking the strata were cutted by fault as an example, the determination methods for border virtual borehole were studied under the four classic conditions for the spatial combination of strata and faults. The relative solutions were presented. This scheme has both theoretical and practical meaning in some extent to constructing the 3D data models which can express complicated geological objects elaborately.3. From the conceptual model of geological objects in mine, the geological objects were abstracted into four types of basic objects such as point, line, surface and body based on the principle of object oriented and the body objects were studied especially. According to both the strata were destroyed by the discontinous surfaces such as faults and the angular unconformity, and the inner structures of the partitioned blocks, the body objects were abstracted into block body, multi-layers body, mono-layers body and body element by the hiberarchy of complicated bodies. In this way, the integrality of the earth-science meaning was ensured, the model expression is more convenient. A vector data model about objects in mine were present, the 12 topological relationships between complicated objects and relative data structures were describled, on the basis of the scheme for abstracting objects listed above. The validity and rationality for this model were validated by application experiments. It has some theoretical and practical sense for this model to be used in 3D mining GIS.4. To realize the functions of spatial analyzing and spatial querying in 3D GIS, the idea for constructing independence fault model was presented on the basis of the research in existence. Based on the data from boreholes and derived, an independence fault model was presented which with duo-TIN surface structure. This model includes 9 geometric elements, and 14 kinds of topological relationships can be expressed. It can describle the spatial characteristics of fault surface independently, and can reflect the composing structures of strata on both two blocks of the fault as well. This may be helpful for realizing the spatial analyse and spatial query functions on the basis fault surface. On basis of this model, the modeling methods and modeling flow were discussed based on data source of geological observation, drillhole, ichnography and section map.5. The topological bodies were introduced to express the topological relationships between complicated objects based on the point set topology. The constructing methods for topological bodies of block, multi-layers body and mono-layers body were explored. A topology frame was presented for decrible the topological relationships between complicated objects.