High Fidelity 3D Modeling Of Ground Fissure And Integration With Geological Model

The ground fissure is a kind of typical regionaland slow degeneration geological disasters that have serious damaged to the urban housing construction, roads,bridges, underground pipes, other municipal facilities and all kinds of urban construction and the safety of people’s life, brought the extensive and profound influence to the urban planning and economic development. A new challenge of the prevention for the ground fissure disaster is put forward to the urbanization and informationization. We urgently need to make full use of the multi-source heterogeneous data of the ground fissure to establish thehigh fidelity 3D ground fissure structure model of global efficiency and local complex which will guide the geological professionals to intuitively understand the underground space, to strengthen the discriminant ability of tectonic ground fissures. All these will guide the engineering practice scientifically, rationally plan and use urban underground space and provide reliable technical support for regional development.In this paper, 3D GIS and 3D GMS technology are comprehensivelyused for the special phenomenon of urban geological disaster to explore the characteristics of multi-source heterogeneous data, 3D spatial data model and method ofhigh-fidelity 3D model in ground fissure. This paper main research content includes:(1)The analysis of characteristics of ground fissure entity objects and multi-source heterogeneous data, this paper puts forward the parameterized extraction method ofthe ground fissures according to the standard of spatial data standardization. For comprehensive utilization of multi-source heterogeneous datato simulatethe complex spatial geometry in high fidelity, this paper puts forward the integration organizationof source and object-oriented.It is a new solutio for the ground fissures space geometry data integration.(2)In view of the ground fissure’s space geometric feature, the geometry spatial data model of ground fissure in semantic unity is be proposed.Based on the thought of object-oriented, the entity object of ground fissure is described according to the requirement of different scales and different accuracy. The point entity of ground fissures is describedby space geometry point; the linear entity of ground fissures is describedby segment with end to end; the planar entity of ground fissures is describedby B-rep; the volume entity of ground fissures is described in different ways: one is the model of boundary surface(plane, curved surface);The other is volume model of subdivision entities in grid element. And the corresponding data structure was designed.(3)3D modeling mathematical algorithm of 3D modeling ground fissure was proposed, and defined its applicable range and conditions: using borehole and survey data in the earth’s surface as the core data source, expressingthe regional extension form and space distribution rulein the combination of multiple planes. The obvious advantages of mathematical algorithm is to fully take into account the characteristics ofdata’s sparseness and uneven distribution of the ground fissures, and dynamically, rapidly, efficiently to build the 3D model in the study area. Using the method can reflect the distribution and development regularity in the study area, and also can predict the spatial distribution outside of the study area.(4)The modeling method of "Controlling Line" is proposed based on rich section data in microscopic local area, and introduced the four key technologies:correspondence problem, branching problem, tiling problem, fitting problem.This method can reproduce the detailed features(such as fault displacement, thickness, Angle) of the 3D ground fissure, and surrounding strata seamless.(5)Designing the 3D visualization and spatial analysis prototype system of the complex ground fissure as a case of xi ’an ground fissure to verify(geological model, ground fissure model) and engineering model(model of subway)zooming, browsing, roaming, cutting etc.