Study On The 3D Data Model And Algorithm Of Urban Underground Space Based On The Field Frame

The underground space, including mass geologic information data associated with projects, provides the environment for human project activities. It is one of the key issues for many scholars that how to build a 3D information system which can visualize the underground space and dig the geologic information behind.This research focused on the modeling of urban the spatial field presentation is put forward idea based on the geologic cognition of urban underground space, in the view of the effect of human activities to the underground space. The key technical issues, including 3D data model, data structure, 3D modeling method, and analyzing algorithms, etc, are researched. In details, this dissertation includes:Firstly, the whole urban underground space is described as a models Three concepts, the source field, the source field function g(o,f,t) and the living region of project entity, are introduced according to the difference between the cognizance of the overground and the underground. And these concepts are embedded into the 3D data model. The specialist knowledge and geographical cognitions are introduced into this model, to make it easier to numerical analyze and spatial relation description.Secondly, there are two kinds of objects: engineering entities and geological entities in the real geographical world. Based on the relation between the real and the digital geographical world is described by UML language, A integrated data model is put forward. In this model, the engineering entities using regular geometric cell model and the geological entities using TIN surface model, are united into the same data model by the source field function g (o, f, t) to describe the state of source field. At last the hierarchical system of class is list.Thirdly, on the base of the study above, kinds of modeling methods are designed and realized, for the objects of many strata (including succession stratum, submerge stratum, pitch out stratum, lenticular stratum) and an underground power station. In order to solve the problems existing in the surface modeling, a set of new methods are put forward, including reference TIN, splitting surface into slices and sub-blocking...