A Parameterized Three-dimensional Modeling Method Of The Basic Type Of Geological Structure

Due to the difficulty of obtaining the geological body modeling data,the traditional data based on nonparametric three-dimensional(3D)modeling method is not suitable for the 3D modeling of bedrock area.Based on the analysis of the characteristics of the geological structure and the definition of the modeling parameters,we design a new parametric modeling method to solve the problem that the bedrock area can not be modeled because the data is difficult to obtain,and carry out the system implementation and experimental verification.In view of the complexity of the morphological changes of the geological body,the basic geological structure(fold structure and fault structure)of small and medium scale is taken as the research object,and the easily obtained planar geological map as the main data source,we carry out parametric 3D modeling method construction research.The main contents and conclusions of the study are as follows:(1)Study on the method of determining the boundary of basic geological structure modeling.Because of the characteristics of the unclear boundary between the fold structure and fault structure,we mainly study the method of boundary determination.For the case of an anticline or a syncline existence alone,the "symmetric repetition"characteristic of the fold structure is used to determine its boundary;In the case of anticlines and syncline adjacent,the boundary of the common area is determined by the Voronoi spatial subdivision method and the terrain feature to extract the mountain or valley boundary.With respect to the boundary of the fault structure,we studied the boundary determination method of tense fault,oblique fault and strike fault and its combination from the point of view of the cutting method.(2)Parametric modeling of fold structures.Considering that the fold has its own unique geometric characteristics,this paper defines the folds modeling parameters by analyzing the characteristics of the fold structure.And the modeling parameters of fold based on folds are studied emphatically.And the construction of the 3D model of the folds is realized on the basis of the inferred section.(3)Study on parametric modeling method of fault structure.Based on the analysis of the geometric elements and fault displacement of the fault structure,the fault modeling parameters(fault,formation and fault cutting methods,etc.)are defined.Meanwhile,the fault modeling parameters are further studied,and the fault plane and stratigraphic surface are constructed.Finally,in the light of the gap between the fault surface and the stratum surface,the suture or cutting treatment was carried out.(4)Realization of parametric modeling system for basic geological structure types.Based on the above research results,the main functions of prototype system of basic geological structure parametric modeling include fold structure,fault structure boundary extraction,parameter modeling of fold structure and parameter modeling of fault structure.The process and results of parametric modeling of fold structure and fault structure are presented to verify the feasibility of this method by applying the data of Muyunling anticline and Diaojiayu fault data respectively.This studies the parametric modeling method of the basic geological structure type,which break the dependence of the traditional modeling method on the data,and provide a supplement to the traditional modeling method.This method can not only satisfy the requirement of 3D modeling of the geological structure of objective existence,but also meet the needs of virtual geological structure restoration modeling.