| Due to the complexity,variability,uncertainty and nonlinearity of geological problems,with the constraints of geological rules,it is necessary to study specific model constraint rules and three-dimensional modeling methods according to the shape characteristics of geological bodies to ensure that the model can more meet the geological structure shape,geological structure relationship,evolution law of geological interface and mineralization law of hosted deposits.However,there is no specific geological constraint rule for different types of complex shaped orebodies,which leads to the constructed interpolation constraint often difficult to characterize complex geological conditions,and there are obvious differences between the modeling results and geological reality expectations.Taking the thin orebody as an example,it is difficult and time-consuming to interpolate an effective and reliable model by using the traditional interpolation method and manually constructing interpolation constraints.The existing three-dimensional modeling methods for thin orebodies are difficult to construct interpolation constraints,and there are large errors between the models generated by some methods and the actual orebodies.In addition,the increasing complexity of the model and the higher demand of geologists for modeling accuracy are often accompanied by the lower modeling efficiency of the three-dimensional modeling of the ore body,so improving the efficiency of model reconstruction is an issue that can not be ignored in the process of ore body modeling.In order to improve the efficiency and quality of 3D modeling of complex shaped orebodies,this paper focuses on the difficulties of thin(vein)orebodies modeling,and studies the 3D modeling method of thin(vein)orebodies that integrates the constraints of geological rules.Based on the idea of separating the geological sampling data of upper and lower layers and building the models of upper and lower layers respectively,this paper proposes a 3D modeling method of thin orebody based on grid modeling technology and implicit modeling technology.On this basis,two constraint rule making methods based on Boolean operation and thickness field are proposed,which change the traditional thin orebody model building mode.It optimizes the process of reconstructing the contour surface of the model in the implicit modeling technology of orebody,reduces the redundant voxels during surface reconstruction,and improves the efficiency and quality of model reconstruction.A thin orebody modeling software is designed and developed,and it is applied to the thin orebody modeling of real mines.Through the three-dimensional modeling method combined with geological rule constraints proposed in this paper,the modeling efficiency of thin orebody is improved.The orebody model constructed can truly represent the characteristics and mineralization trend of thin orebody and meet the practical application requirements of mines.The main contributions of this research are as follows:(1)A grid modeling technology for thin orebody based on bicubic Coons surface is proposed.This method can accurately divide,model and splice the interpreted orebody contour,and model a more complete and better quality orebody model.A new method of automatically dividing the closed loop is proposed,which can greatly shorten the modeling time.In addition,the sub grids can be combined without human intervention.The problem of dividing closed loops based on contour polylines with complex shapes is solved,and the modeling efficiency based on complex cross contours is improved.(2)This paper studies a method based on implicit modeling technology to model thin orebodies by constructing interpolation constraint rules,which overcomes the problem that the existing three-dimensional modeling methods of orebodies can’t better establish constraint rules for thin orebodies,and the constructed orebody model can’t better meet the geological structure shape.By automatically constructing modeling rules and constraints that meet the geometric characteristics of thin orebodies,the automation of implicit modeling of orebodies is improved,the modeling effect of this type of orebodies is optimized,and the good respect for prior geological knowledge is guaranteed in the modeling results.(3)An efficient model reconstruction optimization method is studied,which breaks through the bottlenecks of the previous technology and algorithm reconstruction,such as excessive computational redundancy,low modeling efficiency and incomplete model reconstruction,and realizes rapid and efficient model reconstruction.An improved seed growth method is proposed to automatically obtain seed voxels according to seed points,which improves the efficiency and accuracy of model reconstruction.In addition,the process of surface reconstruction is improved by using the signed marching cube method,the invalid voxels that do not intersect with the target isosurface are filtered by the low-cost rough evaluation step,and the effective voxels that intersect with the target isosurface are accurately evaluated by the higher-order fast multipole method through the accurate evaluation step,which speeds up the evaluation speed and improves the modeling efficiency.(4)Based on the above research results,a 3D modeling software suitable for thin orebody is designed and developed by using the method of platform + plug-in.Based on the characteristics of implicit modeling technology,the overall architecture of the modeling software,operation constraint primitives,data organization and database form are designed.The 3D modeling software for thin orebody is developed,and the mining geological data collection,constraint addition,interpolation calculation and model construction are realized.Taking the actual data of a tin mine in Yunnan,a coal seam mine in Inner Mongolia and a copper mine in Zambia as examples,the modeling effect of this software is shown. |
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