3D Geologic Modeling Method Based On Knowledge-Drive

Three-dimensional(3D)geological modeling has very important research significance and application value in urban planning,engineering construction,gas reserves,digital mining and many other fields.At present,there are many data-driven modeling methods,but the modeling methods are limited by relying too much on modeling data in practical application.For this reason,based on geomorphological features,this paper studies a modeling method of bedrock surface with geomorphological features constraints.Based on a superposed principle of strata,a 3D stratum modeling method based on principle of superposition is studied.According to the geometric characteristic that the slope aspect of monocline is consistent with its dip direction,a 3D modeling method of knowledge-driven monocline structure is studied.The knowledge-driven modeling method studied in this paper reduces the dependence on the data to a certain extent,and provides a new idea for the modeling of bedrock areas with sparse data.The main research conclusions and results of this paper are as follows:(1)The modeling method of bedrock surface with geomorphological features constraints.According to the characteristics of modern geomorphology,it can reflect the geomorphological knowledge of bedrock's depth to a certain extent.On the basis of dividing different geomorphic elemental types,the estimation methods of bedrock's depth in different geomorphological types are studied,and the construction of bedrock surface model is realized.Experiments show that this method improves the modeling accuracy of bedrock surface in sparse area of drilling to a certain extent.(2)The 3D stratum modeling method based on principle of superposition.Based on the superposed principle of strata,a method for calculating elevation information of strata surface is established.According to the bedrock's constraints on the strata,a stratigraphic boundary approach based on bedrock surface constraints is established.On this basis,the construction of 3D stratum model is realized.Experiments show that the three-dimensional stratigraphic model constructed by this method is more accurate and complete than the model by relying solely on drilling data and spatial interpolation,and stratigraphic range in the model is closer to the actual range.(3)The 3D modeling method of knowledge-driven monocline structure.Based on the geometric characteristic that the slope aspect of monocline is consistent with its dip direction,the boundary lines and boundary planes of the monocline are determined by dividing the boundary line segments of rock strata.And based on Morphing technology,the interpolation points of the rock strata are generated,and on this basis,the construction of the 3D geological model of the monocline structure.Experiments show that this method can construct a more accurate 3D geological model of monocline structure based on digital geological map and DEM.So the method has certain feasibility and practicability.(4)Knowledge-driven 3D geological modeling results.Based on 3,629 Engineering Boreholes and basic geological maps in Nanjing,the model of Nanjing bedrock Surface was constructed.According to 70 engineering boreholes and DEM in a district of Xianlin,in Nanjing,the 3D stratigraphic model of about 45 square kilometers was constructed in this area.The model is more accurate and complete,and the stratigraphic morphology in the model is closer to the real strata.According to the digital geological map and DEM of Zijin Mountain in Nanjing,the 3D geological model of monocline structure was constructed in Zijin Mountain,which reflects the monocline structure of Zijin Mountain to a certain extent.