Research On Highway 3D Geological Model And Geological Knowledge Base Of Alternatives Selection

Geology is the critical factors for highway alternatives selection in karst regions.The three-dimensional terrain model of highway alignment design has been established by the current BIM software and other mainstream alignment design software without the knowledgeassisted function during design process.Therefore,providing designers with more geological information support has become an urgent problem to be solved.This article takes highway geological 3D model as the research object,and studies the modeling of geological 3D model,and takes the alternatives selection in karst region as an example to construct the alternatives selection geological knowledge base.The thesis established a three-dimensional geological model,including three modules: three-dimensional geological modeling module,geological vertical sectioning module and cross sectioning module.Based on the geological borehole data,a three-dimensional geological borehole-related algorithm including a searching algorithm for key geometric spacial points and a three-dimensional borehole entity drawing algorithm is proposed,a three-dimensional geological modeling algorithm based on DEMs + ATP is proposed,and the three-dimensional geology model is established.A vertical sectioning algorithm is proposed,and the geological vertical sectioning module is established.The cross custom sectioning algorithm and the perpendicular to the alignment sectioning algorithm are proposed,and the geological cross sectioning module is established.The thesis establishes a geological alternatives selection knowledge base,including digital geological object module,knowledge reasoning module under CAD+GIS environment and knowledge base management module.Based on the interpretation results of geological remote sensing,the geological feature input mode and feature insertion process are designed,and the digital geological object model is established.Combining the reasoning mechanism based on spatial relationship and the reasoning mechanism of uncertainty rules,a knowledge reasoning module under CAD+GIS environment is established.Based on the rule knowledge base and the case knowledge base,a structure of knowledge base management module is constructed.The three-dimensional geological model established in the thesis can provide information such as geological lithology,stratum distribution,and borehole information during the alignment design process.The three-dimensional geological model is integrated with the digital geological object model to form a three-dimensional geological alternatives selection environment.The knowledge base provides rule guidance and case references for the process of alternatives selection,and achieves information support for highway alternatives selection.The research results of the thesis have theoretical and practical value for improving the degree of knowledge in the alignment design process and promoting the scientific design and decisionmaking of highway geological alternatives selection.