Research On Modeling Of Large-scale Zonal 3d Geographical Environment And Application Method Of Route Selection

China's medium and long-term railway network planning has outlined the "eight vertical and eight horizontal" high-speed railway blueprint.In recent years,the continuous increase of railway investment has put forward higher requirements for the cycle and quality of railway design.Intelligent railway construction requires a deep integration with modern information technology at all stages of road survey,design,construction and operation.Among them,how to integrate modern surveying and mapping technology and realize 3D geographic environment modeling of lines is the key support to realize intelligent route selection.Therefore,starting from the comprehensive analysis of topography,geology,terrain,environment and other factors,this paper studies the modeling of large-scale zonal 3D geographic environment and its application method of route selection,mainly completing the following four aspects of work:(1)3D Terrain Modeling Method Based on Modern Surveying and Mapping TechnologyBased on the basic theory of terrain modeling and supported by various mainstream surveying and mapping technologies,this paper studies the 3D terrain modeling method based on UAV data,existing map data and 3D laser scanning data,and establishes the 3D terrain of line selection area.(2)3D Modeling and Visual Representation Method of Unfavorable GeologyThis paper studies 3D geological environment modeling method,obtains bad geological information of route selection area by means of modern survey technology,realizes storage and query of spatial and non-spatial geological data by standardized data processing process,and completes plane and 3D bad geological modeling of route selection area in GIS platform based on the concept of digital elevation model.(3)Modeling Method of Large-Scale Zonal Geographic EnvironmentAccording to the characteristics of railway strip line selection,using the powerful functions of ArcGIS software such as data processing,spatial analysis and modeling,the dynamic superposition of influencing factors of railway strip line selection is completed on the established 3D terrain,and the strip geographic environment model is constructed.The important topographic indicators are obtained by surface analysis of the model,and the influencing range of influencing factors is obtained by buffer analysis.(4)Route Selection Method Based on Multi-Source Information FusionBy using the function of geographic database,all kinds of influencing factors of line selection are managed in a unified way to realize the integration and fusion of multi-source data;adopting the theory of multi-objective decision-making,using the analytic hierarchy process,a comprehensive line selection model is established,and the cost distance algorithm is used to obtain the optimal route scheme;the method of line selection in unfavorable geological areas is studied emphatically,taking a landslide project of Xikang Second Line as an example to realize 3D route selection ideas.