Research On 3D Modeling Of Unfavorable Geology And Application Method Of Railway Route Selection

Being the major artery of traffic,railway plays a vital role in economic and social development.Railway construction needs acceleration according to the newly revised Medium and Long-Term Railway Network Planning,and,has ushered in new opportunities for development with the implementation of the Belt and Road Initiative,especially in central and western regions.However,route selection has been restricted by the complex geological factors in the regions.It usually detours unfavorable geology with plane methods in traditional route selection modes,which will lead to the missing of optimization scheme of some vertical occasions,and it will also impose negative impact on later operation.It is of great significance to the implementation of the integrated line selection scheme of plane and elevation on how to use modern survey and design means to effectively manage the unfavorable geological information along the railway route area using information technology,and to realize the effective expression of bad geological areas,especially the expression of three-dimensional entities considering drilling information so as to get visual expressions of unfavorable geology.Therefore,the thesis mainly carries out research work from the following aspects:(1)Construction of Unfavorable Geology Information Bank based on GISAccording to the requirements of route selection survey and design,this paper analyzes the methods of collecting unfavorable geological information,and make a deep research on the standardized processing method of the information,especially for the standardized processing of drilling data.Considering the change of stratigraphic coordinate caused by oblique holes,the classification,sequence and numbering of the inner layers of boreholes are improved,which provides the basis for the subsequent modeling of discrete stratified geological entities.This paper also studies the spatial expression method of unfavorable geological information and realizes the construction and information query of unfavorable geological based on GIS.(2)3D Modeling Method of Unfavorable Geology in Route Selection AreasRelative theory of digital terrain model was referenced to construct the terrain environment of the route selection areas,and by overlying the corresponding digital orthophoto image,the terrain is truly expressed with the realization of the 3D geographical environment.A 3D model of unfavorable geology was built in ArcScene with the standardized drilling data,superimposed with the bad geological area in 3D terrain environment,the 3D route selection geographic environment that contains bad geological information was constructed.(3)Optimal Method of Route selection in Unfavorable Geological regionsAccording to the principle of geological route selection and the concept of modern route selection design,the geological route selection method was studied based on the Integrative Data Model of Vector & Raster.A route selection optimization model which takes the minimum comprehensive cost as the objective function was constructed considering the construction investment,later operation,environmental protection cost,geological impact cost etc.Geology,environment and operation were taken as the analytic indexes to establish the hierarchical structure model of line selection in bad geological areas.This paper also studies the comparison method of route selection in unfavorable geological areas,and realizes the optimal decision-making in 3D terrain line selection environment.(4)Optimal Scheme of Local Line Selection based on 3D Geological EntitiesRoute selection in a section of the Sichuan-Tibet railway was taken as an example to build the 3D terrain model,superimposed with bad geological entity information,the local 3D model of the line was established.Two different route schemes were designed by means of visual route selection,namely,plane detour and underpass,which covers the shortage of scheme-missing issues caused by single plane detour,and the idea that meets the design needs of route selection based on the integration of plane and elevation was thus formed.