Collinear Alignment Design Study On High-Grade Roads And Rail Transit Within City Cluster Transport Corridor

Some large-scale urban agglomerations have formed in the more economically developed regions of China,and the transportation corridors have formed between major cities within the urban agglomerations.In the main transport corridors,it is common for road traffic and rail transportation to be laid in parallel.Different traffic routes in the same traffic corridor are planned in a unified manner and deployed in parallel or collinearly,which is an important measure to increase the capacity of traffic corridors,save space,and optimize the road network structure.The paper summarizes the relevant research results at home and abroad,and analyzes the characteristics of China's urban agglomeration transport channels and passenger demand.According to the research results at home and abroad,the concept of parallel and collinearity of high-grade roads and rail transit is proposed,and the necessity and applicable conditions of the collinear setting of roads and rail transit are analyzed.The traffic types and design speeds studied in this paper were selected according to the traffic characteristics and travel requirements of the urban agglomeration transport routes.The design standard system and design concept of road and rail transportation are studied,and the similarities and differences between the two geometric designs are analyzed.The crosssectional layout of roads and rail transit collinear lines and their advantages and disadvantages are studied.The problems that collinear setting may face are analyzed,and the principle of layout of collinear lines is proposed.By studying the calculation principle of high-grade road and rail traffic line design indicators combined with the requirements of collinearity,through calculation,we have obtained the line design indicators such as straight lines,circular curves,and easement curves that meet the collinear design,as well as longitudinal slopes,slope lengths,and verticals.Curve and other profile design indicators.A flat and vertical combination design method that satisfies the collinear setting is proposed.Finally,through the design analysis of the collinear section of the Beijing New Airport Expressway,the Beijing Subway New Airport Line,the Jingxiong Intercity Railway,and the local Tuanhe Road,the paper examines the results of this study.