Transportation Organization Plan Optimization Of High-Speed Railway Freight Train Based On Competitiveness Analysis

With the sustained and steady growth of China’s economy,China’s logistics industry is developing at a high speed,and the demand for fast freight transportation is increasing rapidly.Relying on the advantages of high-speed railway network,as an important measure to further promote the structural reform of supply side,high-speed rail express service,has operated in 505 cities in China,,and will expand the effective supply year by year.High-speed rail express effectively improved the transportation efficiency and reduced the social logistics cost.In September 2018,CRRC launched the world’s first freight Electric Multiple Units(EMU)train with a speed over 250 km/h,its operation will further exert the advantages of high-speed rail express network in terms of timeliness,low cost and reliability,and will also have a significant impact on the market structure of China’s express transportation.Faced with the huge social demand and development potential,it is urgent to study the transport organization theory on high-speed rail express business to rationally allocate transportation resources and improve the adaptability of product supply structure to transportation demand and freight structure changes.Based on this,this dissertation analyzed the influence of relevant factors on the market share rate of high-speed rail express,designed the calculation method of freight flow share rate of high-speed rail express products,studied the high-speed railway freight train operation plan and its timetabling method,which has important theoretical significance and practical value for the further development of high-speed rail express business.The research work of this dissertation mainly includes the following aspects:(1)The utility function of high-speed rail express was constructed.And the competition relationship between high-speed rail express and highway and air transport was quantitatively analyzed.The sensitivity analysis method was used to analyze the influence mechanism of relevant factors on the high-speed rail express market share rate,which provided a theoretical basis for product designing and marketing planning of high-speed rail express services.(2)The utility function system of high-speed rail express products was also constructed.The calculation models of freight flow sharing rate of high-speed rail express products under two scenarios of considering transportation supply capacity and not considering transportation supply capacity were proposed,which provided a necessary reference for the rational allocation of railway transportation resources.(3)The theory and method of two-stage train operation plan making based on the high-speed railway express train alternative set were studied.In the first stage,the high-speed railway freight train alternative set model,which aims at minimizing operating cost of high-speed rail express train and considers the constraints of capacity and demand satisfaction,was constructed.A column generation algorithm which fits large-scale network was designed to solve the model.In the second stage,the high-speed rail express flow assignment model,which aims at maximizing the benefit of high-speed rail express business and considers the economic benefits of the trains,the coupling constraint of freight flow and train flow,was set up to ensure the economic benefits of operating high-speed rail express trains.Finally,taking the Harbin-Dalian high-speed railway as an example,a high-speed railway freight train operation plan and its freight flow assignment plan were designed.(4)The comprehensive optimization method for timetabling of high-speed rail express trains considering the freight flow distribution assignment,EMU rolling-stock plan and maintenance plan based on the existing high-speed railway passenger train timetable was studied.A comprehensive optimization model for the timetabling of high-speed rail express trains with the objectives of lowest transportation cost,shortest time-space path,minimum number of EMUs and minimum number of maintenance was constructed.A Lagrangian relaxation algorithm adapted to hyper scale variables was designed to solve the model.The original problem was decomposed into the"space-time shortest path sub-problem with additional constraints"and the"shortest path sub-problem with resource constraints",and the classical algorithm of dynamic programming-labeling method was applied to solve these two sub-problems.Finally,taking the Harbin-Dalian high-speed railway as an example,based on the calculation results of market share of the high-speed rail express,freight flow sharing rate of high-speed rail express products,and train operation plan of high-speed rail express,a comprehensive optimization plan including high-speed rail express train timetable,train assignment plan and EMU rolling-stock plan was designed to verify the effectiveness of the proposed models and algorithms.