Research On Calculation Method Of High-speed Railway Capacity Based On Abstract Train Timetable

The passing capacity of the high-speed railway is the constraint condition of railway transportation organization and also the guarantee of its orderliness and efficiency.By accurately evaluating the railway carrying capacity,we can ensure that it meets the design standards and construction needs.This can help railway operators adjusts the transportation organization reasonably,organizes the invested resources efficiently,and achieves the coordination and matching of the station and line capacity.With the rapid development of high-speed railway construction in our country,the railway network structure has changed.More efficient operations management techniques are needed with the significant change in corresponding productivity layout,transportation resources,and train routes.However,the existing research on railway transportation capacity calculation often lacks the mining and analysis of the operation characteristics of the current transportation plan.And it isn’t easy to systematically find a more reasonable transportation organization mode to fully use the capacity under the coordination of station and line capacity.At the same time,the high-speed railway capacity calculation in existing studies is not accurate enough to meet the requirements of the railway transportation organization.Therefore,this paper intends to analyze and study the capacity of the high-speed railway and put forward a set of calculation methods for the capacity under the network condition.Based on the analysis and extraction of train stops’ structure,an abstract train timetable model was proposed to describe the relationship between the train stops and the occupancy of time-space resources.Then,the paper puts forward the method of important time-space node evaluation of the high-speed network.Furthermore,the identification method of importance nodes is the entry point of capacity calculation to comprehensively and accurately calculate the station and line passing capacity.The specific research work is as follows.(1)The paper proposed an abstract train timetable model and high-speed railway capacity calculation framework.By analyzing the calculation requirements of high-speed railway passing capacity under networked conditions,this paper puts forward the representation method of high-speed railway capacity under cross-line train cooperation.The influence of train stop structure on the train timetable is analyzed,and the space-time resource occupation of the train timetable is also quantified.The paper puts forward an abstract train timetable model based on the train stop structure characteristics.The abstract train timetable model defines time-space resources between two adjacent train paths as the "cost" and also defines the order of trains as the path of the abstract train point.An advanced calculation method framework for capacity under network conditions is put forward.(2)This part identifies and analyzes important space-time nodes in a large-scale high-speed railway operation network.This paper proposes the time-space train origin-destination(OD)service network(OD-TS network)to describe the railway transportation service.And a network construction method is designed to build the OD-TS network according to the train operation information in the timetable.We further develop an improved k-shell decomposition method to quantify the node importance for the directed-weighted networks.Case studies are carried out based on China’s high-speed railway train timetable.We study the OD-TS network from three perspectives(the global network,the railway hubs,and the stations)and analyze the spatiotemporal details of the railway operation.(3)This part proposed a high-speed railway key hub station capacity calculation method.Firstly,we analyze the calculation requirements and expression methods of the station carrying capacity of high-speed railway hub stations under the operation conditions of various route types.The analysis shows that when studying the saturated station operating capacity of high-speed railway hub stations,the operating trains of stations should meet certain arrival conditions to reserve the difference of train stops in the line.In addition,considering whether to consider the proportion fluctuation condition of cross-line trains,we propose the single-objective and multi-objective calculation models of the station carrying capacity,respectively,and design the Lagrangian relaxation algorithm and NSGA-Ⅲ algorithm to solve them,respectively.Finally,Taking Jinan West Railway Station as an example,the model and algorithm are verified.(4)Calculation method of carrying capacity of high-speed railway line considering the proportion fluctuation of cross-line trains.Firstly,we discuss the characteristics of the train timetable with the maximum carrying capacity when considering the space-time demand of the passenger flow to varying degrees.Moreover,on account of the relationship between the stop structure of adjacent trains in the train timetable and the utilization of space-time resources of the train timetable,the paper establishes the abstract train path model under the condition of different stop demands in different periods based on the abstract train timetable proposed in this paper.The train lines linking method and NSGA-Ⅲ algorithm are designed to solve the model for the given and unknown conditions of the train stop plans.Finally,Ji-Qing high-speed railway and Beijing-Shanghai high-speed railway are taken as examples to verify the model and algorithm.