Analysis And Research On Carrying Capacity Of Urban Rail Transit Network

Development of urban rail transit has become an important means to alleviate traffic congestion in big cities,reduce pollution and achieve the goal of building a livable city.With the large-scale construction of some urban rail transit lines in my country,the rail transit lines have changed from single line to multi-line,and gradually formed a line network.Under the background of networked operation of rail transit,the research focus of its transportation capacity problem must be shifted from station and line to line network.The calculation and evaluation of the carrying capacity of the urban rail transit network is a brand-new research field with strong exploratory nature.The urban rail transit network is studied as a system.Due to its complexity,its concepts and calculation methods are rarely involved.How to provide a reasonable calculation method needs to be systematically researched and deepened from the aspects of its conceptual system framework.Therefore,it is necessary to study the carrying capacity of urban rail transit network in this paper.This paper firstly analyzes the most basic line relationships in the urban rail transit network,discusses five typical urban rail transit network structure types,and provides necessary preparations for the research on the transportation capacity of the line network system.Then,the calculation methods of the station capacity and the line capacity of the urban rail transit system are discussed respectively,which are used as the basis for the study of the transport capacity of the line network system.Then,the topology structure of urban rail transit network is analyzed,and the influencing factors of urban rail transit passenger route selection,including congestion conditions,service level and queuing time,etc.are comprehensively considered,and a more accurate and reasonable passenger travel route is established based on the passenger utility model.Impedance function,using the improved Logit model to calculate the probability of passenger route selection.A two-layer programming model is established,which takes the maximum OD passenger flow that can be achieved by the line network as the upper-level goal,and considers the balanced distribution of the line network passenger flow under the influence of the superimposed factors of rail transit passenger flow as the lower-level goal to solve the actual carrying capacity of the line network.method for solving the model.Finally,based on the design network of some rail transit lines in Chengdu,an empirical study on the carrying capacity of the designed line network is carried out using the above theories and calculation methods,and the main ways and measures to strengthen the carrying capacity of the urban rail transit line network are analyzed.Coordination of transportation capacity between stations and lines under the condition of urban rail transit network.