Research On The Effective Carrying Capacity Of Urban Rail Transit From The Perspective Of "Passenger-Train-Station"

With the continuous and rapid development of the national economy and the continuous improvement of urbanization level,China’s urban rail transit is in the stage of great development and construction.Many cities have reached the state of urban rail transit network operation.In Beijing,Shanghai,and other big cities,the construction,and operation scale of urban rail transit have exceeded many big cities in the world.China is moving forward from a big rail transit country to a powerful rail transit country,and the operation concept is gradually changing from the pursuit of high service quantity to high service quality.How to put forward the evaluation method of the urban rail transit system’s effective carrying capacity under the new situation has become an important issue in the pursuit of improving service and safety levels.Besides,if the planning,design,and operation management departments cannot reasonably evaluate the effective carrying capacity of stations and lines,formulate scientific design planning,and effective operation organization scheme,it may cause the problem of passenger overcrowding.It will not only reduce the comfort of passengers but even lead to conflicts between passengers,such as pushing,trampling,and so on.Around these problems,this paper puts forward the concept of "effective carrying capacity" of urban rail transit to improve the service quality and safety level of urban rail transit.In this paper,the effective carrying capacity of urban rail transit train,station,and platform is studied from the perspective of the multi subsystem of passenger,train,and station.The main work includes the following four aspects.(1)As for the effective carrying capacity of the train,once the vehicle type and the number of marshaling cars are determined,the carrying capacity of the train mainly depends on the selection of the vertical seat density.To maintain the service level within the tolerance range of passengers,it is also necessary to conduct an in-depth study on the passenger seat density when studying the effective carrying capacity of trains.In this paper,the car seat density is taken as the breakthrough point,aiming at the shortcomings and deficiencies of the existing calculation methods of car seat density,according to the different characteristics of different groups of people and different travel purposes,passengers have different tolerance to the level of service,combined with the three environmental factors of car seat density,standing time and waiting time,based on the existing crowding force model,A time-space comprehensive tolerance perception model based on interval fuzzy number is proposed to reasonably calibrating the vertical seat density of the car,to achieve the purpose of calculating the effective carrying capacity of urban rail transit trains.(2)In terms of the effective carrying capacity of the station,considering the tolerance requirements of passengers to the service level of station facilities and equipment,combined with the characteristics of passengers’ travel behavior,the system dynamics model of passenger flow is established.Combined with the previous calibration of the vertical seat density of the carriage,the simulation calculation of multiple subsystems of passenger,train,and station is carried out by using Vensim software,By adjusting the passenger flow intensity and observing the passenger flow status at the bottleneck of the station,the number of existing facilities and equipment configuration and the effective carrying capacity under the layout structure of the station are analyzed.(3)In terms of the effective carrying capacity of the platform,the bottleneck of the effective carrying capacity of the station is mostly limited to the platform,and the platform is the "person station vehicle" passenger flow interaction platform of urban rail transit.In this paper,from the point of view of the multi subsystem of passenger,train,and station,combined with the multi-attribute characteristics of passenger flow,platform,and train,the calculation model of effective bearing capacity of urban rail transit platform is established.The attributes given by the model not only include the arrival and departure information and the remaining space limit of the train but also increase the boarding and alighting attributes of the station passenger flow.These attributes change dynamically with the operation of the train.This paper selects the most widely used Island station configuration as the research object,through the design of multi-group sensitivity simulation analysis experiment,analyzes the influence factors of platform effective bearing capacity from multiple perspectives under multiple scenarios,and finally proposes a comprehensive adjustment scheme combined with the model results,and compares the results with the simulation experiment reference group to verify the effectiveness of the model.(4)Based on the calculation and analysis method of the effective carrying capacity of train,station,and platform,this paper designs the framework,function,and workflow of the monitoring system of the effective carrying capacity of urban rail transit,and puts forward the decision-making process to deal with passenger congestion.On the one hand,real-time monitoring and statistics of passenger flow can realize real-time monitoring of carrying capacity and early warning of weak links in the system;On the other hand,according to the simulation results and the analysis of decision-making,it can give support to adjust the operation phase plan.To sum up,this study has completed a complete set of practical application methods from the theoretical calculation of the effective bearing capacity of urban rail transit train,station,and platform to the formulation of operation organization optimization adjustment strategy.It can provide scientific and effective theoretical support for urban rail transit in improving service quality,reducing safety risk,and improving operation efficiency.