Study On Theory And Method Of Calculating Carrying Capacity Ofhigh Speed Railway

Railway capacity has been extensively investigated for the purpose of utilizing rail infrastructure in a possible efficient strategy. Nevertheless, the estimation of high speed rail (HSR), which is different from common railways in many aspects, is still a challenge work needed to be solved. Consequently, this work focuses on the capacity estimation of HSR corridor using both optimization modeling methodand mathematical modeling method. We study this case from the perspectives of improving the passengers’s time-space accessibility, ensuring the reliability of train operation and pursuing the shortest total travel time. Specific content are as follows:After analyzing factors influencing the capacity of HSR, this paper classifies them according to the nature and establishes the influence function of each single factor on HSR capacity. Meanwhile, this paper takes the quality of passenger service as an important factor to calculate the HSR capacity on the basis of service nature of high speed railway passenger transport. We use mathematical optimization method to study the HSR capacity from these two aspects: passengers’ time-space accessibility and train operation reliability. At the same time, we propose a multi-agent simulation software NetLogo based on multi-agent technology for HSR train operation in purpose of shortening total travel time. We take Beijing-Shanghai high speed railway as an example to run the simulation. And the feasibility, accuracy and applicability of the method are proved.The main research content and results are as follows:(1)HSR capacity optimization model considering passenger space-time accessibilityPassenger space-time accessibility not only reflects the service capacity of the railway network, but also reflects the passengers’ perception of the railway network transport capacity. Therefore, the space-time accessibility of passengers is an important consideration to establish the optimization model of HSR capacity. It is how to make the passengers realize the spatial displacement in the travel time budget as far as possible under the condition of the train running chart. In this paper, we aim to minimize the number of unreachable ODs in the run graph, and to construct a high-speed railway capacity optimization model based on time and space accessibility. The Lagrangian relaxation algorithm is used to solve the model. Taking Beijing-Shanghai high-speed railway as an example, this paper analyzes the available capacity under the condition of considering the passenger’s space-time accessibility.(2)HSR capacity optimization model considering passenger service quality and reliabilityConsidering the actual situation of China’s high speed railway, this paper constructs the model by taking full account of the passenger service quality and the train running reliability. A detailed analysis of the objectives and constraints, proposed a two-stage optimization model. The first stage model is based on the passenger’s OD requirement to determine the number and grade of required trains; the second stage model is a multi-objective integer programming model to estimate the capabilities of high-speed railway. The branch and bound algorithm is extended and applied to the proposed model,and a case study is performed to Beijing-Shanghai high speed railway. The results show that the objectives have essential impacts on the railway capacity, and so weighted coefficients of the objectives should be adjusted to obtain the optimal capacity.(3)Simulation of HSR operation on multi-agent and capacity calculationOn the basis of analyzing train operation process and parameters, three layer intelligent model of high-speed railway running process simulation is introduced to this complicated system. The state transition model, communication mechanism and coordination mechanism of train intelligent body are presented. Experiments show that the simulation system of income a conclusion and real measured data are basically consistent, can be as realistic high-speed railway carrying capacity calculation tool for high speed railway through computing power has a practical guiding significance which is very beneficial.In order to calculate the passing capacity of high speed railway, a simulation process is built on the basis of multi agent theory. At the same time, its system of monitoring and controlling is designed on actual Beijing-Shanghai high speed railway operating parameters. In the process of simulation realization of the multi agent model,NetLogo multi agent software is used. After analyzing statistical data such as average speed, stop time, average buffer time, departing time interval on dynamic regulation and etc, the maximum train passing capacity is calculated considering passenger service quality.The interaction model and simulation process between the influencing factors and the passing capacity are different in the situation of the high speed railway through the capacity calculation. Therefore, the organizers could choose or determine the combination of models which can make a balance between the level of passenger service and transport needs to achieve a coordinated, realistic and meet the model multi-objective needs of the harmonious results according to the concrete requirements of the actual transportation organization.