Study On Optimization Of Urban Rail Transit Network

The rapid and sustained development of China’s society and economy has brought good development opportunities to major cities,but also caused many development problems.The traffic congestion problem is a common problem existing in the rapid development of major cities.Most cities in China are committed to solving their own traffic congestion problems by taking relevant measures.Urban rail transit has become the first choice for major cities to solve the problem of urban traffic congestion due to its characteristics of rapidity,large traffic volume,safety and environmental protection.In recent years,with the acceleration of the construction of urban rail transit in China,the scale of the line network has been continuously expanded and the system has been continuously enriched.The urban rail transit system in major cities has gradually been characterized by network operation.Under the background,optimizing the existing urban rail transit network will be the focus of urban rail transit construction in China.Therefore,the paper uses complex network theory to study the optimization problem of urban rail transit network to provide a certain theoretical basis for the optimization of urban rail transit network.First,the paper introduces the basic concepts of complex networks,and analyzes the topological characteristic parameters of complex networks such as degree and degree distribution,shortest path and average shortest path,clustering coefficient and intermediary;Two methods of building complex networks are mainly described: Space L method and Space P method.Next,the topology parameters of the Chengdu metro network are analyzed using the established complex network topology characteristic parameters.Based on the calculation of the relevant feature quantities,the scale-free characteristics of the Chengdu metro network are verified and it proves that the Chengdu metro network is a complex network,indicating that the complex network theory can be applied to the field of urban rail transit;the paper defines the key stations of urban rail transit and identifies the key stations of the Chengdu metro network by combining with importance contribution matrix.Finally,on the basis of introducing the accessibility and robustness of the urban rail transit network,with the goal of optimizing the accessibility and robustness of the urban rail transit network,the topological characteristics optimization model of the urban rail transit network are established with the reasonable constraints of the line network;taking the established topological characteristic optimization model as the lower layer model,considering the optimal average travel cost of passengers of the entire network and the passenger flow allocation as constraints,the paper establishs a two-layer optimization model of the urban rail transit network to achieve the optimization of the urban rail transit network;Taking the Chengdu subway network as an example,the paper uses simulated annealing algorithm to solve the model,and realizes the optimization of the Chengdu subway network.