Research On Location Of Urban Rail Transit Emergency Rescue Stations Based On Complex Network Theory

As an important place for storing and managing rescue resources,an urban rail transit(URT)emergency rescue station is the material basis for rescue resource allocation and dispatch,and plays a key role in effectively reducing the impact of emergencies.At the same time,as the URT gradually enters the era of networked operation,the network characteristics of the rail transit network become increasingly apparent.The abnormality or interruption of a site(a certain section)in the network cannot be ignored,if not timely rescue,may cause the collapse of the whole network.Therefore,combined with the related theories of network science and location,the location of URT emergency rescue station is studied and ensures that URT emergency management system can provide timely and effective rescue services.On the basis of a comprehensive analysis of network operation characteristics,basic characteristics of emergencies,the function orientation of emergency rescue station and the URT rescue network is divided into three levels,namely network-level,regional-level and site-level rescue stations.Then,point out the problems existing in the planning of emergency rescue stations during the construction and operation of URT in China.Based on the above background,the factors and conditions that should be considered in location planning for UTR emergency rescue station are put forward,which lays a theoretical and applied foundation for the modeling of emergency rescue station location.The URT network is considered as a complex network and node vulnerability analysis is introduced into the location modeling to improve the coverage level for the stations with high vulnerability.Therefore,it is necessary to carry out the research on the vulnerability of URT stations before the location modeling.First,the definition of URT vulnerability is defined based on the perspective of complex network.It is proposed that the vulnerability of URT station is composed of three factors: exposure,sensitivity and adaptability,and determines the evaluation index system of vulnerability.Finally,the comprehensive vulnerability index of rail transit nodes is calculated based on grey correlation analysis method.The node comprehensive vulnerability index is used to assign weights to the nodes in the location modeling of emergency rescue station.The coverage rate is determined according to the vulnerability degree of each node.Based on that,a location model is established.In the research on location modeling of emergency rescue station in URT,the principles and targets for the location model are proposed in this paper on the basis of the above research foundation.Based on this,a hierarchical multi-objective location model suitable for planning and decision-making of URT emergency rescue stations is constructed.The location model considers three objectives: minimizing construction costs,minimizing the average rescue response time and maximizing the coverage rate of the emergency rescue station to the demand point.On this basis,several optimization algorithms are compared and analyzed,and the simulated annealing algorithm is improved for the location model.Then,taking the URT network of Nanjing as an example,a case study is carried out.In the case study,different location scheme plan based on decision maker preferences with different costs,rescue efficiencies,and coverage was designed.Next,a comparative analysis of the location decision results validates the feasibility and effectiveness of the proposed model and algorithm.Finally,related suggestions for the location of URT emergency rescue station are given.