Research On Optimization Of Train Timetable During Urban Rail Transit Operational Disruptions

As a public transport system widely used today,urban rail transit can effectively alleviate the congestion of urban road traffic.However,with the continuous expansion of urban rail transit network scale,the urban rail transit system also increases the uncertainty that affects the operational safety of urban rail transit while providing better travel services.Once the system breaks down,the disrupted shuttle train is unable to pass normally,and there is even a complete disruption of the whole operation line.The rapid accumulation of passengers in the platform greatly reduces the passengers’ comfort,and the crowded queue in closed environment seriously threatens the passengers’ safety in the metro station.Therefore,in the case of sudden interruption of urban rail transit lines,adopting the adjustment strategies such as current limiting scheme,large departure time interval,small intersection and bus bridging service to reasonably optimize the rail transit operation plan,analyzing the interaction between passenger flow and operation adjustment,reconstructing the spatial and temporal distribution of passenger flow in the rail transit network,and relieving the pressure of passenger flow at the turn back station have practical significance for improving the service quality and operation safety of urban rail transit operation.Firstly,the paper summarizes the interruption characteristics of the urban rail transit operation and classifies different interruption scenarios.By analyzing the influence of disruption incident on train operation and passengers transport,different response strategies for interruption is put forward.Accordingly,the paper analyzes their impact on the timetable optimization in the case of urban rail transit operation disruption from the aspects of passenger travel demand,operation conditions and operation resources,so as to provides a better theoretical support for the construction of the optimization model of urban rail transit train schedule.Secondly,combined with the safe operation organization scheme of urban rail transit lines,the paper establishes the train schedule adjustment model under the operation disruption scenario.The small intersection strategy is used to reconstruct the spatial and temporal distribution of passenger flow in the rail transit line,which minimizes the waiting time of the passenger platform while guaranteeing the passenger travel demand in the uninterrupted section.In addition,the paper proposes an improved adaptive genetic algorithm to solve the model,and designs an example to verify the timetable optimization model and feasibility of the algorithm.At last,according to the current emergency management measures of urban rail transit line,the bus bridging service are adopted to transport stranded passengers in the interrupted section to reduce the pressure of passenger flow in turn-back station.Considering the limited capacity of passengers on the platform and the available number of emergency buses,the paper establishes the optimization model of urban rail transit train schedule under the simple bus bridging service mode as well as studying the interaction mechanism between the emergency measures of bus bridging service and the safety guarantee of stranded passengers in the case of operation disruption.Example application is designed to prove the rationality and feasibility of the optimization model of train schedule adjustment under the operation disruption.