| With the expansion of urban rail transit network and the extension of line mileage,the traditional all station stops operation scheme will lead to extremely long journey time for long-distance passengers,which cannot meet the original intention of rapid access of urban rail transit.Therefore,the Express-local train scheme(operating both the all-stop train and the skip-stop train in the same line)is widely used in recent years for it can shortening the passengers travel time and promoting the matching of the transport capacity.However,most of the existing research on the Express-local schemes are focusing on an independent rail line.Under the trend of gradually connecting lines into network,the travel demand of the cross-line passengers will bring additional conditions for the multi-line station-stop scheme.So,how to set up the network train operational scheme and ensure its effect has become a valuable research field,which could also be adapted to the development trend of the urban rail transit network.Therefore,this thesis focuses on the optimization methods of the network train operation scheme under the fixed passenger structures.And attempts to provide some theoretical guidance for operating enterprises.The main tasks are as follows:(1)Firstly,according to the train operation process,the thesis systematically sorts out the influencing factors affecting the feasibility of the skip-stop plan.Then concludes the prerequisites for developing the scheme:1)Summarizes the rail alignment and facility requirements from the worldwides typical skip-stop train cases.2)Summarizes the passenger flow characteristics on both single line and line network.After that,the network attributes of the urban rail transit system are discussed,which proved that the optimization research under network condition is more difficult than single-line study.And the difficulties and the key points of this study are clarified.(2)From the perspective of shortening total travel time of all passengers,the thesis proposed a station stop optimizing model for the urban rail transit single line with the case of unbalanced train departure and one time overtaking.The model takes the frequencies of the all-stop train and skip-stop train,the departure interval of the two trains,the stopping station,and the overtaking station as decision variables.The microbial genetic algorithm was designed to solve the mixed variables nonlinear model Then the thesis applied the model into City X for case study.the result shows that passengers under the Express-local scheme can saves 11114minutes of travel time compared with the all-stop scheme,with an optimization rate of 1.89%.(3)Based on the singe-line optimization model,a combined model of optimizing the network train operation plan and the departure schedule is established by adding the decision variables of line departure time.So that could synchronize the multi-line train stops and optimize the waiting time of cross-line passengers simultaneously.The thesis then designed an improved algorithm which integrates the evolutionary strategy into the genetic algorithm to improve the solution efficiency.Model applied into the double-line network in City Y for case studies.Four controlled cases were calculated.Case i,both lines apply the all-local train scheme;Case ii/Caseiii,one line apply the Express-local train scheme and the other apply the all-local scheme;Case iv,both lines apply the Express-local scheme.As a result,Case iv come with the best results.Comparing with the previous three cases,the total travel time of passengers in Case iv was optimized by 4.6%,4.0%and 5.3%respectively?(4)In addition,the article analysis the application conditions of passenger flow under specific single-line and double-line scheme.Based on the sensitivity analysis of each key elements in the model,the critical value range for each element under each operation condition has been calculated.Also,other operation conclusions about the skip-stop train operations that could be adopted for operators are provided. |
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