Combinatorial Research Of Rail Marshalling Yard Layout And Railcar Blocking Problems

ABSTRACT:Reform of railway freight transport in China was officially launched in June,2013which is the first reform action after the China Railway Corporation established. This reform is in order to improving quality and efficiency of railway freight transportation. And with the high-speed railway network has been constructing, he volume of railway freight will continue increasing. In this context, the marshalling yards which are decreased in number undertake more and more freight tasks. Therefore this situation makes much higher efficiency request in marshalling yards’reclassifying capacity and car flow organization plan.The marshalling yards layout optimization means rational reclassifying capacity configuration. The key point of marshalling yards layout optimization has changed, from the location problem to how to make the maximum effectiveness of existing marshalling yard layout. As the division of labor and layout of marshalling yards is highly association, one change of marshalling yards reclassifying capacity configuration will affect the division of labor and other marshalling yard’s loading degree, even the whole situation of car flow organization in network will be modified. Meantime, the car flow organization is the basis of marshalling station layout planning. So there is important to make collaborative optimization of marshalling station layout planning and car flow organization from a global perspective.In the present paper we study the optimization of Railway marshalling station cost on the basis of railway marshalling station layout planning and car flow organization. This paper based on the international research results, optimizes the railway marshalling station layout planning and car flow organization, builds up a bi-level programming model. However, because of the complicate relationship of the variables in upper level and lower level, the model has been transformed and simply. Finally this paper uses Tabu search algorithm to solve the bi-level programming model, an example is given and received the optimum railway marshalling station layout planning and car flow organization plan of the model railway network, to verify the model and algorithm is feasible and effective.The major research content and innovation in the dissertation presented as follows:1、Introduce the theory of railway marshalling station layout planning and car flow organization plan, specially the connection and influence between each other. 2、The upper level aims at minimizing the sum costs of investment, car flow organization, and equipment capacity waste. The exclusive cost of investment, the uniqueness of layout plan, and equivalent plan exclusion are constraints to optimize marshalling station layout. The goal of lower level is to minimize the cost of car flow organization, considering the uniqueness of car flow organization, the capacity of marshalling, delivery and reception as limitations. Marshalling station layout plan according to the upper level adjusts the technical parameters, and then those are put into the lower level, optimize and generate the train formation plans and marshalling plans, be feedback to the upper level.3、Due to the complicate relationship of the variables in upper level and lower level, the model has been transformed and simply. Finally this paper uses Tabu Search algorithm to solve the bi-level programming model,4、An example is given and received the optimum railway marshalling station layout planning and car flow organization plan of the model railway network, to verify the model and algorithm is feasible and effective.