Research On Optimization Of Operation Organization At Combination Station In The Loading End Of Heavy Haul Railway

The combination station in the loading end plays an important role in the collecting and distributing system of heavy haul railway.The main function of the combination station in the loading end is to combine and comb the heavy haul trains transported to the unloading end so as to give full play to the transportation ability of heavy haul railway.Meanwhile,the decomposition and adjustment of loopback empty trains are also done in the combination station in the loading end to provide a guarantee of sufficient wagons for loading points.It is of great necessary to optimize the operation organization at combination station in the loading end for the purpose of improving and increasing the service level and transportation profit of the collecting and distributing system of heavy haul railway.This paper tries to optimize the organization of combination station in the loading end of heavy haul railway,and the main researches of this paper are as follows.(1)This paper summaries the relative literatures focused on the wagon flow organization of heavy haul railway,station operation organization of conventional and heavy haul railway all around the world,and describes the current developments and organization characteristics of heavy haul railway in China,as well as transportation organization form of heavy haul trains.Besides,the operation procedures at the combination station are elaborated and the necessity of operation organization optimization of the combination station is discussed.(2)Focused on the situation of excessive occupation of arrive-and-depart tracks and station capacity tensity,the factors influencing proportion of heavy haul trains are analyzed.An integer linear programming model to minimize the occupation rate of arrive-and-depart tracks in the combination station is established with the wagon flow equilibrium,daily locomotive deliverability and carrying capacity of heavy haul railway as constraints.A realistic case is constructed to verify the effectiveness of the model based on Shenchinan station in China.(3)To guarantee the successful implementation of macroscopical wagon flow organization scheme at the combination station,optimization research on the train combination problem at the combination station in the loading end of a heavy haul railway is carried out.A pure 0-1 integer linear programming model is established with minimizing the sum of total waiting time of all inbound trains at the current combination station and total extra decomposition time of all outbound trains composed by inbound trains with different destinations at the successor stations as objective.Series of practical transportation requirements such as tractive weight of outbound trains,wagon flow connection time and cancelling of outbound trains are taken into consideration.Train data in the literature are used to construct a realistic case study so as to verify the effectiveness of the model proposed in this paper.The superiority of the model is proved by comparing the train combination scheme obtained by this model with train combination schemes obtained by existing heuristics in the literature and empirical method used in practice.This paper focuses on the optimization of operation organization at the combination station in the loading end of heavy haul railways and has a certain practical guiding significance for the combination station organization.Besides,it enriches and improves the current theory system of heavy haul transportation at a certain degree.