Research On Product Design And Collection Distribution System Organization In Railway Freight Corridor Based On Improvement Of Transport Capacity

During the past decades, many constructions of railway corridors and passenger railway lines have been carried out. The transport capacity of railway corridor has been released which helps to improve the railway transport service. Meantime, the structure of transport demand has changed due to the development of the society and economy. The freight that charactered with high value-added and scattered grows rapidly and continuously. However, the traditional transit organization pattern is not suit to the development of transport demand, which aims to obtain maximum transport capacity while ignoring service quality. Consequently, the market share ratio of railway decreases slowly and it is urgent for the railway to improve the service quailty, which is crucial for the competitiveness and economic benefit of railway. The railway corridor is the skelecton of railway network. The improvement of railway corridor service can achieve maximum benefit to the railway with little effort. This dissertation researches the optimization of railway freight products design and collection distribution system organization, and it provides theoretical basis for the using of the transportation resource for railway operators. The main contents include:(1) The basic theory of railway freight corridor is analyzed. The content including the structures, characteristics, modes and utilization patterns of railway freight corridor, the characteristics and requirements of the transport demand, the alluring areas of railway freight corridor, the influence factors and the key points in optimizing the transportation resource. And the railway corridor transportation system is divided into two systems.(2) The railway corridor physical network design and flow assignment problem is investigated. This method is used to study the transportation capacity supply issue. The physical network of railway corridor is built with node splitting which is based on the connection direction of technical station. Based on this network, the network design and flow assignment optimization model is built. According to the character of the model, two approaches are applied which are ILOG Cplex and heuristic algorithm.The heuristic algorithm progress which combined Cplex and Cloud Adaptive Clonal Selection Algorithm is presented. In the heuristic algorithm, the network design plan is resolved by Cloud Adaptive Clonal Selection Algorithm, meanwhile, the flow assignment is resolved by Cplex. The algorithm uses Yen’s algorithm to get the k shortest roads of the OD, previously, which can help to save the time cost. And one case is presented to test the feasibility and efficiency of the model and solution strategies. The result shows that the heuristic algorithm can obtain the global optimum of the problem.(3) The railway corridor transport product design problem is investigated using service network design. The process of railway product layout is proposed. And the introduction of the railway product alternative set reduces the complexity of the problem. The corridor service network is constructed based on the railway transport products. Taken the transport income as the object, the optimal model is set. Both Cplex and a reformed Cloud Adaptive Clonal Selection Algorithm are presented. Besides, another case is presented to test the feasibility and efficiency of the model and solution strategies.(4) An optimization methodology of hub transportation problem is proposed, based on the information of transport products in the railway trunk and transport demand in the hub. The hub transportation optimization problem is divided into collection dispersion problem and empty wagon distribution problem. Considering the collection and dispersion are two reverse processes, the collection optimization problem and empty wagon distribution problem are investigated in the paper. In the collection system, the latest service time of the freight can be got based on the schedule of the regular trains in the trunk. The model is presented with the objective of minimal total time cost of the freight in the hub. For the empty wagon distribution system, the time satisfaction, the restraints of wagon type and the uncertainty of empty wagon demand quantity are considered in a multi-objective chance-constrained programming model. The models are solved by ILOG Cplex engine. Two different solve strategies are proposed for the empty wagon distribution optimization model.(5) HuKun railway freight corridor eastern section and the HangZhou railway terminal are taken as the background, a real example is used to verify the practical value and significance of the study.