Research On The Planning And Optimization Of The Long-term Railway Network

Railway is the national critical infrastructure, the national economy and popular means of transport artery, and its development is related to national economy. The layout and planning is an important foundation for early railway construction work, scientific and reasonable planning is related to the continued and healthy development of rail traffic. Especially the long-term railway network planning, is the blueprint for railway development in future because of its high level and long term.The paper reviews the relationship between the railway history and economy development in the developed countries, the viewpoint is summed up in one sentence that railway has played a vital role in the rapid development of a country's economy in a certain period. China's railway construction is still long way to go, so the layout and planning of railway network is particularly necessary because of the urgent requirements of the coordinated development of the environment, resources, culture and other aspects. In view of this, the paper has systematic studies in the fields of node planning, network design methods, network optimization model and algorithm, and gives us a complete framework and theoretical methods in railway network planning. All the study based on the previous research results and combined with the actual situation of China's railway development. The main contents include:1. By reading and summary a lot of literature, the paper analyzes the domestic and foreign research in the design of transportation network and the layout and optimization of the railway network, points out the inadequacies of existing studies, and proposes the research ideas of this study.2. Through a study of the interaction between transport and demand as well as the formation and evolution of transport network, the paper analyzes the characteristics of total amount and spatial layout of China's future transport demand. Certainly, the analysis is combined with China's regional economic development and resource distribution. At the same time, the paper studies the composition of transport network, analyzes the characteristics of railway network which would implicate the planning of long-term railway network, all this works lay a good foundation for constructing the reasonable mode of long-term railway network planning.3. The paper gives out an explicit point that rail transport is very important in our economic development, and the status and shortcomings in our railway network development are analyzed and summarized. And then, the paper analyzes and studies the factors of the development of transit network scale, summarizes the calculation method used, and then, calculates the reasonable scale of our sub-regional railway network by referencing the scale of foreign developed railway networks. The demand analysis of total scale is an important part in the planning and layout of railway network, it is helpful to attain a macroscopic view in the building of a railway network.4. According to the view of socio-economic and resources distribution and regional development, the paper pinpoints the target and optimization principles and main tasks in the Long-term railway network planning. And then, the paper proposes hierarchical layout mode of rail network, proposes construction methods and models of trunk network, underlying network and system network respectively. The hierarchical layout method of long-term rail network constructed in this paper is in the overall consideration between connections and influence of different layers in the network, it would make the physical form and geometry structure of a more complex structure railway network effectively achieved, to some extent, it could replace the previous qualitative analysis method which ignores the network effect, so it has some theoretical and practical significance.5. The optimization model of the layout of the railway network constructed in this paper is cover both investment decisions and network flow problems, it has the objective of minimizing cost and the constraints of funds, scale, capacity and other relevant conditions. And then, the paper gives an algorithm which could produce the most efficient layout of the railway network. The example of the study show that the model and the algorithm constructed in the paper are efficient, It is proved that the optimization model of the layout of the railway network constructed in this paper has a very good practical value.Finally, the paper summarizes the research and induction, and that the direction of future research.