Theory And Method For Railway Track Maintenance Scheduling

With the rapid development of economy and the improvement of the comprehensive transportation system in China, the demand of railway transportation is increasing, and ensuring the safety of operating is an urgent problem that needs to be solved on the basis of improving the transport capacity railway. During the period of "The12th Five-Year Plan", the scale of the railway in China will reach to12thousands kilometers, and that will alleviate the tensional railway transport situation and the work of the maintenance of the rail infrastructures will also increase rapidly. Railway track is the basis for railway operation, and it is very important to keep the track quality in a good condition for the transportation safety. Adequate track maintenance takes up a lot of time and space resources, it is bad for the releasing of the transport capacity. Compressing the repair time can lead to the insufficient of the track equipment maintenance and affect the quality of transport. The contradiction between the maintenance and transportation will severely restrict the development of the railway transportation. The track maintenance planning and optimization technology are the important means of scientific management to the track maintenance; it can balance the safety of transportation and the economic benefit, and it is an effective way to solve the conflict between the maintenance and transportation. The expertise in this field has accumulated a lot of achievements and experiences, but the research is relative weak in our country. Under the background, based on the actual demand of the railway maintenance management in our country, this dissertation has analyzed the characteristics of the maintenance operation and planning elements systematically, perfected the planning theory system of the track maintenance, and probed the suitable planning methods for the maintenance of the road network. Combined with the optimal allocation of the maintenance resources and the balance of the maintenance and transportation, a reasonable plan of track maintenance was developed and finally the control of the maintenance cost and operation safety was achieved.Railway track maintenance scheduling is complex, which requires identifying the boundary of scheduling at the beginning of the study, and the further factors covered by maintenance planning such as railway track sections, maintenance activities, track condition, maintenance resources, etc. This article developed its research from three aspects including the planning of railway track annual preventive maintenance, prediction method of track condition and high-speed railway track monthly maintenance scheduling based on track condition with summarizing and analyzing relevant theories and research results both domestic and overseas. The specific work and achievements are as follows:(1) Analyzed the characteristic of current track maintenance activities in our country, divided the railway maintenance work into routine work activities and project activities according to frequency, duration and scope of influence; built the optimization model for preventive maintenance planning of railway lines in large-scale network with the target of minimum time occupied for segment line within the network and consideration of limitations in period, maintenance resources, and execution timing; designed heuristic algorithm according to characteristics of the model and conducted analysis on solution results from multiple scenes.(2) Considering the development characteristics of track geometry irregularity and based on gray prediction theory, short-term prediction model with update mechanism for track irregularity was established. After combined correction for the model, validated the perdition accuracy of the model from three aspects with inspection data of track geometry car/comprehensive inspection car. track local irregularity prediction, track irregularity diseases prediction and track section irregularity prediction.(3) Track deterioration phasing was divided and the optimal maintenance time was indicated, according to the track irregularity management standard and the actual production experience. Then, the concept of status time window for track unit segment was proposed. Optimization model of high-speed railway monthly maintenance planning in regional network based on railway status was stablished taking the penalty function of status time window, costs of maintenance and traveling into consideration; improved genetic algorithm model was designed, and after comparing its results with the other general genetic algorithms, the superiority of this algorithm was proved.