| Railway track is one of the most important infrastructure in rail transit, and its quality state has an important influence on running trains’safety, passengers’comfort, track’s life, trains’life and the maintenance costs. Reliability of track is an important index reflecting the track quality state. Through the improvement of track’s reliability, track quality state can be effectively improved, the probability of track facilities’ diseases can be reduced and the safety and stability of running trains can be improved. In the face of the rapid development of rail transit industry and rail transit operating safety requirements, it is particularly important to study the reliability of railway track.On the basis of analyzing the domestic and abroad status of railway track reliability research, this paper firstly analyses the common disease types of railway track and the degradation characteristics of railway track facilities, discusses the applicability of the unitized analysis method in the study of reliability analysis of railway track systems, and divides a track system into three grades, track facilities, track segments and lines as well as two levels, "facility-segment" and "segment-line" based on the unitized analysis method. Secondly, the paper divides the working states of track system according to the track system RAM failure types, analyses the failure mode of track facilities, and then establishes the reliability models on the level of "facility-segment" and "segment-line" step by step by the method of fault tree analysis and the reliability block diagram, thus formatting the reliability hierarchy models of track "facility-segment-line" systems. Thirdly, this paper establishes the reliability evaluation index of the grades of track facilities, track segments and lines, which formulates a complete reliability evaluation index system of track systems, and uses the Markov chain method to put forward the calculating method of track system reliability evaluation index based on the reliability models. Finally, it draws on Beijing Subway Line 13 up main track system to model and evaluate its reliability and to analyze the reliability evaluation results. |
