Abstract: Red-light strap is a kind of fault that often occurs in railway signal equipment. In this paper, the method of fault tree analysis is used to create a fault tree and obtain the minimum cut set by taking the red-light strap fault of 25 Hz track circuits as the top event. Based on the data on such fault from a workshop of Qingdao-Jinan Railway  in recent years, the probability importance is calculated to determine the most important factors leading to the occurrence of the top event, and finally the corresponding maintenance suggestions and measures are put forward.

Key words: 25 Hz track circuit, fault tree analysis, red-light strap

摘要： 红光带故障是铁路信号设备中经常发生的一类故障，运用故障树分析方法，以25 Hz轨道电路红光带故障作为顶事件，建造故障树，求出最小割集，并利用胶济线某车间近年来25 Hz轨道电路红光带故障数据进行概率重要度计算，确定导致顶事件发生的最重要因素，最后提出相应的维修建议和措施。

关键词: 25 Hz轨道电路, 故障树分析, 红光带