A Novel Method for Railway Crossing Monitoring Based on Ambient Vibration Caused by Train-Track Interaction

Railway crossings are critical components in the rail network. They usually degrade faster than the other components. It is therefore vital to monitor their conditions using appropriate methods. This paper proposes to use the ambient vibration caused by the train-track interaction from a distance to monitor the condition of railway crossings. Both impact tests and pass-by measurements were performed on an instrumented crossing. The eigenfrequencies and mode shapes in the frequency range of 10–2000 Hz are first identified by impact tests using three different devices, i.e. a falling weight device, a big hammer and a small hammer. For the pass-by measurement, the dynamic features of both the wheel-crossing impact and ambient vibration are analyzed using time-frequency representations. It is shown that the ambient vibration signals are stationary and contain several characteristic frequencies. Then a method based on the frequency domain decomposition is applied to the ambient vibration signals to further identify the frequency components. It is found that the frequencies identified from the pass-by measurement agree well with the eigenfrequencies identified from the impact test. The proposed method can be further developed to continuously monitor the condition of railway crossings without interrupting train operations.