Monitoring of Insulated Rail Joints Based on Gap Value Measurement

The monitoring of an IRJ would allow targeted maintenance to be carried out, reducing the problems caused by its potential failures. The authors present the results of a test field investigation, that involved the installation of seven longitudinal displacement sensors that continuously record the gap value of insulated rail joints (IRJs). The monitoring of an IRJ would allow targeted maintenance to be carried out, reducing the problems caused by its potential failures. The studied monitoring system was installed in a station of the suburban railway line within the metropolitan city of Bologna (Italy). Analysis of low-and high-frequency recordings was performed. In particular, low-frequency acquisition was used to fit a statistical predictive model that detects a deviation from a standard behaviour and may evidence anomalies. For the high-frequency acquisitions (registered during train passage) some representative quantities, that can provide macroscopic indicators of loss of joint stiffness, were computed. Although gap measurement alone is not exhaustive for identifying all possible failure scenarios, the data acquired by these monitoring devices can represent a possible immediate monitoring solution, based on already available instrumentation, to provide user-friendly predictive analysis systems aiming at improving the railway maintenance.