Long-term diagnostic technology for the monitoring of continuous welded rail on curves in a cold area

In cold areas where the annual rail temperature difference can exceed 90 °C, continuous welded rails (CWRs) on small-radius curves are more likely to buckle or distort owing to the large radial temperature force and large lateral deformation of the rails. To facilitate safe operation of trains in cold areas, a magnetostrictive displacement measurement technique was used to measure the lateral displacement of CWRs in this study. Then, a long-term monitoring system, including a sensor subsystem, a data acquisition and transmission subsystem, and a data analysis and management subsystem, was established for the monitoring of CWRs on small-radius curves and applied in a field test. One year of continuous observation results showed that this monitoring system could effectively realize the functions of real-time acquisition, wireless transmission, and data storage in a cold climate. The collection and analysis of these observation data, including the air temperature, rail temperature, and lateral displacement of the rail, can be further applied for the stability prediction of CWRs on small-radius curves.