Condition Monitoring System For CRTSⅡ Slab Ballastless Track Railway Based On Fiber Bragg Grating Sensors

The jointless track has been widely used in China for reducing the vibration impact through lowering the number of rail joints, made the railway more high-speed and heavy-haul. However, the temperature stress generated in the jointless track of temperature stress type will lead to buckled rail and the broken rail when the stress is too large, which is a threat to the railway operation. Therefore a status monitoring system of CRTS Ⅱ slab ballastless track is necessary and a long-term monitoring is useful for building information base of track status, evaluating and predicting the track status.The development in the world of FBG sensors in railway has been introduced first. A system is designed for monitoring the status of CRTS Ⅱ slab ballastless track based on analyzing the principle of Fiber Bragg Grating (FBG) sensors and the structure of double columns end thorns.The completion of the monitoring system is on the basis of analyzing the sensing principle of FBG sensors and F-T filter demodulation technique. The installation and connection of the sensors of on-site part and central control unit based on VB programming which completed status monitoring, data acquisition, Ethernet transmission, data saving and displaying are implemented. GPRS remote transmission is used for connection on-site control center and remote control center. Remote control center is designed for data receiving, displaying analyzing based on Qt.The application of this system on Beijing-Shanghai Highspeed Railway including the layout of the FBG displacement sensors, strain sensors and temperature sensors which devided into7arrays is also introduced. After the24h’monitoring of105days, the data of field tests show the relationship among temperature, strain and displacement. The stability of FBG sensors in a long-term work can also be seen from a large number of data, which shows that the FBG sensing monitoring system is feasible.