Monitoring system for the freeze-thaw circle around tunnels in a plateau featuring frozen ground

To strengthen the monitoring of a freeze-thaw circle around operating tunnels in a plateau with frozen ground and to better meet the requirements of unattended real-time monitoring for the Qinghai-Tibet railway and high-altitude tunnels in western China, the function of network data transmission and remote control is upgraded and a remote real-time monitoring system for the freeze-thaw circle is proposed on the basis of the original SJX-24T/16T tunnel automatic test system. Thus, automated real-time acquisition and transmission of monitoring data can be realized via the 485-GPRS transition and remote control function. Since 2002, this system has been applied to monitoring of the freeze-thaw circle around the Kunlunshan and Fenghuoshan tunnels on the Qinghai-Tibet railway, and it has successfully obtained large amounts of valuable monitoring data of freezing and thawing around tunnels in the plateau's frozen ground. The results show that this monitoring system is stable and reliable, with the effects meeting design requirements.