Temperature monitoring of soil freezing

Temperature measuring systems can be installed in boreholes to monitor the development of a freezing body, e.g. in shaft or tunnel construction. The advantage of fibre-optic temperature measurements is the high resolution of the measured values along the temperature lance and the precise location of temperature differences.

The freeze shaft method is one of the safest shaft sinking methods in regions with unstable and water-bearing cap rock. The freezing process can be monitored with a fibre-optic temperature measurement system. Thus, the freezing process, the thermal properties of the rocks, inhomogeneous zones of temperature distribution, influences by aquifers, failure of freeze pipes and changes in the freezing body with time can be controlled and identified.

In addition, alarms can be set up in the temperature monitoring system, e.g. in case of damage to the fibre optic cables, data loss, deviation from a reference profile or a sudden change in temperature.