Fires in tunnels are known to lead to explosive spalling of the tunnel linings, mainly due to rapid expansion of water as a result of vaporization in the concrete. In order to determine the moisture content within tunnel linings both a measurement system and a simulation model for prediction purposes was developed as part of a joint research project with the Austrian railways and 3 faculties of the OTH Regensburg.
The development process included the calibration of humidity sensors which were then embedded into the concrete tunnel linings. Data was collected in the Inntal tunnel, Austria over many months. Finally, the data could be used to verify simulations. This was a great success.
