Tunnel Condition Monitoring

Modern transport infrastructure would be inconceivable without tunnels. In Germany, there are more than 400 road, rail and underground tunnels requiring regular maintenance. Many of these tunnels have been in operation for decades, so regular maintenance and repair are becoming increasingly important in order to avoid safety risks and consequential damage. Today, an inspection is performed manually in a slow, costly and unobjective process – the degree of digitization is low. In the near future, however, Building Information Modeling (BIM) will also become standard in tunnel construction. This will require the complete digitization of building surveying. Fraunhofer IPM develops technical measurement solutions for a cost- and time-efficient inspection process during regular operation.

Tunnel Inspection System TIS: measuring geometry, surface and moisture simultaneously

The Tunnel Inspection System TIS by Fraunhofer IPM was developed to enable a fast and efficient inspection of tunnel structures. The TIS provides absolutely referenced and high-resolution information on the 3D geometry, surface structure and wall moisture of tunnels. The multispectral sensor system is based on a multi-wavelength laser scanner that provides additional information on wall moisture. The measuring system is continuously being developed: A novel type of scanning technology and high-performance electronics currently enable measuring speeds that are up to four times higher than what could be achieved with the laboratory demonstrator, while maintaining a comparable data quality. An innovative light deflection unit allows the structure to be measured over an angle of 360° without shadowing. The TIS enables fast and continuous tunnel inspection at significantly increased driving speeds, so that blocking the structure for inspection is no longer necessary. Due to its compact and flexible system design the TIS can be used on a wide variety of mobile platforms such as pigs, trains or road vehicles.