Hohentwiel Motorway Tunnel, main analysis in accordance with DIN 1076



State of Baden-Württemberg

Task definition

Tunnel scan as part of the main analysis in accordance with DIN 1076


  • Recording with the TS3 tunnel scanner
  • Total length 2.5 km

Task definition

Creation of a scan of the tunnel to be used as the basis for the main analysis in accordance with DIN 1076 and preparation of the test report. The newly recorded data was compared with existing inventory data and served as the basis for evaluating the condition of the tunnel and planning repairs.

We were tasked with carrying out the entire process, from the conducting the initial scan to drawing up the test report:

  1. Recording of both tunnel tubes with the SPACETEC TS3 tunnel scanner — high-resolution image profile and thermography data
  2. Examination and evaluation of the scan data
  3. Creation of a damages map using the SPACETEC Tunnel Inspector
  4. Input of the structural damage into the central road information database (SIB, from the German Straßen-Informations-Bank)
  5. Preparation of a test report with an assessment of the tunnel conditions

Reporting based on damage mapping

In the evaluation, the scan data were viewed on a computer screen and examined for any recognisable structural damage. The damage mapping was performed using Tunnel Inspector. The scan data served as the background onto which the identified damages were mapped.

Because the scan data are to scale, the location and extent is known for each instance of damage mapped. Tunnel Inspector automatically compiles the data of each individually mapped element into a list. Statistical functions facilitate the evaluation of specific criteria defined by the user.

The information created in this way is entered into the SIB database.


Damage development

Together with the recordings from 1991 and 1997, data is now available from three scans. Comparing this data provides valuable information on the development of damage.

The adjacent image shows a section of the thermal image from the three measurements. An extensive cold anomaly can be seen in exactly the same position in each measurement. This indicates the presence of mountain water. However, there is no indication that water is entering the tunnel in this section, which suggests the seal is intact. The changing size of the anomaly is likely to be caused by varying climatic conditions.