The full-area tunnel scanner recording of the zero measurement (initial inspection) of the A/B section was carried out in 2001. The first follow-up inspection was carried out 10 years later in 2011. In both measurements, all damaged and rehabilitated areas on the surface were recorded and digitally documented using Dibit software. The task of this bid is now to carry out and evaluate the second full-field follow-up measurement of the vault of the A/B section another 10 years later, in 2021. Based on the two previous images, all visual and geometric changes of the tunnel surface can be recorded.
