NATM Tunneling - Rock Mechanics Based on an Anisotropic Jointed Rock Model - page 644

Subsequently the design and construction of lot 601 will be presented (for this pro-
ject see also Böttcher et al. 1998, Erichsen & Tegelkamp 1998, Tegelkamp et al. 2000,
Wittke et al. 2002, Wittke et al. 2003, Wittke et al. 2006). The gradient and the ground
profile of the tunnel are shown in the longitudinal section in Fig. 20.26. Following lot
92, the tunnel descends towards Bernhausen. From underneath the runway the tunnel
runs horizontally over a length of approx. 1400 m. The following ascending section of
lot 601 ends at the beginning of the cut-and-cover section of lot 602.
Figure 20.27 shows the circular cross-section of the single-track tunnel tube. The 30 -
35 cm thick shotcrete membrane was designed against water pressure and made from
alkali-free dry-mix shotcrete with a low water permeability using spray cement as bond-
ing agent (Section 20.2.3). The internal lining of reinforced concrete was designed with
a thickness of 50 cm. Because of the required internal diameter of 7 m, the excavated
diameter is thus 8.7 m. The excavated cross-section of the tunnel tube is roughly 60 m 2 .
Figure 20.27 Cross-section of the single-track tube, standard profile (Wittke et al. 2006)