TBM Tunneling - Rock Mechanics Based on an Anisotropic Jointed Rock Model - page 715

Figure 21.58 Segmental ring only bedded at the invert, computation assumptions (Wittke et al. 2006)
Figure 21.59 Deformation of a partly bedded segmental ring loaded due to self-weight
(Wittke et al. 2006)
Furthermore, the segments are considerably overloaded, particularly in the area of the
joints as a result of large angular rotations. In Fig. 21.60, the reinforcement of segments
of type I according to plan (Table 21.1) is colored in blue. The reinforcement required
for the segmental lining calculated with standard safety factors is colored in red. Even
if the safety factor is reduced to 1.0 the reinforcement of segments according to plan
is not sufficient (Fig. 21.61). Qualitatively, similar results were also obtained for larger
grouted sections of the annular gap.