TBM Tunneling - Rock Mechanics Based on an Anisotropic Jointed Rock Model - page 707

Figure 21.47 shows a cross-section through the screwing of the longitudinal joint be-
tween stones S1 to S6. The load transmission plane has a height of 17 cm. The longi-
tudinal joints between the keystone K and the boundary stones S1 and S6 are designed
with tongue and groove in order to allow the installation of the keystone at an accurate
position (Fig. 21.48).
Figure 21.48 Longitudinal joint between keystone K and boundary stones S1 and S6, detail
(Wittke et al. 2006)
Static proofs
For the design of the segmental lining, FEM analyses were carried out using WBI pro-
gram systems (Section 10.7).
First, two-dimensional stability analyses were carried out by means of the FE-mesh
represented in Fig. 21.49. The rock mechanical parameters were selected in each case
according to the considered analysis cross-section. The groundwater level depend-
ing on the location of the analysis cross-section was assumed at the ground surface
or 60 m above the tunnel roof, respectively, according to the design water pressure
(Fig. 21.43).