Stress Measurements - Rock Mechanics Based on an Anisotropic Jointed Rock Model - page 540

of stress redistributions due to excavation of the cavern so that rock wedges bounded by
the cavern wall as well as D3 and D3' formed, with a tendency to slide into the cavern.
As a consequence, with these assumptions the stability of the walls could not be proven
without support. The required amount of support, which is illustrated in Fig. 16.23,
was evaluated on the basis of further analyses in which the support measures were sim-
ulated as described in Section 10.5.4.
Figure 16.21 Orientations of discontinuities measured during excavation of the cavern's vault
(Soria & Wittke 1985)
Because of the small data base the in-situ stress state and the rock mechanical parame-
ters needed to be checked by means of back analyses of measured displacements during
the excavation of the cavern.