Engineering Rock Mechanics

Extensions to rock mass classification techniques 205

Site parameters

E Rock mass

0 Discontinuity

El Intact rock

Figure 12.5 Relative importance of rock engineering parameters in the design of

large rock caverns (as established from the literature and compiled by Tamai, 1990).

with pressure tunnel design are shown, and to Figs 12.5 and 12.6 which
show the parameters in order of importance for large underground caverns
and radioactive waste disposal, respectively.
Such histograms can be compiled on the basis of past experience, current
practice and recommended practice (the latter, perhaps, arising from
modelling of design requirements). The histograms in Figs 11.2, 12.5 and

Figure 12.6 Relative importance of rock engineering parameters in the design of

radioactive waste repositories (as established from the literature and complied by

Arnold, 1993).