Page 60 - Engineering Rock Mass Classification_ Tunnelling, Foundations and Landslides

essure for Rock Tunnels and Caverns

assification of Singh et al. (1995)

Recommended support
pressure (MPa)

ndition pv Ph Remarks
(6) (7) (8)
d intact 0 0 —
tified or 0.04–0.07 0 —

moderately 0.0–0.04 0 —

ely blocky, 0.04–0.1 0–0.2 pv Inverts may
ery jointed be required

cky and seamy, 0.1–0.2 0–0.5 pv Inverts may
highly jointed, be required,
arched roof
r zone or preferred
Inverts essential,
ely crushed 0.2–0.3 0.3–1.0 pv arched roof
mically essential
d,

ar and
e