Engineering Rock Mechanics

448 Questions 72.7-72.70: rock mass classification

values. Do your results correspond with a generally accepted relation,
RMR = 9 In Q + 44?

412.6 The diagram below (Singh and Goel, 1999) shows RMR-Q cor-
relations for case studies in India, Scandinavia, UK and USA.

IO

Rock Mass Quality (Q)

The suggested RMR- Q correlation lines shown on the diagram are

A RMR=9hQ+44

B RMR=5.9InQ+43

C RMR=5.4hQ+55.2

D RMR=5hQ+60.8

E RMR= 10.5InQ+41.8

For a rock engineering design project where a correlation between RMR
and Q is required to support the design, which of the correlations would
you choose?

412.7 Imagine that a rock mass classification system is required to
assess the instability of natural slopes in the Italian Alps. List 15-25
parameters that you think would be most useful for such a classification
scheme.

412.8 A rock mass classification system is required for assessing the
suitability of different rock formations for storing compressed domestic
gas in unlined rock caverns along the route of a main gas transmission
line. List the rock parameters that you would use in a rock mass-rock
engineering classification scheme for this objective.

412.9 The following parameter values have been determined for three
rock mass types found along the route of a major new highway tunnel
that passes at a high level through the flank of a mountain range: