Geology Reference
In-Depth Information
Approach for
defining parameters
and analysis
Option
Schematic diagram
parameters from
laboratory or
in
situ
t
ests taken
to be
representative of
zone
1. Treat as
uniform
(continuum)
allowance made
for influence
(but not control)
of
discontinuities
on mass
properties (e.g.
Hoek-Brown)
2. Treat as
uniform but
weakened by
discontinuities
(continuum)
consideration
given to
influence of
strong
inclusions with
deviated failure
paths
3. Treat as
heterogeneous
(continuum)
4. Treat as
discontinuous
due to structural
control
discontinuity
controlled
consideration in terms of their properties. Weathered rocks can similarly
comprise mixes of weak and hard materials but there is also the added
complication of relict rock fabric and structure. The overall nature of the
mass will strongly affect the options for engineering assessment, as
illustrated for slopes in
Figure 5.12.
Geotechnical parameter determina-
tion for such mixed deposits is considered in Section 5.8.
Methods of testing soil and rock are speci
ed in standards such as BS
1377 for soil in the UK (BSI, 1990), BS 5930 for several
field tests (BSI,
1999) and ASTM, more generally in the USA. The International
