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Geotechnical News • June 2012
WASTE GEOTECHNICS
water contamination. These investi-
gations have also helped determine
why some covers may have under-
performed in the past due to sloping
and other geometry effects, natural
conditions, or unsuitable material
properties. Modifications have also
been proposed to traditional design
approaches for improving cover
performance using alternate layering
scenarios and configurations (includ-
ing suction breaks), non-conventional
materials (such as desulphurised
tailings), and techniques to increase
diversion length. There is neverthe-
less a need to pursue this line of work
to evaluate the long-term response of
covers when faced with the natural
degradation of geomaterials and geo-
synthetics exposed to surface condi-
tions, including the effect of climatic
extremes and of root penetration and
other bio-intrusions.
Major geotechnical challenges also
emerge from the Canadian oil sands
industry, which manages the largest
mining projects on the earth. This
industry has disturbed hundreds of
square kilometers of land, and the cor-
responding impact is concentrated into
one specific area, contrary to metal
and iron mines which are distributed
around the country (and elsewhere).
Reclamation and closure practices for
the oil sands industry appear to have
lagged behind production rates. With
the massive expansions proposed over
the next couple of decades, enor-
mous pressure has come to bear on
the industry to accelerate its tailings
management practices. One example
is the aim to reduce the accumulation
of fluid tailings by capturing the fines
in dedicated disposal areas and to cre-
ate trafficable surfaces for progressive
reclamation.
In response for the need to improve
tailings management practices, the
Canadian oil sands industry has
formed a major consortium to share
tailings research and technology in
order to accelerate advanced tailings
management. New technologies being
evaluated by this consortium include:
consolidated/composite and non-seg-
regated tailings, mature fine tailings
(MFT) treatment and atmospheric
drying, MFT centrifugation and dry-
ing, thickened tailings with thin lift
deposition, water capped MFT, and
CO2 enhanced fines capture.
The list of mining geotechnique
considerations are numerous in terms
of issues/challenges linked with rock
mechanics and ground control to mini-
mize dilution and provide safety in the
workplace; soil mechanics and foun-
dation engineering for the design of
dikes and other surface infrastructures;
analysis of groundwater problems
in terms of seepage, drainage, and
water quality; mining in cold regions
with the effect of frost and evolv-
ing permafrost conditions; the use of
geosynthetics in liners and covers; and
the role of engineering geology related
to material characterization and site
selection.
With the foregoing clearly demonstrat-
ing the potential for the development
of new frontiers, the mining industry
is currently seeking the very best and
brightest of researchers, students,
and practicing engineers to become
engaged in the development of
advanced mining geotechnique.
The new CGS Technical Committee
on Mining Geotechnique will take part
in this effort to promote and coordi-
nate these actions. You are welcome to
join by contacting one of its Execu-
tives (at
).
The Authors are Executives of the
Mining Geotechnique Technical Com-
mittee.
Michel Aubertin
École Polytechnique de Montréal,
Murray Grabinsky
University of Toronto, murray.gra-
Dharma Wijewickreme
University of British Columbia,
Ward Wilson
University of Alberta, wwilson2@
ualberta.ca
