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Geotechnical News
June 2013
35
WASTE GEOTECHNICS
Navigating the way toward understanding oil sands tailings
Vivian Giang
WIKIPEDIA defines orienteering as
a sport requiring
navigational skills
using a
map and compass to maneuver
from point to point in diverse and usu-
ally unfamiliar terrain, and normally
moving at speed. Dr. J. Don Scott is an
avid orienteer, having won the Cana-
dian Orienteering Championship in his
age class 12 times, and the sport has
taken him to all corners of the world.
However, in the uncharted territory of
oil sands tailings behaviour, Scott has
proven to be a master orienteer.
In 1980, Scott joined the Faculty
of Engineering at the University of
Alberta as the Alberta Oil Sands
Technology and Research Authority
(AOSTRA) Research Chair in Oil
Sands. There, he made fundamental
contributions to understanding the
behaviour of oil sands tailings and
was one of the earliest researchers
who helped develop the concepts of
segregation behaviour and of com-
posite (or consolidated) tailings (CT).
One of the lasting legacies of his early
research work was the investigation
into the settling and consolidation
behaviour of oil sands mature fine tail-
ings (MFT) through the observation
of two 10-m tailings-filled standpipes.
Research engineer Hal Soderberg and
geotechnical technologist Gerry Cyre
assisted with the development of the
standpipe experiments, and a number
of graduate students have assisted with
the monitoring through the years. This
research has led to an unprecedented
30-year-long oil sands tailings experi-
ment which the University of Alberta
Geotechnical Centre continues to
explore today.
The two standpipes were constructed,
installed and filled with tailings in
1982 inside the I.F. Morrison Struc-
tures Laboratory at the University of
Alberta with funding from AOSTRA.
The objectives of these standpipes
were two-fold: 1) to observe and
evaluate the long-term settling and
consolidation response of the oil sands
tailings; and 2) to use a finite strain
consolidation theory to model the
compression behaviour of the tailings
in the 10-m standpipes. To study the
Standpipe Facts
Made of high density polyeth-
ylene
25-mm thick walls with an in-
side diameter of 914 mm
The bottom 0.5 m of each
standpipe is encircled by a
series of steel bands covered
in fiberglass reinforcement to
prevent bulging of the plastic
due to creep
The base is a 13-mm thick
high density polyethylene
plate
The pore water pressure port
and sample ports are aligned
down the side of the stand-
pipe
The standpipes were located
in a temperature-controlled
building (21
°
C)
The base is a 13-mm thick
high density polyethylene
plate
The pore water pressure port
and sample ports are aligned
down the side of the stand-
pipe
The standpipes were located
in a temperature-controlled
building (21
°
C)
Collecting mature fine tailings samples from the top of the standpipe.