Geotechnical News • June 2017
19
GEOHAZARDS
Introduction by Richard Guthrie, Editor
Spring 2017
Field season is fast approaching
as I write this. Many of us will be
out spending a summer looking at
Geohazards, designing mitigation and
trying to better prepare our commu-
nities, environment, and industries
against the potential impacts of a
geologically and geomorphologically
dynamic earth. Much has happened
in the world in the last few months.
Many of us have been watching the
drama of the Oroville Dam unfold in
the western US. At the same time, the
US political drama between policy
and science has being simultane-
ously unfolding. New developments
will require geotechnical knowledge
and the application of geotechnical
engineering. It behooves all of us,
regardless of politics, to continue to
learn, develop and apply our knowl-
edge and experience for the betterment
of society.’’
At least part of our jobs lay in under-
standing the tools and technologies
available to us. For this reason, we
present an article on Structure from
Motion, a relatively new photogram-
metric technique that is being used to
provide better kinematic, geologic,
and geomorphologic interpretations
based on both newly acquired imagery
(air photographs, digital hand-held
cameras, and UAVs) and historical
air photographs. I hope you find it
interesting.
Next issue, despite the unfolding
drama to the south, we will provide
information about, and access to, a
free Canadian tool that integrates
downscaled models from GCMs
(global climate change models) into
hydrologic studies used to guide com-
munities, dams, and culvert sizing
(among other things).
Letters
I received and excellent letter from
Dick Jackson of Ontario who added
some missing details to the article I
wrote last quarter. An edited version of
his letter is here (please note that any
errors are mine, not Dick’s):
Thanks Dick for the feedback and the
important historical update! For those
of you who haven’t seen Logan’s
initial sketches, I’ve included them
below the letter:
April 02, 2017
Dear Rick:
I read your Geohazards article in Geotech News with interest. I have long been interested in the history of the applied
earth sciences and worked with Frank Patton to get his early papers archived by the CGS. Your article was fascinating in
many aspects. A few points:
• Logan, in 1842, made the first known descriptions of failures in what is now recognized as Leda Clays and in a field
book he sketched a major landslide (Legget, 1979).
• You didn’t mention two events that most profoundly affected practice in Europe and here – the Vaiont landslide
disaster and the Aberfan coal-mine tailings disaster – both in the 1960s. It was because of Vaiont that BC Hydro had Frank
Patton develop the prototype Westbay system to monitor the Downie landslide above the Revelstoke dam.
• In mentioning Terzaghi, you might have mentioned how he believed that ALL graduate civil engineers should have
been taught ‘geology for engineers’. He advocated a two-semester course combined with field trips taught by “a geologist
who appreciates the requirements of engineers and an engineer who has learned from personal experience that geology is
indispensable in the practice of his profession’’.
• It is worth noting that so many of the great geotechnical engineers are most interested in geology. Here at the Univer-
sity of Waterloo, my close colleague Maurice Dusseault was allowed to substitute structural geology for structural engi-
neering while studying at the University of Alberta for his BSc in civil engineering. Morganstern is another with strong
geological interests. Terzaghi, of course, was the model. He even married a geologist, which I believe is probably the best
advice.
• I appreciate your celebration of John Clague, Steve Evans and Oldrich Hungr. But also remember it was Fredlund
and his followers who put unsaturated zone soil mechanics on the map and Soil Vision in Saskatoon and Geo-Slope in
Calgary that have produced such useful software. It was Hodges and Freeze who did the first simulations back in the
1980s of slope failure.
Regards, Dick Jackson
Geofirma Engineering Ltd.,
Heidelberg, Ontario
