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Geotechnical News • March 2017
In 1982 members of the Canadian
Geotechnical Society conceived the
idea of a book recording the develop-
ment of geotechnical engineering
in Canada. Since a number of the
early practitioners were still living at
the time, foremost among them Bob
Hardy and Bob Legget, the approach
was intended to create “a living his-
tory ... through the eyes and recollec-
tions of living engineers, to show the
humanity that underlies the develop-
ment of major geotechnical projects
in Canada.”
As this book is now out-of-print, we
will be publishing excerpts from it
over the next few editions of
Geotechnical News. Ultimately, a pdf
copy will be available
.
Geotechnical Engineering in Canada
An Historical Overview
Cyril E. Leonoff
Terrain of Canada
The civil engineers charged with
the physical building of Canada
have faced an awesome challenge.
Geographically it is the third-largest
country in the world, comprising the
northern 40 percent of North America,
bounded by three oceans and covering
a land area of 3,851,809 square miles.
Spanning the continent a distance of
3,842 road miles, between the Pacific
at Vancouver, British Columbia and
the Atlantic at Halifax, Nova Scotia,
Canada has a scant population of some
30 million — barely eight persons
per square mile — with 90 percent of
these people strung along the south-
ern border. Yet much of the mineral,
oil, and water resource base to be
exploited lies in the remote north and
offshore.
The Pleistocene geology of Canada
is prevalent. Canada has the largest
glacial soil mantle of any country
(indeed an almost complete absence
of unglaciated areas and their residual
soils) and correspondingly the largest
area of enclosed fresh water. The geo-
morphology ranges from the lowlands
of Hudson Bay, the Eastern Arctic,
and the St. Lawrence Valley, through
the Precam brian Shield where the soil
mantle is thin and bedrock exposed,
across the interior plain of the Prairie
Provinces, to the Cordilleran mountain
ranges of the far West.
The diverse, unconsolidated sediments
comprising the earth’s crust, broadly
described as soil, constitute so large
a portion of the earth’s surface that
few civil engineering projects can
be carried out without dealing with
some type of soil. As well, some of the
largest man-made structures ever built
- earth dams, dykes, canals, tunnels,
railroads, and highways are composed
largely of earthwork.
The problems to be solved in Canada
by the geotechnical engineer are
seemingly endless. About half of the
land is underlain by permanently
frozen ground, or permafrost. Some
500,000 square miles are covered
by sphagnum moss and decayed and
fossilized vegetation, popularly called
muskeg. Sensitive marine clay of the
Champlain Sea — Leda Clay — lies
in the St. Lawrence and Ottawa val-
leys; the lacustrine clay of infilled
glacial lakes fills areas such as that
around Lake Agassiz in Manitoba.
Treacherous clay-shale — Bear-
paw Shale — underlies much of the
Prairies. Massive rock slides, such as
the Frank and Hope slides, occur in
the Cordillera, while great landslides
also happen in the dry silt benches of
the Thompson River railway belt, and
“drowned valley clay” covers the floor
of the Pacific Coast tidal estuaries and
fjords. Moreover more than half of
the Canadian population is subject to
potential seismic hazard.
Early Civil Engineering Works
The challenges faced by the early 19th
century Canadian civil and military
engineers involved the construction
of canals and locks, used to connect
water transportation routes and to
provide military defence —Welland
Canal (1824-1829) and Rideau Canal
(1826- 1832). The construction of
railways and their appurtenant works,
such as bridges and tunnels, began
in the 1830s-40s, serving to connect
the scattered segments of the fledging
nation — the Grand Trunk between
Sarnia and Montreal (1845-1862), the
Intercolonial to the Maritime Prov-
inces (1858-1876), and the Canadian
Pacific (1881-1886) to the West.
By mid-century, engineered roads
were being constructed for commu-
nication and transportation between
settlements and for resource exploi-
tation — the Cariboo Wagon Road
(1862-1866) from Yale, B.C. through
the Fraser Canyon to the gold-rush
town of Barkerville, and the Daw-
COMMEMORATIVE EDITION
