34
Geotechnical News • March 2018
J.W. (John) Gadsby, Thurber
Consultants
V. (Victor) Milligan, Golder
Associates
L. (Laval) Samson, Terretach
F. (François) Tavenas, Université
Laval, and
W.A. (Bill) Trow, Trow Group.
The Standing Committee on Structural
Design asked the Subcommittee on
Foundations to write the first draft of
the Canadian Manual on Foundation
Engineering. It was published as a
318-page document in 1975 as a “draft
for public comment” by the NRC
Associate Committee on the National
Building Code (NRC, 1975, Figure 1).
The preface of the 1975 Draft Edition
included the following paragraphs:
“It provides a “state of the art”
report on foundation engineering
containing recommended
procedures for the design,
installation and construction
of foundations. It is intended
to assist the enforcing official
and the designer in satisfying
the intent of Section 4.2
(Foundations) of the National
Building Code of Canada 1975
[NBCC, 1975]. …
Although the Manual was
originally intended as a
supplementary document …,
no decision has yet been made
on its final format and source
of publication. The Associate
Committee [of the National
Building Code] has, therefore,
agreed to release this material in
its preliminary form in advance of
this decision to obtain wide public
review.”
The draft consisted of 8 chapters.
Chapter 1 provided an introduction,
and noted that the draft did not present
the subject matter in “strict specifi-
cation form” as used in the NBCC
because of the difference between
“in-place geological materials and
conditions compared with that of
manufactured or preselected materials
brought to the construction site…”.
The introduction went on to say that,
largely because of the variety of mate-
rials and conditions, “foundation engi-
neering” is less precise than structural
design and “remains, to an important
extent, an art based upon experience
and judgement”.
Chapter 1 also included a note on the
limitations of use of the manual, and
the need for experience and judge-
ment:
“The methods presented
… are applicable to most
design problems. It should be
understood, however, that strict
use of these methods will not
always yield the best technical
or most economical solutions.
Moreover, the design of unusual
structures or the occurrence of
unusual subsurface conditions
may require the use of novel
design approaches or methods of
analysis beyond the scope of this
Manual.
…in the engineering application
of the methods shown, neither this
Manual nor the textbooks and
papers to which it refers should
be considered a substitute for
the experience and judgement
of a person familiar with the
complexities of foundation
practice.”
Chapters 2 and 3 included definitions,
symbols and units of terms, and clas-
sification systems for soil and rock,
respectively.
Chapter 4 summarized subsurface
investigations and laboratory testing
of soils, rock and groundwater, and
included a synopsis of, and an appen-
dix on, “Problem Soils, Rocks and
Conditions”.
Chapters 5, 6 and 7 covered the topics
of excavation and retaining struc-
tures, shallow foundations and deep
foundations, respectively: basic and
alternative design methods; the “limits
of validity” of each; references; and
comments on specific construction
problems.
Chapter 8 presented a number of
commentaries on specific topics: the
standard penetration test; relative
density of cohesionless soils; founda-
tions on swelling and shrinking clays;
frost action; pile driving formulas;
earthquake-resistant design; and the
pressuremeter test.
This document, although published
in draft, was quickly embraced by the
geotechnical community in Canada
and elsewhere. Comparisons were
made to US “NAVFAC” (Naval
Facility Engineering Command) DM
[
Design Manual
] 7
Soil Mechanics,
Foundations and Earth Structures
(NAVFAC, 1971).
The 1975 Draft Edition sold for $3.00
(approximately $15.00 in 2017 dol-
lars). It is not known how many copies
were printed. A French version of
this document was not translated or
published.
Because the 1975
Draft Edition
asked
for “public comment”, many Canadian
geotechnical engineers provided writ-
ten comments to the Associate Com-
mittee on the National Building Code.
Hugh Golder provided his com-
ments in the form of a, self-described
“subjective”, 5-page detailed book
review in the
Canadian Geotechni-
cal Journal
(Golder, 1976). Golder,
in his inimitable style, had insight-
ful philosophical comments on the
purpose, the title of the document
and the order and arrangement of
the chapters, and offered his sug-
gestions on all these general topics.
He then reviewed each chapter and
offered suggestions where appropri-
ate. After providing some relatively
harsh comments on some aspects of
the document, and some accolades
on others, Golder concluded with
“By and large, the Manual is good. It
displays painstaking and conscientious
work by experienced engineers”. He
indicated that his review was intended
to “arouse interest in the draft of the
Manual” to encourage geotechnical
engineers to read it. “The greater the
number of experienced engineers who
COMPUTING IN GEOTECHNICAL ENGINEERING
From the GS Board
