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Geotechnical News • December 2012
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CANADIAN GEOTECHNICAL SOCIETY NEWS
line than Peck as to the inter-rela-
tionship and importance of analysis
in arriving at judgment. So if you are
currently a sorcerer’s apprentice in a
consulting organization, read the refer-
ences appended, take what you find to
heart and practice what is preached.
As explained by Marr, this educational
research has found critical thinking to
be an essential skill and one that can
be developed in the education process.
This is a very important point; ele-
ments of judgment can be taught. But
I think to nurture judgment in others
you have to be able to exercise it.
Therefore it will largely remain, with
notable exceptions, up to consultant
groups to continue to run our “finish-
ing schools”. And by consultants I
mean both the independent firms as
well as the “in-house” geotechnical
teams found in a few large organiza-
tions.
Reflecting on what I have been doing
for the past four decades or more –
and how I got here today – I must
conclude that as a consultant, geo-
technical engineering is as much an
avocation as it is a vocation. For me
the vocation part was and remains the
business side and what we consultants
call fully chargeable. To a consultant,
profit is not a four letter word, but loss
is. Contributing to keeping a large
and growing consultancy profitable
year after year is no easy matter. The
avocation part describes all the effort
required to stay technically current in
an exponentially growing literature,
apart from pleasure to be gained in
finding a mystery resolved. What has
changed for me is in the beginning
I needed to haunt the library, now it
is mostly the internet. Of course the
vocation part has always adamantly
resisted doing anything that was obvi-
ously going to be boring so one must
keep current. But there was a synergy
to this as one enables the other. But
the bottom line for those interested in
advice is that it was never a 40 hours a
week effort.
Finally, I must reflect on what we call
the observational method as this was
a lodestone to my career. Proposed
by Terzaghi and formalized by Peck
(1969) it fully clarified for me how
to proceed in the face of the many
uncertainties and risk that charac-
terizes projects in our geotechnical
world. It provides a vital vehicle by
which predictions embracing the range
of possibilities can be organized, and
judgment exercised. I would say that
arguably another definition of judg-
ment is managing uncertainty and the
observational method gives us the
framework for doing just that. And to
be clear, the root cause origin of this
uncertainty is the variability of the
geology at each and every project site
we work on, as was so well described
in Legget’s 1979 lecture.
The observational method is far from
just collating observations, and it
is not “learn as you go” either, as
some think. If you have not read
and comprehended this basis for the
observational method I can only say
that your geotechnical education has
been deficient. It is all about getting
to an optimum solution, not the most
conservative one, unless the client has
a schedule or other constraints that
demand a high degree of conserva-
tism. Basically, expect the likely as
you have established it to be, but plan
for the worst by knowing beforehand
what contingency measures could
be taken. Observe critical elements
of performance, being prepared to
execute fall-backs in a timely manner
– having predetermined that there will
be the resources and schedule to do
so. If these conditions cannot be met,
then one must revert to a design based
on the least-favorable conditions. Now
there are a few “potential” clients out
there that really only want you on their
project to use your liability insurance
to underwrite their risks. Avoid them
like the plague, but if you cannot,
the observational method properly
deployed is a greater shield than all the
boiler plate and exculpatory clauses
the lawyers can dream up in both your
contracts and reports; and such clients
will not like it. But the well-informed
client will understand and appreciate
what you are doing.
To conclude: to the next generation of
aspiring practicing geotechnical engi-
neers and consultants here today at the
65th Canadian Geotechnical Confer-
ence – study and apply the elements of
critical thinking, and good fortune in
your careers should follow.
References:
Legget R.F. 1979 Geology and
geotechnical engineering. ASCE
JGED 105(GT3)
Marr W.A. 2006 “Geotechnical
Engineering and Judgment in the
Information Age” Keynote address
GeoCongress 2006, Atlanta
Peck R .B. 1969 Advantages and
limitations of the observational
method in applied soil mechanics.
Geotechnique , 19(2).
Peck R.B. 1980 Where has all the
judgment gone? CGJ 17, pp584-
590
Vick S.G. 2002 Degrees of belief sub-
jective probability and engineer-
ing judgment. Reston VA. ASCE
Press, 978-0-7844-0598-7
Upcoming conferences
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66th Canadian Geotechnical
Conference - GeoMontreal
2013 - Call for Abstracts
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Montreal, Quebec, Canada, from
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October 3rd, 2013.