Geotechnical News • June 2012
19
GEOTECHNICAL INSTRUMENTATION NEWS
Introduction by John Dunnicliff, Editor
This is the seventieth episode of GIN. One full-length article this time,
three more brief articles about remote methods for monitoring defor-
mation, and a book review.
Fully–grouted piezometers
This has been an on-going topic in
GIN, started by the two-part article in
June 2008 by Contreras et al. Here’s
an update by the same authors. The
article is longer than I usually allow
for GIN, but because some practi-
tioners still doubt the value of the
method, I wanted to give adequate
space in an attempt to dispel any
doubts.
Remote methods for monitoring
deformation
In the previous episode of GIN there
were one-page articles about four dif-
ferent remote methods for monitoring
deformation: terrestrial laser scanning;
terrestrial interferometric synthetic
aperture radar; robotic total stations;
and reflectorless robotic total stations.
Here are three more:
• Satellite interferometric synthetic
aperture radar: SInSAR, including
DInSAR and PSInSAR, by Franc-
esca Bozzano.
• Digital photogrammetry, by Raul
Fuentes and Stuart Robson.
• Differential global positioning
system: D-GPS, by Rob Nyren and
Jason Bond.
As I said in the previous episode, there
are two important action items for
you:
• I recognize that, if you’ve had
experience with any of these
methods, you may not agree with
all that the authors say. If that’s
the case, or if you’d like to add
something that would be useful to
readers of GIN, please send me a
discussion.
• We’ve included the commercial
sources in North America that we
know about, but are likely to have
missed some. If you know of oth-
ers, please tell me, and I’ll include
those in a future GIN.
Nobody has yet responded to this
challenge. PLEASE—GIN shouldn’t
be just me, and authors who have had
their arms twisted—we’re all in this
together!
Manual of geotechnical
engineering
Here’s a review of a new 101-chap-
ter book, available in hard copy and
on-line. As I’ve written in the review,
in my view the full manual is a ‘must
have’ for the libraries of all firms
which practice geotechnical engi-
neering. The more I read, the more
impressed I am! Specialists should
have their own copies of relevant
individual chapters. Although writ-
ten for the UK scene, this in no way
diminishes its value elsewhere.
There are two chapters about monitor-
ing and instrumentation. One about
why we use the technology, how we
plan for using it, and what we do in
the field. The other about the gadgets,
and what they’re used for.
In a lighter vein, the chapter on geo-
technical risks includes some wonder-
ful quotations. For example (reprinted
with permission from the author, Tim
Chapman):
• “If a builder builds a house for
someone, and does not construct it
properly, and the house which he
built falls in and kills the owner,
then that builder shall be put to
death.”
Hammurabi’s Code of
Laws. 1700 BC. Mesopotamia
.
• “…as we know, there are
known
knowns
; these are things that we
know we know. We also know that
there are
known unknowns
; that
is to say we know there are some
things we do not know. But there
are also
unknown unknowns
–
the ones we don’t know we don’t
know.”
Donald Rumsfeld.
• “Quality is never an accident; it
is always the result of intelligent
effort.”
John Ruskin (1819-1900),
who wrote on subjects ranging
from geology to architecture,
myth to ornithology, literature to
education, and botany to political
economy.
• “It is unwise to pay too much, but
worse to pay too little. When you
pay too much, you lose a little
money, that’s all. When you pay
too little, you sometimes lose
everything, because the thing you
bought was incapable of doing the
things it was bought to do. The
common law of business balance
prohibits paying a little and getting
a lot. It can’t be done. If you deal
with the lowest bidder, it is as well
to add something to the risk you
run. And if you do that you will
have enough to pay for something
better. There is hardly anything
in the world that someone can’t
make a little worse and sell a little
cheaper—and people who consider
price alone are this man’s lawful
prey.”
John Ruskin (1819-1900).
Those of you who know my
views about low-bidding instru-
mentation tasks will recognize
these sentiments. He’s singing
my song! And he wasn’t an
engineer!
The next continuing education
course in Florida
This is scheduled for April 7-9, 2013
at Cocoa Beach. Details of this year’s
course are on
.
ufl.edu/geotech. The 2013 course will
