20
Geotechnical News • September 2012
GEOTECHNICAL INSTRUMENTATION NEWS
Introduction by John Dunnicliff, Editor
This is the seventy-first episode of GIN. Three minus three articles this
time. To explain—one week before going to press there were three,
but the week has brought challenges (and frustrations!). I won’t bore
you with the details. I’m consoled by the fact that, after many weeks
of rain, the sun is finally shining here in the Mother Country.
Manual of geotechnical
engineering
My review of the excellent “ICE
Manual of Geotechnical Engineering”
was in June GIN. In my introduction
to GIN I included some quotations
from the chapter on geotechnical risks,
including one attributed to Donald
Rumsfeld. I’ve since received an
e-mail from Don Shields, indicating
that the correct source is our much-
respected geotechnical colleague Elio
D’Appolonia (D’App). Here is part of
Don’s e-mail:
In your introduction to your
review of
ICE Manual of
Geotechnical Engineering
you
repeat a quotation from the
Manual attributed to Donald
Rumsfeld. To whit:
“... as we know, there are things
that we know we know. We
also know that there are known
unknowns; that is to say we
know there are things we do not
know. But there are also unknown
unknowns - the ones we don’t
know we don’t know.”
I first heard this statement more
than 30 years ago (probably
in 1979) from a much nicer
person than Rumsfeld. The nicer
person is Elio D’Appolonia,
who appeared at a hearing on
the future of uranium mining in
British Columbia.
During his testimony, Dr.
D’Appolonia made exactly
the same statement to the
commissioners that is now
attributed to Rumsfeld. I
remember Elio’s statement
perfectly because it was one of
those moments when one says
to oneself: Why didn’t I think of
that!
Now I ask myself: How do I go
about getting D’Appolonia credit
for this statement?
Answer to Don—right here!
The next continuing education
course in Florida
This is scheduled for April 7-9, 2013
at Cocoa Beach. Details are now on
.
Also see the announcement on facing
page.
Closure
Please send contributions to this
column, or an abstract of an article for
GIN, to me as an e-mail attachment in
MSWord, to
, or by
mail: Little Leat, Whisselwell, Bovey
Tracey, Devon TQ13 9LA, England.
Tel. +44-1626-832919.
Yasas! (Greece)
Errata
There is a significant error in the article “Update of the fully-grouted
method for piezometer installation” by Contreras et al, published in
the June 2012 episode of GIN (page 20). The cement-bentonite grout
mix given near the beginning of the section subtitled “Laboratory”
should be 2.5:1:0.3, NOT 1:2.5:0.3.
