Hi Jeff,

RE: QUISIBIS RIVER BRIDGES NO. 1.5

You might want to contact the Geotechnical Research Centre of the University
of Western Ontario

http://www.engga.uwo.ca/Research-Centre/Centre/GRC/default.htm
<http://www.engga.uwo.ca/Research-Centre/Centre/GRC/default.htm> 

A couple of contacts are: 

Dr. K. Y. Lo (Director of the Centre), 

mailto:[log in to unmask]

and Dr. J. Q. Shang (Associate Professor).

mailto:[log in to unmask] <mailto:[log in to unmask]> 

Through a consultant, they conducted static controlled stress triaxial tests
on undisturbed silt samples from a bridge site in northern NB.  This was
carried out in 1995.

We also have results from static piezocone tests (CPT with porewater
pressure measurement) carried out at the site before, during and after
vibro-replacement work (1997), as well as SPT and field vane work done
during the design phase.  

I would be glad to send you information we have on the site and the tests,
which contained about 60 feet of very loose, uniform silt, if you are
interested.  Give me a few days to get Departmental approval to release the
information, etc.  We have never really done much (budget, time, etc.),
other than design and construct the bridge approaches, with the info we
collected, and personally I would be glad to see somebody use it.

We probably also still have lots of samples, both SPT and undisturbed (well
Shelby tubes anyway, probably dried to powder by now) that our lab would
probably like to get rid of, if you want those too. 

The material was ML, with about 5% sand, and < 5 % clay (0.002 mm).  It was,
of course, non-plastic, with an in-situ void ratio of 0.9 to 1.0.
Uniformity coefficient was around 3.

 Michael R. Bleakney
Geotechnical Engineer
New Brunswick Department of Transportation
Structures & Materials Branch
PO Box 6000
FREDERICTON, NB
E3B 5H1
CANADA

Tel:	(506) 453-2674
Fax:	(506) 457-6714
E-mail: [log in to unmask]


	-----Original Message-----
	From:	Jeff Farrar [SMTP:[log in to unmask]]
	Sent:	Monday, January 04, 1999 3:37 PM
	To:	[log in to unmask]
	Subject:	Info Request - Seismic Strength of Silts (ML)

	I am interested in performing some research on the cyclic strength
of Silt
	(ML).  This study would prepare silt specimens of differing
consistencies
	and the consolidation/shear behavior of the material would be
defined using
	*Critical State* or *State Parameter* type relationships.  Cyclic
and
	monotonic shear testing would be performed on specimens at differing
	consistencies.  Possible model cone penetrometer or vane shear
testing would
	be performed on the same specimens to relate the seismic behavior to
readily
	measured field tests.

	I am asking for information from the Geotech discussion group on any
similar
	studies.  I am aware of some cyclic strength testing of Silt soils,
but
	generally, these tests are at one void ratio or on undisturbed
soils, and
	they do not relate behavior to field testing.  If you have performed
cyclic
	strength testing of Silts, please contact me so I can formulate a
worthwhile
	research program statement.

	A work statement for competitive R&D contract will be developed
based on
	your input.  This contract will likely go to a university with prior
	experience in this type of testing.

	Thanks for your input!

	Jeff Farrar
	Earth Sciences and Research Laboratory
	Bureau of Reclamation
	Denver Federal Center Bldg 67
	PO Box 25007 D-8340
	Denver CO 80225
	303-445-2333
	fax 445-6341
	[log in to unmask]  
	


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