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Re: Re[2]: Compaction tests

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Twenty years ago, working for Rockwell International, I was the principle
design engineer for portions of the (now deactivated) Solar One power
plant near Barstow, CA.  The thermal storage vessel contained about 5,000
CY of compacted clean gravel and course sand.  At that time, nuclear
densometers could not reliably be used to measure compaction.  The only
known device was the "NGI Device" developed by the Norwegean Geotechnical
Institute.  It measured compaction in clean course materials by measuring
the dilitation (swelling) of the surface as a calibrated probe was
driven.  Once calibrated to the materials in question, it was a very
quick and reliable method for controlling compaction.   I understand that
at least a few soils labs have and use these devices......FWIW

Russ Nester, SE, GE
rnester(--nospam--at)juno.com


__________________________________________________________________
On Fri, 14 Sep 2001 13:04:34 -0700 TBenson(--nospam--at)lowney.com writes:
> I assume you are talking about a very clean 3/4-inch crushed rock, 
> with less
> than 5 percent fines.  Many believe 3/4-inch crushed rock is self 
> compacting. 
> Obviously, it is impossible to perform a sand cone test in uniform 
> 3/4-inch
> crushed rock (sand cone sand will flow into rock void space), and 
> although you
> can perform a nuclear gauge tests if you drive your source shaft 
> into this
> material hard enough, the results will be perplexing.  The 
> difficulty is the
> compaction curve (e.g. modified Proctor, ASTM D 1557-00).  You will 
> not get a
> curve (more of a horizontal line).  Water content will have little 
> impact since
> the void space is so great, and all the hammer pounding will have 
> little impact
> on the density.  If you really want to get into it, what would be 
> your rock
> correction?  ASTM would have you replace the whole sample.  So no, 
> you cannot
> test crushed rock as you would a "soil."  I think seeing the 
> material in the
> field could be instructive for you.
> 
> Tom Benson at Lowney Associates
> 251 East Imperial Highway, Suite 470
> Fullerton, CA 92835-1063
> (714) 441-3090
> FAX: (714) 441-3091
> see: www.lowney.com
>
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> Geotechnical & Environmental Engineering Services
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> 
> ____________________Reply Separator____________________
> Subject:    Re: Compaction tests
> Author: seaint(--nospam--at)seaint.org
> Date:       9/14/2001 10:04 AM
> 
> I don't have my soils text here with me.  I think with a nuclear 
> density
> meter, something about the size of the rocks makes the test 
> inaccurate.
> I'll look for something this weekend.
> 
> Conrad
> 
> ----- Original Message -----
> From: "Alden Manipula, E.I.T." <amanipula(--nospam--at)novagroupinc.net>
> To: <seaint(--nospam--at)seaint.org>
> Sent: Friday, September 14, 2001 12:13 PM
> Subject: RE: Compaction tests
> 
> 
> > It's fill behind a small retaining wall.  Can you explain to me 
> why it
> isn't possible.  Thanks.
> >
> > -----Original Message-----
> > From: Conrad Guymon [mailto:conrad(--nospam--at)karren.com]
> > Sent: Friday, September 14, 2001 10:59 AM
> > To: seaint(--nospam--at)seaint.org
> > Subject: Re: Compaction tests
> >
> >
> > Are you talking about structural fill or a free-draining gravel 
> fill?
> They are not the same.  If you are talking about a gravel fill, the 
> soils
> > engineer is correct.
> >
> >
> > ----- Original Message -----
> > From: "Alden Manipula, E.I.T." <amanipula(--nospam--at)novagroupinc.net>
> > To: "SEAINT Listserve" <seaint(--nospam--at)seaint.org>
> > Sent: Friday, September 14, 2001 11:11 AM
> > Subject: Compaction tests
> >
> >
> > > I just had a soils engineer claim that he couldn't test 3/4" 
> clean
> > granular fill with his nuke gauge.  Is this a correct statement?
> > >
> > > Alden Manipula
> > >
> > >
> 
> 
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