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Re[2]: Re[2]: Compaction tests

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T. (Soils Engineering),

Remember, the material described is used as "fill behind a small retaining
wall." Your test method (which by the way is ASTM D 5030-89), although great for
flatlands in Azusa (and other cobble and boulder alluvial fans), would be
cumbersome (but not impossible) for this wall backfill application.  Also, you
have described how to obtain in-place density, but not relative compaction. 
What maximum density standard will you compare your in-place density to?  How
practical is all this for "fill behind a small retaining wall" (I'm assuming a
wall less than 5-feet in height not supporting a structure surcharge)?  I don't
know why I'm defending this unnamed geotechnical engineer working for Alden, but
I think it would be a bit overkill to perform the labor intensive D 5030 test in
a "small retaining wall" drain rock backfill.

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: Re[2]: Compaction tests
Author: seaint(--nospam--at)seaint.org
Date:       9/15/01 6:15 AM


TBenson(--nospam--at)lowney.com said:

There exists an ASTM test that performs in-situ density on a much larger 
scale than is the case for the standard sand-cone density ASTM D1556 or the 
Nuclear Gauge (ASTM d2922).  A large diameter test, up to six feet in 
diameter is used with plastic liner and water to measure the volume of the 
test hole.  A base volume is determined at the start of the test, after the 
test site is leveled and the template is secured into place.  The template is 
usually a round or square metal frame.  Once the area is leveled, a plastic 
liner is placed and water is poured into the frame to determine the initial 
area.  The hole is then excavated with all material coming out of the hole 
weighed and moisture content of material is determined by oven-drying.  The 
weights are made with large capacity field scales (also the material can be 
transported back to the laboratory and weighed).  The plastic is then 
replaced in the excavated hole and water is once again used to determine the 
volume of the hole.  This volume, less the initial volume of the leveled area 
represents the volume of the material excavated.  The weight of the material 
excavated divided by the volume is the density.  The wet-density divided by 1 
+ the moisture content expressed as decimal is the dry density.  The excated 
hole is the approximate shape of a parabola of revolution.  The size of the 
template can be smaller depending on the maximum size aggregate used.

T Bayne
Soils Engineering, Inc.

> 
> 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
> ---------------------------------------------------------------------------
> Geotechnical & Environmental Engineering Services
> ---------------------------------------------------------------------------
> 
> 
> ____________________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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-- 

Soils Engineering, Inc.

L. Thomas Bayne
CE 26106 GE 125 expires 3/31/02



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