Estimating Field void ratio to meet the targeted Degree of Compaction

[soildynamics]

I have the grain size distribution for a purely sandy soil
are there any relations or guidances in literature allowing one to predict the maximum void ratio (Emax) and minimum void ratio (Emin) of that sand give the grain size distribution ?
This is because I want to estimate my field ratio Efield corresponding to
Relative density:[(Emax-Efield)/(Emax-Efield)]= 90%

Thanks

 

[fattdad]

I have no idea how to do this. For the benefit of the discussion; however, I want to be clear on what you propose.

Take a field density measurement (ala nuke gauge or sand cone).
Knowing specific gravity, calculate the void ratio.
Compare the field void ratio to the emax and emin.

This, of course, would be needed for the case that you just can't get a meaningful moisture-density relationship (a.k.a., Proctor) for the sample.

I'd think that there may be some estimate from D-sizes to get an emax and emin, I just don't know what it is.

Is your end-game compaction control or characterizing a natural in-situ condition?

Looking forward to what others have to say. . . .

f-d

¡papá gordo ain’t no madre flaca!

 

[soildynamics]

fattdad

I cannot do lab tests. I am a PhD researcher performing analytical and numerical works.
I want to estimate e(min) and e(max) from specific gravity and grain size distribution of the sands.
Please see:

http://cat.inist.fr/?aModele=afficheN&cpsidt=14481030

However it is not easy to get this paper and I thought that others may refer me to similar sources
Thanks

 

[dgillette]

As a general rule, uniformly graded soils have lower min and max, and min and max closer together, in comparison with more broadly graded soils. Beyond that, I think you are wishing for the moon if you want a credible number without testing.

Surely there is some undergrad at your school who would sneak into the school lab and run the min and max tests for $50 and a case of beer. Even if you got just the max, you could knock off 2 lb/ft^3 and be pretty close to 90% (and keep the beer for yourself). Regardless, you need some actual factual data.

An RD of 90% is some pretty dense stuff; typically we spec 70% for dam embankments.

 

[dirtsqueezer]

soildynamics,

Your reference looks pretty comprehensive.

There is no literature that I am aware of using a general empirical data that will give you an Emax. Your Efield would of course have to be measured using field equipment which any standard nuclear density gauge would do. I think the problem with using literature to determine the characteristics of a field condition is that Emax will still differ according to grain shape, mineralogy of clay and sand particles, overburden, ect., which is likely to vary from location to location, and which will likely not be reflected in the literature.

Let me know if your search turns up any results though. It's an interesting way of doing things.

Best of luck.

dirtsqueezer

 

[VAD]

You may get some information from Foundation Engineering Handbook by Fang-2nd Edition. This book provides a Table giving e min and e max for different soil classes and different max size of particles for cohesionless soils.

 

[theCorkster]

soildynamics:

Check out Figure 1-12 in the USBR Earth Manual (1998). They've compiled a table with different cohesionless soils showing mininum - maximum test results that may help answer your question.

 

[dgillette]

I was wondering why 90% RD. That's mighty dense, and would require a LOT of compactive effort. A well built dam embankment would typically spec'ed as 70-75%.

 

[soildynamics]

VAd and theCorkster : thanks for your valuable refernces

By the way I just put 90% as an example numbetr. My actual required RD that is reportedly acceptable for precluding liquefaction of the materials I have is 65 %.