Shrinkage factors for sand 3

[DirtPusher]

Does anybody have a good rule of thumb for shrinkage factors
for sand. The material is described as coarse to fine with
"some" clay. Moisture content is unknown. Previous development
is unknown but, thought to be original ground. What I am looking for is the difference between the volume of naturally occurring material vs compacted material.

Thanks

 

[fattdad]

Do a Proctor.
Take a nuke test of the native soil.
Determine the in-situ relative compaction.
Contrast that value to what you've specified.
Determine the "shrinkage factor."

You will likely find that the in-situ density is close to what you want to specify. Let's say it's 93 percent and you want 95 to 100. So, that's an increase of about 5 percent.

Usually, shrinkage factors are a more relavent concern when you are trucking in dirt. What's end-dumped in the back of a truck has very low relative compaction. Your shrinkage factor could easily be 15 percent.

Hope this helps.

f-d

¡papá gordo ain’t no madre flaca!

 

[DirtPusher]

Thanks, you confirmed my thoughts. The excavated volume is
in the 200,000 cy range and most of it must be trucked off the
site and wasted. The shrinkage factor will have an equally
important bearing on the total number of truckloads hauled. The haul is long enough to have a serious cost impact.

Thanks again

 

[fattdad]

Ah, the opposite of a shrinkage factor, eh?

f-d

¡papá gordo ain’t no madre flaca!

 

[DirtPusher]

It's not just the swell factor, there is a good bit of compacted fill on the site. The shrinkage factor there will also affect the number of loads hauled off.

 

[SirAl]

Shrinkage factor 15%
Insitu dry density maybe 95% SPD but will vary

 

[Grouser]

If you are estimating truck counts, it is the fluff factor you are interested in. The soil will "fluff" as it is being excavated. "Fluff" is very moisture content dependent. It may pay to spread and dry the soil before trucking in order to reduce the fluff and decrease the trucks.

If this is borrow to be compacted at another site then both fluff and shrinkage are considerations. A sieve analysis or three (various areas of site) will help characterize the soil's characteristics and can help with the fluff and shrink estimates.


Cheers

 

[TDAA]

For trucking, the weight of the material will likely limit the amount in the truck. After getting the shrinkage for the compacted on-site material, use the cubic yards of waste and the in-bank unit weight for an approximation on the trucking.

 

[DirtPusher]

Thanks, it looks like opinions vary. I normally work
with Georgia red dirt and rock. Sand/sand clay mixtures
are out of my league, estimating wise.

 

[fattdad]

According to the OP, the question is the difference between the volume for naturally occurring material and compacted material. I find it hard to believe that the natural density and the compacted density represents a 15 percent decrease in volume.

f-d

¡papá gordo ain’t no madre flaca!

 

[TDAA]

I agree f-d.

I have worked with wind-blown, hydro-compactive sands that were only up around 7-8%.

 

[DirtPusher]

Thanks to all. It doesn't matter much any more. The job
has been bid and we were not successful. If I run into
this situation again, I will have the naturally occurring
soil nuked for in place density.

Again, thanks to all.