Successful Earthwork Fill Factor Computation

[LincolnPE]

I would like to take a poll of geotechs, and if there are any experienced earthwork contractors out there, of how they have arrived at computing successful Fill factors for earthwork hauling.

In other words, how much Fill material does it take to fill a 1 cubic yard hole?

Three scenarios:

1) All Fill is coming from the site, dug up from its insitu density.
2) All Fill is coming from offsite borrow.
3) All Fill is a combination of #1 and #2 above.

We need to account for not only relative compaction, but all losses and inefficencies encountered throughout the whole excavation, compaction, and transportation process.

 

[slabongrade]

I have a spreadsheet I made for fill/borrow. If you would like a copy, let me know.
moisture content, specific gravity, density, void ratio all factor in.
alangolightly@rjwe.com

 

[fattdad]

from the truck, I'd use 20 percent. After all, it's about as loose as it gets, so that'd be a relative density of 0 percent, which equiates to about 75 percent relative compaction.

from native soils, I guess it depends on the in-situ density. You can always do some nuke testing in the excavation area to document the in situ degree of relative compaction. Let's say it's at 95 percent relative compaction, in situ. Well, there'd be no shrink or swell factor, unless 100 percent RC is specified.

I just don't think there is some universal answer, but I appreciate the question.

f-d

¡papá gordo ain’t no madre flaca!

 

[cvg]

really depends a lot on the existing soil type, moisture content and density, borrow source and conditions as well as on the final desired compaction, on the type of equipment and the process used. these factors are generally based on local knowledge, so not really sure what the point of the inquiry is. you need to ask a local geotech or a local earthwork contractor

a recent project around here had 15% shrink (not from the truck) for excavation factor and 0.2 feet of ground compaction. I would expect far greater shrinkage from the truck.

 

[racookpe1978]

Natural re-compaction after putting it in the new hole from the truck? Or impact and rolling for compaction in the new hole? Either will be slightly greater compacting than the original (natural) of the fill dirt, but rolling or impact will compress the fill dirt more than natural settlement.

It's ironic that you have dig 1.2 cubic feet of natural dirt to transport 1.5 or 1.6 cubic feet of loose dirt to put in an empty hole that will only hold 1.0 cubic feet of compacted dirt. Percent of sand compared to loam is biggest factor in the re-compacting percent.

 

[BigH]

Easiest way is to pay volume in place. I don't get involved with bulking and compacting factors as all jobs I have been involved with over the last nearly 20 years as used the volume in place for measurement. I am not a contractor so of course this might be important to him.

 

[LincolnPE]

Thanks BigH...

I should say now that the intent and purpose is to help civil engineers develop an earthwork balanced site as they iterate through their road and site grading design. The civil design software tracks Cut, Reusable Cut and required Fill volumes. The cumulative volume is tracked for balance, and is equal to the Net of only the Reusable Cut and Fill volumes. These all have User provided factors with Cut and Fill factors typically >=1, and Reusable Fill factor less < 1.