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Volume of Dirt per Tri-Axle Truck

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cnstengineer

Civil/Environmental
Nov 26, 2011
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I just want to get an idea of what everyone uses for a tri-axle truck volume.
How many Cubic Yards of dirt do you figure per tri-xle truck load? I'm looking for an in situ volume of dirt. And by dirt I mean a well to finely graded material, not bouldery.
Also, I'm located in Pennsylvania. I believe other states have different weight restrictions on trucks.
I've always used 10 - 12 CY? How about you?
 
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How many loads of dirt from the same site are you looking to haul out? What is the soil type? Granular? Peat? It can vary.

We typically call in a nuke test for soil density when we have over 1000 C.Y. to haul if we don't have any other records from the area. The test is cheap and gives us a formal basis to accept payment (seek engineer/owner's approval beforehand). Tri's typically haul 10-12 but the difference between the two is 20% which can add up on larger projects.
 
10 to 12 sounds about right. What are you using for density 90 pcf?

You could back into a volume. Download PennDoT Pub 194. It gives legal loads for various axle spacings, subtract out the truck weight then figure the yardage.
 
A tri-axle dump body will be more on the order of 18-22 cy. Most dump bodies are limited to 96 inches wide because of road clearance issues. Most are also 40 to 48 inches deep, though some will go to 54 inches deep. That leaves only the length as a major variable. Most tri-axles will handle a 16 to 18-foot body. So that gives (16x8x4)/27= 19 cy and (18x8x4)/27= 21 cy ....these are "liquid" volumes....for soil, mounding will apply.

Keep in mind that someone who purchases a tri-axle cab and chassis will want to put as much of a body on there as they can get!

Also, if your state or area does not require the load to be covered during transit, the driver will mound the soil up over the body height as much as he can get by with.
 
Haul trucks should have net weight of what their hauling. Let's say it's 20 tons. You should have a proctor and some idea of the moisture content. If the moisture content is 12 percent and that's in the range for specified compaction you should then be able to calculate how big a hole it'll fill. So, if the maximum dry density is 115 pcf and it's at 12 percent moisture and they are targeting 95 percent compaction, the 20 ton truck would fill a hole that's 326.9 cf (12.1 cy).

Now if they actually get 100 percent compaction, that'd be 310.6 cf (11.5 cy).

f-d

¡papá gordo ain’t no madre flaca!
 
Why not get the actaul inplace weight of a cubic foot of soil and have all trucks go through a scale, loaded and empty each trip for a couple days. then cut it to every couple days. Then you know what they are hauling.

Richard A. Cornelius, P.E.
 
assuming GVW of 60,000 lbs (you can google this)
100 pcf loose
120 pcf in-place

you would be lucky to get more than about 16 yards per load (in-place), all depending on both the loose density as well as the in-place density
 
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