Volume Calculation

[sacprasanna]

Hi all,

I am new to volume calculation theory.I want to know what is mean by cut factor and fill factor.

Pls help,

[ToddRogers-WPM · Accepted solution]

That is your "fluff" and "compaction" factor.  Here in Texas it's about 15% for both.  So to put that in the calculations, it would be 1.15 for both.

[Joe-Bouza]

The stars at night are big and bright.....

[BrianHailey · Accepted solution]

You need to know why you are using a cut/fill factor before just applying it. For example, I have a site with excess dirt. I need to haul this dirt off site. How many trucks will this take? Each truck hold 10 yards (I have no idea what the capacity of a truck is so I just picked a nice number to make the math easy). I have 10,000 yards of dirt to haul off the site. How many truck loads will this take?  

If you answered 1,000 you are wrong. When you pull the dirt out of the ground and drop it in a truck, it is not as dense (aka compact) as it was in the ground. This is where a cut factor would come into play. Assuming a "fluff" of 20%, you would need to haul not 10,000 yards but 10,000*1.2 yards or 12,000 yards, that's an additional 200 truck loads.

Another example, I'm pulling dirt from this part of the site and putting it over here. Pulling one yard of dirt will only fill a hole 0.8 yards big. In this case you could use a cut factor of 0.8 or a fill factore of 1.25.

Hope this helps.

[castled071049]

The eyes of Texas are upon you, 'til Gabriel blows his horn.

[LeafRiders · Accepted solution]

Great discription from Brian. The Cut and Fill factors may be provided from a geotechnical firm or some type of analysis of the earth material you're dealing with. The standard rule of thumb should be 1.0 unless provided a number to use that is verified. As Brian mentioned this could heavily distort the amount of dirt you need in-place. In the event it's provided at a later date you can apply this to your numbers without reworking anything in Civil 3D.

[sacprasanna]

Thanks all,I understand it