Borrow Problem

[klmccllg]

I was working an example problem tonight with the number of trucks needed to carry borrow to fill a site. I calculated the borrow correct but the answer took the weight of solids in borrow to fill the weight of solids in fill. I understand the difference but I figured the volume of borrow would just be divided by volume of truck. I'm not sure if this question makes since and I can post the problem if it helps get a better explaination. Any advice?

 

[maryannette]

Post the problem. It's been awhile since I've done any of that, but if I can't help you someone else surely can.

 

[Capt Worley PE]

Not a civvie, but maybe it has something to do with the max gross weight on the truck axles????

 

[MonteBiker]

I was working an example problem tonight with the number of trucks needed to carry borrow to fill a site. I calculated the borrow correct but the answer took the weight of solids in borrow to fill the weight of solids in fill. I understand the difference but I figured the volume of borrow would just be divided by volume of truck. I'm not sure if this question makes since and I can post the problem if it helps get a better explaination. Any advice?

Without seeing the exact problem, it is hard to help figure out where the missed step is but let me give it my best shot given what you have above. If I was to take a guess, you are missing the fact that you are really trying to duplicate the existing conditions where you are putting the soil. That being said, imagine a simplified problem of just solids and air (no water) and I am guessing unrealistic numbers. The borrow site is 50lb/cf. The fill site requires 100lb/cf. This means that for every cubic ft you need at the fill site, you need to borrow two. If you need 10cf of fill, you go to your borrow pit and get (10cf of fill)*((100lb/cf fill)/(50lb/cf of borrow)) and you would get 20cf of borrow. When they bring the soil to the site, they will have to compact it to the right size.

From what you are describing, this is not just a problem of volumes, it is also a problem of mass (via density). It is not asking you how much volume is at each site...

The water going from one site to another is variable, you can dry out soil or add water as needed to get other properties but the thing which you can not change is how much of the solids you are moving. That is why the problem is really only talking about solids.

Please let me know if that answers your question.

 

[IlPadrino]

I'm going to guess it's a problem similar to the one I explained here. Take a look and if that doesn't help, post the problem and I'm CERTAIN you'll get an answer.

 

[klmccllg]

Exactly the answer I needed. Thanks

 

[IlPadrino]

Exactly the answer I needed. Thanks

You're welcome!