Cut and Fill Calculation/ Easy Q

[Ramz7887]

I'm trying to find an equation list or some sample problems for cut and fill questions. I haven't done these in a while and kinda of forgot how.

Thanks

 

[cousink]

This may be related to your request. It is real simple to produce an estimate of cut and fill volumes. Since we are just wrapping up a cross-sectional analysis for a site design by hand, I want to share our easy method, if not just to provide a perspective.

We began by reviewing the site and defining the grading concept. The site is a rectangle that is high in the NE corner and deep in the SW corner. To level the site for purposes of water storage, we are mostly filling it up beginning at the SW corner.

Based on a drawing showing the PLs, existing and proposed contours, we took six sections of the site at 50 ft intervals from the west PL to the east PL. To help us organize the sections, we defined the east PL as station zero, and then we marked every half station on the plot until the west PL. For each section, we plotted the existing elevations and the proposed elevations. The area beneath where the proposed grade exceeds the existing was reserved for a fill computation. The area beneath where the existing grade exceeds the proposed was reserved for a cut computation.

Sta 0+00

--------------------------
,,,,'
,,,,,''''''''''
,,,,,,''''''

(S) (N)

Where - is the proposed grade and , or ' is the existing.

The volumes were computed using a spreadsheet. For example, the computation for the fill volume between stations zero and a half is shown (all units are "English"):

("Station") (Fill Area) (Average Fill Area) (Volume)
0+00 100
150 150*50/27
0+50 200

Using this example, we would estimate that the required fill of the westernmost fifth of the site would be 278 CY.

This was a fairly detailed earthwork quantity analysis that could have been performed even more accurately and much more quickly in AutoCAD or MicroStation.

Is this what you are after?

 

[cousink]

There are a couple typos in the above post. Please note the CORRECTION (deletion) below.

Based on a drawing showing the PLs, existing and proposed contours, we took six sections of the site at 50 ft intervals from the west PL to the east PL. To help us organize the sections, we defined the WEST (east) PL as station zero, and then we marked every half station on the plot until the EAST (west) PL. For each section, we plotted the existing elevations and the proposed elevations. The area beneath where the proposed grade exceeds the existing was reserved for a fill computation. The area beneath where the existing grade exceeds the proposed was reserved for a cut computation.

 

[Ramz7887]

It is for a detention basin and the area proposed is an odd shaped polygon.

 

[Ramz7887]

without uniform elevation

 

[cousink]

Could you break the polygon down into a few rectangles and take even cross-sections from those?

 

[MEM1]

Check out

http://www.ezysurf.com

This program runs inside autocad and is extremely affordable. It will do earthwork computations for you.

 

[LHA]

MEM1:
I couldn't get there with your address. I found it here, haven't had time to try it, but I will. For $55, it is a steal, IF it works.

It says "2004 to R13". Do you know if it keeps working on newer AutoCadd's?

Engineering is the practice of the art of science - Steve

 

[MEM1]

Not sure, drop Paul an email and ask him. They very well could work on 06 and 07, but I don't know for sure. I use it with map 5 which I believe is AC 2002. I use it all the time when designing feedlot runoff controls. Now be aware the earthwork volumes will only be as accurate as the survey. If you want/can, send me the files and I will run it for you to show you what it can do. Make sure all of your breaklines are drawn in. I most likely won't know where they belong.

 

[rmadrid]

takes a rectangular cross section comparing the proposed and existing surfaces and use the moment area equation

 

[queque]

rmadrid --Can you define the moment equation and how to use it? Where is a reference for it?
Thank you.

 

[queque]

mem1 What is your email address?

 

[MEM1]

smurrisonatcox.net

Replace the "at" with appropriate symbol
Scott