Bounded Volumes

[greg_garcia]

I originally placed this under a similar thread and reposted this to keep the focus on bounded volumes.

I am trying to figure out the Bounded volumes calculation for C3D and I am getting ridculous volumes, maybed I am just going about this in the wrong manner, but even the C3D help says:

Use the Bounded Volume utility to calculate the volume of an area as defined by a polyline,or polygon, or parcel.

You can quickly calculate and display the net volume, cut, and fill for a bounded area on a volume surface.

NoteFor volume surfaces, the volume of the bounded area is based on the difference elevations that were originally used to calculate the volume surface. For terrain surfaces, the volume is calculated from the 0 elevation to the elevations in the bounded area.

If this is calculated from the 0 elevation how is this going to help me, the volume seems to be calculating from 0 to my 4938 elevation instead of 4935 to 4938. Do I have to move my polyline/polygon to the bottom elevation of my ditch and then calculate?

[sinc]

I'm not aware of a way in Civil 3D of getting the volume between a certain range of elevations, unless maybe if you count the Stage Storage extension.

The bounded volumes in Civil 3D are like the Parcel volumes in Land Desktop, i.e. to get the total cut/fill in a particular area. It's basically "volume within the specified horizontal boundary". You create a Volume surface first, then you calculate a bounded volume using the Volume surface and your horizontal boundary.

[curlinpw]

i still don't see any benefit for the bounded volume.
I you are using real world elevations, the bounded volume has no use. you would have to convert you surface to 0 elevation at your lowest point, then it stilll would not work? Existing and finished grade surfaces seem to work just fine, but sometimes i need a volume to an existing elevation. That is what i thought bounded elevation would provide, but appaerntly not. Something like a slice routine would be great, like in 3d mmodeling for solids.

[sinc]

If you are looking for a volume to a certain elevation, just create a flat surface at your target elevation, then compare your surface with the flat surface.

For example, if you have a pond in your EG surface and you want to find the volume to the 3500' contour, draw a polyline around your pond and set it to Z=3500. Then use that polyline to create the flat comparison surface. Then compute a volume between your EG surface and the new 3500' surface.

I agree that there should be a way to do this without creating a comparison surface, but it's not too difficult to do.

[Shine Co]

Sorry I could not find a right forum, so i'll just post it under this thread.
How can I create a right triangle with a given area and baselength in AutoCAD, in one go.