Volume Boundary Creates Incorrect Volume

[ThomasGlidewell]

Video Link of Problem

I have an issue with using Bounded Volume or Adding a Boundary to Volume Surface things so bad... = incorrect volumes.. sometimes extremly incorrect.. I understand that the surface retraingluate when a boundary is added but this could be horrible if not checked. Please let me know if there is a fix or reason for this.

Thanks

Civil 3D 2012 all sp's

[tcorey]

Instead of deleting lines, what if you create a hide boundary to remove the TIN in a particular area.

[neilyj666 · Accepted solution]

If you are (as Tim suggested) just deleting the TIN lines then Civil 3D is behaving perfectly correctly as how will the triangulation algorithm know that you want to exclude the area?

You need to add a HIDE boundary to "remove" the lines in the building area and then when you rebuild the surface it should be ok.

If this doesn't work then you'll neeed to post the dwg for someone to look at

[david.dixon]

I am having a similar issue with using bounded volumes and parcel volume report methods returning incorrect volumes.

The Bounded volumes method seems to not like boundaries that can potentially have DTM lines that cross open areas and includes these areas in the calculations even when they occur outside of the boundary.  Think of a “C” shaped boundary; bounded volumes method seems to include the open area between the top and bottom of the “C”.  not good.  Bounded and Parcel volumes work fine for boundaries which are generally rectangular in shape.

So to arrive at the correct volume, I developed the proposed surface from points, breaklines, and contours as normal, then applied the limits as an Outer boundary to the proposed surface with Non-destructive breaklines checked on, reran the volume calcs using a TIN volume surface (EG vs FG) as before, and now the volumes are in-line with what I expected and with what I calculate manually.