Hi Everyone:
It can be done.
When you export to ACAD what is happening to your figures is they are being exploded.
Because the figures have elevations, they are being exploded to 3DPOLYLINES.
A 3DPOLY can not display an arc segment.
Here's what has to happen:
Step 1. insert the figures into the Civil3D Drawing
Step 2. select a figure in the drawing. The ribbon will switch to "Figure Mode."
Step 3. Select "Edit Elevations" from the figure-modify panel
Step 4. Select "Elevation Editor" from the "Edit-Elevations panel"
Step 5. Select all the verticies of the figure in the list view of the editor
Step 6. type 0.00 in one of the elevation cells. This will update all the vertices to 0.00 elevation.
Step 7. Repeat for all other 3D figures with ARC segments incorporated.
Step 8. Export the drawing to ACAD.
Hope that sheds some light on the situation
Craig Bailey
_______
Craig T. Bailey, PE, LLS, PSM
Bailey Associates
www.bailey-associates.com