There are various ways to export a Civil 3D drawing to AutoCAD. Unfortunately, there are cases in which some options do not work, they either cause a fatal error or they create a corrupted AutoCAD drawing. The different options are explained below.
OPTION 1: Go to the Output ribbon and use the Export Civil 3D Drawing command:
OPTION 2: Use the File - Export - Export to AutoCAD - 2010 Format command (to display the Civil 3D menu bar, type MENUBAR in the command line and enter value 1):
OPTION 3: Save the Civil 3D drawing as a new drawing and use the AECOBJEXPLODE command (this command explodes all Civil 3D objects).
Save the Civil 3D drawing as a new drawing, e.g. Drawing1.dwg.
Detach all the external references.
Create a new drawing, e.g. Drawing2.dwg.
Type INSERT in the command line, browse for Drawing1.dwg, tick off Insertion point and Scale and tick on the Explode option:
Note: If you ticked the Explode option and the drawing does not explode, use the AECOBJEXPLODE command.