1) Export to AutoCAD - Allows you to save your Civil 3D drawing to new autocad file as exploded version without destroying your current Civil 3D drawing.
2) Explode - Explode command to your Civil 3D object like Corridor simply explode it and break your corridor as cad objects like lines or polylines.
I would recommend you using the first one if you wish to send cad copy of your Civil 3D drawing and use explode only if you need to explode. (Just be careful with explode) If unsure create back up of your drawing and test them.
