Baked Brep as a solid/surface

Hey guys, i made a parametric bridge in grasshopper.
I want that all the surfaces are one object. I tried that with the Cap Holes and in rhino everything is fine after baking:
But when i want to export it, so i can open it in autocad or to have it correct for sofistik, i only get the line output:
I also tried to change the export settings to 2007 solids, but i wont change.

Thanks for your time!

Hi -
I’m not sure to which extend this is a Grasshopper question. It sounds like a Rhino export question.
What do you see in Rhino when you import the file that you exported?
Can you post the Rhino file?

yeah it might be, i dunno either… but i thought that i have to tell grasshopper, that this should be a solid object.
If i open it with rhino or any cad programm i just see the lines like in my autocad picture.GH Brücke.3dm (188.5 KB) GH Brü (9.9 KB)