I don't mind if you agree or not WarpfactorZ, it looks like whats left of a floor to me and it is in line with the idea of 4 floors in the saucer rim as many here have shown.
The area exposed by the damage is far too large (height) an area to be just one floor, whether you like it or not.
You can clearly see a single corridor through that hole. The three rows of rectangles along the circular wall is unmistakable, and as the ship pans by in the film, it is plain as day. I don't know what else to tell you.
In fact, someone show me where it is conclusively established that there are four or five decks along the saucer rim. 'Cause I don't think it ever was. Everyone is attacking me because I refuse to believe this, but in reality the deck plan of the Enterprise you're defending isn't canon.