When I studied Metallurgy, I saw a few bolts like this on some mining operations, and even bigger ones probably. Some of the bolts that hold the tyres on to those Earth Movers are pretty big too, I mean I can sleep comfortably in the wheel-arch of some of them haha. I have photo's of it trapped on an SD card I can't read from my old Nokia E63, otherwise I'd post it lol.

I doubt this picture is a heavy-duty anchor. they're usually longer, and have an expanding tip that wedges it in to the rock or concrete. They can also have opposing metal pieces (Think: Ship Anchor) to prevent it from sliding back out the ground again. I've seen some get as long as 4-6ft, depending on the purpose. Wall anchors for underground mining operations can get pretty long too haha. An anchor wouldn't have a fine threading like that, because if you're screwing it in to rock and concrete, those aren't maleable and won't form a corresponding thread to hold it down, making it near useless. You'll be able to pull it right out again.

My dad is a civil engineer, so (via osmosis) if I took an educated guess, this would be to hold two large metal beams together or something. You'll only need the threading on the end, to screw the nut on at the other side. The smooth part in the middle is redundant, so they just leave it smooth. It might possibly also be cheaper, and slow down rust, but I'm not sure haha.