A few years ago Ky DOT switched to this type of RW monument
Here is the standard drawing for how they are to be set.
Around here there are a lot of places where you hit rock way before you get to 30" deep. Notice note 4 says the length can be reduced and note 5 says they are supposed to be set flush. The only way you know it won't drive 30" is to drive it. It's easy enough to cut the pipe off, but how would you get the riveted cap off and put back onto the top of the then flush with the ground pipe?
They come from Berntsen. According to their website it looks like they were intended for wetland and soft soil conditions. They can be a bear to set in other places.
We were asked to set somewhat similar monuments in an area where the lime stone was close to the surface. I remember pounding in a probe first to figure out if we'd have to cut. If we had to cut, we had to grind off a rivet that held on the piece that the cap sat on, then re-drill the pipe and put a screw through the hole to hold the top piece. If I remember right it took a while and some of the ones away from the road took longer because back then we didn't have cordless tools and had to keep running back to the truck to use the inverter. Good luck.
I'm thinking about just cutting the top rivets off and removing the force fit cap to start with, make something to drive the pipe with it till it's tight, cut it off and then drill a hole and use a bolt to put the cap back on. Probably be quicker than doing it all in the field. But it's gonna be hard to get the hole drilled so the cap fits tight. Real PITA
Short of welding them on I don't have a better idea right off hand, sounds like what your thinking of will take the least amount of time in the field. Unless one of the on line MENSA members here has a better idea, I'd say run with it.
Why don't you ask KyDOT what they do and/or recommend? I would imagine their own forces have had to set these, and I especially imagine that they have been asked this before.
Ky DOT never sets the monuments as far as I know. They are always part of the construction contract. I'm pretty sure they are gonna say set whatever the spec says. This requirement just came about a couple of years ago. Used to be concrete monuments usually set by the fencing or seeding contractor.
