Bricks, Masonry, Asphalt and Concrete - Building driveway pillars

Ok, got the original question answered, but now a new one...

I have a concrete culvert running under the driveway. I am in central NC and frost line here is at worst 8". The culvert in the middle of the driveway is below that. Does this not count because the culvert is open to the air? On the ends there is about 12" of culvert exposed. As part of my pillars I want to cover the ends. The pillars will be built to one side and I will extend a wall over the culvert.

My old neighborhood there were a couple houses that did what I want to do. Do I need to be concerned about frost heave and movement with the culvert? Can I dig under the ends and pour footings? Should I just plan on a drystack of stones around the ends?

The best way to do this is pour your footing 8" wider than the finished size on all 4 sides. Build a concrete block form about 3" narrower than the finished size. Then, you can mortar in the rock on the block base. Don't build it first and then add the dirt or concrete as it will have too much internal pressure and fail. PLEASE be sure to install conduit for your wiring. I am in the process now of tracing down the reason for a customer's lights (8 of 'em) not working. I finally found it. The numb brain that installed the underground electrical, as I found out, laid the UF cable on the ground with junctions and all, and had the concrete steps poured directly on it. Well, one slip of the concrete steps and it crushed the UF causing all the conductors to short to each other. All 8 columns now have to be disassembled in order to correct this problem.

I plan to install conduit - the electrical will come later this year anyway. Thanks for the tip on adding the block.