Termite and Wood Boring Insects - Will this get rid of termites?

I know my garage hasn't had sill plates for a while. The sills are buried in the dirt. Well finally I cut the wall open and took a look at what I was dealing with. I saw a bunch of termites run for there lives which didn't suprise me much. Anyways my plan of action is to cut maybe the bottom 12 inches or so out of all the walls and pour a 12 inch cement foundation. I'm going to put a pressure treated 2 by on the foundation for a sill plate and sit the wall on that.

My question is, as far as I know, this will get rid of the termites, right? I believe termites live in the ground, and if they can't get back to the ground they die off. Is this correct? So once I disconnect their path to ground, aslong as there are no mud tunnels appearing, I need not worry about the termites in my framing. They will just die?

Soil should be professionally treated with termiticide to create a chemical barrier to keep termites at bay. Check with local building code office re: recommendations for construction.