I want to build a 16 x 24 storage barn out back. Due to slope and access I am planning on a pole foundation and wood floor. I want it to be beefy enough to park my Kubota BX tractor (about 1800#) inside. I was planning on sinking 6x6 posts, three tripled 2x6 beams spaced 8 feet apart on top of the posts, then floor joists across those topped by 3/4 plywood. All of the dimensional lumber would be treated wood. Can I go 6 feet apart on the posts under those beams? Would 2x6s be strong enough for the floor joists? What would you experts recommend?

I had a plumber apparently mistake a load bearing wall for a non-load bearing wall and he bored 3"+ holes in 2X6's to route some water lines. The damage is done (definitely more than 40% of 2X6 is gone) and I want to shore it up if I can. It's about 4 or 5 studs in a row on a 15' tall wall. One happens to be a double stud. That helps a little. I've seen stud shoes as one solution. Is there a better (stronger) framing solution? I was thinking of puting some kind of "headers" (2X8 or 2X10) between the studs above where the bores are and then adding a 2X6 sideways from the bottom plate up to the header. The "header" would only be transferring load to the 2X6 due to whatever screws or nails would be used to attach it. Don't know if that's going to help significantly. I can't really double all the studs at this point. There's too much stuff in the way already to go all the way to the top plate. (Yes, it's a 15' high wall build it one section, no horizontal members in between). I could double the studs up to some kind of header above the bores. He made the bores much bigger than he really had to for the pipes (*%@#@) so I could fit a 2X2 next to the 2X6's without bothering the pipes (they're pex water supply lines). Any other ideas???