parking on hill

Sobro wrote:
I agree that the bottom layer of PT 6x6 (don't bother with RR ties, they're heavy, dirty, and you need a chainsaw to cut them) should be below grade. In fact, you need to dig about two inches deeper than the 5-1/2 inch tall 6x6 and fill the bottom two inches with gravel for drainage underneath and the gravel helps with leveling that first 6x6. It takes a long time to get the first one because you have to be very fussy about drainange and level.

You'll need to remove the top layer of organic-filled soil from the entire landing pad site so it doesn't compost and settle over time.

If you are only going three feet high, you don't need deadmen, which are 6x6's set perpendicular to the wall length in roughly the middle of the height of the wall. You can use a garden hose with water in it as a level to determine just how tall your wall has to be at the back. Just Google how to do what the Egyptians did with their garden hoses :) A string level will also work.

Use a drill with a long bit to bore a hole in the 6x6 and a sledgehammer to pound rebar through the first 6x6 at least 1 foot into undisturbed ground. Mark the outside of the 6x6 with a pencil where each rebar went so you don't accidentally try to drive a long screw or another rebar into an existing one from a 6x6 above (ask me how I know).

Stagger your joints as you go up, of course. I would backfill with gravel so drainage isn't a problem. The gravel should be typical road basecourse for your area. It will drain just fine when compacted without using larger sized stones.

Add your backfill 6 inches at a time (called a "lift") and compact that lift before adding more. You'll have to rent a vibratory plate compactor or a high school student wielding a hand plate compactor and you can also drive a vehicle over the parts you can reach to speed compaction along.

Go ahead and backfill up to where you think the concrete slab will be and use it as just a gravel top for a year so that everything has a chance to settle before you pour concrete.

He will definitely need dead men, hes parking a tralor on it. The deadmen will insure it will not bow or move when its in place. In fact i would go down 2 courses. Set it with rebar or a cross, and use the railroad tie screws for the rest.