we over dig the hole 3ft, width wise. Gives us room to walk around outside of the hole as we bolt together the steel panels and set the turn buckles that hold the walls up straight..
that three feet is then filled with roughly 6-8in of concrete sometimes more. I get a truck minimum of 5 yards so sometimes its really thick..
depending on the pool, the steel is set 6in higher than original grade. that way the pool is set up higher than just about anything around so no water rolls in. Plus that gives us a plus to get rid of a lot of extra dirt.
any dirt that isn't used in backfill or for grading off the yard will be trucked off or piled somewhere on site for the customer to use later..