Would like to build a concrete cattle guard frame.
8'x15' bottom, 3' sides
I plan on using I-beams running across the 8ft portion and lay pipe running across these I-beams for the 15ft width. I would like for the I-beams to rest on a lip within the sides. In other words, the sides would be stair stepped and I would place the I-beam on the step instead of the floor. My problem is I can't figure out how to build this step/lip. I am assuming that the floor would be poured first by itself. How do I form this stair step/lip for the I beam to rest on? Thanks very much in advance.