I'm replacing what was decking steps with concrete. The base that's been dug away varies from sandy to clay to a mix with soil. Gonna build a wood frame for the concrete, but with the soft base could I get away with adding reinforced steel bars knocked in to hold all the concrete in place. At the bottom there is an old double skin wall which is solid and have dug a footing channel next to that to act as an anchor. Example steel rod in the pic.