COMoss

I have no clue how thick the floor is, but it's been supporting a Honda Accord since the house was new. I'm planning to build a storm shelter in the back part of the garage with (filled) concrete block, topped with at least 10" of post-supported, reinforced concrete for a roof. Wall height about seven feet, four feet below grade. I'm thinking I can spread the load from the width of the block (8") to nearly triple that if I epoxy 24" x 24" x 1/2" steel plates to the floor, then center the block on that. Shear strength at floor level will be huge with the steel and concrete surfaces covered in epoxy. To anchor the block to the steel, center rebar in the blocks, then weld the rebar to the plate, then fill the finished walls with concrete. That should provide outstanding ballistic protection. I don't want to create a line of excessive weight with the walls pressing down along an 8"-wide path. 18-wheelers have 18 wheels to spread their loads so their tires don't auger into the pavement- wouldn't tripling the effective surface area at the bottom of a wall kind of do the same thing? It's a 7-foot high shelter, not a skyscraper. What do you think?