See attached diagram (Uploaded)of the pad-under-footer design at:
http://files.engineering.com/getfile.aspx?folder=7757f5c5-2dd3-4b2e-8d50-1aa00d6cda83&file=Footer - Pad Under Footer.jpg
My concern is that a lot of the point load is distributed to the regular 12"x20" footer rather than the pad...
Regarding soil compaction: we do call for 95% compaction beneath footers as well as slabs on grade. However, the engineer is not involved in construction of the homes. I doubt the builders do anything other than drive their trucks and equipment over the soil before they start to dig the footers...
I am working with an architect here in central Florida who insists on using large reinforced concrete pads under standard 12"x20" monolithic footers for high point loads on exterior CMU walls. Vertical reinforcement is provided between the bond beam and footer - 3,000 PSI concrete filled cells...
