The Army Corps of Engineers chimes in with a mention of concrete foundation problems related to soil conditions and other factors. The military deals with a wide variety of buildings and structures and has different needs for exterior concrete slabs than does Joe Homeowner. There are no pads for artillery pieces or helicopters at my house. The report notes:

“Foundation design is determined
not only by the weight of the superstructure, but also by occupancy, use, and the load-bearing capacity of the soil at the site. Soil conditions may change over a period of time and introduce maintenance and repair problems even in initially well-designed foundations.

Foundations are subject to deterioration, whether from material or construction deficiencies or from environmental conditions.”

There’s that “We have problems with our soils,” thing again.

The paper is titled: Maintenance and Repair of Architectural & Structural Elements of Buildings and Structures. Here is a link to the entire report.