Settling concrete slabs are a major concern in new construction in the Des Moines area market. Builders are no longer mechanically compacting soil but using a soak method. In theory that should work. Generally, they place a steel pipe with a hose attached about 1 foot in from the basement wall after itis backfilled. They run water slowly through the pipe overnight. This is done to check both the ability of the French drains along the foundation for plugs and problems with carrying water to the sump pit. A major area of concern though, is that point where the driveway joins the floor of the garage. This area is a common source of voids under the concrete where the backfill occurred. Builders tend to skip that area as the dig was usually only a few feet deep before the footings are poured. A simple sign that there could be a problem is a gutter/downspout system dumping near the edge of the slab. The photograph shows an area which should be tapped on with a hammer. Listening for a change in pitch as that occurs will usually indicate a void. Mudjacking with a good polymer or slurry is the best solution, short of tearing outthat section of the driveway.