For a construction project, 10 ft of compacted earth fill is placed in preparation for erecting a building. At one of the building’s interior locations, a machine foundation 20 ft square will be...

For a construction project, 10 ft of compacted earth fill is placed in preparation for erecting a building. At one of the building’s interior locations, a machine foundation 20 ft square will be installed at floor level to support equipment weighing 2,000 kips. What net stress increase results below the center of the machine in the original soil mass, 5 ft under the natural ground surface? Assume a unit weight of 125 pcf for the compacted fill. Assume the Boussinesq conditions apply