Wave Form Analysis
This figure shows the acceleration (m/s2) versus frequency (hz). This was taken on the garage floor. This pattern is seen all over the structure, although in some cases there is more distortion. I think this is due to the vibration dissipating and a result of structural characteristics.
Traffic vibrations or construction vibrations occur at lower frequencies, <100 hz. Also, those types of vibrations occur over a range of frequencies which would look like a mound, not narrow bands like shown here.
I suspect the reason these vibrations feel so awful but might be undetectable to many people is that the frequencies are really high and occur in these really discrete bands.