The use of the indicated formulas is possible only in the absence of resonance in the very mass of the soil surrounding the source of oscillations.
With resonance, a sharp change in the amplitudes of oscillations is obtained when the source fluctuations change. On one of the forested factories near Arkhangelsk by research by the Simological Institute of the Academy of Sciences in 1931. It was found that when switching working sawmills from the period t = 0.26 sec. for the period t = 0.17 sec. The amplitude of the oscillations of the foundation of the sawmill (in this case, the sources of oscillations) increased 2.5 times, while the amplitude of the oscillations of the boiler installation increased by 7 times. Such an increase in the amplitude of the oscillations clearly indicates the presence of a resonance phenomenon.