## 4 Discussion  
### Comparative Analysis of the PPAs  
As it can be noticed in the above summaries (see Tables 2-4 and Figure 4), the most intense acceleration time histories occurred in the direction of generated vibrations--i.e., in vertical direction (z). The maximum values of vibration acceleration (PPAz), registered during the first stage of tests (the source of vibration in the distance L\({}_{\text{s}}\) = 15 m from the building) in the measurement point No. 4 (MP4, L4 = 7.5 m)--outermost of the building, and the nearest to the source of vibrations did not exceed PPAz = 0.248 m/s\({}^{2}\)--in the case of Wacker Neuson DPU 6055 vibrating plate compactor,  
Figure 4: The PPAs—stage III (source of vibration at the distance of 5 m from the building) in directions: (a)—x; (b)—y; (c)—z. and 0.546 m/s\({}^{2}\)--in the case of the MTS V8 hydraulic compactor (mode X1). At the same measurement point, in the second stage of tests (the source of vibration in the distance of Ls = 10 m from the building) the PPAs reached respectively 1.291 m/s\({}^{2}\) and 2.195 m/s\({}^{2}\) (mode X1). Predominant vibration acceleration values in the vertical direction are also present in the third stage of research (stage III--source of vibrations at a distance of 5 m from the building), in which case the PPAz values registered at the measuring point closest to the working compactors (MP4B, L4B = 3.75 m) are respectively for the plate compactor and hydraulic compactor PPAz = 3.571 m/s\({}^{2}\) and 12.215 m/s\({}^{2}\) (mode X1). In terms of the potentially harmful influence of vibrations on the building, vibrations transmitted to the ground medium in a horizontal plane are more significant. The maximum values of surface acceleration vibration propagated in the longitudinal direction x, and were recorded at a measurement point that was located at a distance of 7.5 m from the building (MP4) are less intense than in the vertical direction, and in the first stage of the study (Ls = 15 m), they do not exceed PPAx = 0.178 m/s\({}^{2}\) (plate compactor) and 0.461 m/s\({}^{2}\) (MTS V8 compactor, mode X1), and respectively, 0.967 m/s\({}^{2}\) and 1.984 m/s\({}^{2}\) in the second stage of the study (Ls = 10 m). In the third stage of research, at the measurement point that was most distant from the building (MP4B, L4B = 3.75 m), the maximum PPAx values were, respectively, 2.094 m/s\({}^{2}\) and 6.580 m/s\({}^{2}\). In the case of vibrations recorded in a transverse direction (y), in relation to the assumed measurement profile, PPay values are usually two-three times lower than in the longitudinal direction x. At the measuring points located closest to the vibration source, they were presented respectively for the plate and hydraulic compactor: 0.059 m/s\({}^{2}\) and 0.335 m/s\({}^{2}\) (stage I), 0.395 m/s\({}^{2}\) and 0.698 m/s\({}^{2}\) (stage II) and 1.108 m/s\({}^{2}\) and 1.928 m/s\({}^{2}\) (stage III). It follows that in the furthest measurement points (MP4 and MP4B), the vibration levels that are generated by the hydraulic compactor MTS V8 were almost twice as high as those generated by the reversible plate compactor. While the acceleration values recorded along the adopted measurement profile decreased with the distance from the source of vibration, unfortunately, damping and absorption of vibrations did not proceed, as it was due to the known theoretical dependence of the geometrical attenuation, and the absorption of vibrations, as in continuous and homogeneous types of ground [17], which points to the exponential nature of fading of vibrations along with distance covered by the waves. This problem is further highlighted in earlier works by the authors [7].