## 4 Discussion
### Effect of Ground-Borne Vibrations on the Building
Examples of values that were obtained as a result of single integration of signals and the removal of the linear trend (using the Sigview software) are given in Table 8. By comparing the data from Tables 7 and 8, it can be seen that in the case of a hydraulic compact MTS V8 operating in X1 mode, by integrating signals, it was possible to achieve from \(-5.4\%\) to \(+13.1\%\) lower or higher values of PPVi in the direction of the dominant vibration component (x direction). In the vertical direction (z), the differences in relation to the signal from the GEA sensor were \(+0.6\%\), to a maximum of \(+15.3\%\). The largest differences in PPVi values occurred in the transverse direction (y)--even up to \(-43.7\%\), in relation to the values determined by using the GEA transducer. Such significant differences in the transverse direction (y), and rather acceptable differences in the case of other measurement directions, most probably do not result from numerical integration errors, but only due to the lack of technical possibility to synchronize the start and end of measurements by using two completely different measurement systems (even several-second time shifts between individual files are possible). The data compiled in Table 5 to Table 8 show, that in the most unfavorable case, on the foundation wall of a residential building subjected to the analyses, components of vibration velocities did not exceed PPVi = 2.4 mm/s in (see Table 7, stage III: direction x, hydraulic compact in X1 mode compacting soil at a depth of 0.4 m). In accordance with the guidelines of key European standards, regarding the assessment of the impact of ground-borne vibrations on buildings ([23; 25; 26; 27]) such orders of magnitude of peak component particle velocities recorded at the foundation of the building should not cause any damage to buildings in good technical condition (even cosmetic damages), as the two most stringent standards in this matter: DIN 4150-3 [23] and BS 5228-4 [26] as thresholds (named respectively, as: \"guideline value\" or \"vibration limits\") for residential buildings indicate PPVi = 5 mm/s--in the case of short-term vibrations with dominating frequencies from 5 Hz to 10 Hz, and PPVi = 5 mm/s (recorded on the top floor of the building)--regardless of the frequency in the case of short-term vibrations [23], and PPV = 5 mm/s--regardless of the frequency in the case of BS 5228-4 standard [26]:  
\[\text{PPVmax}=2.4\text{ mm/s}<5\text{ mm/s}.\]  
However, it should be taken into account that buildings near which construction works that are related to the compaction of soil may be carried out, do not necessarily have to be in a good technical condition. Then, according to [26], PPVi limit values should be reduced by 50%--up to PPV level = 5 mm/s in the case of intermittent vibration and 2.5 mm/s, in the case of continuous vibrations. Considering that during the compaction of the soil using the MTS V8 compactor, the building's resonance vibrations have occurred at least several times and we have to deal with vibrations affecting the structure of the building in a continuous way. In this situation, the building in question would be on the verge of an appearance of minor or cosmetic damage to buildings. \[\text{PPVmax}=2.4\text{ mm/s}\approx 2.5\text{ mm/s}.\] \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Device/Mode/Depth of Compaction** & **PPVx** & **PPVy** & **PPVz** \\ \hline MTS V8/\(\chi\)1/0.4 m & 2.228 & 0.185 & 0.893 \\ MTS V8/\(\chi\)1/1.2 m & 1.892 & 0.343 & 0.860 \\ MTS V8/\(\chi\)1/1.9 m & 1.270 & 0.574 & 1.165 \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Peak component particle velocities at the foundation wall of the building (signal integration using _Sigview_ software)—stage III, mm/s.