## 3 Results
### Analysis and Evaluation of Measured Data  
While monitoring the blasts, the vibrations were measured during the daytime when the operational blasts were carried out in Trebejov Quarry. The vibrations lasted 200-250 ms with shock impulses. Since there was no repeated long-lasting (more than 500 ms) seismic loading of the monitored object, the wave energy was absorbed by the object in a way so as not to disturb its equilibrium state. The influence of 250 ms vibrations with repeated shock impulses did not result in steady periodic loading of the monitored object, which did not exceed the limit values (STN EN 1998-1/NA/Z1) [51]; the particle velocity v\({}_{\text{d}}\) = 3.0 mm.s\({}^{-1}\) could not have damaged the monitored object. An example of the measured values for the individual experimental blasts is shown in the records of the Svantek 985 A device (Table 6). Figures 8 and 9 display the maximum values of the particle velocity and acceleration on standpoints S1 and S2 (building No. 91 in the village of Trebejov) during blasts No. 693, 694, 695, 696, 697 and 698. At the S1 standpoint, the Vibrograph Minimate PRO 6 was set on the reference standpoint (STN EN 1998-1/NA/Z1) [51]--foundations of the building. It monitored the effects of the vibrations on the building. At blasting No. 693, the seismic effects of one individual borehole with charge capacity, which is applied in the blasting operations in Trebejov Quarry, were measured. At blasting No. 694, the seismic effects of two boreholes with doubled charge capacity were measured. The maximum particle velocity was not doubled (Figure 8). At blasting No. 695, the seismic effects of two boreholes with doubled charge capacity and with a millisecond delay of the second blast of 5 ms were measured. The maximum particle velocity was nearly doubled, meaning that there was an accumulation of the amplitudes of the seismic wave initiated by the first and second blasts. At blasting No. 696, the seismic effects of two boreholes with doubled charge capacity and a millisecond delay of the second blast of 10 ms were measured. The maximum particle velocity was lower than that at blasting No. 695, meaning that a partial attenuation of the amplitudes of the seismic wave generated by the first and second blasts occurred. At blasting No. 697, the seismic effects of two boreholes with doubled charge capacity and a millisecond delay of the blast of the second borehole of 15 ms were measured. The maximum particle velocity was equal to that of blasting No. 696, meaning that a partial attenuation of the amplitude of the seismic wave generated by the first and second blasts occurred. At blasting No.698, the seismic effects of two boreholes with doubled charge capacity and with a millisecond delay of the blast in the second borehole of 20 ms were measured. The maximum particle velocity was lower than that at blasting No. 696 and 697, meaning that a higher attenuation of the amplitude of the seismic wave generated by the first and second blasts occurred. The value of the maximum particle velocity was equal to or lower than that at blasting No. 693; half capacity of blasting No. 698 was blasted (Table 2), (Figure 8). \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Blasts No.** & **Profile** & **Position of the Measurement** & \(\mathbf{a_{\text{wmax,v}}}\) & \(\mathbf{a_{\text{wmax,v}}}\) & \(\mathbf{a_{\text{wmax,z}}}\) \\  & & & **[mm.s\({}^{-2}\)]** & **[mm.s\({}^{-2}\)]** & **[mm.s\({}^{-2}\)]** \\ \hline
693. & - & S2/Svantek & 28.05 & 42.36 & 49.20 \\
694. & - & S2/Svantek & 47.64 & 49.09 & 78.25 \\
695. & - & S2/Svantek & 48.19 & 45.49 & 51.70 \\
696. & - & S2/Svantek & 35.72 & 49.31 & 58.68 \\
697. & - & S2/Svantek & 27.41 & 52.24 & 58.68 \\
698. & - & S2/Svantek & 24.43 & 44.87 & 19.54 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Measured values of peak acceleration in blasts (source: author).