# Prediction of Blast-Induced Ground Vibration Using an Adaptive Network-Based Fuzzy Inference System
## 3 Tunnel Site and Measurements  
During the construction of the 7.6 km long motorway section Pluska-Ponikve (Slovenia) two tunnels had to be built. Above the tunnel tube was a house, which was exposed to vibrations due to the blasting (Figure 2). Therefore, the vibration levels were monitored. The house had a basement and two upper floors. The load-bearing walls of the house were built using stone and lime mortar with an estimated compressive strength of 0.5 MPa. The floors were built from reinforced concrete slabs. The facility where the monitoring was performed is shown in Figure 3.  
The measurements of vibrations induced by blasting in the tunnel tubes were obtained using Minimate Plus (Instantel) measuring equipment with a triaxial geophone, which was placed on the load-bearing wall of the building at the height of 0.6 m above the ground. A continuous record mode was used to record multiple events automatically with no dead time between blast events. The geophone records a blast event and then continues to monitor, ready to record the following events. The geophone records all blast events with a PPV exceeding the 0.2 mm/s. The blasting in two tunnel tubes was carried out from March to the end of July 2008. During this period, there were 48 measurements of blasting  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Equations Named After Authors** & **Equations** \\ \hline USBM [34] & \(PPV=K\Big{(}\frac{d}{\sqrt{Q_{MAX}}}\Big{)}^{-B}\) \\ [PERSON]–[PERSON] [35] & \(PPV=K\Big{(}\frac{d}{\sqrt{Q_{MAX}}}\Big{)}^{-B}\) \\ Langefors–[PERSON] [36] & \(PPV=K\Big{(}\sqrt{\frac{Q_{MAX}}{d^{2/3}}}\Big{)}^{B}\) \\ \hline \hline \end{tabular}
\end{table}
Table 2: Different vibration predictor equations.  
Figure 3: Facility where the monitoring was performed.  
Figure 2: Tunnel tube map—highway Pluska–Ponikve.  
events. On the wall of the building, the PPV was measured in the longitudinal, vertical, and transverse directions. For each blasting event, the vibration frequency, amplitude, and peak particle velocity were recorded, as can be seen in Figure 4. The deviations of the fundamental natural frequencies can influence the structural strength of the building. However, for failure mechanisms such as bending and shear, where the building is forced to follow the oscillatory movements of the ground surface, the deviation of the fundamental natural frequencies of the building is of minor importance [31]. Table 3 presents the measurements of 40 of the blasting events that were used to define the site constants \(K\) and \(B\) (training data), while Table 4 contains the remaining eight measurements that were used to evaluate the prediction capability of the conventional vibration predictors (testing data). Before the blasting of the tunnel tubes, the 7 cracks were found on the outer walls of the building (see, Figure 5). We mapped the cracks and measured their width. The movements or displacements of these cracks were observed with installed plaster seals. During the blasting, it was revealed that the cracks did not enlarge, and no new cracks formed.  
Figure 4: Records of vibrations caused by blasting event. (**a**) transverse vibrations, (**b**) vertical vibrations and (**c**) longitudinal vibrations.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Measurement No.** & **Explosive (kg)** & **Distance (m)** & **PPV (mm/s)** & **Frequency (Hz)** \\ \hline
1 & 33 & 104 & 2.2 & 43 \\
2 & 36 & 63 & 7.3 & 57 \\
3 & 40 & 106 & 2.8 & 47 \\
4 & 42 & 71 & 4.