# Urban Quarry Ground Vibration Forecasting: A Matrix Factorization Approach
## 4 Measurement of PPV  
### Collection of Ground Vibration Data  
In this section, we discuss the method of collecting ground vibration data. To measure the ground vibrations caused by blasting, devices were placed in contact with the ground. Figure 3 shows a schematic of the experimental setup. The instruments for measuring ground vibrations due to blasting include the three-axis micro vibration detector MODEL-2205B (dimensions: 150 mm \(\times\) 100 mm \(\times\) 80 mm) by Showa Measuring Instruments Co. Tokyo, Japan) and accelerometers 608T No.E189, 608T No.E190 (dimensions: \(\phi\) 13.8 mm \(\times\) H 25 mm, resonance frequency: 30 kHz), 708 LF C516, 708 LF C518 (dimensions: \(\phi\) 13.8 mm \(\times\) H 28 mm, resonance frequency: 50 kHz) by Teac Corporation Tokyo, Japan). Although only one Teac accelerometer is illustrated in Figure 3, two-four accelerometers were used during measurements to increase measurement points. The am \begin{table}
\begin{tabular}{l l l l} \hline \hline
**Parameter [Unit]** & **Overview** & **Max** & **Min** & **Ave.** \\ \hline PPV [mm/s] & Peak Particle Velocity & 1.81 & 0.184 & 0.625 \\ MIC [kg] & Amount of explosive used simultaneously within 8 ms & 32.5 & 23.0 & 26.1 \\ Distance [m] & Parallel distance from the blasting point to the measuring point & 482 & 207 & 350 \\ Difference elevation [m] & Difference in elevation between the blasting point and measuring point & 44.0 & 1.00 & 19.2 \\ Direction [\({}^{\circ}\)] & Angle of the line connecting the blasting point to the measuring point & 349 & 18.7 & 290 \\ \multirow{2}{*}{ Blast-latitude [\({}^{\circ}\)]} & \multirow{2}{*}{Latitude of the blasting point} & 39.988 & 39.985 & 39.986 \\ \multirow{2}{*}{ Blast-longitude [\({}^{\circ}\)]} & \multirow{2}{*}{Longitude of the blasting point} & 140.08 & 140.08 & 140.08 \\ \multirow{2}{*}{Measure-latitude [\({}^{\circ}\)]} & \multirow{2}{*}{Latitude of the measuring point} & 39.990 & 39.985 & 39.988 \\ \multirow{2}{*}{Measure-longitude [\({}^{\circ}\)]} & \multirow{2}{*}{Longitude of the measuring point} & 140.07 & 140.08 & 140.08 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Data used in the measurement data matrix. Figure 2: Blast design at target site. plifier used was Teac's SA-611 CHARGE AMPLIFIER and the data logger used was the DM3100 by GRAPHTEC (Yokohama, Japan). The OPS021 application by the same company was used to set the measurement conditions. Using these devices, ground vibrations due to blasting were measured. When using the data logger outdoors, the engine was turned off and the ACC power source was used to eliminate the effects of vibrations from vehicles. Figure 4a shows the ground vibration data measurement points used in this study. The map is cited from Google Maps. For the collection of ground vibration data, the measuring devices shown in Figure 4a were installed at about 50 points located around the marked quarry. Although the map indicates approximately 50 measurement points, in reality, multiple accelerometers were used at the same location, resulting in data from 100 measurement points. Typically, ground vibrations due to blasting decrease as the distance from the blasting point increases. Therefore, it is essential to set the measuring devices in advance to avoid measurement failures. The OPS021 settings used for data collection can be broadly categorized into amplifier settings, trigger settings, and memory settings. Figure 4b-d show the settings screens for the amplifier, memory, and trigger, respectively. In the amplifier settings (Figure 4b), one can set the name, input, range, and filter for each channel (CH). The name can be set freely for each CH. For the input, one can choose between DC and AC, with AC being chosen for this data collection. The accelerometers used in this experiment output vibration values in volts (V or mV). The range indicates the upper and lower limits of the vertical axis (voltage values) when displaying the measured ground vibration waves in the application.