Lower frequency limit of measuring system, in Hz (±3 dB) | Maximum level, in dB |
0.1 Hz or lower-flat response1 | 134 peak. |
2 Hz or lower-flat response | 133 peak. |
6 Hz or lower-flat response | 129 peak. |
C-weighted-slow response1 | 105 peak dBC. |
1 Only when approved by the regulatory authority.
Distance (D), from the blasting site, in feet | Maximum allowable peak particle velocity (V max) for ground vibration, in inches/second1 | Scaled-distance factor to be applied without seismic monitoring2 (Ds) |
0 to 300 | 1.25 | 50 |
301 to 5,000 | 1.00 | 55 |
5,001 and beyond | 0.75 | 65 |
1 Ground vibration shall be measured as the particle velocity. Particle velocity shall be recorded in three mutually perpendicular directions. The maximum allowable peak particle velocity shall apply to each of the three measurements.
2 Applicable to the scaled-distance equation of paragraph (d)(3)(i) of this section.
30 C.F.R. §816.67