(a) No person in any commercial district may generate or cause to be generated any ground-transmitted vibration that is perceptible to the human sense of touch measured at (i) the outside boundary of the immediate space occupied by the enterprise generating the vibration if the enterprise is one of several located on a lot, or (ii) the lot line if the enterprise generating the vibration is the only enterprise located on a lot.
(b) No person in an I-1 or I-2 district may generate or cause to be generated any ground-transmitted vibration in excess of the limits set forth in subsection (e) of this section. Vibration shall be measured at any adjacent lot line or residential district line as indicated in the table set forth in subsection (e) of this section.
(c) The instrument used to measure vibrations shall be a three-component measuring system capable of simultaneous measurement of vibration in three mutually perpendicular directions.
(d) The vibration maximums set forth in subsection (e) of this section are stated in terms of particle velocity, which may be measured directly with suitable instrumentation or computed on the basis of displacement and frequency. When computed, the following formula shall be used: PV = 6.28 F x D, Where: PV = Particle Velocity, Inches-Per-Second, F = Vibration Frequency, Cycles-Per-Second, D = Single Amplitude Displacement of the Vibration, Inches. The maximum velocity shall be the vector sum of the three components recorded.
(e) Table of Vibration Maximums
TABLE OF VIBRATION MAXIMUMS | ||
Zoning District | Particle Velocity, Inches-per-Second | |
Adjacent Lot Line | Residential District | |
I-1 | 0.1 | 0.02 |
I-2 | 0.2 | 0.02 |
(f) The values stated in TABLE OF VIBRATION MAXIMUMS may be multiplied by two for impact vibrations (i.e., discrete vibration pulsations not exceeding one second in duration and having a pause of at least one second between pulses).
(g) Vibrations resulting from temporary construction activity that occurs between 7 a.m. and 7 p.m. shall be exempt from the requirements of this Section.
(Ord. 074-10. Passed 12-20-10.)