How to check vibration against US criteria
The dB(V) vibration level used in Korean and Japanese regulation has no equivalent in United States law, so a direct translation would be misleading. American practice splits the question in two. Transit, rail, and construction vibration is judged in VdB against the impact criteria in the FTA Transit Noise and Vibration Impact Assessment Manual, while blasting is judged in peak particle velocity against USBM RI 8507 and the OSMRE limits in 30 CFR 816.67. This calculator runs both checks side by side.
The vibration level is computed as 20 log10(v / 1 microinch per second) using the RMS velocity you enter, so 0.004 in/sec works out to about 72 VdB. That is exactly the FTA Category 2 criterion for residences exposed to frequent events; occasional events allow 75 VdB and infrequent events 80 VdB, while vibration-sensitive Category 1 buildings are held to 65 VdB.
On the blasting side, USBM RI 8507 sets 0.50 in/sec for plaster-on-lath and 0.75 in/sec for drywall below 10 Hz, rising to 2.0 in/sec above 40 Hz, and OSMRE allows 1.25, 1.00, or 0.75 in/sec depending on distance from the blast. VdB and PPV are not interchangeable because one is an RMS value and the other a peak. State and local rules, permit conditions, and preblast survey requirements may be stricter, so confirm with the permitting agency and have a vibration consultant review disputed measurements. Criteria are as published and in effect in September 2026.
Frequently asked questions
No. The dB(V) vibration level index used in Korean and Japanese law has no US counterpart. American practice evaluates transit and construction vibration in VdB referenced to 1 microinch per second, and blasting vibration in peak particle velocity in inches per second.
Not reliably. VdB is based on an RMS velocity while PPV is a peak value, and the ratio between them depends on the waveform and crest factor of the event. Measure each quantity with the instrument setting the applicable criterion expects.