Blasting Scaled-Distance & PPV Estimator

About the Blasting Scaled-Distance & PPV Estimator

The scaled-distance calculator assists mining engineers, demolition experts, and seismologists in actively mitigating blast-induced ground vibration. By correlating explosive charge weight with the physical distance to nearby structures, you can reliably estimate Peak Particle Velocity (PPV) and ensure operational compliance with strict vibration limits.

How it works

1. Input the distance from the blast hole to the nearest sensitive structure.
2. Enter the maximum weight of explosives detonated per 8-millisecond delay.
3. Review the Scaled Distance factor and estimated PPV to confirm your blast design remains within safe limits.

Frequently asked questions

How is Scaled Distance calculated?

Scaled Distance is calculated by dividing the physical distance to the structure by the square root of the maximum charge weight per delay.

What is Peak Particle Velocity (PPV)?

PPV is the maximum speed at which a particle of ground moves back and forth as a seismic wave passes through it. It is the primary metric for predicting structural damage.

What Scaled Distance guarantees compliance without a seismograph?

Under federal surface mining regulations, maintaining a Scaled Distance of 50 or greater typically allows operators to blast without deploying a seismograph.

Why are explosive weights calculated 'per delay'?

Blasting relies on millisecond delays between holes to stagger seismic energy. Only the maximum weight of explosives firing within an 8-millisecond window is considered the active charge.

References

• OSMRE (Office of Surface Mining Reclamation and Enforcement) Blasting Performance Standards
• USBM RI 8507 Structure Response and Damage Produced by Ground Vibration