Put theory into practice. GeoSonics/Vibra-Tech’s custom mapping analysis helps you reduce ground vibration and get more out of your blasting holes.
GeoSonics/Vibra-Tech’s Vibra-Map is the original delay selection program available for commercial evaluation of blasting delays. Based in scientific wave motion theory, the analysis performed is designed to reduce ground vibration and can subsequently improve blasting fragmentation in the pit through the efficient design of blasthole detonation.
Blasting vibration is driven by the maximum pounds per delay detonated within milliseconds. For single hole blasts the blast is over and done. However, with multiple holes and multiple deck blasts, the overlapping patterns can reinforce the initial detonation wave, amplifying the resulting vibration. This causes higher ground vibration at off-property structures and increases complaints. It may also increase the low-frequency content of the waves generated, affecting the natural response of the adjacent structures and further increasing complaints. Longer duration delays cause structures to respond longer and with more effects. Delay selection to change frequency and affect off-site structure response is critical.
The Vibra-Map program uses single hole signature blasts for initial wave generation. With mapping and mathematical evaluation of the wave motion, time periods may be developed where cancellation of vibration pulses is achieved. While zero vibration is not possible, significant reductions in the motion can be achieved and provide a significant reduction in off-site motions.
Vibra-Map successes indicate reduction in vibration energy at the low natural frequency of the site. The reduction in energy at the natural frequency of the site helps reduce off-property concerns about ground vibration. The reduction in energy at the low natural frequency of the site alters the response of the structure, decreasing the amplification from ground motion into the building. This significant change has been responsible for reducing complaints and taking vibration levels out of the range of highest damage potential when compared to U.S. Bureau of Mines limitations. Further measurement and testing with Iso-Seis demonstrates successful results.