Freda Serwaa Frimpong is the author if this article
People living near quarries and surface mines in Ghana often notice that some blasts seem louder or more “violent” than others, even when the company says it used the same number of explosives.
This raises important questions about why some days feel worse than others for nearby communities.
Recent field work from my blasting study suggests that everyday weather and local terrain can play a big role.
Instead of looking only at explosive weight and distance, the project examined conditions such as temperature, wind and the height of the ground between the blast and the seismographs that recorded air overpressure.
These simple factors are present at every quarry, but they are often ignored when people judge whether a blast was “too strong”.
The study found that changes in weather and terrain can either increase or reduce the air pressure from blasts by the time it reaches homes and other structures.
This helps explain why noise and vibration complaints can vary from day to day, even when designs follow the same guidelines and the same number of explosives is used.
For Ghana, where many communities live close to quarry and mining operations, this has practical implications.
Taking basic weather and terrain information into account when planning blasts and placing seismographs or other sensors could help operators choose better blasting times and reduce complaints.
It would also give regulators and local leaders a more realistic picture of blast effects, based not only on paperwork but also on how conditions in the air and on the ground can change what people actually feel.
Freda Serwaa Frimpong
PhD Student, Mining Engineering
A member of the energetic Research Team
Missouri University of Science & Technology
Source:
www.ghanaweb.com