Prediction and Minimisation of Blast Vibrations from the Footwallens

Christen, Peter (2004). Prediction and Minimisation of Blast Vibrations from the Footwallens Honours Thesis, School of Engineering, The University of Queensland.

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Author Christen, Peter
Thesis Title Prediction and Minimisation of Blast Vibrations from the Footwallens
School, Centre or Institute School of Engineering
Institution The University of Queensland
Publication date 2004
Thesis type Honours Thesis
Supervisor Shivakumar Karekel
Total pages 122
Language eng
Subjects 091405 Mining Engineering
Formatted abstract
The Xstrata Copper, Mount Isa Copper Mines, like many other hard rock mines has the potential to experience vibration issues. These issues have environmental, social, safety and production impacts. This thesis has been compiled to document the causes and effects of vibrations experienced at Mount Isa, in addition to suggesting alleviation strategies.

The aims of this thesis are to create a method of accurately predicting vibrations at Mount Isa as well as to establish a blast design that has the ability to produce minimal vibrations without impacting on the other functions of the blast. The goal of accurately predicting vibrations was achieved through the characterisation of sitespecific attenuation characteristics and the use of the principle of superposition to simulate vibrations. This process also makes use of the Monte Carlo method to assess the range of possible vibrations associated with variations in the attenuation characteristics. The simulation model was then used to predict vibrations resulting from different blast designs to determine what effect changes to the blast hole diameter and detonation method would have on the vibrations.

Through the use of this analysis it was established that electronic delay detonators could significantly reduce vibrations from all designs due to their accurate firing times and their ability to have specifically set delay intervals. The optimal Peak Particle Velocity (PPV) response from the 140mm diameter design was reduced from 13.2mm/s when using pyrotechnic delay detonators to 8.5mm/s when using electronic delay detonators. In contrast to this the alterations made to the blast hole diameter was only able to achieve a reduction of 0.3mm/s to 12.9mm/s (127mm diameter blast hole). When the options were combined the optimal PPV blast vibration was 5.8mm/s (102mm blast hole diameter fired at 29ms) assuming the blast duration was kept constant with the original, pyrotechnically fired blast. Conversely, if the designs based on varied blast hole diameters were fired within the same duration as the optimal 140mm blast hole diameter design (32ms intervals) the vibrations produced for all of the other designs considered would increase.

In Conclusion although this thesis is specifically dedicated to the Footwall Lens of the Mount Isa Copper Mines the analysis carried out can be adapted to other operations to assist with alleviation of blast vibration issues.
Keyword Footwallens

Document type: Thesis
Collection: UQ Theses (non-RHD) - UQ staff and students only
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Created: Thu, 11 Dec 2014, 10:51:09 EST by Asma Asrar Qureshi on behalf of Scholarly Communication and Digitisation Service