DOI https://doi.org/10.36487/ACG_rep/1410_36_Mohanty
Cite As:
Mohanty, B, Zwaan, D & Trivino, L 2014, 'Investigation of stope blast designs in a deep underground mine through vibration analysis', in M Hudyma & Y Potvin (eds),
Deep Mining 2014: Proceedings of the Seventh International Conference on Deep and High Stress Mining, Australian Centre for Geomechanics, Perth, pp. 525-532,
https://doi.org/10.36487/ACG_rep/1410_36_Mohanty
Abstract:
A comprehensive blast monitoring program was carried out in multiple stopes at depths between 2,000 and 2,350 m levels in a deep underground copper–nickel mine. The diagnostic tools employed weremulti-station high frequency (>10 kHz) and high-g (50-100 g) triaxial accelerometers, at distances ranging from 10 to 50 m from the blasts. A total of over 30 production blasts were monitored in both low-stress and high-stress stopes, with the objective of determining the energy release characteristics of both single and multiple deck blasts, and identify the degree of malfunction if any in explosive energy release as indicated by the resulting blasting vibrations at these deep levels, and specific to each blast design. Packaged water-gel explosives with an average charge weight of 35 kg/deck were employed in 162 mm diameter boreholes in these fan-drilled blasts. Analysis showed that only ~30% of the explosive decks yielded acceptable levels of energy (40-100% of the expected levels), whereas an equal number either failed or yielded <40% of the expected vibration energy. It points to an unacceptable level of blast malfunctions, which would adversely affect dilution control and overall productivity. The various possible causes of these malfunctions have been discussed and remedial measures proposed to overcome these problems.
References:
Bjarnholt, G & Holmberg, R 1976, ‘Explosives expansion work in underwater detonations’, in DJ Edwards & SJ Jacobs (eds), Proceedings of the 6th International Symposium on Detonation, US Government Printing Office, Washington, pp. 540-550.
Farnfield, R 1996, ‘So you think you are monitoring peak particle velocity’, Proceedings of the 12th Symposium on Explosives and Blasting Research, International Society of Explosives Engineers, Cleveland, pp. 13-20.
Fleetwood, KG, Villaescusa, E, Li, J & Varden, R 2009, ‘Comparison of traditional near-field vibration prediction models with three-dimensional vibration scaling and blast wave energy’, in JA Sanchidrian (ed.), Proceedings of the 9th International Symposium on Rock Fragmentation by Blasting: FRAGBLAST 9, CRC Press, Boca Raton, pp. 579-588.
Lee, R, Rodgers, J & Whitaker, K 2000, ‘Explosives malfunctions in decked blasts’, Proceedings of the 26th Annual Conference on Explosives and Blasting Technology, International Society of Explosives Engineers, Cleveland, pp. 25-34.
Mohanty, B 1981, ‘Energy, strength and performance; and their implication in rating commercial explosives’, Proceedings of the 7th Annual Conference on Explosives and Blasting Technology, International Society of Explosives Engineers, Cleveland,pp. 293-306.
Mohanty, B & Yang, R 1997, ‘Blasting vibrations and explosives performance’, Proceedings of the 13th Annual Symposium on Explosives and Blasting Research, International Society of Explosives Engineers, Cleveland, pp. 15-28.
Mohanty, B 2000, ‘The Underwater Test as a tool for rating explosives’, Proceedings of the 26th Annual Conference Explosives and Blasting Technology, vol. 2, International Society Explosives Engineers, Cleveland, pp. 9-24.
Mohanty, B 2009, ‘Intra-hole and inter-hole effects in typical blast designs and their implications on explosives energy release and detonator delay time—A critical review’, in JA Sanchidrian (ed.), Proceedings of the 9th International Symposium on Rock Fragmentation by Blasting: FRAGBLAST 9, CRC Press, Boca Raton, pp. 23-31.
Mohanty, B, Zwaan, D & Malek, F 2013, ‘Diagnostics of Production Blasts in a Deep Underground Mine’, Engineering and Mining Journal, pp. 52-57.
Segarra, P, Sanchidrian, JA, Lopez, JM, Querol, E & Guiterrez, J 2009, ‘Assessment of the error of blast vibration measurements’, in JA Sanchidrian (ed.), Proceedings of the 9th International Symposium on Rock Fragmentation by Blasting: FRAGBLAST 9, CRC Press, Boca Raton, pp. 551-560.