Empirical approach to estimate rock mass damage from long-hole winze (LHW) blasting

Abstract

Long-hole winze (LHW) blasting is a critical stage of production in underground sublevel open stoping; however, its influence on potential excavation damage is often overlooked. In addition, recent developments in uphole LHW practices are implementing longer firing lengths, sometimes exceeding 15–20 m on a single blast. This has the potential to increase the likelihood of blast-related damage. This paper introduces an empirical approach to determine long-hole winze firing heights to minimise near-field rock mass damage. The degree of damage is estimated from the amplitude of peak particle velocities induced by the LHW blasts. Modelling was conducted to evaluate the relationship between peak particle velocity (PPV) as a function of LHW firing heights and distance to a point of interest. A hypothesis was established and further verified with direct measurements from a comprehensive near-field vibration monitoring programme conducted at a large sublevel open stoping operation in Australia. An empirical model to estimate PPV as a function of a non-dimensional factor was established. The model is defined by the ratio of the distance to a point of interest and the LHW firing height. This model may be used to determine the recommended advance and firing phases of a LHW to minimise potential damage to open stope boundaries.

Keywords

Long-hole winze blasting Underground production blasting Blast damage Damage modelling Peak particle velocity

Get full access to this article

View all access options for this article.

References

Dexin

1997. A case study on long hole raising by shooting to relief holes. Transactions of Nonferrous Metals Society of China, 7, (3), 159–162.

Dobran

M F.

1996. Comparison of techniques used to develop a slot raise, in Proceedings of the 22nd Annual Conference on Explosives and Blasting Technique, Orlando, Florida, Cleveland, OH, International Society of Explosives Engineers, 120–135.

Favreau

R. F.

, Kuzyk

G. W.

, Babulic

P. J.

, Morin

R. A.

and Tienkamp

N. J.

1989. The use of computer blast simulations to improve blast quality. The Canadian Mines and Metallurgical Bulletin, 82, (921), 34–42.

Ferreira

P. H.

2003. Improved technologies in longhole blast hole drilling, applied to dropraising and longhole stoping as well as the application of a small twin boom mechanized drilling. The Journal of the South African Institute of Mining and Metallurgy, 103, (1), 233–240.

Fleetwood

K. G.

and Villaescusa

2010. Blast vibration monitoring and elastic wave reflection models to assess blast-induced damage to mine infrastructure – an underground case study, in Proceedings of the 20th International Symposium on Mine Planning and Equipment Selection, Fremantle, Australia, Victoria, Australia, The Australasian Institute of Mining and Metallurgy, 165–178.

Furtney

J. K.

, Cundall

P. A.

and Chitombo

G. P.

2010. Developments in numerical modeling of blast induced rock fragmentation: Updates from the HSBM project, in Proceedings of the 9th International Symposium on Rock Fragmentation by Blasting – Fragblast 9, Granada, Spain (ed. Sanchidrián

), London, Taylor & Francis Group, 335–342.

Hassell

, Villaescusa

, de Vries

and Player

2015. Stope blast vibration analysis at Dugald River Mine, Proceedings of the 11th International Symposium of Rock Fragmentation by Blasting, Sydney, AusIMM, 221–231.

Onederra

I. A.

, Chitombo

G. P.

, Cundall

P. A.

and Furtney

J. K.

2010. Towards a complete validation of the lattice scheme in the Hybrid Stress Blasting Model (HSBM), in Proceedings of the 9th International Symposium on Rock Fragmentation by Blasting – Fragblast 9, Granada, Spain (ed. Sanchidrián

), London, Taylor & Francis Group, 343–351.

Onederra

I. A.

, Furtney

J. K.

, Sellers

, & Iverson

2013. Modelling blast induced damage from a fully coupled explosive charge, International Journal of Rock Mechanics and Mining Sciences, 58, 73–84.10.1016/j.ijrmms.2012.10.004

10.

Persson

, Holmberg

and Lee

1994. Rock blasting and explosives engineering, Boca Raton, FL, CRC Press, 244–248.

11.

Villaescusa

2000. A review of sublevel stoping, in Proceedings of MassMin 2000, Brisbane, Queensland, Victoria, Australia, The Australian Institute of Mining and Metallurgy, 577–582.

12.

Villaescusa

2014a. Blast monitoring of sublevel open stoping production blasting, research project (unpublished), Kalgoorlie, Curtin University of Technology.

13.

Villaescusa

2014b. Geotechnical design for sublevel open stoping, Boca Raton, FL, CRC Press, 19–45 and 245–312.10.1201/b16702

14.

Villaescusa

and Neindorf

L. B.

2000. Damage to stope walls from underground blasting, in Proceedings of Sixth International Conference on Structures under Shock and Impact, Cambridge, Massachusetts (eds. Jones

and Brebbia

C. A.

), Southampton, WIT Press, 129–140.

15.

Villaescusa

, Onederra

and Scott

2004. Blast induced damage and dynamic behaviour of hangingwalls in bench stoping, Fragblast – The International Journal of Blasting and Fragmentation, 8, (1), 23–40.

16.

Villaescusa

, Tyler

and Scott

1997. Predicting underground stability using a hangingwall stability rating, in Proceedings of Environmental & Safety Concerns in Underground Construction, Rotterdam, Netherlands (eds. Lee

, Yang

and Chung

), Rotterdam, A.A. Balkema, 171–176.