Rock fracturing mechanisms by blasting
Optimizing blast fragmentation and reducing the damage from it are two important research subjects in this field. Detonation and explosive charge induces three sets of tension cracks in the monolith rock. Radial tension cracks are formed under the influence of the pressure wave whose cylindrical propagation induces tension. Along with the explanation of how radial cracks are formed, formulation is given as to how their length can be calculated using laboratory and drill and blast parameters. Cracks subparallel with the free surface (face) are related with amounts of absorbed and recoverable strain energies. The distance between subsequent cracks can be calculated using the results of simple load-unload laboratory tests. Third sets of tension cracks are formed as a result of excessive deformation of the beam or cantilever formed by radial cracks. Once the length of the cracks and the distance between them are known, it is possible to apply these results for estimation of fragment sizes and blasting pattern design.
CUNNINGHAM, C. (1983) The Kuz-Ram Model for production of fragmentation from blasting. In: Proc. 1st Symp. on Rock Fragmentation by Blasting, Lulea. Lulea.
CUNNINGHAM, C. (2006) Blasthole Pressure: What it really means and how we should use it. In: Proceedings of the annual conference on explosives and blasting technique, 32, pp. 255.
ESEN, S., ONEDERRA, I. and BILGIN, H. A. (2003) Modelling the size of the crushed zone around a blasthole. International Journal of Rock Mechanics and Mining Sciences, 40, pp. 485-495.
GHEIBIE, S. et al. (2009) Modified Kuz—Ram fragmentation model and its use at the Sungun Copper Mine. International Journal of Rock Mechanics and Mining Sciences, 46, pp. 967-973.
GOODARZI, M., MOHAMMADI, S. and JAFARI, A. (2015) Numerical analysis of rock fracturing by gas pressure using the extended finite element method. Petroleum Science, 12, pp. 304-315.
HU, R. et al. (2015) Numerical study on crack propagation by using softening model under blasting. Advances in Materials Science and Engineering.
HUSTRULID, W. and LU, W. (2002) Some general design concepts regarding the control of blast-induced damage during rock slope excavation. In: Proc. 7th Rock Fragmentation by Blasting.
KWON, S. et al. (2009). An investigation of the excavation damaged zone at the KAERI underground research tunnel. Tunnelling and underground space technology, 24, pp. 1-13.
MAVKO, G., MUKERJI, T. and DVORKIN, J. (2009) The rock physics handbook: Tools for seismic analysis of porous media. Cambridge university press.
OLSSON, M. and BERGQVIST, I. (1996) Crack lengths from explosives in multiple hole blasting. In: Proceedings of the Fifth International Symposium on Rock Fragmentation by Blasting, Fragblast-5, Montreal, Quebec, Canada, pp. 187-91. Monteral.
OUCHTERLONY, F. (1997) Prediction of crack lengths in rock after cautious blasting with zero inter-hole delay. In: Fragblast, 1, pp. 417-444.
OUCHTERLONY, F. (2005) The Swebrec© function: linking fragmentation by blasting and crushing. Mining Technology, 114, pp. 29-44.
OUCHTERLONY, F., OLSSON, M. and BERGQVIST, I. (2002) Towards new Swedish recommendations for cautious perimeter blasting. In: Fragblast, 6, pp. 235-261.
SAHARAN, M. R. and MITRI, H. S. (2008) Numerical procedure for dynamic simulation of discrete fractures due to blasting. Rock mechanics and rock engineering, 41, pp. 641-670.
TORBICA, S. and LAPCEVIC, V. (2014) Rock breakage by explosives. European International Journal of Science and Technology, 3, pp. 96-104.
TORBICA, S. and LAPČEVIĆ, V. (2015) Estimating extent and properties of blast-damaged zone around underground excavations. Rem: Revista Escola de Minas, 68, pp. 441-453.
WHITTAKER, B. N., SINGH, R. N. and SUN, G. (1992) Rock fracture mechanics: principles, design, and applications. Elsevier.
YI, C., SJÖBERG, J. and JOHANSSON, D. (2017) Numerical modelling for blast-induced fragmentation in sublevel caving mines. Tunnelling and Underground Space Technology, 68, pp. 167-173.
ZHU, Z., MOHANTY, B. and XIE, H. (2007) Numerical investigation of blasting-induced crack initiation and propagation in rocks. International Journal of Rock Mechanics and Mining Sciences, 44, pp. 412-424.
This work is licensed under a Creative Commons Attribution 4.0 International License.