ABSTRACT To investigate the dynamic fracture mechanism related to blast-induced borehole breakdown and crack propagation, 2D distinct element commercial code was used. The dynamic stresses, material status and velocity vectors are plotted and shown to evaluate rock mass failure under blast load. This paper focuses on the propagation and dynamic effects of blast waves in continuum rock masses. In order to investigate the effect of high strain rate loading on rock mass failure, a numerical simulation was conducted. The 2D distinct element code was used to model blast load effect on rock failure and stress distribution through the rock mass due to blast wave propagation. The blast loading history was simplified and applied to the blasthole walls. Accordingly, the interaction of explosive energy transferred to the rock mass from the blasthole pressure was examined as a function of time. A Mohr-Coulomb material model was used for host rock to allow for plastic failure calculations. The conducted numerical study describes the role of dynamic stresses in blasting in a qualitative manner. On the other hand, a free face boundary was considered as a common blast operation which is conducted in surface mining.
Cite this paper
Z. Aliabadian, M. Sharafisafa and M. Nazemi, "Simulation of Dynamic Fracturing of Continuum Rock in Open Pit Mining," Geomaterials, Vol. 3 No. 3, 2013, pp. 82-89. doi: 10.4236/gm.2013.33011.
 S. Mchugh, “Crack Extension Caused by Internal Gas Pressure Compared with Extension Caused by Tensile Stress,” International Journal of Fracture, Vol. 21, No. 3, 1983, pp. 163-176. doi:10.1007/BF00963386
 J. R. Brinkman, “Separating Shock Waves and Gas Expansion Breakage Mechanisms,” Proceedings of the Second International Symposium on Rock Fragmentation by Blasting, Keystone, Colorado, 1989, pp. 6-15.
 A. S. Paine and C. P. Please, “An Improved Model of Fracture Propagation by Gas During Rock Blasting—Some Analytical Results,” International Journal of Rock Mechanics and Mining Sciences, Vol. 31, No. 6, 1994, pp. 699-706. doi:10.1016/0148-9062(94)90009-4
 A. Minchinton and P. M. Lynch, “Fragmentation and Heave Modeling Using a Coupled Discrete Element Gas Flow Code,” In: B. Mohanty, Ed., Proceedings of the 5th International Symposium on Rock Fragmentation by Blasting, Balkema, Rotterdam, 1996, pp. 71-80.
 A. Munjiza, J. P. Latham and K. R. F. Andrews, “Rock Fracture and Fragmentation Model in Coupled Analysis of Explosive Induced Rock Fragmentation,” Proceedings of the 6th International Symposium on Rock Fragmetation by Blasting, The South African Institute of Mining and Metallurgy, 1999, pp. 187-190.
 D. E. Grady and M. E. Kipp, “Continum Modeling of Explosive Fracture in Oil Shale,” International Journal of Rock Mechanics and Mining Sciences, Vol. 17, No. 3, 1980, pp. 147-157. doi:10.1016/0148-9062(80)91361-3
 R. H. Nilson, W. J. Proffer and R. E. Duff, “Modeling of Gas-Driven Fractures Induced by Propellant Combustion within an Explosion Cavity,” International Journal of Rock Mechanics and Mining Sciences, Vol. 22, No. 1, 1985, pp. 3-19. doi:10.1016/0148-9062(85)92589-6
 F. V. Donze, J. Bouchez and S. A. Magnier, “Modeling Fractures in Rock Blasting,” International Journal of Rock Mechanics and Mining Sciences, Vol. 34, No. 8, 1997, pp. 1153-1163.
 G. W. Ma, H. Hao and Y. X. Zhou, “Modeling of Wave Propagation Induced by Underground Explosion,” Computers and Geotechnics, Vol. 22, No. 3-4, 1998, pp. 283-303. doi:10.1016/S0266-352X(98)00011-1
 R. P. Jensen and D. S. Preece, “Modeling Explosive/Rock Interaction during Presplitting Using ALE Computation Methods,” Proceedings of the 6th International Symposium on Rock Fragmentation by Blasting, The South African Institute of Mining and Metallurgy, 1999, pp. 199-202.
 S. H. Cho and K. Kaneko, “Influence of the Applied Pressure Waveform on the Dynamic Fracture Processes in Rock,” International Journal of Rock Mechanics and Mining Sciences, Vol. 41, No. 5, 2004, pp. 771-784.
 D. C. Wyliie and C. W. Mah, “Rock Slope Engineering,” 4th Edition, Taylor & Francis, London, 2005.
 R. E. Danell and L. Leung, “Computer Simulation of Blast Fracture and Fragmentation of Rocks,” 2nd International Symposium on Rock Fragmentation by Blasting, Keystone, Colorado, 1987.
 Z. L. Wang, Y. C. Li and R. F. Shen, “Numerical Simulation of Tensile Damage and Blast Crater in Brittle Rock Due to Underground Explosion,” International Journal of Rock Mechanics and Mining Sciences, Vol. 44, No. 5, 2007, pp. 730-738. doi:10.1016/j.ijrmms.2006.11.004
 R. E. Goodman, “Methods of Geological Engineering in Discontinuous Rocks,” West Publishing, St. Paul, 1976.
 P. A. Cundall, “Numerical Modelling of Jointed and Faulted Rock,” In: H. P. Rossmanith, Ed., Mechanics of Jointed and Faulted Rock, A. A. Balkema, Rotterdam, 1990.
 C. S. Desai, M. M. Zaman, J. G. Lightner and H. J. Siriwardane, “Thin-Layer Element for Interfaces and Joints,” International Journal for Numerical and Analytical Methods, Vol. 8, No. 1, 1984, pp. 19-43.
 R. T. Coates and M. Schoenberg, “Finite Difference Modeling of Faults and Fractures,” Geophysics, Vol. 60, No. 5, 1995, pp. 1514-1526. doi:10.1190/1.1443884
 S. G. Chen and J. Zhao, “A Study of UDEC Modeling for Blast Wave Propagation in Jointed Rock Masses,” International Journal of Rock Mechanics and Mining Sciences, 1998, Vol. 35, No. 1, pp. 93-99.
 T. G. Sitharam, J. Sridevi and N. Shimizu, “Practical Equivalent Continuum Characterization of Jointed Rock Masses,” International Journal of Rock Mechanics and Mining Sciences, Vol. 38, No. 3, 2001, pp. 437-448.
 R. D. Hart, “An Introduction to Distinct Element Modelling for Rock Engineering,” In: J. A. Hudson, Ed., Comprehensive Rock Engineering, Vol. 2, 1996, pp. 245-261.
 E. Lopez, “Drilling and Blasting of Rocks,” A. A. Balkema, Netherlands, 1997.
 Z. Zhu, H. Xie and B. Mohanty, “Numerical Investigation of Blasting-Induced Damage in Cylindrical Rocks,” International Journal of Rock Mechanics and Mining Sciences, Vol. 45, No. 20, 2008, pp. 111-121.
 A. M. Starfield and J. M. Pugliese, “Compressional Waves Generated in Rock by Cylindrical Explosive Charges: A Comparison between a Computer Model and Field Measurements,” International Journal of Rock Mechanics and Mining Sciences, Vol. 5, No. 1, 1968, pp. 65-77.