An Investigation into the Performance of Bottom Air-Deck Method in the Presence of Water, Using SPH-FEM

نوع مقاله : مقاله پژوهشی

نویسندگان

1 Dept. of Mining Engineering, Shahid Bahonar University of Kerman, Kerman, Iran

2 Dept. of Mechanical Engineering, Shahid Bahonar University of Kerman, Kerman, Iran

10.22034/anm.2025.21431.1631

چکیده

The use of the bottom air-deck method in open-pit blasting has been widely accepted by researchers as an efficient technique. In this method, leaving an empty space (air-deck) at the bottom of the blast hole improves the blast results. However, if the blast hole is filled with water, the presence of water may affect the blast results. In such cases, it is necessary to study the effect of the water in the air-deck area on blasting performance. In this research, a numerical method was used to investigate the effect of the presence of water in the blast hole on the blasting results in the bottom air-deck method. Considering the advantages of the SPH method in modeling the fractures caused by blasting and the advantage of the FEM method in terms of processing time, the combined SPH-FEM method was used to carry out the simulation. The Dehghan-Banadki empirical model was employed to validate the model and determine the SPH parameters. The results showed that due to the incompressibility of water, more pressure produced by the explosive detonation is transferred to the rock, Additionally, water causes attenuation of the blast wave and reduces the wave frequency. In a dry blast hole, despite the decrease in the initial wave pressure compared to a water-filled blast hole, multiple reflections of the wave in the empty space lead to longer duration waves and absorption of explosive energy by the rock. The peak effective stress taken at different distances around the blast hole in the air-deck area showed that the maximum stress applied to the rock in the water-filled blast hole is higher. The results also indicated that the total length of fractures in the dry blasting condition is 13.15 m, while in the water-filled blast hole blasting, it is 12.5 m. Therefore, the total length of fractures in the dry blast hole is only 5% more than in the water-filled blast hole. In other words, the presence of water in the air-deck area does not have a negative effect on the blasting results, and thus, this method can also be used in water-filled blast holes.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

An Investigation into the Performance of Bottom Air-Deck Method in the Presence of Water, Using SPH-FEM

نویسندگان [English]

  • Mehrdad Moradi 1
  • Mohammad Ali Ebrahimi Farsangi 1
  • Hamid Mansori 1
  • Mohsen Saffari Pour 2
1 Dept. of Mining Engineering, Shahid Bahonar University of Kerman, Kerman, Iran
2 Dept. of Mechanical Engineering, Shahid Bahonar University of Kerman, Kerman, Iran
چکیده [English]

The use of the bottom air-deck method in open-pit blasting has been widely accepted by researchers as an efficient technique. In this method, leaving an empty space (air-deck) at the bottom of the blast hole improves the blast results. However, if the blast hole is filled with water, the presence of water may affect the blast results. In such cases, it is necessary to study the effect of the water in the air-deck area on blasting performance. In this research, a numerical method was used to investigate the effect of the presence of water in the blast hole on the blasting results in the bottom air-deck method. Considering the advantages of the SPH method in modeling the fractures caused by blasting and the advantage of the FEM method in terms of processing time, the combined SPH-FEM method was used to carry out the simulation. The Dehghan-Banadki empirical model was employed to validate the model and determine the SPH parameters. The results showed that due to the incompressibility of water, more pressure produced by the explosive detonation is transferred to the rock, Additionally, water causes attenuation of the blast wave and reduces the wave frequency. In a dry blast hole, despite the decrease in the initial wave pressure compared to a water-filled blast hole, multiple reflections of the wave in the empty space lead to longer duration waves and absorption of explosive energy by the rock. The peak effective stress taken at different distances around the blast hole in the air-deck area showed that the maximum stress applied to the rock in the water-filled blast hole is higher. The results also indicated that the total length of fractures in the dry blasting condition is 13.15 m, while in the water-filled blast hole blasting, it is 12.5 m. Therefore, the total length of fractures in the dry blast hole is only 5% more than in the water-filled blast hole. In other words, the presence of water in the air-deck area does not have a negative effect on the blasting results, and thus, this method can also be used in water-filled blast holes.

کلیدواژه‌ها [English]

  • Rock blasting
  • Air-deck
  • Water-deck
  • SPH-FEM
  • LS-Dyna
[1]       Ozer, U. (2008). Environmental impacts of ground vibration induced by blasting at different rock units on the Kadikoy–Kartal metro tunnel. Engineering geology, 100(1-2), 82-90.
[2]       Jhanwar, J. C., Jethwa, J. L., & Reddy, A. H. (2000). Influence of air-deck blasting on fragmentation in jointed rocks in an open-pit manganese mine. Engineering Geology, 57(1-2), 13-29.
[3]       Jhanwar, J. C., & Jethwa, J. L. (2000). The use of air decks in production blasting in an open pit coal mine. Geotechnical & Geological Engineering, 18, 269-287.
[4]       Sazid, M., & Singh, T. N. (2013, May). Mechanism of air deck technique in rock blasting-a brief review. In Fourth Indian Rock Conference, no. May (pp. 29-31).
[5]       Jhanwar, J. C. (2011). Theory and practice of air-deck blasting in mines and surface excavations: a review. Geotechnical and Geological Engineering, 29(5), 651-663.
[6]       Rowlands, M. D. (1991, November). Separating explosive charges with air gaps to improve fragmentation whilst reducing explosive usage: Proc 2nd Conference on Large Open Pit Mining, Latrobe Valley, 3–6 April 1989 P105–107. Publ Melbourne: AusIMM, 1989. In International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts (Vol. 28, No. 6, p. A371). Pergamon.
[7]       Correa, C. E. (2003). Use of air-decks to reduce subdrillings in Escondida mine. Fragblast, 7(2), 79-86.
[8]       Chiappetta, R. F. (2004). New blasting technique to eliminate subgrade drilling, improve fragmentation, reduce explosive consumption and lower ground vibrations. Journal of explosives engineering, 21(1), 10-12.
[9]       Floyd, J. (2004). Power deck optimization. Power Deck Company. Blast Dynamics.
[10]   Askari Badoee, M. J., Ebrahimi Farsangi, M. A., Mansouri, H., & Mansour Panahi, A. M. (2018). Application of power-deck in wet candition, case study, Goharzamin iron ore mine. 12th International Symposyom on Rock Fragmentatin by Blasting.
[11]   Zarei, M., Shahabi, R. S., Hadei, M. R., & Louei, M. Y. (2022). The use of air decking techniques for improving surface mine blasting. Arabian Journal of Geosciences, 15(19), 1545.
[12]   Zhu, Z., Mohanty, B., & Xie, H. (2007). Numerical investigation of blasting-induced crack initiation and propagation in rocks. International Journal of Rock Mechanics and Mining Sciences, 44(3), 412-424.
[13]   Bendezu, M., Romanel, C., & Roehl, D. (2017). Finite element analysis of blast-induced fracture propagation in hard rocks. Computers & Structures, 182, 1-13.
[14]   Gui, Y. L., Bui, H. H., Kodikara, J., Zhang, Q. B., Zhao, J., & Rabczuk, T. (2016). Modelling the dynamic failure of brittle rocks using a hybrid continuum-discrete element method with a mixed-mode cohesive fracture model. International Journal of Impact Engineering, 87, 146-155.
[15]   Rabczuk, T., Zi, G., Bordas, S., & Nguyen-Xuan, H. (2010). A simple and robust three-dimensional cracking-particle method without enrichment. Computer Methods in Applied Mechanics and Engineering, 199(37-40), 2437-2455.
[16]   Rabczuk, T., & Belytschko, T. (2004). Cracking particles: a simplified meshfree method for arbitrary evolving cracks. International journal for numerical methods in engineering, 61(13), 2316-2343.
[17]   Rabczuk, T., & Belytschko, T. (2007). A three-dimensional large deformation meshfree method for arbitrary evolving cracks. Computer methods in applied mechanics and engineering, 196(29-30), 2777-2799.
[18]   Rabczuk, T., Bordas, S., & Zi, G. (2010). On three-dimensional modelling of crack growth using partition of unity methods. Computers & structures, 88(23-24), 1391-1411.
[19]   Fan, H., Bergel, G. L., & Li, S. (2016). A hybrid peridynamics–SPH simulation of soil fragmentation by blast loads of buried explosive. International Journal of Impact Engineering, 87, 14-27.
[20]   Morris, J. P., Rubin, M. B., Block, G. I., & Bonner, M. P. (2006). Simulations of fracture and fragmentation of geologic materials using combined FEM/DEM analysis. International Journal of Impact Engineering, 33(1-12), 463-473.
[21]   Fakhimi, A., & Lanari, M. (2014). DEM–SPH simulation of rock blasting. Computers and Geotechnics, 55, 158-164.
[22]   Xu, J. X., & Liu, X. L. (2008). Analysis of structural response under blast loads using the coupled SPH-FEM approach. Journal of Zhejiang University-SCIENCE A, 9(9), 1184-1192.
[23]   Gharehdash, S., Shen, L. M., Gan, Y. X., & Flores-Johnson, E. A. (2016). Numerical investigation on fracturing of rock under blast using coupled finite element method and smoothed particle hydrodynamics. Applied Mechanics and Materials, 846, 102-107..
[24]   Ning, Y., Yang, J., An, X., & Ma, G. (2011). Modelling rock fracturing and blast-induced rock mass failure via advanced discretisation within the discontinuous deformation analysis framework. Computers and Geotechnics, 38(1), 40-49.
[25]   Wang, Z. L., Li, Y. C., & Shen, R. F. (2007). Numerical simulation of tensile damage and blast crater in brittle rock due to underground explosion. International Journal of Rock Mechanics and Mining Sciences, 44(5), 730-738.
[26]   Liu, M. B., & Liu, G. (2010). Smoothed particle hydrodynamics (SPH): an overview and recent developments. Archives of computational methods in engineering, 17, 25-76.
[27]   Gingold, R. A., & Monaghan, J. J. (1977). Smoothed particle hydrodynamics: theory and application to non-spherical stars. Monthly notices of the royal astronomical society, 181(3), 375-389.
[28]   Vignjevic, R., & Campbell, J. (2009). Review of development of the smooth particle hydrodynamics (SPH) method. In Predictive modeling of dynamic processes: a tribute to professor Klaus Thoma (pp. 367-396). Boston, MA: Springer US.
[29]   Feng, Y., Jianming, W., & Feihong, L. (2012). Numerical simulation of single particle acceleration process by SPH coupled FEM for abrasive waterjet cutting. The International Journal of Advanced Manufacturing Technology, 59, 193-200.
[30]   Rabczuk, T., & Eibl, J. (2003). Simulation of high velocity concrete fragmentation using SPH/MLSPH. International Journal for Numerical Methods in Engineering, 56(10), 1421-1444.
[31]   Hu, Y., Lu, W., Chen, M., Yan, P., & Zhang, Y. (2015). Numerical simulation of the complete rock blasting response by SPH–DAM–FEM approach. Simulation Modelling Practice and Theory, 56, 55-68.
[32]   Gharehdash, S., Shen, L. M., Gan, Y. X., & Flores-Johnson, E. A. (2016). Numerical investigation on fracturing of rock under blast using coupled finite element method and smoothed particle hydrodynamics. Applied Mechanics and Materials, 846, 102-107.
[33]   Wang, Z. L., Huang, Y. P., Li, S. Y., & Xiong, F. (2020, October). SPH-FEM coupling simulation of rock blast damage based on the determination and optimization of the RHT model parameters. In IOP conference series: earth and environmental science (Vol. 570, No. 4, p. 042035). IOP Publishing.
[34]   Melnikov, N. V., & Marchenko, L. N. (1970, November). Effective methods of application of explosion energy in mining and construction. In ARMA US Rock Mechanics/Geomechanics Symposium (pp. ARMA-70). ARMA.
[35]   Mel’Nikov, N. V., Marchenko, L. N., Zharikov, I. F., & Seinov, N. P. (1979). A method of enhanced rock breaking by blasting. Soviet Mining, 15(6), 565-572.
[36]   Hayat, M. B., Alagha, L., & Ali, D. (2019). Air decks in surface blasting operations. Journal of Mining Science, 55, 922-929.
[37]   Moxon, N. T., Mead, D., & Richardson, S. B. (1993). Air-decked blasting techniques: some collaborative experiments. Transactions of the Institution of Mining and Metallurgy. Section A. Mining Industry, 102.
[38]   Lucy, L. B. (1977). A numerical approach to the testing of the fission hypothesis. Astronomical Journal, vol. 82, Dec. 1977, p. 1013-1024., 82, 1013-1024.
[39]   Liu, G. R., & Liu, M. B. (2003). Smoothed particle hydrodynamics: a meshfree particle method. World scientific.
[40]   Nguyen, V. P., Rabczuk, T., Bordas, S., & Duflot, M. (2008). Meshless methods: a review and computer implementation aspects. Mathematics and computers in simulation, 79(3), 763-813.
[41]   Liu, G. R., & Liu, M. B. (2003). Smoothed particle hydrodynamics: a meshfree particle method. World scientific.
[42]   Libersky, L. D., Randles, P. W., Carney, T. C., & Dickinson, D. L. (1997). Recent improvements in SPH modeling of hypervelocity impact. International Journal of Impact Engineering, 20(6-10), 525-532.
[43]   Vignjevic, R., De Vuyst, T., Campbell, J. C., & Source, C. (2006). A frictionless contact algorithm for meshless methods. Computer Modeling in Engineering and Sciences, 13(1), 35.
[44]   LS-DYNA. (2015). Keyword user’s manual, Version R9.0.1. Livermore, CA. Livermore Software Technology Corporation.
[45]   Gharehdash, S., Barzegar, M., Palymskiy, I. B., & Fomin, P. A. (2020). Blast induced fracture modelling using smoothed particle hydrodynamics. International Journal of Impact Engineering, 135, 103235.
[46]   Swegle, J. W., Hicks, D. L., & Attaway, S. W. (1995). Smoothed particle hydrodynamics stability analysis. Journal of computational physics, 116(1), 123-134.
[47]   Koneshwaran, S., Thambiratnam, D. P., & Gallage, C. (2015). Performance of buried tunnels subjected to surface blast incorporating fluid-structure interaction. Journal of Performance of Constructed Facilities, 29(3), 04014084.
[48]   Jhanwar, J. C. (1998). Investigation into air-deck blasting and its influence on blast performance and economics in open-pit mines. Unpublished ME Thesis, Department of Mining Engineering, Visvesvaraya Regional College of Engineering, Nagpur University, Nagpur, India, 142.
[49]   Johnson, G. R., & Holmquist, T. J. (1999). Response of boron carbide subjected to large strains, high strain rates, and high pressures. Journal of applied physics, 85(12), 8060-8073.
[50]   Ai, H. A., & Ahrens, T. J. (2006). Simulation of dynamic response of granite: A numerical approach of shock-induced damage beneath impact craters. International Journal of Impact Engineering, 33(1-12), 1-10.
[51]   Ma, G. W., & An, X. M. (2008). Numerical simulation of blasting-induced rock fractures. International Journal of Rock Mechanics and Mining Sciences, 45(6), 966-975.
[52]   Dobratz, B. M. (1972). Properties of chemical explosives and explosive simulants (No. UCRL-51319; UCRL-51319 (REV. 1)). comp. and ed.; Lawrence Livermore National Lab.(LLNL), Livermore, CA (United States).
[53]   Banadaki, M. D., & Mohanty, B. (2012). Numerical simulation of stress wave induced fractures in rock. International Journal of Impact Engineering, 40, 16-25.
[54]   Banadaki, M. M. D. (2010). Stress-wave induced fracture in rock due to explosive action (p. 128). Toronto: University of Toronto.
[55]   Moradi, M., Mansouri, H., Ebrahimi Farsangi, M. A., & Saffari Pour, M. (2024). Modelling of bottom air-deck blasting in a Single Hole, Using the SPH–FEM Method. Geotechnical and Geological Engineering, 1-21.
[56]   Thote, N. R., & Singh, D. P. (2000). Effect of airdecking on fragmentation: A few case studies of Indian mining. Explosives and Blasting Technique. Rotterdam.
[57]   Chiappetta, R. F. (1992, June). Precision detonators and their applications in improving fragmentation, reducing ground vibrations and increasing reliability—a look into the future. In Proceeding of 4th high tech seminar blasting technology instrumentation and explosives applications. Tennessee (pp. 1-39).