Abstract
In mining, the explosive filled in each borehole is usually initiated by the detonator. However, the effect of the location of the detonator (i.e. initiation location), which determines the propagation direction of the detonation wave, cannot be ignored. In this study, the influence mechanism of initiation location was analyzed with the help of numerical simulation. Two blasting experiments were also conducted to study the effect of initiation location. The results indicate that the initiation location plays an important role in the distribution of the explosion energy transmitted to the surrounding rock mass. For the vertical borehole blasting, the peak particle velocity below the borehole can be reduced by 21.0–59.0% under bottom initiation, when compared to top initiation. The blast-induced damage of the remaining rock mass below the borehole is also weaker by 5.0–8.9% under bottom initiation. However, the problem of under break might become serious if the detonator is moved downwards in foundation excavation. The explosion energy is preferentially transmitted to the same orientation of the detonation wave during rock blasting. The bottom initiation, recommended by most previous researchers, is not always the best choice. The location of the detonator should be changed according to the onsite situations.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Abozena AM (1977) Radiation from a finite cylindrical explosive source. Geophysics 42(7):1384–1393. https://doi.org/10.1190/1.1440799
Blair DP (2010) Seismic radiation from an explosive column. Geophysics 75(1). https://doi.org/10.1190/1.3294860
Cui ZD (2011) Effect of water–silt composite blasting on the stability of rocks surrounding a tunnel. Bull Eng Geol Environ 70(4):657–664. https://doi.org/10.1007/s10064-010-0346-3
Ebrahimi E, Monjezi M, Khalesi MR et al (2016) Prediction and optimization of back-break and rock fragmentation using an artificial neural network and a bee colony algorithm. Bull Eng Geol Environ 75(1):27–36. https://doi.org/10.1007/s10064-015-0720-2
Favreau RF (1969) Generation of strain waves in rock by an explosion in a spherical cavity. J Geophys Res 74(17):4267–4280. https://doi.org/10.1029/jb074i017p04267
Fry RS, Nicholls JA (1974) Blast initiation and propagation of cylindrical detonations in mapp-air mixtures. AIAA J 12(12):1703–1708. https://doi.org/10.2514/3.49582
Gong M, Li JH (2002) A research on stress field of column and strip-shaped charge in different detonated points. J Univ Sci Technol Beijing 3(005). (In Chinese). https://doi.org/10.3321/j.issn:1001-053X.2002.03.005
Heelan PA (1953) Radiation from a cylindrical source of finite length. Geophysics 18(3):685. https://doi.org/10.1190/1.1437923
Hu YG, Lu WB, Chen M et al (2012) Comparison and improvement of blasting damage models for rock. Rock Soil Mech 33(11):3278–3284. (In Chinese). https://doi.org/10.16285/j.rsm.2012.11.012
Hu H, Lu W, Yan P et al (2017) A new horizontal rock dam foundation blasting technique with a shock-reflection device arranged at the bottom of vertical borehole. Eur J Environ Civ Eng. https://doi.org/10.1080/19648189.2017.1399168
Jordan DW (1962) The stress wave from a finite, cylindrical explosive source. J Math Mech 11(4):503–551. https://doi.org/10.1512/iumj.1962.11.11032
Knock C, Davies N (2013) Blast waves from cylindrical charges. Shock Waves 23(4):337–343. https://doi.org/10.1007/s00193-013-0438-7
Lee EL, Hornig HC, Kury JW (1968) Adiabatic expansion of high explosive detonation products. (report UCRL-50422). Lawrence Radiation Laboratory, University of California, Livermore
Leng ZD, Lu WB, Chen M et al (2016) Explosion energy transmission under side initiation and its effect on rock fragmentation. Int J Rock Mech Min 86:245–254. https://doi.org/10.1016/j.ijrmms.2016.04.016
Li HB, Xiang X, Li JC et al (2011) Rock damage control in bedrock blasting excavation for a nuclear power plant. Int J Rock Mech Min 48(2):210–218. https://doi.org/10.1016/j.ijrmms.2010.11.016
Liu L, Chen M, Lu WB et al (2015) Effect of the location of the detonation initiation point for bench blasting. Shock Vib (6-7):1-11. https://doi.org/10.1155/2015/907310
Liu KW, Li XH, Li XB et al (2016) Characteristics and mechanisms of strain waves generated in rock by cylindrical explosive charges. J Cent South Univ 23(11):2951–2957. https://doi.org/10.1007/s11771-016-3359-7
Long Y, Zhong MS, Xie QM et al (2012) Influence of initiation point position on fragmentation by blasting in iron ore. Fragblast 10:111. https://doi.org/10.1201/b13759-14
Lu WB, Hu YG, Yang JH et al (2013) Spatial distribution of excavation induced damage zone of high rock slope. Int J Rock Mech Min 64(6):181–191. https://doi.org/10.1016/j.ijrmms.2013.08.030
Onederra IA, Furtney JK, Sellers E et al (2013) Modelling blast induced damage from a fully coupled explosivecharge. Int J Rock Mech Min 58(58):73–84. https://doi.org/10.1016/j.ijrmms.2012.10.004
Plewman RP, Starfield AM (1965) The effects of finite velocities of detonation and propagation on the strain pulses induced in rock by linear charges. JS Afr Inst Min Metall 66:77–96
Shen XM, Niu XQ, Lu WB et al (2016) Rock mass utilization for the foundation surfaces of high arch dams in medium or high geo-stress regions: a review. Bull Eng Geol Environ 1-19. https://doi.org/10.1007/s10064-016-0892-4
Sichel M (1977) A simple analysis of the blast initiation of detonations. Acta Astronaut 4(3):409–424. https://doi.org/10.1016/0094-5765(77)90059-5
Starfield AM, Pugliese JM (1968) Compression waves generated in rock by cylindrical explosive charges: a comparison between a computer model and field measurements. Int J Rock Mech Min 5(1):65–77. https://doi.org/10.1016/0148-9062(68)90023-5
The Professional Standards Compilation Group of Peoples Republic of China (SL47-94) (1995) Technical specification for construction of rock foundation excavation of hydraulic structures. Water Resources and Electric Power Press. (In Chinese), Beijing. https://doi.org/10.13751/j.cnki.kjyqy.2013.03.117
Triviño LF, Mohanty B, Milkereit B (2012) Seismic waveforms from explosive sources located in boreholes and initiated in different directions. J Appl Geophys 87(12):81–93. https://doi.org/10.1016/j.jappgeo.2012.09.004
White JE (1963) Shear waves from explosive sources. Geophysics 28(6). https://doi.org/10.1190/1.1439296
Xiao SY, Su LJ, Jiang YJ et al (2017) Numerical analysis of hard rock blasting unloading effects in high in situ stress fields. Bull Eng Geol Environ 1–9. https://doi.org/10.1007/s10064-017-1067-7
Xu N, Wu J, Dai F, Fan Y et al (2017) Comprehensive evaluation of the stability of the left-bank slope at the baihetan hydropower station in Southwest China. Bull Eng Geol Environ 1–22. https://doi.org/10.1007/s10064-017-1018-3
Yang JH, Lu WB, Jiang QH et al (2016) Frequency comparison of blast-induced vibration per delay for the full-face millisecond delay blasting in underground opening excavation. Tunn Undergr Sp Tech 51:189–201. https://doi.org/10.1016/j.tust.2015.10.036
Zhang ZX (2005) Increasing ore extraction by changing detonator positions in lkab malmberget mine. Fragblast 9(1):29–46. https://doi.org/10.1080/13855140500082600
Zhang BP, Zhang QM, Huang FL (2001) Detonation physics. Weapon Industry Press, Beijing (In Chinese)
Acknowledgements
This work is supported by National Natural Science Fund Project of China (51779190) and Hubei Province Technical Innovation Program (2017ACA102). The authors wish to express their thanks to all supporters.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Gao, Q., Lu, W., Yan, P. et al. Effect of initiation location on distribution and utilization of explosion energy during rock blasting. Bull Eng Geol Environ 78, 3433–3447 (2019). https://doi.org/10.1007/s10064-018-1296-4
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10064-018-1296-4