• Title/Summary/Keyword: Dry hole pumping system

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A Study of a Pilot Test for a Blasting Performance Evaluation Using a Dry Hole Charged with ANFO (건공화 공법의 발파 성능 평가를 위한 현장 시험에 관한 연구)

  • Lee, Seung Hun;Chong, Song-Hun;Choi, Hyung Bin
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.42 no.2
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    • pp.197-208
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    • 2022
  • The existence of shallow bedrock and the desire to use underground space necessitate the use of blasting methods. The standard blasting method under water after drilling is associated with certain technical difficulties, including reduced detonation power, the use of a fixed charge per delay, and decoupling. However, there is no blasting method to replace the existing blasting method. In this paper, a dry hole charged with ANFO blasting is assessed while employing a dry hole pumping system to remove water from the drill borehole. Additional standard blasting is also utilized to compare the blasting performances of the two methods. The least-squares linear regression method is adopted to analyze the blasting vibration velocity quantitatively using the measured vibration velocity for each blasting method and the vibration velocity model as a function of the scaled distance. The results show that the dry hole charged with ANFO blasting will lead to greater damping of the blasting vibration, more energy dissipation to crush the surrounding rock, and closer distances for the allowable velocity of the blasting vibration. Also, standard blasting shows much longer influencing distances and a wider range of the blasting pattern. The pilot test confirms the blasting efficiency of dry hole charged with ANFO blasting.