Journal of Korean Tunnelling and Underground Space Association (한국터널지하공간학회 논문집)

Korean Tunnelling and Underground Space Association (한국터널지하공간학회)
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Comparative analysis of cutting performance for basalt and granite according to abrasive waterjet parameters

연마재 워터젯 변수에 따른 현무암 및 화강암 절삭성능 비교분석

  • Park, Jun-Sik (Dept. of Civil & Environmental Engineering, Pusan National University) ;
  • Cha, Hyun-Jong (Dept. of Civil Engineering, Pusan National University) ;
  • Jo, Seon-Ah (Structural & Seismic Technology Group, Next Generation Transmission & Substation Laboratory, KEPCO Research Institute) ;
  • Jung, Ju-Hwan (Structural & Seismic Technology Group, Next Generation Transmission & Substation Laboratory, KEPCO Research Institute) ;
  • Oh, Tae-Min (Dept. of Civil & Environmental Engineering, Pusan National University)
  • 박준식 (부산대학교 사회환경시스템공학과) ;
  • 차현종 (부산대학교 토목공학과) ;
  • 조선아 (한전 전력연구원 차세대송변전연구소 구조내진연구실) ;
  • 정주환 (한전 전력연구원 차세대송변전연구소 구조내진연구실) ;
  • 오태민 (부산대학교 사회환경시스템공학과)
  • Received : 2022.07.22
  • Accepted : 2022.08.16
  • Published : 2022.09.30
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Abstract

To overcome the limitation of conventional rock excavation methods, the excavation with abrasive waterjet has been actively developed. The abrasive waterjet excavation method has the effect of reducing blasting vibration and enhancing the excavation efficiency by forming a continuous free surface on the rock. However, the waterjet cutting performance varies with rock fracturing characteristics. Thus, it is necessary to analyze the cutting performance for various rocks in order to effectively utilize the waterjet excavation. In this study, cutting experiments with the high pressure waterjet system were performed for basalt and granite specimens. Water pressure, standoff distance, and traverse speed were determined as effective parameters for the abrasive waterjet cutting. The cutting depth and width of basalt specimens were analyzed to compare with granite results. The averaged cutting depth of basalt was shown in 41% deeper than granite; in addition, the averaged cutting width of basalt was formed by 18.5% narrower than granite. The results of this study are expected to be useful basic data for applying rock excavation site with low strength and high porosity such as basalt.

기존 암반 굴착공법이 갖는 한계점을 극복하기 위해 최근 연마재 워터젯 공법을 활용하는 연구가 활발히 진행되고 있다. 연마재 워터젯 암반굴착 공법은 암반에 연속적인 자유면을 형성하여 발파 시 발생하는 진동을 저감하고 굴착효율을 증진시키는 효과가 있다. 그러나 연마재 워터젯 절삭성능은 암반의 물리적 성질에 따라 변화한다. 따라서, 다양한 물리적 성질을 가진 암반이 혼재하는 굴착현장 특성상 효과적인 워터젯 활용을 위해서는 다양한 암종의 절삭성능을 분석하는 것이 필수적이다. 본 연구에서는 현무암과 화강암을 대상으로 수압, 이격거리, 이송속도를 변화시키며 절삭실험을 수행하고 결과를 분석하였다. 실험결과, 현무암은 화강암보다 평균적으로 약 41% 깊게 절삭되고, 절삭 폭은 약 18.5% 좁게 형성되었다. 본 연구결과는 향후 현무암과 같은 강도가 낮고 공극이 큰 암반 굴착현장에서 연마재 워터젯을 적용할 시 유용한 기초자료로 활용될 것으로 기대된다.

Keywords

Acknowledgement

본 연구는 국토교통부/국토교통과학기술진흥원의 지원으로 수행되었음(과제번호 21CTAP-C164123-01).

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