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2021 Vol.23, Issue 3 Preview Page

Research Paper

Analysis of rock removal shape according to overlapping width of waterjet cutting

워터젯 절삭폭 중첩에 따른 암반제거 단면형상 분석

Tae-Min Oh1*
,
Dong-Yeup Park2
,
Jun-Sik Park3
,
Gye-Chun Cho4
오 태민1*
,
박 동엽2
,
박 준식3
,
조 계춘4
1Assistant Professor, Dept. of Civil and Environmental Engineering, Pusan National University
2Master Student, Dept. of Civil and Environmental Engineering, KAIST
3Master Student, Dept. of Civil and Environmental Engineering, Pusan National University
4Professor, Dept. of Civil and Environmental Engineering, KAIST
1정회원, 부산대학교 사회환경시스템공학과 조교수
2비회원, KAIST 건설및환경공학과 석사과정
3비회원, 부산대학교 사회환경시스템공학과 석사과정
4정회원, KAIST 건설및환경공학과 정교수
*Corresponding Author
31 May 2021. pp. 167-181
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Abstract

New type of rock excavation method using a waterjet system is being developed to secure economic feasibility and to reduce vibrations during excavation. In waterjet rock excavation, overlapping of cutting width is essential for high efficiency. In this study, cutting experiments for granite specimens were performed using abrasive waterjet system according to the overlapping ratio and standoff distance. Based on the experimental results, the granite cutting performance was analyzed according to the overlapping ratio. In addition, removal shapes of the cross-section were analyzed in terms of the cutting depth, width, and volume after waterjet cutting. When the overlapping ratio is less than 58%, rock specimens are partially removed due to the insufficient overlapping ratio. However, when the overlapping ratio exceeds 67%, overcutting phenomenon is observed. For the partial overlapping ratio (i.e., 25~75%), cutting efficiency is increased in the removal volume. This study is expected to be used as the important basic data for determining the optimum overlapping ratio when the waterjet system is applied for rock excavation.

Keywords
Waterjet excavation
Removal shape
Overlapping width
Rock cutting

터널굴착의 경제성 확보 및 굴착 시 발생하는 진동저감을 위해 워터젯 시스템을 활용한 새로운 형태의 암반 굴착공법이 개발되고 있다. 워터젯 절삭을 이용한 효율적인 암반 굴착을 위해서는 워터젯 절삭폭의 중첩과정이 필수적이다. 본 연구는 초고압 연마재 워터젯 시스템을 이용하여 절삭폭 중첩도 및 이격거리에 따른 화강암 시편 절삭실험을 수행하였다. 실험결과를 바탕으로 중첩도 단계에 따른 화강암 절삭성능을 분석하였다. 그리고 형상인자를 절삭깊이, 절삭폭, 그리고 절삭부피로 분류하여 중첩 절삭 후 단면의 형상을 분석하였다. 절삭폭 중첩도가 58% 이하가 되면 중첩이 충분하지 않아 연속적인 암반제거가 불가능하였다. 반면 절삭폭 중첩도 67% 이상에서는 과절삭 현상이 확인되었다. 한편 부분중첩(25~75%) 조건에서는 기존 워터젯 절삭에 비해 효율적인 부피제거가 가능한 것으로 분석되었다. 해당 연구는 워터젯을 활용한 암반 굴착 시 최적 중첩도를 결정하기 위한 중요한 기초자료로 활용될 수 있을 것으로 기대된다.

키워드
워터젯 굴착
제거형상
중첩폭
워터젯 절삭
References
1
Anwar, S., Axinte, D.A., Becker, A.A. (2013), “Finite element modelling of overlapping abrasive waterjet milled footprints”, Wear, Vol. 303, No. 1-2, pp. 426-436. 10.1016/j.wear.2013.03.018
2
Billingham, J., Miron, C.B., Axinte, D.A., Kong, M.C. (2013), “Mathematical modelling of abrasive waterjet footprints for arbitrarily moving jets: part II-overlapped single and multiple straight paths”, International Journal of Machine Tools and Manufacture, Vol. 68, pp. 30-39. 10.1016/j.ijmachtools.2013.01.003
3
Kim, J.G., Song, J.J. (2015), “Abrasive water jet cutting methods for reducing blast-induced ground vibration in tunnel excavation”, International Journal of Rock Mechanics and Mining Sciences, Vol. 75, pp. 147-158. 10.1016/j.ijrmms.2014.12.011
4
Momber, A.W., Kovacevic, R. (2000), “Particle-size distribution influence in high-speed erosion of aluminium”, Particulate Science and Technology, Vol. 18, No. 3, pp. 199-212. 10.1080/02726350008906836
5
Oh, T.M., Cho, G.C. (2016), “Rock cutting depth model based on kinetic energy of abrasive waterjet”, Rock Mechanics and Rock Engineering, Vol. 49, No. 3, pp. 1059-1072. 10.1007/s00603-015-0778-y
6
Oh, T.M., Cho, G.C., Ji, I.T. (2013), “Effects of free surface using waterjet cutting for rock blasting excavation”, Journal of Korean Tunnelling and Underground Space Association, Vol. 15, No. 1, pp. 49-57. 10.9711/KTAJ.2013.15.1.049
7
Oh, T.M., Joo, G.W., Cha, Y., Cho, G.C. (2019), “Effect of garnet characteristics on abrasive waterjet cutting of hard granite rock”, Advances in Civil Engineering, Vol. 2019, Article ID 5732649, pp. 1-12. 10.1155/2019/5732649
8
Park, S.S., Kim, H.Y., Ahn, J.H. (2016), “Characteristics of abrasive water jet milled surface by overlap cutting”, Journal of The Korean Society of Manufacturing Technology Engineers, Vol. 25, No. 2, pp. 118-123. 10.7735/ksmte.2016.25.2.118
9
Pierri, L.C., Santos, R.P.D., Passos Junior, J.J.D., Pains, A.M., Noronha, M.A.M. (2019), “High pressure abrasive water jet for excavation purpose: a tridimensional approach for cutting strategy”, REM-International Engineering Journal, Vol. 72, No. 1, pp. 25-30. 10.1590/0370-44672018720042
10
Shin, J.H., Moon, H.K., Choi, K.C., Kim, T.K. (2009), “Evaluation of the blast-restriction zone to secure tunnel lining safety”, Journal of Korean Tunnelling and Underground Space Association, Vol. 11, No. 1, pp. 85-95.
11
Wang, F., Zhou, D., Zhou, X., Xiao, N., Guo, C. (2020), “Rock breaking performance of TBM disc cutter assisted by high-pressure water jet”, Applied Sciences, Vol. 10, No. 18, pp. 6294. 10.3390/app10186294
Information
  • Publisher :Korean Tunneling and Underground Space Association
  • Publisher(Ko) :한국터널지하공간학회
  • Journal Title :Journal of Korean Tunnelling and Underground Space Association
  • Journal Title(Ko) :한국터널지하공간학회 논문집
  • Volume : 23
  • No :3
  • Pages :167-181
  • Received Date : 2021-04-07
  • Revised Date : 2021-04-23
  • Accepted Date : 2021-04-23
  • DOI :https://doi.org/10.9711/KTAJ.2021.23.3.167
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