Tunnel and Underground Space (터널과지하공간)

Korean Society for Rock Mechanics and Rock Engineering (한국암반공학회)
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Field Application of Hydraulic Rock Splitting Technique to Biotite Granite

흑운모화강암 지역에 대한 수압암반절개기술의 현장 적용

  • Received : 2017.09.27
  • Accepted : 2017.10.25
  • Published : 2017.10.31
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Abstract

Hydraulic rock splitting is a technique which leads to failure of rockmass by means of water injection with a pressure higher than the tensile strength of rockmass, using straddle packer installed in boreholes drilled from free surface. Field tests were conducted in this study for several slopes of biotite granite according to various designs for borehole layout and water injection. Test results showed that new cracks were generated to connect to adjacent holes or that pre-existed cracks were propagated by injection, finally leading to failure. In particular, this study suggests the possibility of controlling the direction of generated cracks with guide slot, since new cracks were generated parallel to the guide slots carved on a borehole wall before injection. Various types of borehole layout and injection methods should be further developed for the practical uses, considering the factors influencing on crack generation.

수압암반절개기술은 천공된 시추공에 설치된 이중패커의 인터벌에 암반의 인장응력 이상의 수압을 가하여 균열을 발생시킴으로써 암반을 절개시키는 방법이다. 본 연구에서는 흑운모화강암 사면에 대하여 다양한 배열설계 및 주입설계에 따라 수압암반절개기술을 현장에 적용하였다. 실험 결과, 주입에 따라 새로운 균열이 발생되어 주변 공과 연결되거나 기존 균열이 연장되어 암반이 파괴되었다. 특히, 본 실험에서는 유도 슬롯과 평행한 방향을 지닌 균열이 발생되어 균열 생성방향을 제어할 수 있는 가능성을 제시하였다. 균열생성에 대한 제어 기술을 발전시키기 위해선, 균열생성에 영향을 미치는 여러 요소를 고려한 다양한 배열설계 및 주입설계를 암반 현장에 적용하여야 할 것이다.

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References

  1. Chang, C., Jo, Y., Oh, Y., Lee, T.J., and Kim, K.-Y., 2014, Hydraulic Fracturing In Situ Stress Estimations in a Potential Geothermal Site, Seokmo Island, South Korea, Rock Mech Rock Eng, 47 1793-1808. https://doi.org/10.1007/s00603-013-0491-7
  2. Choi, S., Shin, H., Park, C.-S., Bae, J., Lee, H., Park, J., and Jeon, H., 1999, In-situ stress determinations by hydraulic fracturing in deep inclined boreholes for the design of underground oil storages, Korean Geotechnical Society, 15(4), 185-205 (in Korean with English abstract).
  3. Haimson, B., 1978, The hydrofracturing stress measuring method and recent field results, Rock Mechanics and Mining Sciences, 15, 167-178. https://doi.org/10.1016/0148-9062(78)91223-8
  4. Haimson, B., Lee, M.-Y., and Song, I., 2003, Shallow hydraulic fracturing measurements in Korea support tectonic and seismic indicators of regional stress, Rock Mechanics and Mining Sciences, 40, 1243-1256. https://doi.org/10.1016/S1365-1609(03)00119-9
  5. Lee, H. and Yang, H., 1997, Applied Rock Mechanics, Seoul National University Press.
  6. Lee, J.C., 2013, Shale-gas production optimization by fluid selection: incorporating laboratory analysis of fluid rheology in Korea domestic polymers, The Graduate School in Sejong University.
  7. Lee J.C., 2014, Shale Gas Prospecting, Development of the Latest Technology Trends, High-Tech Intelligence Analysis, 1-6.
  8. Lee, S.H., Lim, J.S., and Jang, W.Y., 2016, The Effects of High Pressure Water Contact State on Hydraulic Fracturing, Tunnel and Underground Space, 26(3), 409-417 (in Korean with English abstract). https://doi.org/10.7474/TUS.2016.26.5.409
  9. Lin, W., Yamomoto, K., Ito, H., Masago, H., and Kawamura, Y., 2008, Estimation of Minimum Principle Stress from an Extended Leak-off Test Onboard the Chikyu Drilling Vessel and Suggestions for Furture Test Procedures, Scientific Drilling, 6, 43-47. https://doi.org/10.5194/sd-6-43-2008
  10. Mun, H.J., Shin, S.R., Lim, J.S., Jeong, W.K., and Jang, W.Y., 2014, A Study on the Model for Effective Hydraulic Fracturing by Using Guide Hole, Tunnel and Underground Space, 24(6) 440-448 (in Korean with English abstract). https://doi.org/10.7474/TUS.2014.24.6.440
  11. Ouchterlony, F., 1972, Analysis av Spanning still standet Kruig Nogra Olika Geometrier Med Radiellt Ricktade Sprickor 1 Ett Oandlight Plant Medium Under Inverkanav Expansion krafter, Swedish Tectonic Research Foundation Report, DS.
  12. Park, J.O. and Lee, D.H., 2016, Development of Hydraulic Rock Splitting Technique for Rock Excavation, The Journal of Engineering Geology, 26(3), 353-360 (in Korean with English abstract). https://doi.org/10.9720/kseg.2016.3.353
  13. Yim, S.B. and Seo, Y.S., 2009, A new method for the analysis of measured displacements during tunnelling using control charts, The Journal of Engineering Geology, 19(3), 261-268 (in Korean with English abstract).