Tunnel and Underground Space (터널과지하공간)

Korean Society for Rock Mechanics and Rock Engineering (한국암반공학회)
권호 표지
DOI QR코드

DOI QR Code

Penetration of Compacted Bentonite into the Discontinuity in the Excavation Damaged Zone of Deposition Hole in the Geological Repository

심층처분장 처분공 주변 굴착손상영역에 존재하는 불연속면으로의 압축 벤토나이트 침투

  • Received : 2020.06.04
  • Accepted : 2020.06.22
  • Published : 2020.06.30
Download PDF
⟨ Previous Next ⟩

Abstract

A mathematical model to simulate more realistically the penetration of compacted bentonite buffer installed in the deposition hole into the discontinuity in the excavation damaged zone formed at the inner wall of the deposition hole in the geological repository for spent fuel is developed. In this model, the penetration of compacted bentonite is assumed to be the flow of Bingham fluid through the parallel planar rock fracture. The penetration of compacted bentonite is analyzed using the developed model. The results show that the maximum penetration depth of compacted bentonite into the rock fracture is proportioned to the swelling pressure of saturated compacted bentonite and the aperture of rock fracture. However, it is in inverse proportion to the yield strength of compacted bentonite. The viscosity of compacted bentonite dominates the penetration rate of compacted bentonite, but has no influence to the maximum penetration depth.

사용후핵연료 심층처분장 처분공에 설치된 압축 벤토나이트 완충재가 처분공 내벽에 형성된 굴착손상영역 불연속면 내로 침투하는 현상을 보다 더 현실적으로 모사할 수 있는 수학적 모델이 개발되었다. 이 모델에서는 압축 벤토나이트의 침투를 평행 평판 암반 절리을 통한 Bingham 유체의 이동으로 가정한다. 개발된 모델에 의해 벤토나이트의 침투현상을 분석한 결과, 암반 절리를 통해 압축 벤토나이트가 침투하는 최대 깊이는 포화 압축 벤토나이트의 팽윤압과 암반 절리의 폭에 비례하며, 압축 벤토나이트의 항복강도에 반비례하였다. 압축 벤토나이트의 점도는 압축 벤토나이트의 침투 속도를 좌우하나, 최대 침투깊이에는 영향을 미치지 않는다.

Keywords

References

  1. Apted, M.J., R. Arthur, D. Bennett, D. Savage, G. Sallfors and H. Wennerstrom, 2010. Buffer erosion: An overview of concepts and potential safety consequences. SSM Report 2010:31, Swedish Radiation Safety Authority, Stockholm, Sweden.
  2. Asada, M. and S. Horiuchi, 2005, High-density bentonite slurry for seepage barrier, J. of Materials in Civil Engineering, 17, 178-187. https://doi.org/10.1061/(ASCE)0899-1561(2005)17:2(178)
  3. Bird, R., W. Stewart, and E, Lightfoot, 2002, Transport Phenomena, Wiley.
  4. Birgersson, M., L. Borgesson, M. Hedstrom, O. Karnland, and U. Nilsson, 2009, Bentonite erosion, Final report, Swedish Nuclear Fuel and Waste Management Company, TR 09-34, Svensk Karnbranslehantering AB.
  5. Borgesson, L., M. Hedstrom, M. Birgersson, and O. Karnland, 2018, Bentonite swelling into fractures at conditions above the critical coagulation concentration, Swedish Nuclear Fuel and Waste Management Company, TR 17-11, Svensk Karnbranslehantering AB.
  6. Cho, W.J., J.O. Lee, and S. Kwon, 2012, An analysis of the factors affecting the hydraulic conductivity and swelling pressure of Kyungju Ca-bentonite for use as a clay-based sealing material for a high-level waste repository, Nuclear Engineering and Technology, 44, 89-102. https://doi.org/10.5516/NET.06.2011.018
  7. Grindrod, P., M. Peletier, and H. Takase, 1999, Mechanical interaction between swelling compacted clay and fractured rock and the leaching of clay colloids, Engineering Geology, 54, 159-165. https://doi.org/10.1016/S0013-7952(99)00071-X
  8. Gustafson, G. and H. Stille, 1996, Prediction of groutability from grout properties and hydrological data, Tunneling and Underground Space Technology, 11, 325-332. https://doi.org/10.1016/0886-7798(96)00027-2
  9. Gustafson, G. and H. Stille, 2005, Stoping criteria for cement grouting, Felsbau, 23, 62-68.
  10. Gustafson, G., J. Claesson, and A. Fransson, 2013, Steering parameters for rock grouting, J. of Applied Mathematics, Vol. 2013, Article ID 269594.
  11. Hassler, L., 1991, Grouting of rock - Simulation and classification, Ph D. Thesis, Dept. of Soil and Rock Mechanics, KTH Stockholm, Sweden.
  12. Hiemenz, P., 1986, Principles of Colloid and Surface Chemistry, Marcel Dekker, NY.
  13. Kanno, T., K. Matsumoto, and H. Sugino, 1999, Evaluation of extrusion and erosion of bentonite buffer, Proc. 7th Int. Conf. on Radioactive Waste Management and Environmental Remediation.
  14. Kanno, T. and Y. Iwata, 2004, Study on model for bentonite buffer intrusion (II), Japan Nuclear Cycle Development Institute, JNC TJ8400 2003-083 (in Japanese).
  15. Kobayashi, S. and H. Stille, 2007, Design for rock grouting based on analysis of grout penetration, Verification using Aspö HRL data and parameter analysis, Swedish Nuclear Fuel and Waste Management Company, R-07-13, Svensk Karnbranslehantering AB.
  16. Komine, H., 2004, Simplified evaluation for swelling characteristics of bentonites, Engineering Geology, 71, 265-279. https://doi.org/10.1016/S0013-7952(03)00140-6
  17. Kwon, S., Lee, C.S., Cho, S.J., Jeon, S.W., Cho, W.J., 2009. An investigation of the excavation damaged zone at the KAERI underground research tunnel, Tunn. Undergr. Space Technol. 24, 1-13. https://doi.org/10.1016/j.tust.2008.01.004
  18. Lee, C., 2012, Characterization of Thermal-Mechanical Behavior of Rock Mass in the Excavation Damaged Zone at KURT. Ph.D. Thesis, Seoul National University, Korea (in Korean with English abstract).
  19. Lee, C., S. Kwon, J.W. Choi and S. Jeon, 2011, An Estimation of the Excavation Damaged Zone at the KAERI Underground Research Tunnel, Tunnel and Underground Space, 21(5), 359-369. https://doi.org/10.7474/TUS.2011.21.5.359
  20. Lloret, A., M. V. Villar, M. Sanchez, A. Gens, X. Pintado, and E. E. Alonso, 2003, Mechanical behaviour of a heavily compacted bentonite under high suction changes, Geotechnique, 53, 27-40. https://doi.org/10.1680/geot.2003.53.1.27
  21. Moreno, L., I. Neretnieks, and L. Liu, 2010, Modelling of erosion of bentonite gel by gel/sol flow, Swedish Nuclear Fuel and Waste Management Company, TR 10-64, Svensk Karnbranslehantering AB.
  22. Neretnieks, I., L. Liu, and L. Moreno, 2009, Mechanisms and models for bentonite erosion, Swedish Nuclear Fuel and Waste Management Company, TR 09-35, Svensk Karnbranslehantering AB.
  23. Park, S. and S. Kwon, 2017, Status of Researches of Excavation Damaged Zone in Foreign Underground Research Laboratories Constructed for Developing High-level Radioactive Waste Disposal Techniques, Explosives and Blasting, 35(3), 31-54.
  24. Pusch, R., 1983, Stability of bentonite gels in crystalline rock- physical aspects, Swedish Nuclear Fuel and Waste Management Company, TR 83-04, Svensk Karnbranslehantering AB.
  25. SKB, Svensk Karnbranslehantering AB, 2010, Choice of Method - Evaluation of Strategies and Systems for Disposal of Spent Nuclear Fuel. Report P-10-47.
  26. Svoboda, J., 2013, The experimental study of bentonite swelling into fissure, Clay Minerals, 48, 383-389. https://doi.org/10.1180/claymin.2013.048.2.16
  27. Tanai, K. and K. Matsumoto, 2008, A study of extrusion behavior of buffer material into fractures, Science & Technology Series No 334, 57-64.
  28. Tang, A., Y. Yui, and N. Barnel, 2008, Thermo-mechanical behaviour of a compacted swelling clay, Geotechnique, 58, 45-54. https://doi.org/10.1680/geot.2008.58.1.45
  29. Yui, Y., A. Tang, L. Qian, W. Yei, and B. Chen, 2011, Thermo-mechanical behaviour of compacted GMZ bentonite, Soils and Foundations, 51, 1065-1074. https://doi.org/10.3208/sandf.51.1065