Tunnel and Underground Space (터널과지하공간)

Korean Society for Rock Mechanics and Rock Engineering (한국암반공학회)
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Estimation of Uniaxial Compressive Strength of Weak Rocks Using Needle Penetrometer

침관입시험을 이용한 연약암반의 일축압축강도 추정

  • 강성승 (조선대학교 에너지자원공학과) ;
  • 오바라 유조 (일본 구마모토대학 대학원자연과학연구과) ;
  • 제동광 (조선대학교 에너지자원공학과) ;
  • 박영호 (조선대학교 에너지자원공학과)
  • Received : 2011.01.05
  • Accepted : 2011.02.21
  • Published : 2011.02.28
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Abstract

This study is to estimate the uniaxal compressive strength (UCS) for the weak rocks using needle penetrometer test. The appropriate ratio of the artificial rocks for this test was cement (C):bentonite (B):water (W) = 1.3:0.7:2.3 or 1.5:0.5:2.0. From the relationship between needle penetration resistance (NPR) measured by needle penetrometer test and an estimated UCS, NPR and UCS tended to increase with increasing the curing period. Also from the relationship between the measured NPR and the measured UCS, NPR-UCS was linearly increased with the curing periods of 3-day to 14-day regardless of the ratio, then in the curing periods of 14-day to 28-day it was nearly constant. In conclusion, the overall relationship between NPR and UCS shows a linear relation for the most part, it means that UCS is possible to be estimated from NPR by needle penetrometer test in the case of weak rocks.

본 연구는 침관입시험을 이용하여 연약암반에 대한 일축압축강도를 추정하기 위한 연구결과를 나타낸 것이다. 침관입시험을 위한 인공암반의 배합비는 시멘트(C):벤토나이트(B):물(W) = 1.3:0.7:2.3 또는 1.5:0.5:2.0이 적절한 것으로 나타났다. 침관입시험에 의해 측정된 침관입저항력(NPR)과 이로부터 추정된 일축압축강도(UCS) 관계에서 NPR과 UCS는 양생기간이 길어짐에 따라 증가하는 경향을 보였다. 또한 침관입시험에 의해 측정된 NPR과 실제 시험에서 얻어진 UCS 관계에서는 NPR-UCS가 배합비와 상관없이 양생기간이 3일~14일까지는 선형적으로 증가하다가 14일~28일에서는 NPR-UCS가 작은 차이를 보이지만 거의 일정한 관계로 나타났다. 결론적으로 전체적인 NPR-UCS의 관계는 대체적으로 선형적인 관계를 보이며, 이것은 연약암반의 경우 침관입 시험에 의한 NPR로부터 일축압축강도를 추정하는 것이 가능함을 의미한다.

Keywords

References

  1. ASTM, 1994, Annual book of ASTM Standards-Soil and Rock, Building Stones, Selection 4, Construction, V.04.08. West Conshohocken, PA, ASTM International.
  2. Bieniawski, Z. T., 1989, Engineering rock mass classifications. New York, John Wiley and Sons.
  3. Erguler, Z. A. and Ulusay, R., 2007, Estimation of uniaxial compressive strength of clay-bearing weak rocks using needle penetration resistance. Proceedings of 11th Congress on International Society of Rock Mechanics, Lisbon, Vol. 1, pp. 256-258.
  4. Erguler, Z. A. and Ulusay, R., 2009, Water-induced variations in mechanical properties of clay-bearing rocks. International Journal of Rock Mechanics & Mining Sciences, Vol. 46, pp. 355-370. https://doi.org/10.1016/j.ijrmms.2008.07.002
  5. Hudson, J. A. and Harrison, J. P., 1997, Engineering rock mechanics - An introduction to the principles. Pergamon.
  6. ISRM, 1978a, ISRM Suggested Methods for Determining Hardness and Abrasiveness of Rocks. International Journal of Rock Mechanics Mining Sciences & Gemechanics Abstract, Vol. 15, pp. 89-97.
  7. ISRM, 1978b, ISRM Suggested Methods for Determining Tensile Strength of Rock Materials. International Journal of Rock Mechanics Mining Sciences & Gemechanics Abstract, Vol. 15, pp. 99-103. https://doi.org/10.1016/0148-9062(78)90003-7
  8. ISRM, 1979, ISRM Suggested Methods for Determining The Uniaxial Compressive Strength and Deformability of Rock Materials. International Journal of Rock Mechanics Mining Sciences & Gemechanics Abstract, Vol. 16, pp. 135-140.
  9. ISRM, 1985, ISRM Suggested Methods for Determining Point Load Strength. International Journal of Rock Mechanics Mining Sciences & Gemechanics Abstract, Vol. 22, pp. 51-60. https://doi.org/10.1016/0148-9062(85)92327-7
  10. Kojima, K., Saito, Y. and Ino-o, M., 1974, Factors of softening of pelitic soft rocks in Chiba Prefecture. 9th Japan National Conference on Soil Mechanics and Foundation Engineering (JSSMFE), pp. 737-740. (in Japanese)
  11. Okada, S., Izumiyo, Y., Iizuka, Y. and Horiuchi, S., 1985, The estimation of soft rock strength around a tunnel by needle penetration test, Tsuchi-to-Kiso, JSSMFE, Vol. 33, pp.35-38. (in Japanese)
  12. Maruto Corporation, 2006, Penetrometer for soft rock: Model SH-70 Instruction manual. Tokyo, Japan.
  13. Ulusay, R., Gokceoglu, C. and Sulukcu, S., 2001, Draft ISRM suggested method for determining block punch strength index (BPI). International Journal of Rock Mechanics & Mining Sciences, Vol. 38, pp. 1113-1119. https://doi.org/10.1016/S1365-1609(01)00078-8
  14. Yamaguch, Y., Nakamura, Y., Nakamura, M., Hakoishi, N., Yamaya, M. and Kato, Y., 2005. Verification of design strength of soft rock foundation for dams by needle penetration test. Journal of Japanese Society for Engineering Geology, Vol. 46, pp. 20-27. https://doi.org/10.5110/jjseg.46.20