A Study of Characteristic of Friction Angles between Sand and Artificial Rock Interface by Direct Shear Test

직접전단시험에 의한 모래와 인공암석 경계면의 마찰각 특성 연구

  • 양홍석 (서울시립대학교 대학원 토목공학과) ;
  • 이벽규 ((주)새터기술) ;
  • 장승진 ((주)지암컨설턴트) ;
  • 이수곤 (서울시립대학교 공과대학 토목공학과)
  • Published : 2012.08.01

Abstract

Soil-rock interface, mainly founded in Granite region of Korea, is known as one of the important factor of the slope failure at the rainfall due to smaller shear strength than soil itself. However, research of the effect on slope stability by soil-rock interfaces is insufficient. Therefore, a series of direct shear tests were performed in order to investigate the effect of soil-rock interface on slope stability. The method of tests is to get sand itself and sand-artificial rock interface shear strength from different grain size of sands and artificial rock samples. The results of tests show that the friction angle of interface depends primarily on particle size and surface roughness. Interface friction angle ratio ${\mu}(={\delta}/{\Phi})$ is in the range of 0.75 ~ 0.96, this results indicate that interface friction angle is smaller than sand itself.

우리나라 화강암 분포지역에서 주로 발견되는 토사-암 경계면은 토사 자체의 전단강도보다 더 작은 값을 갖기 때문에 강우 시 비탈면 붕괴의 중요한 요인 중 하나로 알려져 있다. 그러나 토사-암 경계면이 비탈면의 안정성에 미치는 영향에 대한 연구가 부족한 실정이다. 따라서 본 연구에서는 토사-암 경계면이 비탈면 안정성에 미치는 영향을 파악하기 위한 기초 연구로써 서로 다른 입도를 갖는 세 종류의 모래와 이를 이용한 인공 암석을 제작하여 모래, 모래-인공암석 경계면에서의 전단강도를 얻기 위한 직접전단시험을 실시하였다. 직접전단시험 결과, 경계면 마찰각은 입도와 표면 거칠기에 따라 변화하며, 경계면 마찰각비 ${\mu}(={\delta}/{\Phi})$는 약 0.75 ~ 0.96의 범위를 갖으며, 이러한 시험 결과들은 모래 자체보다 모래-인공암석 경계면의 마찰각이 더 작은 값을 갖는다는 것을 나타낸다.

Keywords

References

  1. Acar, Y. B., Durgunoglu, H. T. and Tumay, M. T.(1982), Interface Properties of Sands, Journal of the Geotechnical Engineering Division, Vol. 108, No. 4, pp. 648-654.
  2. Al-Mhaidib, A. I.(2005), Shearing Rate Effect on Interfacial Friction Between Sand and Steel, Proceeding of the 15th International Offshore and Polar Engineering Conference(ISOPE-2005), Seoul, Korea, Vol. 2, pp. 633-640.
  3. Butterfield, R. and Andrawes, K. Z.(1972), On the Angles of Friction Between Sand and Plane Surface, J. Terramechanics, Vol. 8, No. 4, pp. 15-23. https://doi.org/10.1016/0022-4898(72)90043-2
  4. Heo, Y.(2000), Shear Strength Characteristics on Interface Between Bed Rocks and Soils, Master's Thesis, Chung-Ang Univ., pp. 120-121.
  5. Indraratna, B. Haque, A. and Aziz, N.(1999), Shear Behaviour of Idealised Infilled Joints under Constant Normal Stiffness, Geotechnique, Vol. 49, No. 3, pp. 331-355. https://doi.org/10.1680/geot.1999.49.3.331
  6. Kanji, M. A.(1974). Unconventional Laboratory Tests for the Determination of the Shear Strength of Soil-Rock Contacts, Proc. of the 3rd Congress of ISRM. Denver 2, pp. 241-247.
  7. Kim, Y. S. and Kim, D. M.(2009), Characteristics of Friction Angles between the Nak-dong River Sand and Construction Materials by Direct Shear Test, Journal of the Korean Geotechnical Society, Vol. 25, No. 4, pp. 102-112.
  8. Lim, C. H.(2002), A Study on Shear Strength Characteristics between Rock and Soil, Master's Thesis, Univ. of Seoul, pp. 45.
  9. Liming, Hu and Jialiu, Pu(2004), Testing and Modeling of Soil-Structure Interface, Journal of Geotechnical and Geoenvironmental Engineering, Vol. 130, No. 8, pp. 851-860. https://doi.org/10.1061/(ASCE)1090-0241(2004)130:8(851)
  10. Lings, M. L. and Dietz, M. S.(2005), The Peak Strength of Sand-Steel Interfaces and the Role of Dilation, Soils and Foundations, Vol. 45, No. 6, pp. 1-14. https://doi.org/10.3208/sandf.45.1
  11. Oh, J. H. and Lee, K. C.(2003), Characteristics of Shear Strength along Boundary Planes of a Failed Slope Using Laboratory Test, Journal of the Korean Society of Civil Engineers, Vol. 23, No. 6C, pp. 373-381.
  12. Patton, F. D.(1968), The Determination of Shear Strength of Rock Masses, Paper Presented to the Terrametric Course of Measurement Systems for Control of Construction and Mining, Denver, Col. pp. 37.
  13. Pereira, J. P.(1997), Rolling Friction and Shear Behaviour of Rock Discontinuities Filled with Sand, Int. J. Rock Mech. & Min. Sci. Vol. 34, No. 3-4, paper No. 244
  14. Potyondy, J. G.(1961), Skin Friction Between Various Soils and Construction Materials, Geotechnique, Vol. 11, No. 4, pp. 339-353. https://doi.org/10.1680/geot.1961.11.4.339
  15. Sun, G. G.(2004), A Study on Landslide Characteristics by using Shear Strength between Rock and Soil, Master's Thesis, Univ. of Seoul, pp. 54-56.
  16. Uesugi, M. and Kishida, H.(1986), Influential Factors of Friction Between Steel and Dry Sands, Soils and Foundations, Vol. 26, No. 2, pp. 33-46. https://doi.org/10.3208/sandf1972.26.2_33
  17. Uesugi, M. and Tsubakihara, Y.(1988), Behaviour of Sand Particles in Sand-Steel Friction, Soils and Foundations, Vol. 28, No. 1, pp. 107-118. https://doi.org/10.3208/sandf1972.28.107