DOI QR코드

DOI QR Code

Dynamic Soil Properties of Frozen and Unfrozen Soils from Terra Nova Bay in Eastern Antarctica

동남극 테라노바만 흙 시료의 동결 및 비동결 상태에서의 동적특성 평가

  • 김재현 (한국과학기술원 건설및환경공학과) ;
  • 권영만 (한국과학기술원 건설및환경공학과) ;
  • 박근보 (극지연구소 극지기후과학연구부) ;
  • 김영석 (한국건설기술연구원) ;
  • 김동수 (한국과학기술원 건설및환경공학과)
  • Received : 2017.02.21
  • Accepted : 2017.03.20
  • Published : 2017.03.31

Abstract

The geotechnical characteristics of frozen ground is one of the key design issues for the construction of infrastructure in cold region. In this study, the dynamic properties (shear modulus and damping ratio) of frozen and unfrozen soils sampled from Terra Nova Bay located in eastern Antarctica, where Jang Bogo station was built, were investigated using Stokoe-type resonant column test (RC). In order to freeze the reconstituted soil specimen, the RC testing equipment was modified by adding a cooling system. A series of resonant column tests were performed in frozen and unfrozen soils with various soil densities and temperatures. The shear modulus (G) and damping ratio (D) of soil frozen at $-7^{\circ}C$ were compared with those of unfrozen soil. In addition, the effect of temperature rise on the maximum shear modulus ($G_{max}$) and damping ratio was experimentally investigated. This study has significance in that the difference of dynamic soil properties between frozen and unfrozen soils and the effect of temperature rise on frozen soil were identified.

극한지에 구조물을 안정적으로 건설하기 위해서는 동결토의 지반공학적 특성을 평가하는 것이 중요하다. 본 연구에서는 남극 제2과학기지(장보고 기지)가 건설된 남극 테라노바만 인근지역의 현장시료를 이용하여 동결토와 비동결토의 동적특성(전단탄성계수, 감쇠비)을 Stokoe 식 공진주 실험기를 이용하여 평가하였다. 시편을 동결시키기 위해 시편의 온도제어가 가능하도록 공진주 실험시스템을 개선하였으며, 다양한 밀도로 조성된 시편에 대해 동결상태와 비동결상태에서 공진주 실험을 수행하였다. 동결토 실험에서는 $-7^{\circ}C$에서 얼린 시료를 이용해 전단변형률에 따른 전단탄성계수와 감쇠비를 획득하였고, 이를 비동결토의 특성과 비교하였다. 또한, 동결토의 온도변화에 따른 최대전단탄성계수와 감쇠비 변화를 실험적으로 평가하여 동결-융해 작용에 의한 지반의 역학적 특성 변화를 확인하였다. 본 연구를 통해 동결토와 비동결토의 동적특성 차이를 확인하였으며, 온도상승이 동결토에 미치는 영향을 확인했다는 점에서 공학적 의의가 있다.

Keywords

References

  1. American Society for Testing and Materials (ASTM) (2003), "Standard Test Methods for Modulus and Damping of Soils by the Resonant-Column Method", ASTM D4015, Philadelphia.
  2. Al-Hunaidi, M.O., Chen, P.A., Rainer, J.H., and Tremblay, M. (1996), "Shear Moduli and Damping in Frozen and Unfrozen Clay by Resonant Column Tests", Canadian Geotechnical Journal, Vol.33, No.3, pp.510-514. https://doi.org/10.1139/t96-073
  3. Arenson, L.U., Johansen, M.M., and Springman, S.M. (2004), "Effects of Volumetric Ice Content and Strain Rate on Shear Strength under Triaxial Conditions for Frozen Soil Samples", Permafrost and Periglacial Processes, Vol.15, No.3, pp.261-271. https://doi.org/10.1002/ppp.498
  4. Arenson, L.U. and Springman, S.M. (2005), "Triaxial Constant Stress and Constant Strain Rate Tests on Ice-Rich Permafrost Samples", Canadian Geotechnical Journal, Vol.42, No.2, pp.412-430. https://doi.org/10.1139/t04-111
  5. Bosscher, P.J. and Nelson, D.L. (1987), "Resonant Column Testing of Frozen Ottawa Sand", Geotechnical Testing Journal, Vol.10, No.3, pp.123-134. https://doi.org/10.1520/GTJ10944J
  6. Choo, Y.W. (1998), "Study on Normalized Shear Modulus Reduction Curves on Cohesionless Soils using Resonant Column/Torsional Shear Tests", Master thesis, Korea Advanced Institute and Science and Technology, Republic of Korea.
  7. Christ, M. and Park, J.B. (2009), "Ultrasonic Technique as Tool for Determining Physical and Mechanical Properties of Frozen Soils", Cold Regions Science and Technology, Vol.58, No.3, pp. 136-142. https://doi.org/10.1016/j.coldregions.2009.05.008
  8. Hardin, B.O. (1978), "The Nature of Stress-Strain Behavior for Soils", Proceedings of the ASCE Geotechnical Engineering Division Specialty Conference, Vol.1, ASCE, Pasadena, California, June, pp.3-90.
  9. Hong, S.S, Park, J.H., Lee, J.S., Lee, J.G., Kang, J.M., and Kim, Y.S. (2012), "Experimental Investigation of Frost Heaving Susceptibility with Soils from Terra Nova Bay in Eastern Antarctica", Journal of the Korean Geoenvironmental Society, Vol.13, No.12, pp.5-16.
  10. Huang, X., Li, D., Ming, F., and Fang, J. (2013), "An Experimental Study on the Relationship between Acoustic Parameters and Mechanical Properties of Frozen Silty Clay", Sciences in Cold and Arid Regions, Vol.5, No.5, pp.569-602.
  11. Kang, M., Kim, S., Hong, S., Kim, Y., and Lee, J. (2014), "Characteristics of Sand-Silt Mixtures during Freezing-Thawing by using Elastic Waves", Journal of the Korean Geoenvironmental Society, Vol.15, No.5, pp.47-56. https://doi.org/10.14481/JKGES.2014.15.5.47
  12. Kim, D.S. and Choo, Y.W. (2001), "Dynamic Deformation Characteristics of Cohesionless Soils in Korea using Resonant Column Tests", Journal of Korean Geotechnical Society, Vol.17, No.5, pp.115-128.
  13. Kim, D.S., Ko, D.H., and Youn, J.U. (2004), "Dynamic Deformation Characteristics of Granite Weathered Soils using RC/TS Tests", Journal of Korean Geoenvironmental Society, Vol.5, No.1, pp.35-46.
  14. Kim, D.S., Youn, J.U., Lee, S.H., and Choo, Y.W. (2005), "Measurement of Gmax of Sands using Bender Element in Resonant Column and Torsional Shear Equipment", Journal of Korean Geotechnical Society, Vol.21, No.10, pp.17-25.
  15. Ladd, R.S. (1978), "Preparing Test Specimens using Undercompaction", Geotechnical Testing Journal, Vol.1, No.1, pp.16-23. https://doi.org/10.1520/GTJ10364J
  16. Lee, J.H., Lee, D.Y., Park, D.G., Kyung, D.H., Kim, G.R., and Kim, I.C. (2016), "Effect of Freezing and Thawing on K0 Geostatic Stress State for Granular Materials", Granular Matter, Vol.18, No.3, pp.1-13. https://doi.org/10.1007/s10035-015-0597-6
  17. Li, J.C., Baladi, G.Y., and Andersland, O.B. (1979), "Cyclic Triaxial Tests on Frozen Sand", Engineering Geology, Vol.13, No.1, pp. 233-246. https://doi.org/10.1016/0013-7952(79)90035-8
  18. Ling, X.Z., Zhang, F., Li, Q.L., An, L.S., and Wang, J.H. (2015), "Dynamic Shear Modulus and Damping Ratio of Frozen Compacted Sand Subjected to Freeze-Thaw Cycle under Multi-Stage Cyclic Loading", Soil Dynamics and Earthquake Engineering, Vol.76, pp.111-121. https://doi.org/10.1016/j.soildyn.2015.02.007
  19. Ling, X.Z., Zhu, Z.Y., Zhang, F., Chen, S.J., Wang, L.N., Gao, X., and Lu, Q.R. (2009), "Dynamic Elastic Modulus for Frozen Soil from the Embankment on Beiluhe Basin along the Qinghai-Tibet Railway", Cold Regions Science and Technology, Vol.57, No.1, pp.7-12. https://doi.org/10.1016/j.coldregions.2009.01.004
  20. Park, J.H., Hong, S.S., Kim, Y.S., and Lee, J.S. (2012), "Characteristics of Elastic Waves in Sand-Silt Mixtures due to Freezing", Journal of Korean Geoenvironmental Society, Vol.13, No.4, pp.27-36.
  21. Park, J.H., Kang, M.G., and Lee, J.S. (2013), "Variation in Characteristics of Elastic Waves in Frozen Soils according to Degree of Saturation", Journal of The Korean Society of Civil Engineers, Vol.33, No.3, pp.1063-1075 (in Korean). https://doi.org/10.12652/Ksce.2013.33.3.1063
  22. Park, J.H. and Lee, J.S. (2014), "Characteristics of Elastic Waves in Sand-Silt Mixtures due to Freezing", Cold Regions Science and Technology, Vol.99, pp.1-11. https://doi.org/10.1016/j.coldregions.2013.11.002
  23. Qi, J., Ma, W., and Song, C. (2008), "Influence of Freeze-Thaw on Engineering Properties of a Silty Soil", Cold Regions Science and Technology, Vol.53, No.3, pp.397-404. https://doi.org/10.1016/j.coldregions.2007.05.010
  24. Ramberg, W. and Osgood, W.R. (1943), "Description of Stress-Strain Curves by Three Parameters", Technical Note 902, National Advisory Committee for Aeronautics, Washington, D.C.
  25. Seed, H.B. and Idriss, I.M. (1970), "Soil Moduli and Damping Factors for Dynamic Response Analyses", Report No. EERC 70-10, Earthquake Engineering Research Center, Univ. of California, Berkeley, Sept., p.37.
  26. Seo, Y.K., Kang, H.S., and Kim, E.S. (2008), "A Study of Cold Room Experiments for Strength Properties of Frozen Soil", Journal of Ocean Engineering and Technology, Vol.22, No.2, pp.42-49.
  27. Simonsen, E. and Isacsson, U. (2001), "Soil Behavior During Freezing And Thawing Using Variable And Constant Confining Pressure Triaxial Tests", Canadian Geotechnical Journal, Vol.38, No.4, pp.863-875. https://doi.org/10.1139/t01-007
  28. Tebaldi, G., Orazi, M., and Orazi, U.S. (2016), "Effect Of Freeze-Thaw Cycles On Mechanical Behavior Of Lime-Stabilized Soil", Journal of Materials in Civil Engineering, Vol.28, No.6, 06016002. https://doi.org/10.1061/(ASCE)MT.1943-5533.0001509
  29. Vinson, T.S., Chaichanavong, T., and Czajkowski, R.L. (1978), "Behavior of Frozen Clays under Cyclic Axial Loading", Journal of Geotechnical and Geoenvironmental Engineering, Vol.104, No.7, pp.779-800.
  30. Wang, D.Y., Zhu, Y.L., Ma, W., and Niu, Y.H. (2006), "Application of Ultrasonic Technology for Physical-Mechanical Properties of Frozen Soil", Cold Regions Science and Technology, Vol.44, pp. 12-19. https://doi.org/10.1016/j.coldregions.2005.06.003
  31. Yoon, Y.W., Kim, S.E., Kang, B.H., and Kang, D.S. (2003), "Dynamic Behavior of Weathered Granite Soils after Freezing-Thawing", Journal of Korean Geotechnical Society, Vol.19, No.4, pp.69-78.
  32. Yao, X., Qi, J., Yu, F., and Ma, L. (2013), "A Versatile Triaxial Apparatus for Frozen Soils", Cold Regions Science and Technology, Vol.92, pp.48-54. https://doi.org/10.1016/j.coldregions.2013.04.001
  33. Zumdahl, S.S. and Zumdahl, S.A. (2008), "Chemistry (8th edition)", Florence, Kentucky: Cengage Learning.