The Journal of Engineering Geology (지질공학)

The Korean Society of Engineering Geology (대한지질공학회)
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Permeability Characteristics of Soft Clay using the Piezocone Test and a Laboratory Test

피에조 콘 시험과 실내시험을 이용한 점토지반의 투수특성 연구

  • Received : 2011.10.17
  • Accepted : 2011.12.21
  • Published : 2011.12.30
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Abstract

The consolidation behavior of soft clay is controlled mainly by its compressibility and deformation characteristics. Soil permeability depends on various soil characteristics, including the soil type and anisotropy. The coefficient of permeability of soft clay is determined by using a laboratory test (the Oedometer test) or a piezocone test. The latter test is useful for estimating the permeability characteristics from $c_h$ and $k_h$ by performing an excess pore-pressure dissipation test. This study seeks to validate an existing theoretical formula in applying it to marine clay, and to assess the relation between $k_h/k_c$ and the mechanical properties of soft clay. Piezocone tests and laboratory tests were performed using sediment from the Yellow Sea and from the South Sea near Korea. We compared $k_h/k_v$ values obtained using the piezocone test and using laboratory consolidation tests. The obtained values are similar to the values obtained by Jamiolkowski et al. (M application); therefore, the latter values are recommended to be used as $k_h/k_v$.

점성토의 압밀거동은 투수성과 변형성에 영향을 받으며 그 중 투수성은 흙의 종류 및 상태, 특히, 이방성에 영향을 받는다. 연약지반의 투수계수는 피에조 콘 소산시험 및 실내압밀시험 (Oedometer test)에 의해 구할 수 있으며, 피에조 콘 시험으로 과잉간극수압 소산측정이 가능하여 수평압밀계수와 수평투수계수 평가에 유용하게 사용된다. 본 연구에서는 국내 서해안 및 남해안 지역의 해성 점성토층을 대상으로 피에조 콘 소산시험을 실시하였으며, 불교란 시료에 대한 실내시험(Oedometer, Rowe cell)을 실시하고 각 이론해 별로 비교 분석을 실시하였다. 연구결과 Jamiolkowski(M적용) 등(1985)의 해로 추정한 kh/kv가 이 연구 대상지반의 투수특성과 가장 유사하게 나타나 국내의 연약지반에서 피에조 콘 소산시험 및 실내시험 (Oedometer test)에 의하여 투수특성(kh/kv, kh)을 평가하는 방법으로서 이들 이론해의 적용을 추천한다.

Keywords

References

  1. ASTM, 1987, Standard Method for Deep Quastic-Static Cone and Friction Penetration Tests of Soils, D3441, American Society of Testing Materials, 546-554.
  2. Baligh, M. M. and Levadoux, J. N., 1980, Pore Pressure Dissipation after Cone Penetration, MIT Dept. of Civil Engineering, Report No. R80-115, Cambridge, MA., 2-139.
  3. Becker, D.E., 1989, The Significance of Anisotropic Considerations for Settlement Prediction of Foundations on clays, Proc. of the 42nd Canadian Geotechnical Conference, Winnipeg, Canada, 83-91.
  4. Gupta, R. C., 1983, Determination of the In Situ Coefficient of Consolidation and Permeability of Submerged Soil Using Electrical Piezoprobe Sounding, Ph. D. Dissertation, Univ. of Florida. 303p.
  5. Jamiolkowski, M., Ladd, C.C., Germaine, J.T., and Lancellotta, R., 1985, New Developments in Field and Laboratory Testing of Soils, State of the art Report. Proceedings of the 11th International Conference on Soil Mechanics and Foundation Engineering, San Francisco, (1), 57-153.
  6. Jamiolkowski, M., Lancellota, R., and Lo Presti, D.C.F., 1995, Remarks on the Stiffness at Small Strains of Six Italian Clays, Proc. of Prefailure Deformation of Geomaterials, Mitachi and Miura, Shibuya, Japan, 817-836.
  7. Lacerda, W. A., Costa-Filho, L. M., and Duarte, A. E. R., 1977, Consolidation characteristics of Rio de Janeiro soft clay, Proceedings of International Symposium on Soft Clay, Bangkok, 231-243.
  8. Levadoux, J. N. and Baligh, M. M., 1986, Consolidation after Undrained Piezocone Penetration I: Prediction, Journal of Geotechnical Engineering, ASCE, 112(GT7), 707-726. https://doi.org/10.1061/(ASCE)0733-9410(1986)112:7(707)
  9. Parry, R. H. G. and Wroth, C. P., 1977, Shear properties of soft clay, Report presented at the Symposium on Soft Clay, Bangkok, Thailand, 250-262.
  10. Robertson, P.K., 1990, Soil classification using the cone penetration test Canadian Geotechnical Journal, 27(1), 151-8. https://doi.org/10.1139/t90-014
  11. Robertson, P.K. and Companella, R.G., 1983, Interpretation of Cone Penetrometer test: Part I : Sand, Canadian Geotechnical Journal, 20(4). 718-745. https://doi.org/10.1139/t83-078
  12. Robertson, P.K., Campanella, R.G., Gillespie, D., and Greig, J., 1986, Use of piezometer cone data, Proceedings of the ASCE Specialty Conference In Situ '86 : Use of In Situ Tests in Geotechnical Engineering, Blacksburg, American Society of Engineers(ASCE), 1263-1280.
  13. Robertson, P.K., Sully, J.P., Woeller, D.J., Lunne, T., Powell, J.J.M., and Gillespie, D.G., 1992, "Estimating Coefficient of Consolidation from Piezocone Tests", Canadian Geotechnical Journal, 29(4), 551-557. https://doi.org/10.1139/t92-062
  14. Roy, M., Tremblay, M., Tavenas, F., and La Rochelle, P., 1982a, Development of Pore pressure in Quasistatic Penetration Tests in Sensitive Clay, Canadian Geotechnical Journal, 19(2), 124-138. https://doi.org/10.1139/t82-015
  15. Roy, M., Tremblay, M., Tavenas, F., and P. La Rochelle., 1982b, Development of Quasistatic Piezocone Apparatus, Canadian Geotechnical Journal, 19(2), 180-183. https://doi.org/10.1139/t82-020
  16. Schmertmann, J.H., 1974, Penetration Pore Pressure Effects on Quasistatic Cone Bearing, qc, Proceedings of the European Symposium on Penetration Testing, ESOPT, Stockholm, 2(2), 345-351.
  17. Teh, C. I., 1987, An Analytical Study of the Cone Penetration Test, D. Phil. Thesis, Oxford University; 917-926.
  18. Teh, C. I. and Houlsby, G. T, 1991, An Analytical Study of the Cone Penetration Tests in Clay, Geotechnique, 41(1), 17-34. https://doi.org/10.1680/geot.1991.41.1.17
  19. Terzaghi, K., 1943, Theoretical Soil Mechanics, John WIley and Sons, New York, 510p.
  20. Torstensson, B.A., 1975, The Pore Pressure Sounding Equipment, Specialty Conference on In-situ Measurement of Soil Properties, Raleigh, North Carolina, American Society of Engineers(ASCE). 48-55.
  21. Torstensson, B.A., 1977, The Pore Pressure Probe. Proceedings. Geoteknikkdagen, Tapir Foreleg, Oslo, 34, 1-15.