Journal of the Korean GEO-environmental Society (한국지반환경공학회 논문집)

Korean Geo-Environmental Society (한국지반환경공학회)
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A Study on the Acquisition Technique of Water Retention Characteristics Based on the Evaporation Method and the Chilled Mirror Method for Unsaturated Soils

증발법과 냉각거울법에 의한 불포화토의 함수특성 획득기법 연구

  • Oh, Seboong (Department of Civil Engineering, Yeungnam University) ;
  • Yoo, Younggeun (Department of Civil Engineering, Korea University) ;
  • Park, Gyusoon (Korea Authority of Life and Infrastructure Safety) ;
  • Kim, Seongjin (Department of Civil Engineering, Yeungnam University)
  • Received : 2022.01.25
  • Accepted : 2022.03.08
  • Published : 2022.04.01
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Abstract

In order to acquire hydraulic characteristics for unsaturated layers, water retention tests were performed and compared by using the evaporation method, volumetric pressure plate extractor (VPPE) and chilled-mirror dew point method. The evaporation and chilled-mirror method are currently developed experimental technology and measure the water retention curve of unsaturated soils quickly and accurately. In the evaporation and VPPE method, the water retention has been measured and compared until 100kPa matric suction and consequently the result of the evaporation method could be verified. In the chilled-mirror method, the water retention has been measured until high level of matric suction and the overall shape of water retention curves could be obtained. As a result of water retention tests, the representative water retention curves were obtained and the applicability of each test method was discussed. Using both the evaporation and chilled-mirror methods, the soil water retention curve can be acquired reasonably for the whole range of matric suction.

불포화층의 수리특성을 획득하기 위하여 증발법, 압력판추출시험, 냉각거울법으로 함수특성시험을 수행하고 비교하였다. 증발법과 냉각거울법은 신시험법으로서 신속하고 정확하게 불포화토의 함수특성곡선을 획득할 수 있다. 증발법과 압력판추출시험에서는 100kPa 범위의 모관흡수력까지 함수특성을 획득하여 비교하였으며, 이로부터 증발법 시험결과를 검증할 수 있었다. 매우 높은 수준의 모관흡수력에서는 냉각거울법을 통하여 함수특성을 측정하고 이로부터 전체적인 함수특성곡선의 양상을 파악할 수 있었다. 모든 함수특성시험을 통하여 얻은 함수특성의 대표곡선을 구하고 각 시험법의 적용성을 비교하였다. 증발법 및 냉각거울법 시험을 병행하면 전체 모관흡수력 범위에서 함수특성곡선을 합리적으로 획득할 수 있었다.

Keywords

Acknowledgement

본 연구는 한국산업기술진흥원 스마트디지털엔지니어링 전문인력양성사업 (P0008475)과 한국연구재단 중견연구자 지원사업 (2019R1A2C1003604)의 2021년 연구비 지원으로 수행되었으며, 이에 깊은 감사를 드립니다.

References

  1. Brooks, R. H. and Corey, A. T. (1964), Hydraulic properties of porous media, Colorado State University Hydrology Paper, Fort Collins, No. 3.
  2. Fredlund, D. G. and Rahardjo, H. (1993), Soil mechanics for unsaturated soils, Wiley, New York.
  3. Fredlund, D. G. and Xing, A. (1994), Equations for the soilwater characteristic curve, Canadian Geotechnical Journal, Vol. 31, No. 3, pp. 521~532. https://doi.org/10.1139/t94-061
  4. Jung, Y. S., Sa, H. D., Kang, S., Oh, S. and Lee, J. S. (2015), Soil water characteristic curve using volumetric pressure plate extractor incorporated with TDR system, Journal of the Korean Geotechnical Society, Vol. 31, No. 8, pp. 17~28 (In Korean). https://doi.org/10.7843/KGS.2015.31.8.17
  5. METER Group Inc. (2021), WP4C manual, URL library.metergroup.com/Manuals/20588_WP4C_Manual_Web.pdf
  6. Mualem, Y. (1976), A new model for predicting the hydraulic conductivity of unsaturated porous media, Water Resources Research, Vol. 12, No. 3, pp. 513~522. https://doi.org/10.1029/WR012i003p00513
  7. Oh, S. and Lu, N. (2014), Uniqueness of the suction stress characteristic curve under different confining stress conditions. Vadose Zone Journal Vol. 13, No. 5, pp. 1~10.
  8. Oh, S., Park, K. H. and Kim, J. W. (2014), A hydraulic conductivity model considering the infiltration characteristics near saturation in unsaturated slopes, Journal of the Korean Geotechnical Society Vol. 30, No. 1, pp. 37~47 (In Korean). https://doi.org/10.7843/KGS.2014.30.1.37
  9. Peters, A. and Durner, W. (2008), Simplified evaporation method for determining soil hydraulic properties, Journal of Hydrology, Vol. 356, Issue 1~2, pp. 147~162. https://doi.org/10.1016/j.jhydrol.2008.04.016
  10. Rawlins, S. L. and Campbell, G.S. (1986), Water potential : Thermocouple psychrometry, Soil Science Society of America Book series-Methods of Soil Analysis, Part 1, pp. 597~618.
  11. Rahardjo, H., Satyanaga, A., Mohamed, H., Ip, S.C.Y. and Shah, R.S. (2019), Comparison of soil-water characteristic curves from conventional testing and combination of small-scale centrifuge and dew point methods, Geotechnical and Geological Engineering, Vol. 37, No. 2, pp. 659~672. https://doi.org/10.1007/s10706-018-0636-2
  12. Schindler, U. (1980), Ein schnellverfahren zur messung der wasserleitfahigkeit im teilgesattigten noden an stechzylinderproben, Arch. Acker Pfl anzenbau Bodenkd. 24, pp. 1~7 (In Deutsch).
  13. Schindler, U., Durner, W., G. von Unold, G. and Muller, L. (2010), Evaporation method for measuring unsaturated hydraulic properties of soils: Extending the measurement range, Soil Science Society of America Journal, Vol. 74, No. 4, pp. 1071~1083. https://doi.org/10.2136/sssaj2008.0358
  14. Schelle, H., Heise, L., Janicke, K., and Durner, W. (2013), Water retention characteristics of soils over the whole moisture range: A comparison of laboratory methods, European Journal of Soil Science, Vol. 64 No. 6, pp. 814~821. https://doi.org/10.1111/ejss.12108
  15. UMS (2015), Manual HYPROP, Version 2015-01, URL www.metergroup.com/hyprop-2/#support
  16. van Genuchten, M. T. (1980), A closed-form equation for predicting the hydraulic conductivity of unsaturated soils, Soil Science Society of America Journal, Vol. 44, No. 5, pp. 892~898. https://doi.org/10.2136/sssaj1980.03615995004400050002x
  17. Wind, G. P. (1968), Capillary conductivity data estimated by a simple method, Water in the Unsaturated Zone: Proc. UNESCO/IASH Symp., Wageningen, Netherlands, pp. 181~191.