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Experimental and numerical investigation of closure time during artificial ground freezing with vertical flow

  • Jin, Hyunwoo (Department of Future and Smart Construction Research, KICT) ;
  • Go, Gyu-Hyun (Department of Civil Engineering, Kumoh National Institute of Tech.) ;
  • Ryu, Byung Hyun (Department of Future and Smart Construction Research, KICT) ;
  • Lee, Jangguen (Department of Future and Smart Construction Research, KICT)
  • 투고 : 2021.07.07
  • 심사 : 2021.11.22
  • 발행 : 2021.12.10

초록

Artificial ground freezing (AGF) is a commonly used geotechnical support technique that can be applied in any soil type and has low environmental impact. Experimental and numerical investigations have been conducted to optimize AGF for application in diverse scenarios. Precise simulation of groundwater flow is crucial to improving the reliability these investigations' results. Previous experimental research has mostly considered horizontal seepage flow, which does not allow accurate calculation of the groundwater flow velocity due to spatial variation of the piezometric head. This study adopted vertical seepage flow-which can maintain a constant cross-sectional area-to eliminate the limitations of using horizontal seepage flow. The closure time is a measure of the time taken for an impermeable layer to begin to form, this being the time for a frozen soil-ice wall to start forming adjacent to the freeze pipes; this is of great importance to applied AGF. This study reports verification of the reliability of our experimental apparatus and measurement system using only water, because temperature data could be measured while freezing was observed visually. Subsequent experimental AFG tests with saturated sandy soil were also performed. From the experimental results, a method of estimating closure time is proposed using the inflection point in the thermal conductivity difference between pore water and pore ice. It is expected that this estimation method will be highly applicable in the field. A further parametric study assessed factors influencing the closure time using a two-dimensional coupled thermo-hydraulic numerical analysis model that can simulate the AGF of saturated sandy soil considering groundwater flow. It shows that the closure time is affected by factors such as hydraulic gradient, unfrozen permeability, particle thermal conductivity, and freezing temperature. Among these factors, changes in the unfrozen permeability and particle thermal conductivity have less effect on the formation of frozen soil-ice walls when the freezing temperature is sufficiently low.

키워드

과제정보

This research was supported by the research project "Development of environmental simulator and advanced construction technologies over TRL6 extreme conditions" funded by the Korea Institute of Civil Engineering and Building Technology (KICT).

참고문헌

  1. Alzoubi, M.A., Nie-Rouquette, A. and Sasmito, A.P. (2018). "Conjugate heat transfer in artificial ground freezing using enthalpy-porosity method: Experiments and model validation", Int. J. Heat Mass Tran., 126(A), 740-752. https://doi.org/10.1016/j.ijheatmasstransfer.2018.05.059.
  2. Alzoubi, M.A., Madiseh, A., Hassani, F.P. and Sasmito, A.P. (2019), "Heat transfer analysis in artificial ground freezing under high seepage; Validation and heatlines visualization", Int. J. Therm. Sci., 139, 232-245. https://doi.org/10.1016/j.ijthermalsci.2019.02.005.
  3. Alzoubi, M.A., Xu, M., Hassani, F.P., Poncet, S. and Sasmito, A.P. (2020), "Artificial ground freezing: A review of thermal and hydraulic aspects", Tunn. Undergr. Sp. Tech., 104, 103534-1-18. https://doi.org/10.1016/j.tust.2020.103534.
  4. Andersland, O.B. and Ladanyi, B. (2004), Frozen Ground Engineering (2nd Edition), John and Wiley Sons, NY, USA.
  5. Chang, M., Mao, T.W. and Huang, R.C. (2016), "A study on the improvements of geotechnical properties of in-situ soils by grouting", Geomech. Eng., 10(4), 527-546. http://dx.doi.org/10.12989/gae.2016.10.4.527.
  6. Comsol Inc. (2021), Comsol Multiphysics User's Manual Ver. 5.6, Comsol Inc., Burlington, MA, USA.
  7. Coussy O. (2004), Poromechanics, John and Wiley Sons, New York, NY, USA.
  8. Frivik, P. and Comini, G. (1982), "Seepage and heat flow in soil freezing", J. Heat Transf., 104(2), 323-328. https://doi.org/10.1115/1.3245091.
  9. Hashemi, H.T. and Sliepcevich, C.M. (1973), "Effect of seepage stream on artificial soil freezing", J. Soil Mech. Found. Div., 99(3), 267-289. https://doi.org/10.1061/JSFEAQ.0001861.
  10. Go, G.H., Lee, J. and Kim, M. (2020), "Influencing factors on freezing characteristics of frost susceptible soil based on sensitivity analysis", J. Korean Geotech. Soc, 36(8), 49-60. https://doi.org/10.7843/kgs.2020.36.8.49.
  11. Huang, S., Guo, Y., Liu, Y., Ke, L., Liu, G. and Chen, C. (2018), "Study on the influence of water flow on temperature around freeze pipes and its distribution optimization during artificial ground freezing", Appl. Therm. Eng., 135, 435-445. https://doi.org/10.1016/j.applthermaleng.2018.02.090.
  12. Jessberger, G.L. (1980), "Theory and application of ground freezing in civil engineering", Cold Reg. Sci. Technol., 3, 3-27. https://doi.org/10.1016/0165-232X(80)90003-8.
  13. Jin, H., Lee, J., Ryu, B.H. and Go, G.H. (2020), "Experimental and numerical study on hydro-thermal behaviour of artificial freezing system with water flow", J. Korean Geotech. Soc., 36(12), 17-25. https://doi.org/10.7843/kgs.2020.36.12.17.
  14. Jumikis, A.R. (1979), "Cryogenic texture and strength aspects of artificially frozen soils", Eng. Geol., 13, 125-135. https://doi.org/10.1016/0013-7952(79)90026-7.
  15. Lackner, R., Amon, A. and Lagger, H. (2005), "Artificial ground freezing of fully saturated soil: Thermal problem", J. Eng. Mech., 131(2), 211-220. https://doi.org/10.1061/(ASCE)0733-9399(2005)131:2(211).
  16. Li, Z., Chen, J., Sugimoto, M. and Ge, H. (2019), "Numerical simulation model of artificial ground freezing for tunneling under seepage flow conditions", Tunn. Undergr. Sp. Tech., 92, 103035. https://doi.org/10.1016/j.tust.2019.103035.
  17. Luckner L., van Genuchten M.T. and Nielsen D.R. (1989), "A consistent set of parametric models for the two-phase flow of immiscible fluids in the subsurface", Water Resour. Res., 25(10), 2187-2193. https://doi.org/10.1029/WR025i010p02187.
  18. Marwan, A., Zhou, M.M., Abdelrehim, M.Z. and Meschke, G. (2016), "Optimization of artificial ground freezing in tunneling in the presence of seepage flow", Comput. Geotech., 75, 112-125. https://doi.org/10.1016/j.compgeo.2016.01.004.
  19. Michalowski, R.L. and Zhe, M. (2006), "Frost heave modelling using porosity rate function", Int. J. Numer. Anal. Meth. Geomech., 30, 703-722. https://doi.org/10.1002/nag.497.
  20. Pimentel, E., Papakonstantinou, S. and Anagnostou, G. (2012a), "Numerical interpretation of temperature distributions from three ground freezing applications in urban tunnelling", Tunn. Undergr. Sp. Tech., 28, 57-59. https://doi.org/10.1016/j.tust.2011.09.005.
  21. Pimentel, E., Sres, A. and Anagnostou, G. (2012b), "Large-scale laboratory tests on artificial ground freezing under seepage-flow conditions", Geotechnique, 62(3), 227-241. https://doi.org/10.1680/geot.9.P.120.
  22. Quang, N.D. and Giao, P.H. (2014), "Improvement of soft clay at a site in the Mekong Delta by vacuum preloading", Geomech. Eng., 6(5), 419-436. http://dx.doi.org/10.12989/gae.2014.6.5.419.
  23. Shen, Y., Wang, Y., Zhao, X., Yang, G., Jia, H. and Rong, T. (2018), "The influence of temperature and moisture content on sandstone thermal conductivity from a case using the artificial ground freezing (AGF) method", Cold Reg. Sci. Technol., 155, 149-160. https://doi.org/10.1016/j.coldregions.2018.08.004.
  24. Shin, H., Kim. J. and Lee, J. (2018), "Effect of groundwater flow on ice-wall integrity", J. Korean Geotech. Soc., 34(11), 43-55. https://doi.org/10.7843/kgs.2018.34.11.43.
  25. Stander, W. (1967) Mathematische Ansatze zur Berechnung der Frostausbreitung in ruhendem Grundwasser im Vergleich zu Modelluntersuchungen fur verschiedene Gefrierrohranordnungen im Schactund Grundbau, Technical University Fridericiana, Institute for Soil Mechanics and Rock Mechanics, Karlsruhe, Germany.
  26. Taha, M.R., Alsharef, J.M.A., Khan, T.A., Aziz, M. and Gaber, M. (2018), "Compressive and tensile strength enhancement of soft soils using nanocarbons", Geomech. Eng., 16(5), 559-567. https://doi.org/10.12989/gae.2018.16.5.559.
  27. Takashi, T. (1969), "Influence of seepage stream on the joining of frozen zones in artificial soil freezing", Proceedings of International Conference on Effects of Temperature and Heat on Engineering Behavior of Soils, Washington, January.
  28. Tandel, Y.K., Solanki, C.H. and Desai, A.K. (2014), "Field behaviour geotextile reinforced sand column", Geomech. Eng., 6(2), 195-211. http://dx.doi.org/10.12989/gae.2014.6.2.195.
  29. Vitel, M., Rouabhi, A., Tijani, M. and Guerin, F. (2016), "Modeling heat and mass transfer during ground freezing subjected to high seepage velocities", Comput. Geotech., 73, 1-15. https://doi.org/10.1016/j.compgeo.2015.11.014.
  30. Wang, B., Rong, C.X., Lin, J., Cheng, H. and Cai, H.B. (2019), "Study on the formation law of the freezing temperature field of freezing shaft sinking under the action of large-flow-rate groundwater", Adv. Mater. Sci. Eng., 2019(1670820), 1-20. https://doi.org/10.1155/2019/1670820.
  31. Yu, W.B., Liu, W.B., Lai, Y.M., Chen, L. and Yi. X. (2014), "Nonlinear analysis of coupled temperature-seepage problem of warm oil pipe in permafrost regions of Northeast China", Appl. Therm. Eng., 70, 988-995. https://doi.org/10.1016/j.applthermaleng.2014.06.028.
  32. Zhou, M.M. and Meschke, G. (2013), "A three-phase thermos-hydro-mechanical finite element model for freezing soils", Int. J. Numer. Anal. Meth. Geomech., 37, 3173-3193. https://doi.org/10.1002/nag.2184.
  33. Zhou, J. and Tand, Y. (2018), "Experimental inference on dual-porosity aggravation of soft clay after freeze-thaw by fractal and probability analysis", Cold Reg. Sci. Technol., 153, 181-196. https://doi.org/10.1016/j.coldregions.2018.06.001.
  34. Zueter, A., Nie-Rouquette, A., Alzoubi, M.A. and Sasmito, A.P. (2020), "Thermal and hydraulic analysis of selective artificial ground freezing using air insulation: Experiment and modelling", Comput. Geotech., 120, 103416. https://doi.org/10.1016/j.compgeo.2019.103416.