Journal of the Korean Geotechnical Society (한국지반공학회논문집)

Korean Geotechnical Society (한국지반공학회)
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Evaluation of Soil Improvement by Carbonate Precipitation with Urease

요소분해효소에 의한 탄산칼슘 침전을 통한 지반 개량 평가

  • 송준영 (연세대학교 토목환경공학과) ;
  • 심영종 (한국토지주택공사 토지주택연구원 건설기술연구실) ;
  • 진규남 (한국토지주택공사 토지주택연구원 건설기술연구실) ;
  • 윤태섭 (연세대학교 토목환경공학과)
  • Received : 2017.08.31
  • Accepted : 2017.09.15
  • Published : 2017.09.30
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Abstract

This study presents the experimental results of $CaCO_3$ formation in sand by the Enzyme Induced Carbonate Precipitation (EICP) method. Concentration of $CaCO_3$ with elapsed reaction time is calibrated by standardized procedure by measuring $CO_2$ pressure, and it increases with time towards asymptotic value. Jumunjin sand saturated with EICP solution shows that both shear wave velocity and electrical conductivity sharply increase as the reaction starts to approach to the constant values after 50 hours of reaction time. Urease concentration of 0.5 g/L exhibits 224% higher final shear wave velocity than that of 0.1 g/L. The nucleation models hint that carbonate tends to precipitate not only at grain contacts but also at grain surfaces. Regardless of urease concentration, electrical conductivity and shear wave velocity follow the unique path. The scanning electron microscopic images and X-ray computed tomographic images validate the spatial configuration of produced $CaCO_3$ in soils.

본 연구에서는 사질토에서의 EICP에 의한 탄산칼슘 침전량을 정량적으로 평가하였다. 생성된 탄산칼슘은 염산과의 반응에 수반되는 이산화탄소 기체 압력 증분을 통해 간접적으로 측정하였으며, 이는 반응이 진행됨에 따라 특정 값으로 수렴하는 경향을 보였다. EICP 용액으로 포화된 주문진표준사의 전단파 속도 및 전기전도도값은 측정된 탄산칼슘량의 수렴시간보다 선행하여 일정한 값에 도달함을 확인하였다. 결정화 모델은 탄산칼슘이 흙 입자간 접촉점과 입자표면에서 생성됨을 나타내며, 이를 통해 최종 전단파 속도 및 최종 전기전도도에 도달하는 시간과 탄산칼슘 생성량의 수렴시간 간의 불일치가 설명 가능함을 보였다. 또한, 용액 농도 0.5g/L를 이용한 최종 전단파 속도는 0.1g/L의 것보다 224% 높은 효율을 나타내었다. 더불어 효소의 농도와 무관하게 전기전도도와 전단파 속도의 상관관계가 있음을 확인하였으며 주사전자현미경과 X-ray CT 이미지 분석을 통해 생성된 탄산칼슘의 공간적 분포를 확인하였다.

Keywords

Acknowledgement

Supported by : 한국연구재단(NRF), 한국토지주택공사 토지주택연구원

References

  1. Park, K. H. and Kim, D. H. (2013), "Effect of Strength and Injection for the Sand Treated Bacteria", Journal of Korean Geotechnical Society, Vol.29, No.2, pp.65-73. https://doi.org/10.7843/kgs.2013.29.2.65
  2. Park, K. H. and Kim, D. (2015), Effect of Mixed Ratios of Ground Improvement Material using Microorganisms on the Strength of Sands, Journal of the Korean Geosynthetic Society, Vol.14, No.2, pp.1-9. https://doi.org/10.12814/jkgss.2015.14.2.001
  3. Park, S. S., Kim, W. J., and Lee, J. C. (2011), Effect of Biomineralization on the Strength of Cemented Sands, Journal of the Korean Geotechnical Society, Vol.27, No.5, pp.75-84. https://doi.org/10.7843/kgs.2011.27.5.075
  4. Park, S. S., Choi, S. K., and Nam, I. H. (2012), "Development of Ground Cement using Plant Extract", Journal of Korean Geotechnical Society, Vol.28, No.3, pp.67-75. https://doi.org/10.7843/kgs.2012.28.3.67
  5. Archie, G. E. (1942), The electrical resistivity log as an aid in determining some reservoir characteristics, Trans. AIMe, Vol.146, No.99, pp.54-62. https://doi.org/10.2118/942054-G
  6. ASTM (2014), Standard test method for rapid determination of carbonate content of soils. ASTM D4373-14, West Conshohocken, PA.
  7. Burbank, M. B., Weaver, T. J., Green, T. L., Williams, B. C., and Crawford, R. L. (2011), Precipitation of calcite by indigenous microorganisms to strengthen liquefiable soils, Geomicrobiology Journal, Vol.28, No.4, pp.301-312. https://doi.org/10.1080/01490451.2010.499929
  8. Cheng, L., Cord-Ruwisch, R., and Shahin, M. A. (2013), Cementation of sand soil by microbially induced calcite precipitation at various degrees of saturation, Canadian Geotechnical Journal, Vol.50, No.1, pp.81-90. https://doi.org/10.1139/cgj-2012-0023
  9. Ecker, C., Dvorkin, J., and Nur, A. (1998), Sediments with gas hydrates: Internal structure from seismic AVO. Geophysics, Vol.63, No.5, pp.1659-1669. https://doi.org/10.1190/1.1444462
  10. Hamdan, N., Kavazanjian Jr, E., and O'Donnell, S. (2013), Carbonate cementation via plant derived urease. In Proceedings of the 18th International Conference on Soi l Mechanics and Geotechnical Engineering, Paris.
  11. Hamdan, N. and Kavazanjian Jr, E. (2016), Enzyme-induced carbonate mineral precipitation for fugitive dust control, Geotechnique, Vol.66, No.7, pp.546-555. https://doi.org/10.1680/jgeot.15.P.168
  12. Lee, J. S. and Santamarina, J. C. (2005), Bender elements: performance and signal interpretation, Journal of geotechnical and geoenvironmental engineering, Vol.131, No.9, pp.1063-1070. https://doi.org/10.1061/(ASCE)1090-0241(2005)131:9(1063)
  13. DeJong, J. T., Fritzges, M. B., and Nusslein, K. (2006), Microbially induced cementation to control sand response to undrained shear, Journal of Geotechnical and Geoenvironmental Engineering, Vol.132, No.11, pp.1381-1392. https://doi.org/10.1061/(ASCE)1090-0241(2006)132:11(1381)
  14. Mortensen, B. M., Haber, M. J., DeJong, J. T., Caslake, L. F., and Nelson, D. C. (2011), Effects of environmental factors on microbial induced calcium carbonate precipitation, Journal of applied microbiology, Vol.111, No.2, pp.338-349. https://doi.org/10.1111/j.1365-2672.2011.05065.x
  15. Nemati, M. and Voordouw, G. (2003), Modification of porous media permeability, using calcium carbonate produced enzymatically in situ, Enzyme and Microbial Technology, Vol.33, No.5, pp.635-642. https://doi.org/10.1016/S0141-0229(03)00191-1
  16. Santamarina, J. C., K. A. Klein, and M. A. Fam (2001), Soils and Waves: Particulate Materials Behavior, Characterization and Process Monitor- ing, 488 pp., John Wiley, Hoboken, N. J.
  17. van Paassen, L. A., Ghose, R., van der Linden, T. J., van der Star, W. R., and van Loosdrecht, M. C. (2010), Quantifying biomediated ground improvement by ureolysis: large-scale biogrout experiment, Journal of Geotechnical and Geoenvironmental Engineering, Vol.136, No.12, pp.1721-1728. https://doi.org/10.1061/(ASCE)GT.1943-5606.0000382
  18. Whiffin, V. S., van Paassen, L. A., and Harkes, M. P. (2007), Microbial carbonate precipitation as a soil improvement technique, Geomicrobiology Journal, Vol.24, No.5, pp.417-423. https://doi.org/10.1080/01490450701436505
  19. Yasuhara, H., Neupane, D., Hayashi, K., and Okamura, M. (2012), Experiments and predictions of physical properties of sand cemented by enzymatically-induced carbonate precipitation, Soils and Foundations, Vol.52, No.3, pp.539-549. https://doi.org/10.1016/j.sandf.2012.05.011
  20. Yun, T. S., Francisca, F. M., Santamarina, J. C., and Ruppel, C. (2005), Compressional and shear wave velocities in uncemented sediment containing gas hydrate, Geophysical Research Letters, Vol.32, No.10.