Stabilization Mechanism for Sands Treated with Organic Acids from Laboratory Tests

유기산 재료를 이용한 사질토의 안정화 메커니즘에 관한 연구

  • Ki, Jungsu (Dept. of Civil and Environmental Engineering, Hanyang University) ;
  • Yee, Eric (KEPCO International Nuclear) ;
  • Lee, Jonghwi (Hyundai Heavy Industries) ;
  • Chun, Byungsik (Dept. of Civil and Environmental Engineering, Hanyang University)
  • Published : 2013.06.01

Abstract

The field of ground amelioration, many construction methods have been developed more prosperously up to now, but even now, the majority focuses on the improvement of ground strength. And they could not suggest concrete solutions to the occurrence of environmental issues. To address this problem, soil improvement methods employing organic acid materials have recently been developed as eco-friendly technologies for increasing the soil strength, but details regarding the basic stabilization mechanism are not known yet. Against this background, this research was conducted to examine the soil stabilization mechanism; for this purpose, unconfined compressive strength and pH tests were conducted by using an improved eco-friendly organic acid material. The test results revealed that the samples processed with the organic acid showed a considerable increase in the unconfined compressive strength over time as compared to the strength of the samples that were processed without the organic acid. It was also confirmed that the organic acid material promoted microbial breeding and improved the soil structure by reducing the volume of the voids in the soil. Therefore, the sustainable development of this method needs to be analysed more in the future.

지반개량분야에서는 수많은 공법들이 지금까지 발전을 거듭하여 개발되어왔다. 그러나 대부분의 공법들은 지반의 강도 증진에만 중점을 두었으며 환경문제 발생에 대한 구체적인 해결방안을 제시하지 못하고 있다. 이에 최근에 들어 친환경적으로 지반의 강도를 증대시키는 방법으로 유기산 재료를 이용한 지반개량이 개발되어왔으나 아직 근본적인 안정화 메커니즘에 대해서는 잘 알려지지 않았다. 따라서 본 연구에서는 친환경 개량재인 유기산 재료를 활용한 일축압축강도시험 및 pH시험을 통해 안정화 메커니즘에 대해 규명하였다. 그 결과, 유기산 처리가 된 샘플이 유기산 처리가 되지 않은 샘플보다 시간에 따른 더 큰 일축압축강도를 보였다. 또한, 유기산 재료에 의해 미생물들의 증식이 촉진되며, 토양의 공극 감소를 통해 토양이 개량된다는 것을 규명할 수 있었다. 향후 유기산 재료를 활용한 지반개량 공법의 지속적인 연구가 필요하다고 사료된다.

Keywords

References

  1. Chang, E. H., Jeong, S. T., Jeong, S. M., Roh, J. H., Park, K. S., Park, S. J. and Choi, J. U. (2011), Deacidification effect of campbell early must via carbonic maceration: effect of enzyme activity associated with malic-acid metabolism, Korean Society of Food Preservation Magazine, Vol. 18, No. 5, pp. 795-802 (in Korean). https://doi.org/10.11002/kjfp.2011.18.5.795
  2. Clough, J. M., Peet, M. M. and Kramer, P. J. (1981), Effects of high atmospheric $CO_2$ and sink size on rates of photosynthesis of a soybean cultivar, Plant Physiol. Vol. 67, No. 5, pp. 1007-1010. https://doi.org/10.1104/pp.67.5.1007
  3. David, M. S., Jeffry, J.F., Peter, G. H. and David, A. Z. (2005), Principles and applications of soil microbiology - 2nd edition, Pearson Prentice Hall, pp. 33-50.
  4. De Muynck, W., N. De Belie, and W. Verstraet. (2010), Microbial carbonate precipitation in construction materials, Ecol. Eng., Vol. 36, No. 2, pp. 118-136. https://doi.org/10.1016/j.ecoleng.2009.02.006
  5. DeJong, J. T., Fritzges, M. B. and Nulein, K. (2006), Microbially induced cementation to control sand response to undrained shear, Journal of Geotechnical and Geoenvironmental Engineering, Vo1. 132, No. 11, pp. 1381-1392. https://doi.org/10.1061/(ASCE)1090-0241(2006)132:11(1381)
  6. Farouk, A., Lamboj, L. and Kos, J. (2004). Influence of matric suction on the shear strength behavior of unsaturated sand, Acta Polytechnica, Vol. 44, No. 4, pp. 11-17.
  7. Kawasaki, S., Ogata, S., Hiroyoshi, N., Tsunekawa, M., Kaneko, K., and Terajima, R. (2010), Effect of temperature on precipitation of calcium carbonate using soil microorganisms, J. Jpn. Soc. Eng. Geol., Vol. 51, No. 1, pp. 10-18. https://doi.org/10.5110/jjseg.51.10
  8. Kim, D. H., Kim, H. C. and Park, K. H. (2010), Possibility of cementation of soft soil using bacteria, 2010 Fall Geotechnical Engineering Conference of Korean Geotechnical Society, pp. 379-391 (in Korean).
  9. Kim, H. C. (2011), Cementation characteristic of soil using bacteria, Master's Thesis, University of Chosun, pp. 1-15 (in Korean).
  10. Lee, J. H., Kim, K. M. and Chun, B. S. (2012). Strength characteristics of soils mixed with an organic acid material for improvement, Journal of Material in Civil Engineering, Vol. 24, No. 12, pp. 1529-1533. https://doi.org/10.1061/(ASCE)MT.1943-5533.0000516
  11. Madigan, M. T. and Martinko, J. M. (2003), Brock biology of microorganisms, 11th ed., Pearson Prentice-Hall, Upper Saddle River, N. J., 15-17.
  12. Michell, J. K. and Santamarina, J. C. (2005), Biological considerations in geotechnical engineering, Journal of Geotechnical and Geoenvironmental Engineering, Vol. 131, No. 10, pp. 1222-1233 (in Korean). https://doi.org/10.1061/(ASCE)1090-0241(2005)131:10(1222)
  13. Park, K. H. (2011), Strength improvement of soft ground with microbial reaction, Master's Thesis, University of Chosun, pp. 14-19 (in Korean).
  14. Park, S. S., Kim, W. J. and Lee, J. C. (2011), Effect of biomineralization on the strength of cemented sands, Journal of KGS, Vol. 27, No. 5, pp. 75-84 (in Korean).
  15. Park, S. S., Choi, S. G. and Nam, I. H.(2012), Development of soil binder using plant extracts, Journal of KGS, Vol. 28, No. 3, pp. 67-75 (in Korean).
  16. Ramachandran, S, K., V. Ramakrishnan and S. S. Bang. (2001), Remediation of concrete using micro-organisms, ACI. Mater., Vol. 98, No. 1, pp. 3-9.
  17. Shimada, K. (1998). Effect of matric suction on shear characteristics of unsaturated fraser river sand, J. Faculty Env, Sci. Tech., Okayama University, Vol. 3, No. 1, pp. 127-134.
  18. Song, H. C., Song, D. S., Jo, D. W., Park, S. W., Choi, S. H., Jeon, B. H., Lee, J. H. and Park, J. H. (2009), Stabilization of heavy metals using Ca-citrate-phosphate solution: effect of soil microorganisms, Korean Society of Environmental Engineers Magazine, Vol. 31, No. 4, pp. 241-248 (in Korean).
  19. Sylvia, D. M., Fuhrmann, J. J., Hartel, P. G. and Zuberer, D. A. (2005), Principles and applications of soil microbiology, Pearson Prentice-Hall, Upper Saddle River, N. J., pp. 23-29.
  20. Whiffin, V. S. (2004), Microbial CaCO3 precipitation for the production of biocement, Ph. D. Dissertation, Murdoch University, Western Australia, pp. 35-41.