DOI QR코드

DOI QR Code

준설 실트질 점토를 이용한 경량기포혼합토의 압축강도 특성

Compressive Strength Characteristics of Light-weight Air Foamed Soil Using Dredged Silty Soils

  • Kim, Donggyu (Dept. of Civil Engineering, Inha University) ;
  • Yoon, Yeowon (Dept. of Civil Engineering, Inha University) ;
  • Yoon, Gillim (Development & Ocean Energy Research Division, Korea Institute of Ocean Science & Technology)
  • 투고 : 2017.01.06
  • 심사 : 2017.03.30
  • 발행 : 2017.05.01

초록

본 연구에서는 실트질 점토와 동물성 기포제 및 시멘트로 제작한 경량기포혼합토의 공학적 특성을 고찰하는 시험을 수행하였다. 현장의 경량기포혼합토는 도로를 위한 연약지반상 성토 및 기존도로의 확장 구간에 성토재료로 사용되어 왔다. 현장에서는 주로 제작 직후의 단위중량과 흐름치를 측정하여 품질관리를 하고 있으며, 실내 시험을 통해 압축강도시험으로 확인한다. 본 연구의 주목적은 경량혼합토의 다른 특성과 흐름치 관계와 더불어 흐름치로부터 시방서에서 요구하는 압축강도를 예측하고자 하는 것이 주요 목적이다. 연구 결과, 준설토의 함수비가 클수록 높은 유동성으로 인해 흐름치가 증가하였고 재료분리로 인해 타설 깊이에 따른 단위중량이 증가하였다. 60cm의 시료 하부는 상부에 비하여 약 2배의 압축강도를 나타내었다. 현장에서의 품질관리는 주로 흐름치에 의존하게 되므로 흐름치와 혼합토의 압축강도를 선행적으로 예측할 수 있도록 Yoon & Kim(2004)이 제시한 정규화계수와의 상관관계를 제시함으로써 흐름치로부터 압축강도를 예측할 수 있도록 하였다. 또한, 흐름치와 정규화계수와의 관계를 제시하였으며 이관계로부터 정규화계수를 산정하고, 이로부터 계산한 압축강도와 실내시험 압축강도를 비교한 결과, 준설토의 초기함수비가 높을수록 유사한 관계가 나타났다. 따라서, 흐름치와 정규화계수의 상관관계를 통해 압축강도를 사전에 예측하여 설계 단계에서 반영할 필요성이 있다고 판단된다.

In this research, laboratory tests were carried out to investigate the engineering properties of Light-Weight Air Foamed Soil (LWAS) based on silty clays with the animal foaming agent and cement. LWAS has been used as an embankment material over soft ground for road and side extension of the existing road. In field, unit weight and flow value is measured right after producing in mixing plant in order to control the quality of LWAS, and laboratory tests are carried out to confirm the quality through compressive strength of LWAS as well. In this research, direct estimation of the specification requirement of strength using flow values in field is the main purpose of the study together with other characteristics. From the test results, it can be seen that flow values increase with the initial water content and unit weight increases with the depth due to material segregation. Compared to the upper specimen, lower end of 60 cm specimen shows about 2 times higher compressive strength. Relationship between flow values and normalized factor presented by Yoon & Kim (2004) was presented. With that relationship, compressive strength can be predicted from flow values in field. From the relationship, the normalized factor was calculated. Thereafter calculated compressive strengths according to the flow values were compared to measured strengths in the laboratory. The higher the initial water content of the dredged soil has, the better relationship between predicted and measured shows. Therefore it is necessary to predict the compressive strength in advance through the relationship between the flow value and the normalized factor to reflect it in the design stage.

키워드

참고문헌

  1. Ahn, G. H. (2011), Engineering characteristics of light-weight soils mixed with air foam and waste tire powder, Master Thesis, Inha University, 75p (in Korean).
  2. Hwang, J. H., Ahn, Y. K., Lee, Y. J. and Kim, T. H. (2010), "Characteristics of the expanded road embankment constructed by lightweight air-mixed soils for a short-term", J. of KSCE, Vol. 30, 4D, pp. 377-386 (in Korean).
  3. Jounouchi, K., Wada, Y. and Tateyama, T. (2009), "On the adaptability of air foam-mixed light weight soil construction method to snowy cold area", National Institute of Civil Engineering - Cold Region, 2009 Research Conference, Tech-52 (in Japanese).
  4. Kang, D. G. and Shin, E. C. (2016), "Experimental study on behavior of the lightweight air-foamed soil considering freezingthawing and soaking conditions", J. of KGES, Vol. 17, No. 5, pp. 37-46.
  5. Kim, Z. C. and Lee, C. K. (2002), "Mechanical characteristics of light-weighted foam soil consisting of dredged soils", J. of the KGS, Vol. 18, No. 4, pp. 309-317 (in Korean).
  6. KS F 2314, Uniaxial Compression Test Method of Soil (in Korean).
  7. Lee, M. A., Kim, S. W., Choi, D. K., Park, L. K. and Kim, T. H. (2012), Effect of curing temperature on the strength characteristics of lightweight air-trapped soil, Journal of the Korean Geotechnical Society, Vol. 28, No. 4, pp. 43-53 (in Korean). https://doi.org/10.7843/kgs.2012.28.4.43
  8. Lee, Y. J., Kim, S. W., Park, L. K. and Kim T. H. (2010), "Compression and tensile characteristics of lightweight air-trapped soil", J. of KGS, Vol. 26, No. 9, pp. 59-69 (in Korean).
  9. Ma, S. J. (2003), "A study on development of lightweight foam filling material for the voids behind tunnel liner using stonedust and application to the old tunnel", J. of Korea Institute for Structural Maintenance and Inspection, Vol. 7, No. 4, pp. 139-147 (in Korean).
  10. Ministries of Oceans and Fisheries (2003), A study on recycling of dredged soil [IV], pp. 20-50 (in Korean).
  11. Park, D. W. and Vo, H. V. (2015), "Evaluation of air-foam stabilized soil of dredged soil waste as a pavement subgrade layer", KSCE Journal of Civil Engineering, Vol. 19, Issue 7, pp. 2091-2097. https://doi.org/10.1007/s12205-015-0134-5
  12. Park, L. K., Kim, T. H. and Seo, Y. K. (2011), "Engineering characteristics of the Lightweight Air-Mixed Soil (LWS) containing silty marine sediment", Marine Georesources & Geotechnology, 29:3, pp. 202-217. https://doi.org/10.1080/1064119X.2011.554966
  13. Song, J. H., Lim, J. C. and Hong, S. W. (2008), "Analysis of compressive strength of lightweight air-mixed soil according to the properties of soil", J. of KGS, Vol. 24, No. 11, pp. 157-166 (in Korean).
  14. Tsuchida, T., Nagai, K., Okumura, T., Kishda, K. and Funada, K. (1995), Mechanical properties of lightweight geo-matrial used for the backfill of quaywalls (Part 1), Proceedings of 31st Conference on Geotechnical Engineering, pp. 2525-2528.
  15. Watabe, Y., Tanaka, M., Saegusa, H., Shinsha, H. and Tsuchida, T. (2009), "Long-term properties of airfoam-treated lightweight soil made from dredged clay", J. of ASTM International, Vol. 6, No. 4, pp. 1-10.
  16. Yoon, G. L. (2016), "Eco-friendly dredged soil and its reclamation and transportation more than 30km", Internal Research Report of Korea Institute of Ocean Science and Technology, pp. 3-10 (in Korean).
  17. Yoon, G. L. and Kim, B. T. (2004), "Compressibility and strength characteristics of light-weighted foam soil", J. of KGS, Vol. 20, No. 4, pp. 5-13 (in Korean).
  18. Yoon, G. L. and You, S. K. (2005), "Behaviors of lightweight foamed soils considering underwater curing and water pressure conditions", J. of KGS, Vol. 21, No. 4, pp. 21-29 (in Korean).