Journal of the Korean Geotechnical Society (한국지반공학회논문집)

Korean Geotechnical Society (한국지반공학회)
권호 표지
DOI QR코드

DOI QR Code

Effects of Various Loading Periods on the Consolidation Characteristics of Remolded Clay - With Special Reference to Gwangyang Marine Clayey Soil -

하중재하기간이 재성형 점토의 압밀특성에 미치는 영향 - 광양항 해성점토를 중심으로 -

  • Hong, Jae-Cheol (Dept. of Rural & Bio-Systems Engrg., Chonnam National Univ.) ;
  • Kim, Jin-Young (Dept. of Rural & Bio-Systems Engrg., Chonnam National Univ.) ;
  • Shim, Jae-Rok (Dept. of Rural & Bio-Systems Engrg., Chonnam National Univ.) ;
  • Kang, Kwon-Soo (Dept. of Civil Engrg., Seonam Univ.) ;
  • Kim, Ju-Hyun (Graduate School of Science and Engrg., Yamaguchi Univ.) ;
  • Baek, Won-Jin (Dept. of Rural & Bio-Systems Engrg., Chonnam National Univ.)
  • 홍재철 (전남대학교 지역.바이오시스템공학과) ;
  • 김진영 (전남대학교 지역.바이오시스템공학과) ;
  • 심재록 (전남대학교 지역.바이오시스템공학과) ;
  • 강권수 (서남대학교 토목공학과) ;
  • 김주현 (야마구치대학교 대학원 이공학연구과) ;
  • 백원진 (전남대학교 지역.바이오시스템공학과)
  • Received : 2013.10.21
  • Accepted : 2014.02.03
  • Published : 2014.02.28
Download PDF
⟨ Previous Next ⟩

Abstract

This study sets it's face to define effects of the various loading periods in normal consolidation area on clay's compression and long-term consolidation characteristics through a laboratory test using homogeneous remolded clay. Moreover, by carrying out a long-term consolidation test which diversifies initial consolidation applicable to effective overburden loading in the various loading period. This study intended to suggest the method predicting the final settlement on the basis of loading periods by comparing and analyzing compression curve's characteristics according to loading weight of each stage and increase in loading period when carrying out the standard consolidation test. From the test results, the study shows that as of the soft clay's compression characteristics on the basis of various loading periods, preconsolidation load has a tendency to be decreased slightly as the loading period is getting more and more longer at each step after initial consolidation load puts on the remolded clay which is caused by secondary consolidation's increase in the latter part of each phase. And those effects have an weaker influence on compression index in normal consolidation area at the same time as secondary consolidation brought out quasi-overconsolidation and stabilization of clay's structure, have an influence re-compression index is increased in overconsolidation area on the other hand.

이 연구에서는, 균질한 재성형 점토를 이용한 실내시험을 통해 정규압밀 영역에서의 하중재하기간이 점성토의 압축 및 장기압밀 특성에 미치는 영향을 명확히 하고자 하였다. 또한 각 하중재하기간에 따른 현장에서의 유효상재하중에 해당하는 초기압밀하중을 변화시킨 장기압밀 시험을 수행하여 표준압밀시험시의 하중단계별 재하방법과 하중재하기간의 증가에 따른 압축곡선의 특성을 비교/분석하여 하중재하기간에 따라 최종침하량을 예측하는 방법을 제안하고자 하였다. 연구 결과 하중재하기간에 따른 점성토의 압축특성은 초기압밀하중을 가한 후 하중재하기간이 증가할수록 주어진 단계에서의 압밀후반부의 2차압밀의 증가로 선행압밀하중이 약간씩 감소하는 경향을 나타내었다. 그와 동시에 2차압밀이 유사과압밀 현상 및 점토골격의 안정화를 유발하여 정규압밀영역에서의 압축지수에 미치는 영향은 미미했으며 과압밀영역에서는 유사과압밀 현상으로 재압축지수의 증가를 유발하는 것으로 나타났다.

Keywords

References

  1. Kim, J. Y. (2011), "Characteristics of 1D-Consolidation for Soft Clay Ground based on a Elasto-Viscous Model", Master Thesis, Chonnam National University.
  2. Kim, J. Y. and Oshima, A. (2006), "A Study on Similarity Rule of Loading Period and Thickness with One-dimensional Consolidation Process for Clay", Journal of the Korean Society of Civil Engineers, Vol.26, No.6C, pp.369-376.
  3. The Japanese Geotechnical Society (2000), Soil Laboratory Tests- Basic and Process-, Showa Information Process Co., Ltd.
  4. Aboshi, H. and Matsuda, H. (1981), "Secondary compression of clays and its effect on settlement analysis", Soils and Foundations, Vol.29, pp.19-24.
  5. Bjerrum, L. (1967), "Engineering geology of Norwegian normallyconsolidated marine clays as related to settlements of buildings", Geotechnique, Vol.17, pp.81-118.
  6. Casagrande, A. (1936), "The determination of the pre-consolidation load and its practical significance", Proceedings, 1st International Confrerence on Soil Mechanics and Foundation Engineering, Cambridge, Vol.3, pp.60-64.
  7. Crawford, C. B. (1964), "Interpretation of consolidation tests", Journal of Soil Mechanics and Foundation Division, ASCE, Vol. 90, No.SM5.
  8. Ladd, C. C., Foott, R., Ishihara, K., Schosser, F., and Poulos, H. J. (1977), "Stress-deformation and strength characteristics", Proc. 9th ICSMFE, Tokyo 2. State of the Art Report, pp.421-494.
  9. Mesri, G. (1973), "Coefficient of secondary compression", Proc. ASCE, Vol.99, SM1, pp.123-137.
  10. Mesri, G. and Codlewski, P. M. (1997), "Time and stress compressibility interrelationship", Jour. of Goetech. Eng. Div., ASCE Vol.103, No.GT5, pp.417-430.
  11. Taylor, D. W. (1948), "Fundamentals of soil mechanics", John Wiley & Sons.
  12. Terzaghi, K. and Peck, R. B. (1948), "Soil mechanics in engineering practice", John Wiley and Sons.
  13. Yoshikuni, H. and Okada, M., Ikegami, S., and Hirao, T. (1995), "One-dimensional consolidation analysis based on an elasto-viscous liquid model", Proc. of the International Symposium on Compression and Consolidation of Clayey Soils, IS-Hiroshima'95, Vol.1, pp.233-238.
  14. Yoshikuni, H. and Moriwaki, T., Ikegami, S., and Nishiumi, H. (1995), "Rebound due to partial unloading and subsequent recompression behavior in 1-D consolidation", Proc. of the International Symposium on Compression and Consolidation of Clayey Soils, IS-Hiroshima'95, Vol.1, pp.233-238.