Journal of the Korean Geotechnical Society (한국지반공학회논문집)

Korean Geotechnical Society (한국지반공학회)
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Experimental Study on the Triaxial Compressive Behaviour of Unsaturated Compacted Silt under Various Suction Levels

다양한 석션 레벨에서의 불포화실트의 삼축압축거동에 관한 실험적 연구

  • Kim, Young-Seok (Geotechnical Disaster & Environment Research Korea Institute of Construction Technology) ;
  • Oka, Fusao (Dept. of Civil & Earth Resources Engrg, Kyoto Univ.)
  • 김영석 (한국건설기술연구원 지반방재.환경연구실) ;
  • 오카 후사오 (일본 교토대학 사회기반공학)
  • Published : 2008.01.31
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Abstract

It has been recognized that the behaviour of unsaturated soil plays an important role in geomechanics. However, up to now, only a few experimental data are available for the technical difficulties related to both volume changes and suction measurements. In this study, the volume changes of unsaturated compacted silty soil were monitored with proximeter during various triaxial compression tests, which gave a realistic estimation in the volume changes of unsaturated soil sample. From the test results, the behaviours of wetting-induced collapses are observed during the drainage/water absorption tests. Under exhausted-drained conditions during shearing, the shear strength increases with an increasing initial suction. On the other hand, the volume changes become small with an increase in the initial suction. And, the volumetric strain during shearing is independent of the confining pressure.

본 연구에서는 불포화토의 역학특성을 해명하기 위하여 4개의 횡변위 계측시스템(proximeter)을 이용하는 방법으로 포화 삼축시험기를 개량하여 불포화 삼축압축시험을 수행하였다. 등방응력조건하에서 다양한 석션을 작용시켜 압축 특성을 검토한 결과, 공시체의 초기 석션 보다 작은 석션을 작용시켰을 경우 흡수에 의한 체적압축(wetting collapse)이 발생함을 알았다. 또한 다양한 석션 레벨 및 구속압에서 삼축압축시험을 수행하여, 불포화토에 미치는 영향을 검토하였다. 그 결과, 초기 석션이 클수록 동일 축변형률에 대한 전단강도가 커지고 체적변형률이 작게 나타났다. 그러나, 구속압에 의한 체적변형률 및 배수량의 변화는 작게 나타났으며, 구속압 보다는 초기 석션에 더 의존하고 있다는 사실을 알았다.

Keywords

References

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