Journal of the Korean Geotechnical Society (한국지반공학회논문집)

Korean Geotechnical Society (한국지반공학회)
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Improved Raining System Using Porous Plate

Porous Plate를 이용한 개선된 레이닝 시스템

  • Choi, Sung-Kun (Dept. of Civil and Environmental Engrg., Korea Univ.) ;
  • Lee, Moon-Joo (Dept. of Civil and Environmental Engrg., Korea Univ.) ;
  • Choo, Hyun-Wook (Dept. of Civil and Environmental Engrg., Korea Univ.) ;
  • Hong, Sung-Jin (Dept. of Civil and Environmental Engrg., Korea Univ.) ;
  • Lee, Woo-Jin (Dept. of Civil and Environmental Engrg., Korea Univ.)
  • 최성근 (고려대학교 사회환경시스템공학과) ;
  • 이문주 (고려대학교 사회환경시스템공학과) ;
  • 추현욱 (고려대학교 사회환경시스템공학과) ;
  • 홍성진 (고려대학교 사회환경시스템공학과) ;
  • 이우진 (고려대학교 사회환경시스템공학과)
  • Published : 2007.06.30
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Abstract

Raining method has been widely used for preparing sand specimen because of its ability to reconstitute the homogeneous specimen with desired relative density and its reliability established by the numerous experiments on diverse influential factors. In conventional raining methods, adjustment of relative density is achieved by controlling the shutter porosity and the whole system is required to be re-adjusted to achieve the target relative density when the granular characteristics are changed. It is also observed from conventional methods that certain degrees of spatial variation in density exist and the limited range of relative density is reproduced. In this paper, raining system with porous plate is proposed. It is shown that the wide range of relative density can be achieved by controlling failing height only. This enhanced system is able to obviate the subtle control of shutter porosity and minimize the effect of falling distance, which in turn ensures the homogeneity of the specimen, especially for low relative density.

낙사법은 요구되는 상대밀도로 반복적으로 시료 조성이 가능하고 다양한 영향요인에 대한 평가를 통해 조성되는 시료의 신뢰성이 확보되었다는 장점을 가지고 있어 챔버 시험을 위한 사질토 시료조성 방법으로 널리 쓰이고 있다. 그러나 개폐율을 조절하여 상대밀도를 조절하는 기존의 방법으로 조성된 시료는 상하부간 상대밀도차가 존재하고, 개폐율 제어만으로 다양한 상대밀도를 구현할 수 없는 단점이 있으며, 입자 특성에 따라 시스템을 재조정하여 상대밀도 조건을 찾아야 하는 단점이 있다. 본 논문에서는 개폐율보다는 낙하고 조절에 의해 다양한 상대밀도의 시료를 조성할 수 있도록 porous plate를 사용한 레이닝 시스템을 제안하여 시험하였다. 그 결과 기존의 문제점인 개폐율의 세분화와 낙하거리의 영향을 최소화 할 수 있었으며 낮은 상대밀도 조성시 문제되었던 시료 상하부간 비균질성을 개선하였다.

Keywords

References

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