Journal of Korea Water Resources Association (한국수자원학회논문집)

Korea Water Resources Association (한국수자원학회)
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Measurements of Permeability Characteristics for Unsaturated Weathered Soils

불포화 풍화토의 투수특성 측정

  • Published : 2000.02.01
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Abstract

Series of tests were carried out to study permeability characteristics of unsaturated soils. The weathered soils taken from Inju, Sungwhan, and Kuri, were selected to have different amount of fine grained soils in order to find a possible correlation between the unsaturated permeability behavior and fine grained soils contents. Measurements of permeability for unsaturated soils were performed with a newly developed apparatus, which modeled after Klute's apparatus(1965a). The apparatus was designed to measure volumetric water content and permeability by applying incremental suction pressure. Permeability and volumetric water content of unsaturated soils generally decreased as density of the soil increased. The relationship between volumetric water content and permeability was not related to the fine grained soils contents because the plots scattered widely. By comparing volumetric water content with permeability, empirical parameters A and B could be determined, which made to be possible to predict unsaturated permeability from soil-moisture characteristics.

본 연구에서는 불포화 투수계수를 측정하기 위하여 Klute(1965a)에 의하여 제안된 정적측정방법의 원리에 axis-translation의 기법을 적용하여 새로운 실험장치를 개발하였다. 이 실험장치는 모관흡수력(matric suction)의 증가에 따른 함수특성과 투수계수의 변화를 동시에 측정할 수 있도록 설계되었다. 실험에는 불포화 투수특성과 No.200체 통과 세립분의 상호관계를 규명하기 위하여 각각 세립함유량이 7.3%(인주), 19.6%(성환), 35.9%(구리)인 시료를 인주, 성환, 구리지역에서 채취하여 사용하였다. 실험결과에 의하면 불포화토의 투수계수와 체적함수는 시료의 밀도가 증가하는 경우 전체적으로 감소하였으며 모관흡수력이 증가함에 따라 점차 비선형적으로 감소하는 거동을 보였다. 또한 불포화토의 투구계수와 체적함수비는 상호 비선형거동을 보였다. 체적함수비와 투구계수를 직접 비교하는 방법으로 경험상수 A,B를 No.200체 통과 세립분의 함유량에 따라 결정하였으며, 경험상수 A, B를 이용하면 직접 흙의 함수특성곡선으로부터 불포화 투수계수를 추정할 수 있다.

Keywords

References

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