DOI QR코드

DOI QR Code

흙의 급속 함수비 측정방법에 관한 연구

A Study on Speedy Water Content Measurement Method for Soils

  • 박성식 (경북대학교 공과대학 건설환경에너지공학부) ;
  • 김주영 (포스코건설) ;
  • 이새벽 (경북대학교 공과대학 건설환경에너지공학부)
  • 투고 : 2016.11.02
  • 심사 : 2016.12.30
  • 발행 : 2017.01.31

초록

본 연구에서는 성토, 보조기층, 옹벽 뒤채움 토사의 함수비를 신속하게 측정할 목적으로 현장에서 주로 사용되는 칼슘 카바이드의 화학적 반응을 이용한 급속 함수비 측정방법의 정확도 및 신뢰성에 대해 연구하였다. 이를 위해 급속 함수비 측정방법에서 얻은 실험 결과와 항온 건조로 및 전자레인지를 이용하여 얻은 결과를 비교, 분석하였다. 함수비시험에는 국내 현장에서 채취한 화강풍화토와 낙동강모래를 비롯하여 모래-카올리나이트 혼합토를 사용하였다. 먼저 급속 함수비시험에서는 20, 22, 24, 26, 28, 30g의 시료를 각각 1, 3, 5분으로 작동하여 시료 양과 작동시간에 따른 함수비의 영향을 비교, 분석하였다. 시료 양과 작동시간이 증가함에 따라 급속 함수비도 일반적으로 증가하였으며, 작동시간보다는 시료 양이 더 큰 영향을 미쳤다. 흙의 통일분류법 상 SM으로 분류된 화강풍화토의 경우에는 24g으로 3분 측정한 급속 함수비가 항온 건조로로 구한 함수비와 가장 유사하였으며, SP로 분류된 낙동강모래의 경우에는 30g으로 3분 측정한 경우가 가장 유사하였다. 낙동강모래에 카올리나이트가 20-50% 함유된 인공 시료의 경우, 급속 함수비는 점토 함유량이 증가함에 따라 증가하는 경향을 보였다.

During a construction of embankment, sub base, or retaining wall backfill, the speedy measurement of water content is necessary. In this study, a test method for field determination of water content of soil by the calcium carbide gas pressure (speedy water content measurement method) was evaluated for its reliability and accuracy. Dry oven and microwave oven methods were also used for water content measurement. In the test, weathered granite and Nakdong River sand in the site and kaolinite were used for water content measurement. The mass of 20, 22, 24, 26, 28, and 30 g of soil was respectively tested for 1, 3, and 5 min. The effect of each sample on water content was compared one another and analyzed. As the mass and testing time increased, the water content increased. The amount of soil was more important factor than testing time for the speedy water content measurement. In order to obtain similar result to that of dry oven method, 3 min of testing time with 24 g of soil was necessary for weathered granite classified as SM and 3 min with 30 g for Nakdong River sand classified as SP. For Nakdong River sand with 20-50% of kaolinite, the water content by speedy measurement increased as the clay content increased.

키워드

참고문헌

  1. ASTM D2216, Standard Test Method for Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass, Annual Book of ASTM Standards, Vol. 04.08, ASTM International, West Conshohocken, PA, pp.1135-1139.
  2. ASTM D4643, Test Method for Determination of Water (Moisture) Content of Soil by the Microwave Oven Heating, Annual Book of ASTM Standards, Vol. 04.08, ASTM International, West Conshohocken, PA.
  3. ASTM D4944, Test Method for Field Determination of Water (Moisture) Content of Soil by the Calcium Carbide Gas Pressure Tester, Annual Book of ASTM Standards, Vol. 04.08, ASTM International, West Conshohocken, PA.
  4. Berney, E. S., Kyzar, J. D., and Oyelami, L. O. (2012), Device comparison for determining field soil moisture content, U.S. Army Engineering Research and Development Center, ERDC/GSL TR- 11-42.
  5. Kim, D. M. (2006), Engineering Characteristics of Weathered Granite Soil-Bentonite Mixtures, Journal of the Korean Geo-Environmental Society, Vol.7, No.6, pp.45-56.
  6. KS F 2306, Test method for water content of Soils, Korean Industrial Standards.
  7. Park, S.-S., Choi, S.-G., and Ryu, J.-H. (2013), A study on the measurement of moisture content in the organic soils, Journal of the Korean Geotechnical Society, Vol.29, No.10, pp.29-37. https://doi.org/10.7843/kgs.2013.29.10.29
  8. Sotelo, M. J., Mazari, M, Garibay, J., and Nazarian, S. (2014), Variability of moisture content measurement devices on subgrade soils, Geo-Congress 2014, Geo-characterization and modeling for sustainability, pp.1425-1432.