Journal of Korean Society of Coastal and Ocean Engineers (한국해안·해양공학회논문집)

Korean Society of Coastal and Ocean Engineers (한국해안·해양공학회)
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A Laboratory Study for Settling Velocities of Cohesive Sediments Entering in Semi-closed Channel

준 폐수로로 유입되는 점착성 퇴적물의 침강속도 산정을 위한 실험적 연구

  • Received : 2014.08.06
  • Accepted : 2014.10.28
  • Published : 2014.10.31
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Abstract

This study aims to estimate settling velocity ($W_s$) for cohesive sediments from water bodies (Incheon Coast, Kulpo Stream and Han River) mainly connected to the Kyeongin Ara-waterway through the laboratory settling experiments. Results of settling tests for these sediments show that $W_s$ values for sediments are quite different each other: $W_s$ values of Kulpo Stream sediments (0.01 < $W_s$ < 3.07 mm/s) are quite similar with those of Han River sediments (0.01 < $W_s$ < 2.97 mm/s) over the whole range of suspension concentration C (0.1 < C < 90 g/ L), while they are quite different with those for Incheon Coast sediments (0.01 < $W_s$ <0.92 mm/s). Qualitative analyses on test results for physico- chemical properties of sediments and waters with respect to settling velocities show that these differences in settling velocities are mainly due to the salinity difference in the water.

본 연구에서는 침/퇴적특성 예측/평가를 위한 기초자료 확보를 목적으로 대표적인 준 폐수로인 경인 아라뱃길 주운수로와 연결된 3개 수역(인천해역, 굴포천, 한강수역)에서의 점착성 퇴적물 각각에 대한 침강속도가 실내실험을 통하여 정량적으로 산정되었다. 침강속도 측정결과, 전체적인 농도구간(0.1 < C < 90 g/L)에 걸쳐 굴포천(0.01 < $W_s$ <3.07 mm/s)과 한강수역(0.01 < $W_s$ < 2.97 mm/s) 하상의 점착성 퇴적물은 대체적으로 거의 유사한 크기의 침강속도 분포를 갖는 것으로 나타났으나, 인천해역 표층 점착성 퇴적물은 이들과는 크게 다른 침강속도(0.01 < $W_s$ < 0.92 mm/s) 분포를 갖는 것으로 나타났다. 한편, 각 수역별 퇴적물의 물리화학적 특성 및 해수(혹은 담수)의 특성들의 비교/분석 결과에 따르면, 이러한 인천해역 점착성 퇴적물의 침강속도 분포의 상이함은 주로 유체의 염도 차에 의해 비롯된 것으로 추정되었다.

Keywords

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