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Measurement and Analysis of Bed Shear Stresses in Compound Open Channels using the Preston Tube

프레스톤튜브를 이용한 복단면 하도의 하상전단응력 측정 및 분석

Du Han Lee1*
,
Myounghwan Kim1
,
Won Kim1
,
Il Won Seo2
이 두한1*
,
김 명환1
,
김 원1
,
서 일원2
1Hydro Science and Engineering Research Institute, Korea Institute of Civil Engineering and Building Technology
2Department of Civil and Environmental Engineering, Seoul National University
1한국건설기술연구원 수자원하천연구소
2서울대학교 건설환경공학부
*교신저자. *Corresponding Author. 
31 December 2017. pp. 207-215
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Abstract

Hydraulic issues such as flow resistance, side wall correction, sediment, erosion and deposition, and channel design have close relation with distribution of bed shear stresses but the measurement of the distribution of bed shear stresses is not easy. In this study the Preston tube which makes possible relatively simple measurement of bed shear stresses is used to analyze the characteristics of bed shear distribution in compound open channels with different depth ratio. The Preston tubes are made and calibrated to develop the calibration formula and then they are applied to measure bed shear stress distribution in 5 cases depth ratio condition of compound channels. The results are compared with former experiment data, and characteristics of bed shear stress distributions are studied with different channel scales and Reynolds numbers. Although bed shear distributions with depth ratio show overall agreement with former studies, some differences are verified in bed shear variation, formation of inflection point in main channel, and distribution near floodplain junction which are due to high Reynolds number. Through the study applicability of the Preston tubes are also verified and characteristics of bed shear distribution in compound channels are suggested with Reynolds number and depth ratio.

Keywords
Bed shear stresses
Compound channels
Depth ratio
Reynolds number
The Preston tube

하도의 흐름 저항, 측벽 보정, 유사량, 하도 침식과 퇴적, 하도 설계 등의 수리학적 문제는 하상전단응력의 분포와 밀접한 관계가 있으나 하상전단응력 분포를 측정하는 것은 쉽지 않다. 본 연구에서는 간편하게 하상전단응력을 측정할 수 있는 프레스톤튜브를 이용하여 복단면의 하도의 하상전단응력 분포를 측정하고 수심비에 따른 전단응력분포 특성을 고찰하였다. 이를 위해 프레스톤튜브를 제작하여 검정실험을 통해 검정식을 개발하였다. 실험은 5가지 수심비 조건에 대해서 수행하여 전단응력분포를 측정하였다. 복단면 하도의 전단응력분포 특성은 기존 실험연구와 대체로 일치하였으며, 레이놀즈수 증가로 발생하는 전단응력의 변동성, 주수로 전단응력의 변곡점 형성, 홍수터 접합부 부근 전단응력 분포 특성 등에서 차이점을 확인하였다. 본 연구를 통해 프레스톤튜브를 이용한 하상전단응력측정 적용성을 확인하였으며 레이놀즈수와 수심비에 따른 복단면 하도의 전단응력분포 특성을 제시하였다.

키워드
하상전단응력
복단면 하도
수심비
레이놀즈수
프레스톤튜브
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Information
  • Publisher :Korean Society of Ecology and Infrastructure Engineering
  • Publisher(Ko) :응용생태공학회
  • Journal Title :Ecology and Resilient Infrastructure
  • Journal Title(Ko) :응용생태공학회 논문집
  • Volume : 4
  • No :4
  • Pages :207-215
  • Received Date : 2017-11-15
  • Revised Date : 2017-12-08
  • Accepted Date : 2017-12-11
  • DOI :https://doi.org/10.17820/eri.2017.4.4.207
Journal Informaiton Ecology and Resilient Infrastructure Ecology and Resilient Infrastructure
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