Experimental analysis of the sedimentation processes in the movable weir by changing the channel slope considering weir operation

Kyung Su Lee; Chang-Lae Jang

doi:10.3741/JKWRA.2018.51.8.729

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2018 Vol.51, Issue 8 Preview Page Next Page

Research Article

Experimental analysis of the sedimentation processes in the movable weir by changing the channel slope considering weir operation 가동보 운영 및 하상경사 변화에 의한 보 상류 퇴사과정의 실험적 분석

31 August 2018. pp. 729-737

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Abstract

This study investigates the sediment processes the Improved-pneumatic-movable weir through laboratory experiments considering changing channel slopes. Experimental results show that the delta migrates towards the weir and the delta height increases as time passes. Moreover, as the delta approaches the weir, the delta migration speed decreases. As the dimensionless delta location increases, the effective height of dimensionless delta and the dimensionless reservoir capacity increases. Therefore, under the same slope conditions, the sediment deposition volume of the delta is small as the channel slope is mild. This means that the channel slope affects the development of the delta in the upstream of the Improved-pneumatic-movable weir. At the beginning of the experiment, the foreset slope is mild. However, the foreset slope of the delta increases with water depth as the delta migrates downstream. Moreover, as the slope is mild, the ratio of delta front length to delta height is close to 1, and the dimensionless delta height and the dimensionless delta migration speed decrease. As the delta height increases, the water depth, the velocity approaching to the weir and the delta migration speed decrease.

Keywords

Delta

Channel slope

Movable weir

Reservoir sedimentation

Sediment processes

본 연구에서는 실내실험을 통하여 개량형 공압식 가동보를 대상으로 수로경사 변화를 고려한 유사의 수리학적 발달 과정을 분석하였다. 분석결과 보에 의하여 형성된 델타는 시간이 증가함에 따라 하류로 이동하며, 델타높이(h_d)는 증가하였다. 또한 보에 도달 할수록 흐름이 약해지면서 델타의 이동속도(S_D)는 감소하였다. 무차원 델타 위치(x_D/x)가 증가할수록 무차원 델타의 유효높이(h_d/h_w)와 무차원 저수지 용량(V_xD/V_x)이 증가였다. 따라서 동일한 조건에서 수로경사(i)가 완만할수록 델타의 퇴적량(Q_s)이 감소하게 되며, 델타의 체적(V_xD) 발달에 큰 영향을 미치는 것으로 나타났다. 통수 초기 델타의 전면경사가 완만하며, 델타가 하류로 이동할수록 델타의 전면경사는 증가하였다. 또한 수로경사(i)가 완만할수록 델타의 전면부 길이 비(h_d/𝛥_S)는 1에 가까워지고, 무차원 델타의 높이(h_d/h)와 무차원 델타의 이동속도(S_D/V₀)가 감소하였다. 델타의 높이(h_d)가 증가할수록 수심(h)은 감소하였으며, 보에 접근하는 유속(V₀)과 델타의 이동속도(S_D)도 감소하였다.

키워드

델타

가동보

저수지 퇴사

퇴사거동

수로경사

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Information

Publisher :KOREA WATER RESOURECES ASSOCIATION
Publisher(Ko) :한국수자원학회
Journal Title :Journal of Korea Water Resources Association
Journal Title(Ko) :한국수자원학회 논문집
Volume : 51
No :8
Pages :729-737
Received Date : 2018-06-06
Revised Date : 2018-06-28
Accepted Date : 2018-06-28
DOI :https://doi.org/10.3741/JKWRA.2018.51.8.729

Journal of Korea Water Resources Association ISSN:2799-8746(Print) 2799-8754(Online) 한국수자원학회 논문집

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