Accuracy Analysis of HEC-RAS for Unsteady Flow Simulation considering the Flow Pattern Variations over the Side-weir of Side-Weir Detention Basin

Sanghyuk Kim; Byungman Yoon; Dongsu Kim; Seojun Kim

doi:10.3741/JKWRA.2016.49.1.29

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2016 Vol.49, Issue 1 Preview Page Next Page

Accuracy Analysis of HEC-RAS for Unsteady Flow Simulation considering the Flow Pattern Variations over the Side-weir of Side-Weir Detention Basin 강변저류지 횡월류부의 흐름 형태 변화를 고려한 HEC-RAS의 하도 내 부정류 모의 정확도 분석

31 January 2016. pp. 29-38

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Abstract

Accurate quantitative assessment of flood control effect of side-weir detention basin as a flood countermeasure was highly required, in which one-dimensional HEC-RAS model has been widely utilized in practice. When the submerged overflow occurred particularly driven by limited storage capacity of a given detention basin, HEC-RAS model could not be sufficiently applicable by guaranteeing acceptable accuracy without reliable benchmark dataset. From this perspective, a dedicated unsteady experiment was planned and carried out to physically realize such submerged overflow for accommodating better accuracy. Subsequently, the experimental results were applied to validate and calibrate HEC-RAS unsteady modeling to provide flood control effect of the detention basin for various inflow scenarios. After following this procedure, the modelled results indicated that there appeared within –5% of difference in stage height and maximum 2.4% accuracy to assess the flood control effect, thereby ensuring the calibrated HEC-RAS unsteady model to be accurate with practically acceptable error range.

Keywords

HEC-RAS

unsteady flow experiment

side-weir detention basin

submerged overflow

error analysis

강변저류지를 홍수방어대책에 포함시키기 위해서는 정확한 홍수조절효과 산정이 필요하며, 이를 위해 현재 실무에서는 1차원 부정류 수치모형인 HEC-RAS를 사용하고 있다. 그러나 강변저류지의 저류용량이 부족한 경우에 발생하는 잠긴 횡월류 흐름에 대해서는 HEC-RAS 부정류 수치모의의 정확도 분석이 수행되지 않았다. 따라서 본 연구에서는 직선수로에 강변저류지를 설치한 경우에 대하여 횡월류부의 다양한 흐름 형태를 재현할 수 있는 부정류 수리실험을 수행하였다. 또한 부정류 수리실험 결과를 이용하여 HEC-RAS 모형의 부정류 수치모의 결과의 정확도를 분석하여 하도 내 수위 오차 및 강변저류지의 홍수조절효과 산정 오차를 제시하였다. 분석 결과 횡월류부에서 잠긴 횡월류 흐름이 발생하는 경우에 대한 HEC-RAS의 수위 계산 결과는 최대 –5% 오차를 보였으며, 홍수조절효과 오차는 최대 2.4%로 나타나 HEC-RAS의 부정류 모의 결과가 비교적 정확한 것을 확인하였다.

키워드

HEC-RAS

부정류 수리실험

강변저류지

잠긴 횡월류 흐름

오차 분석

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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 : 49
No :1
Pages :29-38
Received Date : 2015-09-23
Revised Date : 2015-11-11
Accepted Date : 2015-11-16
DOI :https://doi.org/10.3741/JKWRA.2016.49.1.29

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

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