Estimation of Head Loss Coefficients in Surcharged Rectangular Manholes

Jungsoo Kim; Yonguk Ryu; Jeongho Baek; Sungho Lee

doi:10.17820/eri.2026.13.1.038

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2026 Vol.13, Issue 1 Preview Page Next Page

Original Article

Estimation of Head Loss Coefficients in Surcharged Rectangular Manholes 과부하 사각형 중간맨홀에서의 손실계수 산정

31 March 2026. pp. 38-47

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Abstract

The head loss coefficients of square manholes were quantitatively analyzed through a hydraulic experiment to estimate the energy loss characteristics according to the change in size of the rectangular manholes under surcharged conditions. The change in water head was measured by changing the ratio (b/d, 3.0, 2.5, 2.0) of manhole width (b) and connecting pipe diameter (d) and the inflow rate. A similar pressure head reduction effect was observed under all experimental conditions, and the larger the b/d, the greater the energy loss in the manhole. The head loss coefficients under the conditions of varying water depth ratio(H/d) and width ratio(b/d) were calculated using the average flow velocity of the connecting pipe and the manhole depth. The calculation results showed that the head loss coefficients increased for all three conditions up to H/d 1.0 to 1.4, then decreased, and converged to a constant value when the depth ratio was 2.0 or higher. The average loss coefficients calculated through regression analysis were 0.47, 0.36, and 0.33, respectively. The results of this study were expected to be used as basic data for the reasonable calculation of rectangular manhole loss coefficients in sewer design and urban flood analysis.

Keywords

Head loss coefficient

Sewer design

Surcharged rectangular manhole

Urban flood analysis

과부하 조건에서 사각형 맨홀의 규격변화에 따른 에너지 손실 특성을 산정하기 위하여 수리 실험을 통해 사각형 맨홀의 손실계수를 정량적으로 분석하였다. 맨홀 폭(b)과 연결관경(d)의 비(b/d, 3.0, 2.5, 2.0)와 유입유량을 변화시키면서 수두변화를 측정하였다. 모든 실험 조건에서 유사한 압력수두 감소 영향을 보였으며 b/d가 클수록 맨홀에서의 에너지 손실이 증가하는 것으로 나타났다. 연결관거의 평균 유속과 맨홀 수심을 이용하여 수심비(H/d) 및 b/d 변화조건에서의 손실계수를 산정하였다. 산정 결과, 세가지 조건 모두 H/d가 1.0~1.4까지는 손실계수가 증가하다가, 이후 감소하여 수심비가 2.0이상에서는 일정한 값으로 수렴하는 공통된 경향을 나타냈다. 회귀분석을 통해 산정한 평균 손실계수는 각각 0.47, 0.36, 0.33으로 산정되었다. 본 연구 결과는 하수도 설계 및 도시침수 해석에서 사각형 중간맨홀 손실계수의 합리적인 산정을 위한 기초자료로 활용될 수 있을 것이라고 판단된다.

키워드

손실계수

하수도설계

과부하 사각형 맨홀

도시침수해석

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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 : 13
No :1
Pages :38-47
Received Date : 2026-01-05
Revised Date : 2026-01-10
Accepted Date : 2026-01-10
DOI :https://doi.org/10.17820/eri.2026.13.1.038

Ecology and Resilient Infrastructure ISSN:2288-8527(Online) 응용생태공학회 논문집

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