Hydraulics of Stacked Drop Manholes
Publication: Journal of Irrigation and Drainage Engineering
Volume 137, Issue 8
Abstract
This paper presents the results of an experimental investigation on flows inside stacked drop manholes (SDM). An SDM consists of two identical rectangular or square manhole chambers stacked together at an elevation difference. SDMs for different conditions were assessed on their ability to dissipate the energy of the approaching flow and their suitability to perform adequately under different flow conditions. Flow regimes were classified based on the inflow conditions and geometry of the structure in the first chamber and downstream outflows in the second chamber. An analysis based on the integral momentum equation was developed to estimate pool depths and energy losses under critical flow conditions. A fully surcharged stage with inflow and outflow pipes running full was also tested and velocity profiles were measured at a horizontal center plane to the opening connecting both shafts. Additionally, air flow rates were measured to assess the air demand into a large-height SDM.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The authors gratefully acknowledge Prof. M. Chamani and Prof. Christodoulou for sharing their experimental data. The authors are thankful to Mr. Perry Fedun and Mr. Chris Krath for constructing the model and their assistance during the lab work.
References
Ahmed, A. A., Ervine, D. A., and McKeogh, E. J. (1984). “The process of aeration in closed conduit hydraulic structures.” Proc., Symp. on Scale Effects in Modelling Hydraulic Structures, Vol. 4(13), H. Kobus, ed., IAHR, Madrid, Spain, 1–11.
Camino, G. A., Zhu, D. Z., and Rajaratnam, N., and Manas, S. (2009). “Use of a stacked drop manhole for energy dissipation: A case study in Edmonton.” Can. J. Civ. Eng., 36(6), 1037–1050.
Chamani, M. R., and Beirami, M. K. (2002). “Flow characteristics at drops.” J. Hydraul. Eng., 128(8), 788–791.
Chanson, H. (1998). “Hydraulics of Roman aqueducts: Steep chutes, cascades and dropshafts.” Research Rep. Series, I-R-5, Dept. of Civil Engineering, Univ. of Queensland, Queensland, Australia.
Chanson, H. (2002). “An experimental study of Roman dropshaft hydraulics.” J. Hydraul. Res., 40(1), 3–12.
Christodoulou, G. C. (1991). “Drop manholes in supercritical pipelines.” J. Irrig. Drain Eng., 117(1), 37–47.
City of Calgary. (2000). Stormwater management and design manual, City of Calgary Wastewater and Drainage, Calgary, Canada.
Clausnitzer, B., and Hager, W. H. (1997). “Outflow characteristics from circular pipe.” J. Hydraul. Eng., 123(10), 914–917.
Edwini-Bonsu, S., and Steffler, P. M. (2006). “Modeling ventilation phenomenon in sanitary sewer systems: A system theoretic approach.” J. Hydraul. Eng., 132(8), 778–790.
Ervine, D. A. (1998). “Air entrainment in hydraulic structures: A review.” Proc. Inst. Civ. Eng., 130(3), 142–153.
Falvey, H. T. (1980). “Air-water flow in hydraulic structures.” Water and Power Resource Service E.M. 41, U.S. Bureau of Reclamation, Denver.
Gargano, R., Granata, F., and de Marinis, G. (2008). “Il trasporto d’aria nei pozzetti di salto circolari.” Proc., XXXI Convegno Nazionale di Idraulica e Costruzioni Idrauliche, Perugia, Italy.
Gargano, R., and Hager, W. H. (2002). “Supercritical flow across sewer manholes.” J. Hydraul. Eng., 128(11), 1014–1017.
Gayer, J. A. (1984). “On the hydraulic role of manholes in urban storm drainage systems.” Proc., 3rd Int. Conf. on Urban Storm Drainage, Chalmers Univ. of Technology, Goteborg, Sweden.
Granata, F., de Marinis, G., Gargano, R., and Hager, W. H. (2011). “Hydraulics of circular drop manholes.” J. Irrig. Drain Eng., 137(2), 102–111.
Hager, W. H. (1992). “Drop manholes in supercritical pipelines—Discussion.” J. Irrig. Drain Eng., 118(5), 832–832.
Kusuda, T., and Arao, S. (1996). “Energy losses at circular drop manholes.” Proc., 7th Int. Conf. on Urban Storm Drainage, Hannover, Germany.
Marsalek, J. (1984). “Head losses at sewer junction manholes.” J. Hydraul. Eng., 110(8), 1150–1154.
Moore, W. L. (1943). “Energy loss at the base of a free overfall.” Trans. Am. Soc. Civ. Eng., 108, 1343–1361.
Rajaratnam, N., and Chamani, M. R. (1995). “Energy loss at drops.” J. Hydraul. Res., 33(3), 373–384.
Rajaratnam, N., Mainali, A., and Hsung, C. Y. (1997). “Observations on flow in vertical dropshafts in urban drainage systems.” J. Environ. Eng., 123(5), 486–491.
Rajaratnam, N., and Subramanya, K. (1967). “Flow equation for the sluice gate.” J. Irrig. Drain Eng., 93(IR3), 167–186.
Ramamurthy, A. S., and Zhu, W. (1997). “Combining flows in 90° junctions of rectangular closed conduits.” J. Hydraul. Eng., 123(11), 1012–1019.
Roth, A., and Hager, W. H. (1999). “Underflow of standard sluice gate.” Exp. Fluids, 27(4), 339–350.
Sangster, W. M., Wood, H. W., Smerdon, E. T., and Bossy, H. G. (1958). “Pressure changes at storm drain junctions.” Eng. Series Bulletin, Univ. of Missouri, Columbia, MO.
Shumate, E. D., and Weber, L. J. (1998). “Experimental description of combining flows at an open channel junction.” Proc., Int. Water Resources Engineering Conf., ASCE, Reston, VA.
Smith, C. D. (1995). Hydraulic structures, Univ. of Saskatchewan, Saskatchewan, Canada.
United States Army Corps of Engineers (USACE). (1997). “Chapter 6. Design considerations. engineering and design—Tunnels and shafts in rock.” EM 1110-2-2901, San Diego.
Zhao, C. H., Zhu, D. Z., and Rajaratnam, N. (2004). “Supercritical sewer flows at a combining junction: A model study of the Edworthy trunk junction, Calgary, Alberta.” J. Environ. Eng. Sci., 3(5), 343–353.
Zhao, C. H., Zhu, D. Z., Sun, S. K., and Liu, Z. P. (2006). “Experimental study of flow in a vortex drop shaft.” J. Hydraul. Eng., 132(1), 61–68.
Information & Authors
Information
Published In
Journal of Irrigation and Drainage Engineering
Volume 137 • Issue 8 • August 2011
Pages: 537 - 552
Copyright
© 2011 American Society of Civil Engineers.
History
Received: Nov 14, 2009
Accepted: Nov 25, 2010
Published online: Dec 6, 2010
Published in print: Aug 1, 2011
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.