» Research Note « Increasing the Discharge Capacity of an Ogee Spillway by Bending the Crest

Document Type : Technical Note

Authors

1 M.Sc., Water Engineering, Water Research Institute (WRI) , Tehran, Iran.

2 Professor, Department of Civil and Environmental Engineering, Amirkabir University of Technology, Tehran, Iran.

3 B.Sc., Water Engineering, Water Research Institute (WRI) , Tehran, Iran.

Abstract

The effective length of spillway is an important factor in increasing its discharge capacity and consequently decreasing the head over the spillway crest and the dam height. On the other hand, increasing the straight crest length increases the chute width and volume of excavations. Increasing the effective length of the spillway in a limited width is a method to reduce the construction costs. Curved crest spillway is an example of such methods. In the present work, discharge coefficient of a curved crest ogee spillway is compared with a straight one, both with the same chute width in a physical model.  Results showed that the discharge coefficient of the curved ogee crest is similar to the straight one. Therefore, discharge capacity of the curved ogee was more than the straight one due to its longer length. Based on the results of the present work, designers can increase the discharge capacity of ogee spillways by bending them in a constant chute width. It should be noticed that the transition between the curved ogee and the chute and also the upstream guide walls should be designed so that these transitions make no disturbance and shockwave.

Keywords

References

مهاب قدس (1393). "گزارش طراحی هیدرولیکی سیستم تخلیه سیلاب سد سردشت (مطالعات مدل هیدرولیکی)"
اسماعیلی ورکی، م. و صفررضوی زاده، م. (1392). "بررسی مشخصات هیدرولیکی جریان بر روی سرریزهای کنگره‌ای با پلان نیم‌دایره‌ای"، نشریه آب و خاک (علوم و صنایع کشاورزی)، جلد 27، شماره 1، ص. 232.
Darvas, L. A. (1971). "Performance and design of labyrinth weirs", ASCE, J. Hyd. Eng. 97(8): 1246-1251.
Khatsuria, R.M. (2005). "Hydraulic design of spillways and energy dissipators", CRC PRESS, New York
Kobus, H. (ed.) (1980). "Hydraulic modelling", Bulletin 7, German Association for Water Resources and Land Development.
Lux, F. (1985). "Design and construction of labyrinth spillways", 15th International Commission on Large Dams, Vol. 4, Q. 59, R. 15: pp. 249-273.
Novak, P. (1984) "Scaling factors and scale effects in modelling hydraulic structures", General lecture, in Proceedings of the Symposium on Scale Effects in Modelling Hydraulic Structures, Technische Akademie, Esslingen, Paper 03: 1–6.
Novak, P., Moffat, A.L.B., Nalluri, C. and Narayanan, R. (2006). Hydraulic structures. Fourth Edition.
Schleiss, A. J. (2011). "Labyrinth and piano key weirs" Chapter 1, CRC Press, pp. 3-15
USACE, (1990). "Engineering and design; hydraulic design of spillway", Engineer Manual, EM 1110–2–1603.
USBR, (1987). Design of small dams. Water Resources Technical Publication, Third Edition, pp. 365
WES, (1952).,"Spillway for Genegantslet dam", New York, Tech. Memo. 2–351

Files

History

  • Receive Date: 31 May 2016
  • Revise Date: 12 March 2017
  • Accept Date: 15 March 2017

Share

How to cite

Statistics