Hydraulic Efficiency of Crump Gabion Weirs under Submerged Flow Condition

Document Type : Research Paper

Authors

• mehrdad kheiraei
• manoochehr fathi moghadam

Abstract

Weirs are usually constructed by concrete and are impervious so that the water can only flow above the crest. In this between, Gabion weirs with instinctive characteristics including stability, conductivity and economic justification are strongly advised. In this study, the effects of material size, upstream and downstream slopes were investigated on the discharge reduction factor of gabion crump weirs under submerged flow conditions. For this purpose, 8 models of gabion weirs and 3 models impervious weirs constructed in a horizontal flume with 15m long, 0.3m wide and 0.5m deep. The tests were carried out for different variables, including discharge, upstream and downstream depths, material size and upstream and downstream slopes. The results showed that the flow reduction factor decreased as the ratio of the upstream depth to the downstream (Y2/Y1) increased. For a constant ratio of Y2/Y1, the flow reduction factor decreased when upstream or downstream slope increased. It was found that the material size has no significant effect on the flow reduction factor. Based on regression analysis, an empirical equation was developed for estimation of the flow reduction factor which its correlation coefficient variation was in the range of 0.79 to 0.96.

Keywords

• Crump weir
• Flow reduction factor
• Gabion
• Submerged flow

20.1001.1.20086377.1398.12.42.4.4

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References

1)       احمدی ح، (1392). بررسی آزمایشگاهی ضریب بده جریان از روی سرریزهای تورسنگی. پایانامه کارشناسی ارشد، دانشگاه تبریز، دانشکده کشاورزی.

2)    خیرایی م و فتحی­مقدم م، 1395. عملکرد آبی سرریزهای شیب­دار تورسنگی در شرایط جریان آزاد. مجله مهندسی منابع آب، سال نهم، تابستان 1395، صفحه­های 75 تا 86.

3)       قمشی م و امامقلی­زاده ص، 1387. مکانیک سیالات و هیدرولیک به زبان ساده. انتشارات دانشگاه شهید چمران اهواز.

4)       طاحونی ش، 1388. اصول مهندسی ژئوتکنیک. جلد اول، چاپ هیجدهم، ناشر مؤسسه انتشاراتی پارس آئین.

 

5)       Abou-Seida M. M and Quraishi A. A. 1976. A Flow Equation for Submerged Rectangular Weirs. Proc. ICE, 61(4): 685–696.

6)       Azimi A, Rajaratnam N and Zhu. 2014. Submerged flows over rectangular weirs of finite crest length. Journal of Irrigation and Drainage Engineering 728: 1-12.

7)       Ansar M and Gonzalez-Castro JA. 2003. Submerged weir flow at prototype gated spillways. In Proceedings of World Water and Environmental Resources Congress 2003, Philadelphia PA USA 23–26 June 2003.

8)   Chanson H. 2006. Discussion of discharge through a permeable rubble mound weir. Journal of Hydraulic Engineering 132)4(: 432–434.

9)       Fritz H. M and Hager, W. H. 1998. Hydraulics of Embankment Weirs. Journal of Hydraulic Engineering 124(9): 963–971.

10)   Gogus M, Defne Z and Ozkandemir V. 2006. Broad-crested weirs with rectangular compound cross sections. Journal of Irrigation and Drainage Engineering 132(3): 272-280.

11)   Hager H and Schwalt M. 1994. Broad-crested weir. Journal of Irrigation and Drainage Engineering 120(1): 13-26.

12)   Kells JA. 1993. Spatially varied flow over rock fill embankments. Canadian Journal of Civil Engineering 20: 820-827.

13)   Leu JM, Chan HC and Chu MS. 2008. Comparison of turbulent flow over solid and porous structures mounted on the bottom of a rectangular channel. Flow Measurement and Instrumentation 19: 1-7.

14)   Li B and Garga VK. 1998. Theoretical solution for seepage flow in overtopped rock fill. Journal of Hydraulic Engineering 124)2(: 213–217.

15)   Michioku K, Maeno S, Furusawa T and Haneda M. 2005. Discharge through a permeable rubble mound weir. Journal of Hydraulic Engineering 131(1): 1-10.

16)   Michioku K, Takehara K and Etoh T. 2007. An experimental study on flow field in and around rubble mound river structures. Journal of Hydraulic Engineering 25(2): 37-45.

17)   Mohamed H. 2010. Flow over gabion weirs. Journal of Irrigation and Drainage Engineering 136(8): 573-577.

18)   Sargison JE and Percy A. 2009. Hydraulics of broad-crested weirs with varying side slopes. Journal Irrigation and Drainage Engineering 135)1(: 115–118.

19)   Smith R. A. (1959). Calibration of a Submerged Board-Crested Weir. Journal of Hydraulic Engineering 85(3): 1-16.