Numerical Investigation of the Effect of Groins and Bendway Weirs on Flow and Sediment Pattern Using Mike 3 Flow Model FM

Authors

1 M.Sc. of water structures, Urmia University, Urmia, Iran

2 Assistant Prof. of water engineering, Urmia University, Urmia, Iran

3 Associate Prof. of water engineering, Urmia University, Urmia, Iran

4 M.Sc. of water structures, Tarbiat Modares University, Tehran, Iran

Abstract

Bendway weirs are important multi-purpose structures for erosion control and are implemented to control erosion, restore streams, and improve habitat. Investigation of the effect of weirs’s height on flow pattern and erosion and sedimentation by application Mike 3 Flow Model FM was the aim of this research. The used variables were three flow discharge rates of 120, 150 and 180 (l/s), three weir heights of 0.5y, 0.7y (submerge weirs) and 1.2y (spur) (y is the mean water depth). The length ratio (L/B) was kept constant during experiments (equal to 3 times of water surface width) as well, weir crest slope (flat crest) and weirs angle (60 degree) were also constant. The results showed that the maximum difference between experimental and simulation data of the maximum scour depth at the tip of weirs was about 7.6 %. So a good agreement was found between the model and experimental results. Furthermore, the results revealed that the bendway weirs were more efficient than groins in reducing the velocity magnitude, decreasing the scour at the outer bank side and in decreasing the sediment deposition at the inner bank side. On average, the velocity magnitude at the outer bank side decreased by 81, 85 and 70 % in weirs with heights of 0.3y, 0.7y and 1.2y, respectively. Generally, the results of this research showed that the weirs with a height of 0.7y had the most influence on protection of outer bank.

Keywords

References

Abolghasemi M, 2012. The effects of flow diversion on sediments entering the intake in 90 deg. diversion angle in sinus river. Amirkabir Journal of Civil Engineering 44(1):43-54.
Acharya K and Gautam M, 2012. Evaluation of bendway weir bank stabilization techniques for stream restoration. International Journal of River Basin Management 10(2):171-176.
Blanckaert K and Graf W H, 2004. Momentum transport in sharp open-channel bends. Journal of Hydraulic Engineering (ASCE) 130(3): 186-198.
Derrick DL, 1999. Bendway weir history, theory and design. Available from: http://chl.wes.army.mil/research/hydstruc/ bankprotect/bendweir/work.htp.
FHWA, 1997. Bridge scour and stream instability countermeasures (SI). Federal Highway Administration, Hydraulic Engineering Circular Number 23, FHWA HI-97-030.
FHWA, 2001. Bridge scour and stream instability countermeasures: experience, selection, and design guidance. 3rd ed.                                            
Fischenich JC and Allen HA, 2000. Stream management. ERDC/EL SR-W-00-1, U.S. Army Engineer Research and        Development Center, Vicksburg, MS.
Gu L, Zhang S, He L, Chen D, Blanckaert K, Ottevanger W and Zhang Y, 2016. Modeling flow pattern and evolution of meandering channels with a nonlinear model. Water 8(10):418.
Hemmati M, 2012. Experimental investigation of the effect of length, height and crest slope of bendway weirs on flow and sediment patterns in meandering river. PhD thesis, water science engineering faculty, Shahid Chamran University of Ahvaz.
Hemmati M, Ghomeshi M, Kashefipour M, Shafai-Bejestan M and Lanzoni S, 2012. Experimental investigation of the effects of angle and length of bendway weirs on scouring and sedimentation in a meander river. Journal of American Science 8(9):912-917.
Hemmati M, Ghomeshi, M, Ahmadi H and Lanzoni S, 2015. Scour depth around flat and sloped crest bendway weirs: a laboratory study. International Journal of River Basin Management 14(1): 83-93.
Jarrahzade F and Shafai- Bejestan M, 2011. Comparison of maximum scour depth in bank line and nose of submerged weirs in a sharp bend. Scientific Research and Essays 6(5):1071-1076.
Lagasse PF, Clopper PE, Pagan-Ortiz JE, Zeverbergen LW, Arneson LA, Schall JD and Girard LG, 2009. Bridge scour and stream stability countermeasures. 3rd ed., vols. 1 and 2, 64 HEC-23, FHWA-NHI-09-111, Federal Highway Administration, U. S. Dept. of Transportation, Washington, D. C.
Liaghat A, Mohammadi K, and Rahmanshahi M, 2014. 3D investigation of flow hydraulic in U shape meander bends with constant, decreasing and increasing width. Journal of River Engineering 2(3): 12-23.
Maghrebi M and Ghizil Soflou A, 2013. 3D simulation of flow pattern and sediment transport in two bends with 180 degrees by Mike3. 9th International Conference of River Engineering, 22-24 Jan, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
Mehrdar L, Hemmati M and Yasi M, 2016. Experimental investigation of the effect of height and crest slope of bendway weirs on flow pattern in a 90-degree bend. Iranian Journal of Soil and Water Research 47(3)505-516.
Naderkhanlou V, 2013. 3D simulation of hydrodynamic and salinity in Gotvand-Olya dam. M.Sc. thesis, faculty agriculture of Tarbiat Modares University
Slajaghe A, Salehi-Neishabouri AA, Ahmadi H, Mahdavi M and Ghodsian M, 2005. Experimental investigation of three dimensional flow pattern in river bends. Iranian Journal of Natural Resources 58(1): 25-33.
Wang SSY and Yafei J, 2005. Simulation of flows around a submerged weir in channel bendways. Journal of Hydraulic Engineering ASCE 131(8): 682-693.
 
 
Water and Soil Science
Volume 28, Issue 1
May 2018
Pages 159-171

Files

Share

How to cite

Statistics