Experimental Investigation on the Effect of the Bendway Weir Angle on the Erosion and Sedimentation Pattern in Meandering River

Document Type : Original Article

Authors

1 PhD. Student, Department. of Hydraulic Structures. Shahid Chamran University, Ahwaz, Iran

2 Professor, Department of Hydraulic Structures. Shahid Chamran University, Ahwaz, Iran

Abstract

Bank erosion is one of the important management issues, especially in meandering rivers. Bendway weirs have recently become among the most popular structures in erosion control along the meanders. Bendway weirs are the stone structures constructed in outer bank to change the flow direction from outer bank to the center of the channel so as to prevent erosion. In this study it has been attempted to investigate the effect of angle of bendway weirs on the pattern of erosion and sedimentation. Three angles of 60°, 75° and 90° and three flow rates of 120, 180 and 230 liter per second were examined. Other structural parameters such as length, height, and distance were kept constant. Continuous injection of sediment with d50= 1.6 mm  formed a live bed.
The results of this study showed that the cross-section area of sedimentary bar in the inner bank decreased by an order of 13 to 48 percents as a result to the construction of weirs. The minimum and maximum of decrease were corresponded to the angles of 90° and 60°, respectively. The maximum scour depth to weir height ratio in the outer bank wall was very evident for the angle of  but not so noticeable for other two angles. The maximum amount of this ratio was 4.6 at 90°. Sedimentation and scouring patterns showed that the sedimentation between weirs and thereby protecting the outer bank were better for the angles of 60° and 75°. Angle of 90° is not recommended for construction of bendway weirs.
 

Keywords

References

ابوالقاسمی،م. (1385)، کنترل رسوب ورودی به آبگیر در پیچان رود، رساله دکتری دانشگاه تربیت مدرس.
رامش، س.، جراح‌زاده، ف.، مشکور­نیا،ه. و شفاعی بجستان، م. (1389)، وضعیت پروفیل طولی فرسایش و رسوب تحت تأثیر سرریز Bendway در خم 90 درجه تند، نهمین کنفرانس هیدرولیک ایران، تهران.
Abad, J. D., Rhoads, B. L., Guneralp, I. and Gorcia, M.H. (2008) “Flow structure at      difference stages in a meander-bend with Bendway weirs.” Journal of  Hydraulic Engineering  ASCE, 134(8), pp. 1052-1063.
Derrick, D.L. (1999). Bendway Weir History, Theory and Design. Downloaded from (http://chl.wes.army.mil/research/hydstruc/bankprotect/bendweir/work.htp) on 6/21/04.
Darrow, J. (2004) “Effects of Bendway Weir Characteristics on Resulting Flow Conditions.” M.S. Thesis, Colorado State University, Fort Collins, CO.
Fischenich, J. C., and Allen, H. A. (2000) “Stream management.”  ERDC/EL SR-W-00-1, U.S. Army Engineer Research and Development Center, Vicksburg, MS.
ICBIP (Indian Central Board of Irrigation and Power) (1971) “Manual on River Behavior, Control and Training.”  Publication No. 60, New Delhi.
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 Vol. 6(5), pp. 1071-1076, 4 March, 2011. Available online at http://www.academicjournals.org/SRE
Kinzli, K.D., and Thornton CH. I. (2009) “Predicting velocity in bendway weirs eddy fields.”  Published online in Wiley Inter Science (www.interscience.wiley.com) DOI: 10.1002/rra.1289
LaGasse, P. F., Schall, J. D., and Richardson, E. V. (2001) “Stream stability at highway structures.” 3rd ed., HEC-20, FHWA-NHI-01-002, Federal Highway Administration, U. S. Dept. of Transportation, Washington, D. C.
Sclafani, P. (2010) “Methodology for predicting maximum velocity and shear stress in a sinous channel with bendway weirs using 1-D HEC-RAS modeling results.”  M.S. Thesis, Colorado State University, Department of Civil Engineering, Fort Collins, CO.
Shields, F.D. Jr., Knight, S.S., and Cooper, C.M. (1998) “Addition of spurs to stone toe protection for warm water fish habitat.” Journal of the American Water Resources Association 34, pp. 1427–1436.
USACE (1981) “The streambank erosion control evaluation and demonstration.” Act pf 1974  Section 32, Public Low 93-251, U.S. Army Corps of  Engineers (USACE), Final Report  to Congress, Waterways Experiment Station, Vicksburg, Mississippi.
Watson, C.C. (2003) “Dikes, Dikes, Dikes. CE 610 Stream Restoration-Class Notes.”  Spring  2003. Colorado State University, Fort Collins, CO.
 
 
Iran-Water Resources Research
Volume 8, Issue 3
July 2013
Pages 66-76

Files

History

  • Receive Date: 09 July 2011
  • Accept Date: 10 November 2012

Share

How to cite

Statistics