Experimental Study on the Effect of Single Spur-dike with Slope Sides on Local Scour Pattern

Document Type : Original Article

Authors

1 Department of Civil Engineering, Islamic Azad University of Shahr-e-Qods, Tehran, Iran.

2 Department of Civil Engineering, Shomal University, Amol, Iran.

3 Department of Civil Engineering, Tarbiat Modares University, Tehran, Iran.

4 Water Engineering Research Institute, Tarbiat Modares University, Tehran, Iran.

Abstract

Constructing the spur-dikes is one the most efficient methods for protecting river banks. The spur-dike in the flow path leads to local scour around this structure. Scour around the spur-dike is one the major problems that might endanger the stability of the structure. Therefore, estimating the scour around this structure based on the flow condition and geometry of the spur- dike is highly important. The experiment was conducted in laboratory flume 6m long, 0.45 m width and 0.45 m deep and with median diameter of particle size 1.48 mm and the maximum local scour around the direct upright and trapezoidal spur-dike (with slope side) and the effect of Froude number and spur-dike side slope on geometry of local scour are investigated. According to the results, by increasing the Froude number and spur-dike side slope, the maximum scour depth and hole dimension of scour is increased, also sedimentation length is increased but its height is decreased and the amount of bed changes toward downstream is increased.

Keywords

Main Subjects


1. Kuhnle RA, Alonso CV, Shields FD. Geometry of scour holes associated with 90 spur dikes. Journal of Hydraulic Engineering. 1999;125(9):972-8.
2. Ghodsian M, Tehrani S. Scour  around groins. International Journal of Sediment Research. 2001;16(1):60-8.
3. Nagy HM. Maximum depth of local scour near emerged vertical wall spur dike. Alexandria Engineering Journal. 2004;43(6):819-29. 
4. Nagy HM. Hydraulic evaluation of emerged and submerged spur-dikes: temporal bed evolution and equilibrium state characteristics. Alexandria Eng J. 2005;44(2):279-90.
5. Ardeshir A, Karami H, Saneie M, editors. Experimental study on the effect of secondary groyne on local scouring around first groyne. 7th International Civil  Engineering  Conference,  Tarbiat  Modarres  University,  Tehran,  Iran;
2005.
6. Nasrollahi A, Ghodsian M, Neyshabouri S. Local scour at permeable spur dikes. J Appl Sci. 2008;8(19).
7. Fazli M, Ghodsian M, Neyshabouri SAAS. Scour and flow field around a spur  dike  in  a  90  bend.  International  Journal  of  Sediment  Research. 2008;23(1):56-68.
8. Zhang H, Nakagawa H. Characteristics of local flow and bed deformation at impermeable and permeable spur dykes. Annual Journal of Hydraulic Engineering, JSCE. 2009;53:145-50.
9. Masjedi A, Akbari I, Abyar H. Evaluating scour at L-shape spur dike in a 180 degree bend. World Applied Sciences Journal. 2011;15(12):1740-5.
10. Teraguchi H, Nakagawa H, Kawaike K, Yasuyuki B, Zhang H. Effects of hydraulic structures on river morphological processes. International Journal of Sediment Research. 2011;26(3):283-303.
11. Osman MA, Saeed HN. Local Scour Depth at the Nose of Permeable and Impermeable  Spur  Dykes.  University  Of  Khartoum  Engineering  Journal.2012;2(1).
12. Van Den Heever ADD. An investigation of the use of groynes as a means of riverbank erosion protection: Stellenbosch: Stellenbosch University; 2013.
13. Ettema R. Scour at bridge piers. 1980.