The influence of the submergence ratio of submerged vanes on the slope of the hole around the pier groups in a sharp bend

Document Type : Research Paper


Department of Civil Engineering, Faculty of Engineering, Persian Gulf University, Bushehr, Iran.



Bridges are metal or concrete structures, which make road connections across rivers when installed over river paths. When flooding or scouring occurs, several issues including bridge destruction and interruption of road connections arise. There are a variety of methods of protecting such structures, one of which is application submerged vanes. This research shows how two vanes with different submergence ratio affected decrease in local scour surrounding one pier and groups of piers installed in a 180-degree bend. The scour around pier groups either in a transverse position to the flow or with a longitudinal direction was analyzed. This finding suggested that applying vanes decreased the deepest scour around the piers in all the tests, and its maximum effect occurred in triad longitudinal pier groups. By raising the submergence ratio, bed scour depth at the outer bank reached its minimum size in longitudinal pier groups. In transverse pier groups, the first scour hole near the outer bank increased in depth in the presence of vanes. By using the vanes, the slope of the scour hole towards the inner bank grew larger than that towards the other bank. The maximum slope of the outer bank happened in the triad transverse pier group at an approximate value of 0.63. The most significant impact of submerged vanes on reducing the upstream slope was observed in a single pier with 75% submerged vanes and triad longitudinal piers with 25% submerged vanes, resulting in reductions of about 50 and 74% respectively compared to piers without vanes.


Main Subjects

  1. Voisin A, Townsend RD, (2002). Model testing of submerged vanes in strongly curved narrow channel bends. Canadian journal of civil engineering, 29:37-49. DOI: 10.1139/L01-078
  2. Tan SK, Yu G, Lim SY, Ong MC, (2005). Flow structure and sediment motion around submerged vanes in open channel. Journal of waterway, port, coastal, and ocean engineering, 131:132-136. DOI: 10.1061/~ASCE!0733-950X~2005!131:3~132!
  3. Ghorbani B, Kells JA, (2008). Effect of submerged vanes on the scour occurring at a cylindrical pier. Journal of Hydraulic Research, 46:610-619.
  4. Bhuiyan F, Hey RD, Wormleaton PR, (2010). Bank-attached vanes for bank erosion control and restoration of river meanders. Journal of Hydraulic Engineering, 136:583-596. DOI: 10.1061/ASCEHY.1943-7900.0000217
  5. Azizi R, Bejestan MS, Ghomeshi M, (2012). Scour depth at the edge of different submerged vanes shapes. Journal of Applied Sciences, 362-368. DOI: 10.3923/jas.2012.362.368
  6. Barani GA, Shahrokhi Sardo M, (2013). Experimental Investigation of Submerged Vanes’ Shape effect on river-bend stability. Journal of Hydraulic Structures, 1:37-43.
  7. Azizi S, Farsadizadeh D, Arvanaghi H, Abbaspour A, (2016). Numerical Simulation of Flow Pattern around the Bridge Pier with Submerged Vanes. Journal of Hydraulic Structures, 2:46-61. DOI:22055/jhs.2016.12856
  8. Vaghefi M, Ghodsian M, Salimi S, (2016). Scour formation due to laterally inclined circular pier. Arabian Journal for Science and Engineering, 41:1311-1318.
  9. Dey L, Barbhuiya AK, Biswas P, (2017). Experimental study on bank erosion and protection using submerged vane placed at an optimum angle in a 180 laboratory channel bend. Geomorphology, 283:32-40. DOI: 1016/j.geomorph.2017.01.022
  10. Maatooq JS, Adhab BA, (2017). Effect of Distance of the Submerged Vanes from the Outer Bank on Sediment Movement within 180 Bend. American Journal of Engineering and Applied Sience, 10:679-684. DOI: 10.3844/ajeassp.2017.679.684
  11. Shabanlou S, Azimi H, Ebtehaj I, Bonakdari H, (2018). Determining the scour dimensions around submerged vanes in a 180 bend with the gene expression programming technique. Journal of Marine Science and Application, 17:233-240.
  12. Vaghefi M, Motlagh MJTN, Hashemi SS, Moradi S, (2018). Experimental study of bed topography variations due to placement of a triad series of vertical piers at different positions in a 180 bend. Arabian Journal of Geosciences, 11:1-13.
  13. Biswas P, Barbhuiya AK, (2019). Effect of submerged vane on three dimensional flow dynamics and bed morphology in river bend. River research and applications, 35: 301-312.
  14. Zarei E, Vaghefi M, Hashemi SS, (2019). Bed topography variations in bend by simultaneous installation of submerged vanes and single bridge pier. Arabian Journal of Geosciences, 12:1-10.
  15. Bejestan MS, Yabbarehpour E, Kashefipour SM, (2021). Enhancing transverse mixing by using triangular vane in the straight channel. Ain Shams Engineering Journal. 12:1385-1397.
  16. Safaripour N, Vaghefi M, Mahmoudi A, (2022). Experimental study of the effect of submergence ratio of double submerged vanes on topography alterations and temporal evaluation of the maximum scour in a 180-degree bend with a bridge pier group. International Journal of River Basin Management, 20:427-441.
  17. Chooplou CA, Vaghefi M, Akbari M, (2023). Effect of repositioned submerged vanes on local scour variations around a pier in a bend: experimental investigation. International Journal of Environmental Science and Technology, 20:8627-8640.
  18. Keshavarz A, Vaghefi M, Ahmadi G, (2024). Collars for Scour Reduction Around Different Shapes of Bridge Piers in a 180° Sharp Bend. International Journal of Civil Engineering, 1-19.
  19. Vaghefi M, Zarei E, Ahmadi G, Behroozi AM, (2023). Experimental analysis of submerged vanes' configuration for mitigating local scour at piers in a sharp bend: Influence of quantity, length, and orientation. Ocean Engineering, 289:116267.
  20. Hamidi M, Sadeqlu M, Khalili AM, (2024). Investigating the design and arrangement of dual submerged vanes as mitigation countermeasure of bridge pier scour depth using a numerical approach. Ocean Engineering, 299:117270.
  21. Safaripour N, Vaghefi M, Mahmoudi A, (2024). An experimental comparison of 3D velocity components around single and twin piers installed in a sharp bend under the influence of upstream implemented vanes. Applied Water Science, 14:1-24.
  22. Raudkivi AJ, Ettema R, (1983). Clear-water scour at cylindrical piers. Journal of Hydraulic Engineering, 109:338-350.
  23. Chiew YM, Melville BW, (1987). Local scour around bridge piers. Journal of Hydraulic Research, 25: 15-26.