Irrigation Sciences and Engineering

Irrigation Sciences and Engineering

Effect of Netted Collar on Local Scouring around the Bridge Cylindrical Pile Groups

Document Type : Research Paper

Authors
Nasrin Bahrami 1
Mehdi Ghomeshi 2
1 PhD Graduated of Hydraulic Structures, Lorestan Univversity
2 Professor Hydraulic Structures Department, Faculty of Water and Environmental Engineering, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
10.22055/jise.2018.25526.1756
Abstract
The problem of scouring of bridge piers has been of interest to hydraulic experts for decades. Various methods have been proposed to control scour, one of which is the use of a netted collar. In this study, the effect of the presence of netted collars on the scouring of bridge cylindrical pile groups under clear flow conditions was investigated. For this purpose, a flume with a length of 6 m and a width of 73 cm was used, and the effect of collars with openings of 0%, 30%, 50%, and 70% was examined at levels of 0.5D above the bed (where D is the diameter of the pier) and on the bed during nine experiments. At the level on the bed, all collars were highly effective, and the 30% netted collar completely controlled the scour around the first pier. At the 0.5D level, the 30% netted collar reduced the scour depth by 58% compared to the no-collar condition, while the efficiency of the collars with openings of 0%, 50%, and 70% at this level was 4%, 0%, and 15%, respectively. In general, efficiency increased as the collar level decreased.
Keywords
Local Scouring
Cylindrical Pile Group
Clear Water
Netted Collar
Inhibition of Scouring
Subjects
  • Alem, Z., 2012. Effect of netted collar on the scour of bridge abutment. M.S.C. Thesis. Faculty of Water Science Engineering, Shahid Chamran University of Ahvaz. (In Persian).

 

  • Breusers, H. and Raudkivi, A., 1991. Hydraulic design considerations. Balkema, Rotterdam, the Netherlands.

 

  • Chiew, Y. and Melville, B., 1987. Local scour around bridge piers. Hydraulic Research, 25(1), pp.15-26. https://doi.org 1080/00221688709499285.

 

  • Hannah, C., 1978. Scour at Pile Groups. Research Rep. No. 28-3.

 

  • Heidarpour, M., Afzalimehr, H and Izadinia, E., 2010. Reduction of local scour around bridge pier groups using collars. International Journal of Sediment Research, 25(4), pp.411-422. https://doi.org/10.1016/S1001-6279(11)60008-5.

 

  • Hemmati, M., Gholizadeh., N. and Dolatkhah, S., 2016. Experimental Investigation of the Effect of Diameter and Placement Level of Lattice Collars on Scour Reduction around Bridge Pier. Irrigation Science and Engineering, 39(4), pp.111-122. https://doi.org/22055/jise.2016.12500 (In Persian).

 

  • Hoffmans, G. and Verheij, H., 1997. Scour Manual, 96. CRC Press.

 

  • Jalili, A., 2013. Effect of using netted collar on bridge piers scouring. M.S.C. Thesis. Faculty of Water Science Engineering, Shahid Chamran University of Ahvaz. (In Persian).

 

  • Karimaee-Tabarestani, M. and Zarrati, A.R., 2012. Effect of collar on time development and extent of scour hole around cylindrical bridge piers. International Journal of Engineering (IJE), 25(1), pp.11-17. https://doi.org/5829/idosi.ije.2012.25.01c.02.

 

  • Khademi, Kh., 2012. Investigation of the effect of longitudinal and lateral space of submerged vanes on local scour in abutment of bridge. P.H.D. Thesis. Faculty of Water Sciences Engineering, Shahid Chamran University of Ahvaz. (In Persian).
  • Khozeymehnezhad, H., Ghomshi, M. and Shafai Bajestan, M., 2014. Comparison of Symmetrical and Unsymmetrical Rectangular Collars on Reduction of Local Scour at Bridge Abutment. Irrigation Sciences and Engineering, 37(2), pp.1-12. https://dor.isc.ac/dor/20.1001.1.25885952.1393.37.2.1.1. (In Persian).

 

  • Melville, B. and Sutherland, A., 1988. Design method for local scour at bridge piers. Hydraulic Engineering, 114(10), pp.1210-1226. https://doi.org/10.1061/(ASCE)0733-9429(1988)114:10(1210).

 

  • Melville, B., 1992. Local scour at bridge abutments. Hydraulic Engineering, 118, 615-631. https://doi.org/10.1061/(ASCE)0733-9429(1992)118:4(615).

 

  • Melville, B. W. and Chiew, Y.-M., 1999. Time scale for local scour at bridge piers. Hydraulic Engineering, 125(1),59-65. https://doi.org/10.1061/(ASCE)0733-9429(1999)125:1(59).

 

  • Oliveto, G. and Hager, W. H., 2002. Temporal evolution of clear-water pier and abutment scour. Hydraulic Engineering, 128, 811-820. https://doi.org/10.1061/(ASCE)0733-9429(2002)128:9(811).

 

  • Raudkivi, A. J. and Ettema, R., 1983. Clear-water scour at cylindrical piers. Hydraulic Engineering, 109(3), pp.338-350. https://doi.org/10.1061/(ASCE)0733-9429(1983)109:3(338).

 

  • Shafai Bejestan, M., Khademi, Kh, and Kozeymehnezhad, H., 2015. Submerged vane-attached to the abutment as scour countermeasure. Ain Shams Engineering Journal6(3), pp.775-783.‏ https://doi.org/10.1016/j.asej.2015.02.006.

 

  • Shahsavari, H., Heidarpour, M. and Mohammadalizadeh, M., 2017. Simultaneous Effect of Collar and Roughness on Reducing and Controlling the Local Scour around Bridge Abutment. Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis, 65(2),491-499.‏ https://doi.org/10.11118/actaun201765020491.

 

  • Shojaei, P., Farsadizadeh, D. and Hoseinzadeh Dalir, A., 2011. Effects of Combined Submerged Vanes and Collar on the Scour Reduction around Cylindrical Bridge Piers. Water and Soil Science. 15 (57), pp.23-33. https://dor.isc.ac/dor/20.1001.1.24763594.1390.15.57.3.5.

 

  • Singh, C., Setia, B. and Verma, D., 2001. Collar-sleeve combination as a scour protection device around a circular pier. Proceedings of the Congress-International Association for Hydraulic Research, pp. 202-209.

 

  • Zarrati, A. R., Nazariha, M. and Mashahir, M. B., 2006. Reduction of local scour in the vicinity of bridge pier groups using collars and riprap. Hydraulic Engineering, 132(2),154-162. https://doi.org/10.1061/(ASCE)0733-9429(2006)132:2(154).
Irrigation Sciences and Engineering
Volume 48, Issue 3
Autumn 2025
Pages 95-108

  • Receive Date 19 April 2018
  • Revise Date 25 November 2018
  • Accept Date 27 November 2018
  • Publish Date 05 November 2025