Experimental Study Effect of the Flexible Collar on Bridge Pier Scouring Depth

Document Type : Research Paper

Authors

1 Water Science and Environmental Research Center, Shoushtar Branch, Islamic Azad University, Shoushtar, Iran.

2 Department of Water Sciences, Water Science and Environmental Research Center, Shoushtar Branch, Islamic Azad University, Shoushtar, Iran.

3 Assistant Professor Civil Department, Islamic Azad University, Sepidan Branch, Sepidan, Iran.

4 Department of Water Engineering, Faculty of Civil and Environment Engineering, University of Amir Kabir (Poly Technic), Tehran, Iran.

Abstract

Bridge pier's local scouring is known to be a destructive factor in river engineering science. This phenomenon is widespread in river intersecting structures such as bridge piers, spur dykes, and downstream river structures. Extensive research has been conducted to reduce and control destructive phenomena, and many solutions have been proposed. These solutions are divided into two parts, namely, direct and indirect protection. In this study, the direct method was studied by defining scenarios. Since many bridges are affected by scouring during the operation, in the present study, the collar method, which is known as a direct protection method, in the case of flexible and permeable, is suggested. The technique is presented an adjustable chain collar, three times bigger than the pier's width (w/d=3), and its effect is investigated in clear water conditions. In the defined scenarios, three different diameters of the chain as CI=5 mm, CII=10 mm, and CIII=15 mm were used to control chain shapes' effect, and three dimensionless flow parameters (U/Uc 0.73, 0.85, and 0.96) were selected to investigate the effect of flow conditions. According to the results, the scour depth is related to changes in the diameter of the collar chain, as the final scour depth decreases by increasing the diameter of the chain from CI to CIII. Therefore, in the best conditions, for CIII, the dimensionless ratio of scouring reduction ( ) is equal to 71% near to inception motion parameter (U/Uc=0.96).

Keywords

Main Subjects


  • Adib, A.,Shiri, V. and Shafai Bejestan, M. (2019). On the Local Scour Around Group Piers in Series by Experimental Tests. Journal of Rehabilitation in Civil Engineering 7, 21-34.

 

  • Akhlaghi, E.,Babarsad, M.S.,Derikvand, E. and Abedini, M. (2020). Assessment the Effects of Different Parameters to Rate Scour around Single Piers and Pile Groups: A Review. Archives of Computational Methods in Engineering 27, 183-197.

 

  • Alem, Z.,Ghomeshi, M. and Mohammadi, S. (2013). The application of collar on the scour reduction at bridge rectangular abutment in composit channel. Irrigation and Water Engineering 3, 29-41.

 

  • Bahrami, N. and Ghomeshi, M. (2018). Effect of Netted Collar on Maximum Local Scouring Depth of Cubic Bridge Pile Groups. Amirkabir Journal of Civil Engineering 50, 655-664.

 

  • Chiew, Y.-M. (1995). Mechanics of riprap failure at bridge piers. Journal of hydraulic engineering 121, 635-643.

 

  • Chiew, Y.-M. and Melville, B.W. (1987). Local scour around bridge piers. Journal of hydraulic research 25, 15-26.

 

  • Garg, V.,Setia, B.,Singh, V. and Kumar, A. (2021). Scour protection around bridge pier and two-piers-in-tandem arrangement. ISH Journal of Hydraulic Engineering, 1-13.

 

  • Gohari, S. and Rezaei, M. (2020). Investigating the effect of oblique bed sill on bridge pier scouring with circular cross-section. Journal Management System 12, 100-114. (In Persian).
  • Hemmati, M.,Gholizadeh, N. and Dolatkhah, S. (2017). Experimental Investigation of the Effect of Diameter and Placement Level of Lattice Collars on Scour Reduction around Bridge Pier. Plant protection (scientific journal of agriculture) 39, 111-122. (In Persian).

 

  • Jalili, A. and Ghomeshi, M. (2016). Influence of Netted Collar on Scour depth around of Cubic Bridge Pier. Irrigation Sciences and Engineering 39, 15-25. (In Persian).

 

  • Karimaei Tabarestani, M. (2020). Study on time development of horse-shoe vortex diameter and shear stress at bridge pier.

 

  • Karimi, N.,Heidarnejad, M. and Masjedi, A. (2017). Scour depth at inclined bridge piers along a straight path: A laboratory study. Engineering science and technology, an international journal 20, 1302-1307.

 

  • Khozeymehnezhad, H. and Ghomeshi, M. (2016). Experimental Investigation of Collar Performance with Rough Surface on Local Scour Reduction around Bridge Abutment with Rectangular Section. Water and Soil Science 26, 213-223.

 

  • Melville, B.W. (1997). Pier and abutment scour: integrated approach. Journal of hydraulic Engineering 123, 125-136.

 

  • Melville, B.W. and Chiew, Y.-M. (1999). Time scale for local scour at bridge piers. Journal of Hydraulic Engineering 125, 59-65.

 

  • Raeisi, N. and Ghomeshi, M. (2020). Laboratory investigation of flow pattern and scour around bridge with netted unsymmetrical collar. Journal of Hydraulics 15, 113-128. (In Persian).

 

  • Rajaratnam, N. and Ahmed, F. (1998). Flow around bridge piers. Journal of Hydraulic Engineering 124, 288-300.

 

  • Raudkivi, A.J. and Ettema, R. (1983). Clear-water scour at cylindrical piers. Journal of hydraulic engineering 109, 338-350.

 

  • Safaei, A.,Choramin, M.,Khajavi, S.,Parmoon, A.A. and Arezoo, A.A. (2015). Analyzing the affective parameters on the amount of bridge scour in the vicinity of the rough collar in laboratory model. WALIA journal, 17-21.

 

  • Shafai Bajestan, M.S.,Hassanzadeh, H. and Paydar, G.R. (2018). Performance evaluation of correction coefficients to optimize sediment rating curves on the basis of the Karkheh dam reservoir hydrography, west Iran. Arabian Journal of Geosciences 11, 595. (In Persian).

 

  • Shafai Bejestan, M.,Masjedi, A. and Kazemi, H. (2010). Effects of bridge pier position in a 180 degree flume bend on scour hole depth. JApSc 10, 670-675.

 

  • Shahsavari, H.,Moradi, S. and Khodashenas, S. (2020). Influence of Semicircular Collar Diameter and Its Alignment on Scour Depth and Flow Pattern around Bridge Abutment. Iranian Journal of Soil and Water Research 51, 77-91. (In Persian).

 

  • Solimani Babarsad, M.,Hojatkhah, A.,Safaei, A. and Aghamajidi, R. (2021). Laboratory investigation of deflector structure effect on bridge pier scouring. Irrigation Sciences and Engineering 43, 91-104. (In Persian).

 

  • Solimani babarsad, M. and Safaei, A. (2021). Experimental Study of Scour Around Pier with Inclined Head. Water Resources Engineering 14, 53-72. (In Persian).

 

  • Solimani Babarsad, M.,Safaei, A. and Aghamajidi, R. (2021). Laboratory Study of Cable and Sill Protection on Scouring Pattern Around the Bridge Pier. Iranian Journal of Soil and Water Research 52, 523-538. (In Persian).
  • Taheri, z. and ghomeshi, m. (2018). Experimental study of the effect of netted collar position on scour depth around of oblong-shappe bridge pier.

 

  • Valela, C.,Rennie, C.D. and Nistor, I. (2021). Improved bridge pier collar for reducing scour. International Journal of Sediment Research.

 

  • Wang, L.,Melville, B.W.,Shamseldin, A.Y. and Nie, R. (2020). Impacts of Bridge Piers on Scour at Downstream River Training Structures: Submerged Weir as an Example. Water Resources Research 56, 46-51.

 

  • Yang, Y.,Melville, B.W.,Macky, G.H. and Shamseldin, A.Y. (2020). Experimental study on local scour at complex bridge pier under combined waves and current. Coastal Engineering 160, 103730.

 

Volume 44, Issue 2
September 2021
Pages 53-66
  • Receive Date: 11 July 2021
  • Revise Date: 27 September 2021
  • Accept Date: 28 September 2021
  • Publish Date: 22 June 2021