Laboratory investigation of deflector structure effect on bridge pier scouring

نوع مقاله : مقاله پژوهشی

نویسندگان

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

2 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.

چکیده

Bridge pier local scouring is a crucial factor in bridge destruction. Studies from different researchers have presented solutions to control this phenomenon. These solutions are divided into two parts, namely, direct and indirect protection. In the direct method, the bed is armoured against scouring whereas in the indirect methods the flow pattern around the pier is changed with geometric parameters. This study defined an element called the deflector structure (flow diverter) to divert the bed’s flow streamline in front of the pier. Experimental scenarios were defined by stabilizing the flow conditions with 0.70, 0.83, and 0.97 relative velocities ( ) and 15-, 30-, and 45-degree wedge deflector structure angles with flow direction for two piers with square and circular cross-sections. The results showed that the dimensionless scour depth parameter ( ) close to the particle movement threshold ( ) was reduced by 70 to 75%, respectively relative to the control model for square and circle cross-section. Changing the angle from 45 to 30 and 15 degrees reduces the local pier scouring and increases the deflector structure’s effectiveness.  

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Laboratory investigation of deflector structure effect on bridge pier scouring

نویسندگان [English]

  • Mohsen Solimani babarsad 1
  • Amin Hojatkhah 2
  • Abbas Safaei 2
  • Roozbeh Aghamajidi 3
1 Department of Water Sciences,Water Science and Environmental Research Center, Shoushtar Branch, Islamic Azad University, Shoushtar, Iran.
2 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.
چکیده [English]

Bridge pier local scouring is a crucial factor in bridge destruction. Studies from different researchers have presented solutions to control this phenomenon. These solutions are divided into two parts, namely, direct and indirect protection. In the direct method, the bed is armoured against scouring whereas in the indirect methods the flow pattern around the pier is changed with geometric parameters. This study defined an element called the deflector structure (flow diverter) to divert the bed’s flow streamline in front of the pier. Experimental scenarios were defined by stabilizing the flow conditions with 0.70, 0.83, and 0.97 relative velocities ( ) and 15-, 30-, and 45-degree wedge deflector structure angles with flow direction for two piers with square and circular cross-sections. The results showed that the dimensionless scour depth parameter ( ) close to the particle movement threshold ( ) was reduced by 70 to 75%, respectively relative to the control model for square and circle cross-section. Changing the angle from 45 to 30 and 15 degrees reduces the local pier scouring and increases the deflector structure’s effectiveness.  

کلیدواژه‌ها [English]

  • Bridge pier
  • Deflector
  • Flow diverter
  • Local scour
  • Movement threshold

مراجع

1- Abousaeidi, Z., 2018. Experimental investigation of the effect of debris accumulation on the local scour at bridge pier and abutment. Journal of Water and Soil Conservation, 25(2), pp.267-282. (In Persian).
 
2- Adib, A., Shafai Bejestan, M. and Shiri, V., 2019. On the Local Scour Around Group Piers in Series by Experimental Tests. Journal of Rehabilitation in Civil Engineering, 7(1), pp.21-34.
 
3- 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(1), pp.183-197.
 
4- Chiew, Y.-M. 1995. Mechanics of riprap failure at bridge piers. Journal of hydraulic engineering, 121, 635-643
 
5- Ettema, R. 1980. Scour at bridge piers.
 
6- 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).
 
7- Kayatürk, Ş.Y. 2005. Scour and scour protection at bridge abutments.
 
8- Kumar, V., Raju, K.G.R. and Vittal, N., 1999. Reduction of local scour around bridge piers using slots and collars. Journal of hydraulic engineering, 125(12), pp.1302-1305.
 
9- Lee, S.O. and Sturm, T.W., 2009. Effect of sediment size scaling on physical modeling of bridge pier scour. Journal of hydraulic engineering, 135(10), pp.793-802.
 
10- Melville, B.W., 1997. Pier and abutment scour: integrated approach. Journal of hydraulic Engineering, 123(2), pp.125-136.
 
11- Melville, B.W. and Chiew, Y.M., 1999. Time scale for local scour at bridge piers. Journal of Hydraulic Engineering, 125(1), pp.59-65.
 
12- Nohani, E. and Ebrahimi, S., 2019. Experimental Investigation of the Collar and Vanes on Reduction the Scour Depth of Cylindrical Piers. Iranian Journal of Soil and Water Research, 50(2), pp.411-424. (In Persian).
 
13- 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).
 
14- Rajaratnam, N. and Ahmed, F. 1998. Flow around bridge piers. Journal of Hydraulic Engineering, 124, 288-300
 
15- Raudkivi, A. 1998. Loose boundary hydraulics. 4th edi-tion. Balkema, Rotterdam, The Netherlands,
 
16- Raudkivi, A.J. and Ettema, R. 1983. Clear-water scour at cylindrical piers. Journal of hydraulic engineering, 109, 338-350
 
17- Choramin, M., Safaei, A., 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.
 
18- Hassanzadeh, H., Bajestan, M.S. 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(19), pp.1-9. (In Persian).
 
19- 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(1), pp.77-91. (In Persian).
 
20- Vaghefi, M. and Meraji, S. 2019. The effect of 20% reduction in overlapping length of the upstream submerged vanes of bridge pier on bed topography in sharp 180 degree bend. Modares Civil Engineering journal, 19, 41-55. (In Persian).
 
21- 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(4), p.e2019WR026720.
 
22- Zomorodian, S.M.A., Ghaffari, H. and Ghasemi, Z., 2019. Comparison of Linear and Triangular Arrangements of Submerged Sacrificial Piles on Local Scour Depth around Cylindrical Bridge Piers. Irrigation Sciences and Engineering, 42(4), pp.167-180. (In Persian).
علوم و مهندسی آبیاری
دوره 43، شماره 4
دی 1399
صفحه 91-104

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سابقه مقاله

  • تاریخ دریافت: 20 دی 1399
  • تاریخ بازنگری: 20 بهمن 1399
  • تاریخ پذیرش: 03 اسفند 1399
  • تاریخ انتشار: 01 دی 1399

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