Experimental Investigation of Submerged Vanes Shape Effect on Bridge Pier Scouring

Document Type : Research Paper

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Abstract

Submerged vanes are thin rectangular structures which have angle with respect to the flow direction, creating high and low pressure zones on both sides of the vanes. These structures generate a secondary vortex, change the near-bed flow pattern, and consequently alter the pattern of the sediment transport and erosion within the channel cross section. The function of submerged vanes to reduce scour around the bridge piers and movement of the sediments in the region of vanes, due to down flow in front of them, are affected by arrays of the vanes. Another factor affecting the performance and efficiency of a submerged vane is its shape. In the present study, a physical model was used to investigate the effect of various shapes of vanes including flat-rectangular, convex, concave, flat-convex, flat-concave, reticular, and angled vanes on bridge pier scouring reduction. To this end, a cylindrical bridge pier with the diameter of 2.54 cm was modeled in a 10m-long and 0.3m-wide flume under clear water condition with v/vc=0.96. The length of the vanes was equal to the width of the pier and the vanes were installed on the bed. The highest level of reduction in scour depth was observed for acuminate vanes compared with the unprotected pier. Furthermore, convex vanes showed better performance compared to the flat vanes at angles of attack 20° and concave vanes.

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References

حسینی س­ح، حسین­زاده دلیر ع، فرسادی­زاده د، ارونقی ه و قربانی م­ع، 1391. تأثیر توأم صفحات مستغرق و طوق در کاهش آبشستگی پایه­های مستطیلی با دماغه گرد. نشریه دانش آب و خاک، جلد 22، شماره 3، صفحه­های 87 تا 101.
شجاعی پ، فرسادی­زاده د، حسین­زاده دلیر ع، سلماسی ف و قربانی م، 1391. کاربرد صفحات مستغرق در کاهش آبشستگی پایه استوانه­ای پل­ها.  نشریه دانش آب و خاک، جلد 22،  شماره 1، صفحه های 91 تا 107.
شاهرخی ساردو م و بارانی غ، 1386. مقایسه عملکرد صفحات مستغرق انحنادار و زاویه­دار در کنترل رسوب در انحنا رودخانه، سومین کنگره ملی مهندسی عمران، دانشکده فنی - مهندسی عمران، دانشگاه تبریز.
صانعی م، اژدری مقدم م و حاجی احمدی ا، 1393. بررسی آزمایشگاهی اثر صفحات مستغرق انحنادار با قطاع 60 درجه بر راندمان حوضچه رسوبگیر گردابی. نشریه علمی-پژوهشی مهندسی و مدیریت آبخیز، جلد 6، شماره 1، صفحه­های 83 تا 94.
عزیزی ر، 1391. بررسی اثر شکل بهینه و فاصله­ نصب صفحات مستغرق بر الگوی رسوب در بستر کانال. رساله دکتری تخصصی، دانشکده علوم مهندسی آب، دانشگاه شهید چمران اهواز.
Chiew YM, 1995. Mechanics of riprap failure at bridge piers. Journal of Hydraulic Engineering ASCE 121(9): 635-643.
Chiew YM, Melville BW, 1987.  Local Scour around Bridge Piers. Journal of Hydraulic Engineering ASCE 25(1):15-26.
Ghorbani B and A Karimi, 2007. A comparison of single and double submerged vanes effect on the scour occurring at a cylindrical pier. Pp. 260-276. Proc. of 6th Conf. of hydraulic. Sep. 4-6, Shahrekord, Iran.
Ghorbani B and Kells JA, 2008. Effect of submerged vanes on the scour occurring at a cylindrical pier. Journal of Hydraulic Research, 46(5): 610–619.
Gupta P and Sharma N, 2007. Performance evaluation of tapered vane. Journal of Hydraulic Research 45(4): 472-477.
Melville BW, 1997. Pier and abutment scour-an integrated approach. Journal of Hydraulic Engineering ASCE 123(2): 125-136.
Melvill BW and Sutherland AJ, 1988. Design method for local scour at bridge piers. Journal of Hydraulic Engineering ASCE 114 (10): 1210-1226.
Odgaard AJ and Kennedy JF, 1983. River-bend bank protection by submerged vanes. Journal of Hydraulic Engineering ASCE 109(8): 1161-1173.
Raudkivi A and Ettema R, 1983. Clear-water scour at cylindrical piers. Journal of Hydraulic Engineering ASCE 109(3): 338-350.
Soon-Keat T, Guoliang Y, Siow-Yong L and Muk-Chen, 2005. Flow structure and sediment motion around submerged vanes in open channel. Journal of Waterway, Port, Coastal and Ocean Engineering ASCE 131(3):132-136.
Tafarojnoruz A, Gaudio R and Calomino F, 2012. Evaluation of Flow-Altering Countermeasures against Bridge Pier Scour. Journal of Hydraulic EngineeringASCE 138: 297-305.
Tafarojnoruz A, Gaudio R, Grimaldi C and Calomino F, 2010. Required conditions to achieve the maximum local scour depth at a circular pier. Proc, XXXII Convegno Nazionale di Idraulica e Costruzioni Idrauliche, Farina, Palermo, Italy.
Voisin A and Townsend RD, 2002. Model testing of submerged vanes in strongly curved narrow channel bends. Canadian Journal of Civil Engineering 29(1): 37-49.
 
 
Water and Soil Science
Volume 27, Issue 1
June 2017
Pages 29-41

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