Experimental Study of the Effects of Immersed Vanes Distance from the Bank on Erosion Pattern and Bed Sedimentation

Document Type : Research Paper


1 Ph.D. Educated of Department of Hydraulic Structures, Shahid Chamran University of Ahvaz, Iran

2 Professor of Department of Hydraulic Structures, Shahid Chamran University of Ahvaz. Iran.


 Due to the formation of the secondary and helicoidally vortices in river bend, bed scour at outer bank toe and sedimentation in inner banks can cause dramatic river morphological changes. To manage the sedimentation of the river bed in bends, many techniques have been developed in the past.  In this regard, valuable resources such as Devan (2009), Sharma and Mahapatra (2012), Yun et al. (2012), Jarrahzadeh and Shafai Bejestan (2012), Mashkornia and Shafai Bejestan (1392), Shafai Bejestan et al. (2010), Jia et al. (2009), Abad et al. (2008), Bhuiyan et al. (2010) can be found in the literature. All of these measures are installed at the bed which can initiate a new scour pattern around the structure and destroy the structure itself. Therefore, in the present study a new technique, immersed vane, has been experimentally investigated which are installed above the river bed. MethodologyIn this research, a distorted rigid bed physical model of the Jangiye Karun River bend, which is a 180 degree, downstream of Ahvaz with a horizontal scale of 300 and a vertical scale of 50 is constructed. To investigate erosion and sedimentation of raw materials, polyethylene with an average diameter of 2 mm and a density of 1.1 were used as sediment. The experiments were carried out in discharge of 21.4 liters / s and 15.5cm in depth (depth in the upstream of the bend) equivalent to the Froude number of 0.2 (equivalent to flood discharge with a two year return period in the Karun River).  Adjusting of the flow depth within the model (=15.5cm in all tests) was done by the downstream gate. 7 number of Galvanized vanes with a thickness of 2 mm in dimensions of 6 * 3 cm were welded to a rod. This rod was held by an arm that was attached to the bank. The system was designed to allow the vanes to be placed at any desired distance from the bank.  Vanes are tested in different distances (d) zero, 3, 6, 9, 12 and 15 cm from the outer bank. At the end of each test bed topography was measured and were plotted and compared with the results of the baseline test.


Main Subjects

1-     جـــراح زاده، ف. و م. شـــفاعی بجســـتان، 1391. بررســـی آزمایشگاهی وضـعیت خـط القعـر تحـت تـاثیر وجـود سرریز مسـتغرق در خـم 90 درجـه تنـد . پـژوهش و سازندگی. پژوهشهای آبخیزداری، (97): 29-18.
2-     رامش، س. جراح زاده، ف. مشکورنیا، ه. و م. شفاعی بجستان، 1389. وضعیت پروفیل طولی فرسایش و رسوب تحت تأثیرسرریز Bendway در خم 90 درجه تند. نهمین کنفرانس هیدرولیک ایران. دانشگاه تربیت مدرس .
3-     عبـاس پـور، م. واقفـی، م. و م. قدسـیان، 1389. بررسـی اثـر نسبت استغراق آبشکن های T شـکل مسـتقر در قـوس 90 درجــه بــر توپــوگرافی بســتر. نهمــین کنفــرانس هیدرولیک ایران. دانشگاه تربیت مدرس.
4-     عزیزی، ر. شفاعی بجستان، م. قمشی، م. و ح. موسوی جهرمــی، 1391. تــأثیر شــکل صــفحه ی مســتغرق بــر آبشســتگی موضــعی و الگــوی رســوب گــذاری در کانالهای آبرفتی. مجله دانش آب و خاک، دانشـگاه تبریز. 22(2):  78-67.
5-     مشکورنیا، ه. و م. شفاعی بجستان، 1390. بررسی تأثیر طـول سرریز مستغرق بر تغییرات توپوگرافی بستر در خـم 90 درجه ی تند. دهمین کنفرانس هیدرولیک ایران .دانشگاه گیلان.
6-     منصوری، ا.م. نیشابوری، ع.ا. و ا. هنربخش، 1389. مطالعه سه بعدی تغییرات تراز بستر در قوس 180درجه. فصلنامه مهندسی عمران مدرس، 10(1):50-42.
7-     موسوی، ب. صانعی، م. سلاجقه، ع. و ب. معتمـد وزیـری 1389. بررسی آزمایشگاهی تأثیر طول آبشکن در کـاهش فرسایش کناره­های رودخانه. مجله علمی پژوهشی علوم و مهندسی آبخیزداری ایران. گزارش فنی. 4(12):68-65.
8-     همتی، م. قمشی، م. و س.م. کاشفی­پور، 1391. بررسی آزمایشگاهی تاثیر زاویه­ی سریزهای مستغرق بر الگوی رسوب و فرسایش در پیچانرود. مجله تحقیقات منابع آب ایران. 8(3):76-66.
9-     Abad, J. D. Rhoalds, B. L. Güneralp, I. and M. H. García. 2008. Flow structure at different stages in a meander-bend with bendway weirs. Journal of Hydraulic Engineering, 134(8): 1052-1063.
10- Bhuiyan, F. Hey, R. D. and P.R. Wormleaton. 2010. Bank-attached vanes for bank erosion control and restoration of river meanders. Journal of Hydraulic Engineering, 136(9): 583-596.
11- Duan, J. G. 2009. Mean flow and turbulence around a laboratory spur dike. Journal of Hydraulic Engineering, 135(10):803-811
12- Jarrahzade, F. and M. Shafai Bejestan. 2011. Comparison of maximum scour depth in bank line and nose of submerged weirs in a sharp bend.Scientific Research and Essays, 6(5):1071-1076.
13- Jia, Y. Scott, S. Xu, Y. Huang, S. and S.S.Y Wang. 2009. Numerical study of flow affected by bendway weirs in victoria bendway, the Mississippi river. Journal of Hydraulic Engineering, ASCE, 135(11):902-916.
14- Shafai Bejestan, M. Jarrahzade, F. Ramesh, S and H. Mashkoornia. 2010. Experimental study on bendway weirs. River flow, 2010 Dietrich, Koll, Aberle & Geisenhainer, (Eds): 1347-1352.
15- Sharma, K. and P. Mohapatra, 2012. Separation zone in flow past a spur dyke on rigid bed meandering channel. Journal of Hydraulic Engineering, 138(10): 897–901.
16- Yun, L. Baomin, W and L Yongqiang. 2012. Research on application of removable non-rescue submerged groins in lower yellow river training works. Procedia Engineering, (28): 781 – 785.
Volume 40, Issue 3
December 2017
Pages 21-33
  • Receive Date: 30 January 2016
  • Revise Date: 04 May 2016
  • Accept Date: 17 May 2016
  • First Publish Date: 22 November 2017