کنترل جابه‌جائی عرضی قوس‌های رودخانه‌ای با نصب صفحات شناور

نویسندگان

1 دانشجوی دکتری سازه‌های آبی دانشگاه شهید چمران اهواز

2 استاد گروه سازه‌های آبی دانشگاه شهید چمران اهواز

چکیده

فرآیندهای طبیعی در رودخانه­های مئاندری نظیر آبشستگی در قوس خارجی و رسوب­گذاری در قوس داخلی باعث انتقال عرضی قوس رودخانه در جهت پائین­دست می‌گردند. تاکنون روش‌های متعددی برای کنترل این انتقال ارائه شده است. در این مطالعه اثرات کاربرد صفحات شناور در میزان عمق آبشستگی و رسوب­گذاری در قوس رودخانه بررسی شده است. برای این منظور مدل فیزیکی با بستر متحرک  از قوس 180 درجه رودخانه کارون واقع در جنوب اهواز ساخته شد. هم­چنین اندازه­گیری‌های توپوگرافی بستر فلوم نشان داد که قوس در بازه 130 درجه تا پائین­دست قوس دچار آبشستگی زیادی می‌باشد. از این رو در مدل تعداد هفت صفحه شناور به­صورت متوالی در قوس خارجی بازه فوق نصب گردیدند و تحت سه عدد فرود 18/0، 20/0 و 22/0 مورد آزمایش قرار گرفتند. در تمام آزمایش‌ها عمق جریان ثابت بود. ابعاد صفحات نیز بر اساس توصیه‌های ادگارد برای صفحات مستغرق طراحی شد. با برداشت توپوگرافی بستر توسط متر لیزری و وارد کردن نتایج حاصل به نرم­افزار تک پلات(Tecplot)، وضعیت توپوگرافی ترسیم شد و نتایج به­دست آمده نشان داد که با نصب صفحات شناور بیشینه عمق آبشستگی در سه عدد فرود 18/0، 2/0 و 22/0 به­ترتیب 50 درصد، 50 درصد و 40 درصد کاهش است. هم­چنین کارگذاری صفحات شناور باعث رسوب­گذاری در پاشنه ساحل خارجی شده و باعث ساحل­سازی می­گردد.

کلیدواژه‌ها

عنوان مقاله [English]

Control of Lateral Movement of River Bends by Installing the Floating Vanes

نویسندگان [English]

  • A Sozepoor 1
  • M Shafai Bejestan 2
1 -PhD Student of Water Structures, Faculty of Water Sciences Engineering, Shahid Chamran University, Ahvaz, Iran
2 Prof., Faculty of Water Sciences Engineering, Shahid Chamran University, Ahvaz, Iran
چکیده [English]

Natural phenomena such as bed scouring in the outer bank and deposition in the inner bank of meandering rivers cause lateral migration of the river bend in the downstream direction. So far, different measures have been developed to control this movement. In the present study, the influences of floating vanes application on bed scouring and deposition in river bend has been investigated experimentally. For this purpose, a physical model of Karoon river 180-degree bend at the south of Ahwaz city was constructed. Also flume bed topography measurement showed that the bend scour had been occurred from 130 degrees’ location to the end of the bend. Therefore, seven floating vanes were installed in series at this bendsegment and tested under three different Froude numbers (=0.18, 0.20 and 0.22). The flow depth was kept constant for these tests. The vanes dimensions were designed according the Odgaard’s recommendations for submerged vanes. Bed topography maps were measured using a laser meter and contour lines were plotted using the Tecplot software. The results showed that with installing floating vanes, the maximum scour depth reduced as much as 50%, 50% and 40% for Froude numbers equal to 0.18, 0.20 and 0.22, respectively. It was also found that generally the scour depth not only was shifted toward the inner bend, sedimentdeposition also was observed at the outer bank.

کلیدواژه‌ها [English]

  • Bend
  • Floating vanes
  • Physical model
  • River
  • Sedimentation

مراجع

Atashi V, Shafaai Bejestan M and Ahadyan J, 1391. Evaluation of flow pattern and shear stress in a 90 degree bend using w-weir. Journal of Water Resources Engineering. 5(2):15-28.
Ramesh S, Jarahzade F, Mashkorinyia, V and Shafaai Bejestan M, 1389. The profile of longitudinal erosion and sedimentation is affected by bendway in a 90 degree bend. pp. 102-118. The 9th Iranian hydraulic conference. 18-20 aban, Tehran, Iran.
 Sozepoor A, Shafaai Bejestan M and Ghadoo Y, 1392. Experimental investigation of flow pattern at a 90 degree sharp rectangular bend. Water and Soil Science-University of Tabriz. 23(6): 257-268.
Moradpoor M, Farsadizade D, Hosainzade Dalier A and Aronghi, H, 1391. Experimental investigation of the effect of crochet size on the scouring process of semicircular super dike. pp. 410-419. The 11th Iranian hydraulic conference. 16-19 aban, urmi, Iran. 
Mansoori A.R, Nishabouri A.A, and Honarbakhsh A, 1389. Three-dimensional study of bed level changes in 180 degree bend. Journal of Modares Civil. 10(1): 1-19.
Hemati M, Ghomshi M and Kashefipour S.D, 1391. Experimental investigation of the effect of angular submerged vanes on the Sedimentation and Erosion Pattern in meander. Iranian Water Resources Researches Journal. 8(3): 66-76.
Hemati M, Kashefipour S.D and Ghomshi M, 1392. Experimental investigation on the effect of submerged vanes length on the sedimentation pattern and water level in meander. Journal of Civil and Environmental Engineering. 43(1): 66-76.
Abad JD, Rhoads BL, Guneralp I and Gorcia MH, 2008. Flow structure at difference stages in a meander-bend with Bendway weirs. Journal of Hydraulic Engineering ASCE 134(8): 1052-1063.
Barani GHA and Shahrokhi Sarde M, 2013. Experimental investigation of submerged vanes shape effect on river-bank stability. Scientific Professional Quarterly 1(1): 35-41.
Bahrami Yarahamdi M, Shafai Bejestan M, 2016. Sediment Management and flow patterns at river bend due to triangular vanes attached to the bank. Journal of Hydro-environmental Research 10(1):64-75.
Bhuiyan F, Hey RD and Wormleaton PR, 2010. Bank-Attached Vanes for Bank Erosion Control and Restoration of River Meanders. Journal of Hydraulic Engineering 136(9): 583-596.
Bhuiyan F, Hey RD and Wormleaton PR, 2007. River restoration using W-weir. Journal of Hydraulic Engineering 133(6): 596–609.
Fischenich JC and Allen HA, 2000. Stream management. ERDC/EL SR-W-00-1, U.S. Army Engineer Research and Development Center, Vicksburg, MS.
Jarrahzade F and Shafai Bejestan M, 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.
Junali T and Utpal Kumar M, 2015. Experimental investigation of local scour around submerged vanes. International Journal Innovative Research in Advanced Engineering 2(7): without page.
Odgard Aj, 2010. River Training and Sediment Management with Submerged Vanes, Published by American Society of Civil Engineers.
 Pagliara S, Kurdistani SM and Santucci I, 2013. Scour downstream of J-hook vane structures in straight horizontal channels, Acta Geophysical 61(5): 1211–1228.
Pagliara S, Kurdistani SM and Cammarata L, 2014. Scour of clear water rock W-Weirs in straight rivers. Journal of Hydraulic Engineering 140(4): without page.
Rosgen DL, 2006. The Cross-Vane, W-Weir and J-Hook Vane Structures Description, Design and Application for Stream Stabilization and River Restoration. Wild land Hydrology, Inc. 11210 N. County Road 19 Ft. Collins, Colorado 80524970-568-0002.
Samimi Behbahan T, 2011. Laboratory investigation of submerged vane shapes effect on river banks protection. Australian Journal of Basic and Applied Sciences, 5(12):1402-1407.
Sclafani P, 2010. Methodology for predicting maximum velocity and shear stress in a sinuous channel with bendway weirs using 1-D HEC-RAS modeling results. M.S. Thesis, Colorado State University, Department of Civil Engineering, Fort Collins, CO.
 
دانش آب و خاک
دوره 28، شماره 1
فروردین 1397
صفحه 131-143

فایل ها

هم رسانی

ارجاع به این مقاله

آمار