The application of collar on the scour reduction at bridge rectangular abutment in composit channel

Document Type : Original Article

Authors

1 M.Sc Student of Civil Engineering, Shahid Chamran University;

2 Professor, Faculty of Water Science Engineering , Shahid Chamran University

3 1M.Sc Student of Civil Engineering, ShahidChamran University

Abstract

The fracturing bridge due to scour of foundation (includes bed  and abutment), reveals the necessity of study for  scour predict and the protected methods. Generally,the methods of scour reduction include: placing foundation at the lower level of erosion pit depth, rasing bed resistance and decressing erosion power factors (decreasing downflow and horseshoe vortex). Utilizing a spreadsheat around abutment called collar is one of the methods of power decrease. The collar  decreases the power of downflow and horseshoes vortex around the abutment further it decreases the depth of scour decrease. In this research a collar of  two times than the abutment width exposed to a discharge of  20 and 25 lit/s. The operation of collar in 3 different depths (on the bed, at 2cm above bed and at 4cm above bed) was studied in the scour conditions of clear water and was compared with abutment without collar. the research indicate that collar decreases scour and it showed better operation above the bed.as a  maximum percentage decrease of scour with a discharge of 20 and 25 lit/s is 94% and 93% respectively

Keywords

References

خسروی‌نیا، پ.، ع. حسین‌زاده دلیر، د. فرسادی‌زاده و ا. فاخری‌فرد. 1390. تاثیر طوق در کاهش آبشستگی اطراف آبشکن‌ها. مجله دانش آب و خاک، جلد 21،  شماره 1.
2-  راهنمای روش‌های محاسبه آبشستگی موضعی. نشریه شماره 549.
3- زراتی، ا.ر. و م. عزیزی. 1380. کنترل آبشستگی در اطراف پایه‌های پل. نشریه دانشکده فنی جلد 35، شماره 1، ص 33-21.
4-شفاعی بجستان، م. 1387. هیدرولیک رسوب. انتشارات دانشگاه شهید چمران اهواز .
5-Barbhuiy, A.K. and S. Dey. 2004. Local scour at abutments: A review. Sadhana, 29(5): 449-476.
6-Chiew, Y.M. 1992. Scour Protection at Bridge Piers. Journal of Hydraulic Engineering. 118(9):1260-1269.
7- Dargahi B. 1990. Controlling mechanism of local scouring. Journal of Hydraulic Engineering. 116(10): 1197-1214.
8- Kayaturk, S.Y. 2005. Scour and scour protection at bridge abutment. PhD thesis, Middle East Technical University, Ankara, Turkey.
9-Mashahir, M.B., and A.R. Zarrati. 2002. Effect of Collar on Time Development of Scouring around Rectangular Bridge Piers. The 5th International Conference on.
10-Melville, B.W. 1992. Local Scour at Bridge Abutments. Journal of Hydraulic Engineering, Vol. 118: 615-631.
11- Raudkivi, A.J. 1998. Loose boundary hydraulics. 4th Edition. Rotterdam, Brookfield, VT ,Balkema. P: 496.
12-Singh, C.P., B. Setia and D.V.S. Verma. 2001.Collar-sleeve combination as a scour protection device around a circular pier. Proceedings of Theme D, 29th Congresson Hydraulics of Rivers, Water Worksand Machinery,Chinese Hydraulic Engineering Society, Beijing, pp: 202-209.
13-Zarrati, A.R., H. Gholami and M.B. Mashahir. 2004. Application of Collar to Control Scouring Around Rectangular Bridge Piers. Journal of Hydraulic Research, 42( 1): 97-103.
 

Files

Share

How to cite

Statistics