Evaluation of pier scour reduction using combination of collars, slots and threading method

Subject Areas : Subjects

میلاد مرناض ¹ (دانشجوی کارشناسی ارشد سازههای هیدرولیکی دانشگاه صنعتی خاتم الانبیاء بهبهان)
سید امین اصغری پری ² (دانشیار دانشگاه صنعتی خاتم الانبیاء بهبهان،)
محمود sh ³ (استاد دانشگاه شهید چمران اهواز)

Received: 2015-12-23 Accepted : 2018-10-03 Published : 2018-08-23

Keywords: Scour, pier, collar, slot, threading,

Abstract :

The local scour around the piers is an important factor that causes of the destruction of the bridges. Therefore, to avoid this phenomenon there is scientific solutions to protect the pier against scour. some of the most effective techniques you can use ,are using the collars or threading or slots on the pier. Therefore using the slots is not practical or not suitable to consider as permanent solution and threading is not so effective method so there is an idea to compose threading and slots with collars together in this experimental work that can make slots and threading so more practical and useful in pier scour reduction . there have been created some new tools which name jet-collar , slot-veneer and thread-veneer. at the best condition results shows that some of the collars which have a jagged side as a jet and a collar at other side , so this jet-collar could reduce local scour by 83% at pier side.

References:

1) Abbas chenari, S. and Maleki, H. 2012,
Numerical study of the effect of slitted and non-split
bridge foundation on the shear stress and flow rate
distribution, 11th Iranian Hydraulic Conference,
Urmia University. (In Persian)
2) Aghli, M. and Zomorodian, S.M.A.2013,
Effect of cable and collar on scouring depth around
cylindrical bridge pier in meandering river. Journal
of Irrigation Science and Engineering of Shahid
Chamran University of Ahwaz. 36(3):31-40. (In
Persian)
3) Chiew, Y. M. 1992, Scour protection at bridge
piers. J. Hyd. Eng. ASCE. 118(11): 1260-1269.
4) Ettem, R. 1980. Scour at bridge piers, Report
No.216, University of Auckland, School Of
Engineering, New Zealand.
5) Hazrati, F., Hoseinpour, N., and Hoseinzadeh
Dalir, A. 2016. Investigating the effect of semicircular
collar with rectangular sequence on
reducing scouring of cylindrical pylons.10th
International Conference on River Engineering,
Shahid Chamran University of Ahwaz. (In Persian)
6) Heidarpour, M. 2002. Control and reduction of
local scour at bridge piers by using slot. Proc. River
Flow 2002, Louvain-la-Neuve, A. A. Balkema,
Rotterdam, The Netherlands, 2: 1069–1072.
7) Hua, L., Roger, A., Kuhnle, B., and Barkdoll,
D. 2006, Countermeasures against scour at
abutment Report No. 49 Oxford, Mississippi.
8) Jalili, A. 2013. Laboratory study of the effect
of simple lattice and simple crown on cubical bridge
base scouring, 12th Iranian Hydraulic Conference,
Tehran University of Agriculture and Natural
Resources Campus. (In Persian)
9) Khodabakhshi, A., Sanei, M. and Abde
kolahchi, A. 2012, Laboratory study of the effect
of slope height on the surface of the river bed on
the local scouring of the bridge foundation, 11th
Iranian Hydraulic Conference, Urmia University.
(In Persian)
10) Khozeymehnezhad, H., Ghomeshi, M. and
Shafaeibajestan, M. 2014, Comparison of
symmetrical and unsymmetrical rectangular collars
on reduction of local scour at bridge abutment.
37(2):1-12. (In Persian)
11) Kianpour, E. and Abbasi, S. 2016,
Investigating the effect of slit on reducing scouring
around bridges with FLOW-3D. 10th International
Conference on River Engineering, Shahid Chamran
University of Ahwaz. (In Persian)
12) Melville BW, 1997. Pier and abutment scouran
integrated approach. Journal of Hydraulic
Engineering ASCE 123(2): 125-136.
13) Mashair, M.B., Zarrati, A.R., and Rezayi,
A.R.2004, Time development of scouring around a
bridge pier protected by collar. 2nd International
Conference on Scour and Erosion, ICSE-2,
Singapore, 8 p.
14) Raudkivi, A.J., and Ettema, R., 1983. Clearwater
scour at cylindrical piers. J. Hyd. Eng., ASCE
109(3):338-350.
15) Rostami, M. 2016. Numerical simulation of
the effect of collar performance on the local
scouring of bridges. 10th International Conference
on River Engineering, Shahid Chamran University
of Ahwaz. (In Persian)
16) Sani khani, H., Hoseinzadeh Dalir, A. and
Farsadizadeh, D. 2008, Effect of square strips in
reducing scouring around the Pillars, 4th National
51 مجله ی مهندسی منابع آب / سال یازدهم /تابستان 1397
Congress on Civil Engineering, University of
Tehran. (In Persian)
17) Shafaei bajestan, M. 2008, Theoretical and
practical bases for hydraulic sediment transport.
First Printing, pp. 478-479, Shahid Chamran
University Press, Ahwaz. (In Persian)
18) Tafarojnoruz A., Gaudio R., Grimaldi C., and
Calomino, F. 2010, required conditions to achieve
the maximum local scour depth at a circular pier, Int
Conf of Hyd -2-9
19) Tafarojnoruz A, Roberto G. and Francesco C.
2012. Evaluation of flow-altering countermeasures
against bridge pier scour-American Society of Civil
Engineers. USA 3-7

_||_