عنوان مقاله [English]
نویسندگان [English]چکیده [English]
Bridge pier scour is one of the three main causes of bridge failure. With the prospect of more severe and more frequent floods due to climate change, reducing the risk of bridge failure is becoming increasingly important. Therefore, different methods have been proposed to control scouring around bridge piers. In this study, the effect of bed sill on local scour around bridge piers that are embedded in cohesive soils has been studied experimentally. The bed sill was located in downstream and different distances from the piers. Cylindrical pipes with diameters of 60 mm and 75 mm were used as piers model.Result show that the effects of bed sill distance from piers in reduction of scour depth and scour volume is larger than the other parameter. By reducing the bed sill distance to the piers, scour depth and volume reduced. The best place to install bed sill is right next to the piers. It was found that the scour depth has no direct relationship with the piers Froude number.
Breusers N. H. C. and A. J. Raudkvi. 1991. Scouring, 2nd Hydraulic Structures Design Manual, IAHR, A. A. Balkema, Rotterdam, The Netherlands.
Briaud, J. L., F., Ting, H. C., Chen, S. R., Gudavalli, S., Perugu, and G. Wei. 1999. SRICOS: Prediction of scour rate in cohesive soils at bridge piers. J Geotech Geoenviron. Eng., 125(4): 237–246.
Breusers, N. H. C., G. Nicollet, and H. W. Shen, 1977. Local scour around cylindrical piers. IAHR, J. Hyd. Res., 15(3): 211-252.
Chiew, Y. M. 1992. Scour protection at bridge Piers. JHE, ASCE, 118(9): 260-1269.
Chiew, Y. M. and S. Y. Lim, 2003. Protection of bridge piers using a sacrificial sill. Proc. ICE Water, Maritime and Energy 156(1): 53–62.
Ettem, R. 1980. Scour at Bridge Piers. Report No.216, University of Aucland, School of Engineering, New Zealand.
Franzetti, S., S. Malavasi, and C. Piccinin, 1994. Sull’erosione alla base delle pile di ponte in acque chiare. Proc., XXIV Convegno di Idraulica e Costruzioni Idrauliche, Vol. II, T4 13–24.
Grimaldi, C., R., Gaudio, F., Calomino, A.H. Cardoso. 2009. Control of scour at bridge piers by a downstream bed sill. J. Hyd. Eng., 135(1): 13–21.
Grimaldi, C., R., Gaudio, F., Calomino, A.H. Cardoso. 2009. Countermeasures against local scouring at bridge piers: Slot and combined system of slot and bed sill. J. Hyd. Eng., 135(5): 425–431.
Heidarpour, M. 2002. Control and reduction of local scour at bridge piers by using slot. Proc. International Conf. on Fluvial Hydraulics, 3-6 Sept., Louvain-la-Neuve, Belgium. 2:1069-1072.
Kumar, V., K. G. Ranga Raju, and N. Vittal, 1999. Reduction of local scour around bridge piers using slots and collars. ASCE, J. Hyd. Eng. 125(12): 1302-1305.
Laursen, E. M. and A. Toch. 1956. Scour around bridge piers and abutments. Iowa Highway Res. Board, Bulletin No. 4.
Melville1, B. W. and C. Yee-Meng. 1999. Time Scale for Local Scour at Bridge Piers, J.Hyd. Eng, ASCE, 125(1): 59-65.
Melvill B. W. and Y. M. Chiew. 1999. Time scale for local scour at bridge piers. J Hyd Eng ASCE, 125 (1): 59-65.
Melville, B. W. and A. C. Hadfield. 1999. Use of sacrificial piles as pier scour countermeasures, J.Hyd. Eng, ASCE, 125(11): 1221-1224.
Parola, A.C. and J.S. Jones. 1991. Sizing riprap to protect bridge piers from scour. Transport. Res. Rec. No. 1290, pp: 276-280.
Ting, Francis. C. K., J-S., Briaud, R., Gudavalli , S., Perugu , G. Wei. 2002. Flume test for scour in clay at circular piers. J. Hyd. Eng., 127(11): 969-978.
Zarrati, A. R., M. Nazariha, and M. B. Mashahir. 2006. Reduction of local scour in the vicinity of bridge pier groups using collars and riprap. ASCE, J. Hyd. Eng. 132(2): 154-161.