عنوان مقاله [English]
In this paper, the effects of debris dimensions, pile cape thickness and installation levels, array and diameter piles on the maximum scour depth around inclined bridge pier groups were investigated experimentally. The bridge pier consist of two rectangular piers with 2.5 and 3.5 cm dimensions which mounted at an angle of 28 degrees on a pile cap with 10 cm width, 16 cm length, 3 and 5cm thickness which placed on an array of 2×2 and 2×3 piles with different diameters. The experiments were performed for relative flow depth (y/D) 6.42, 7.85, relative pile cap levels (Z/Tpc) 0, 1, 1.5, relative debris width and 2.85 and length 2, the relative thickness 0.85 and 1.42, in clear water conditions. Comparison of results proved that the effect of increasing flow depth has no significant effect on maximum scour depth. Results that in presence of the debris for pile cap relative level Z/Tpc=0, the maximum scour depth increases about 8.5% in comparison with no debris. For pile cap relative level Z/Tpc=1 presence of the debris increases the maximum scour depth up to 4.5% compared to no debris. By increasing the pile cap relative level to 1.5, presence of the debris causes an increase in the maximum scour depth about 4% in comparison with no debris
Abdeldayem, A. W., Elsaeed, G. H. and Ghareeb, A. A. 2011. The effect of pile group arrangements on local scour using numerical models. Adv. Nat. Appl. Sci. 5(2): 141-146.
Ataie-Ashtiani, B. and Beheshti, A. A. 2006. Experimental investigation of clear-water local scour at pile groups. J. Hydraul. Eng., 132(10): 1100-1104.
Breusers, N. H. C. and Raudkivi, A. J. 1991. Hydraulic Structure Design Manual: Scouring.
Vol. 2. Balkema, Rotterdam, Netherlands.
Coleman, S. E. 2005. Clearwater local scour at complex piers. J. Hydraul. Eng. 131(4): 330-334.
Esmaeili-Varaki, M. Mosapoor, S. and Hatam Jafari, M. 2013. Exprimental study the effect of geometric factors on local scour characteristics around inclined bridge pier groups with foundation. Iranian Water Res. J. 7(13): 141-151. (in Persian)
Esmaeili-Varaki, M. and Saadati-Pacheh-Kenari, S. S. 2015. Investigating experimentally the effect of installation of piers group on foundation on scour depth around bridge piers. J. Water Soil. 25(4.2): 27-39. (in Persian)
Ferraro, D., Tafarojnoruz, A., Gaudio, R. and Cardoso, A. H. 2013. Effects of pile cap thickness on the maximum scour depth at a complex pier. J. Hydraul. Eng. 139 (5): 482-491.
Hannah, C. R. 1978. Scour at Pile Group. Civil Engineering Research Report No.78. University of Canterbury.
Hoseini, S., Esmaeili-Varaki, M. and Fazleola, R. 2016. Experimental investigation of scour around inclined bridge piers group based on piles group. J. Water Soil. 26(4.2): 135-147.
Jones, J. S., Kilgore, R. T. and Mistichelli, M. P. 1992. Effect of footing Location on bridge pier scour. J. Hydraul. Eng. 118(2): 280-290.
Lagasse, P. F., Clopper, P. E., Pagan-Qrtiz, J. E., Zevenbergen, L. W., Arneson, L. A., Schall J. D. and Girard L. G. 2009. Bridge Scour and Stream Instability Countermeasures. Experience, Selection, and Design Guidance. Third Ed. Vol. 2. Publication No. FHWA-NHI-09-111. Hydraulic Engineering Cirular No. 23. U. S. Department of Transportation, Federal Highway Administration.
Lagasse, P. F., Zevenbergen, L. W and Clipper, P. E. 2010. Impacts of debris on bridge pier scour. International Conference on Scour and Erosion (ICSE-5) Scour and Erosion. Nov.
7-10. San Francisco, California.
Lyn, D. A., Cooper, T. J., Yi, Y., Sinha, R. N. and Rao, A. R. 2003. Debris Accumulation at Bridge Crossing. Laboratory and Field Studies. Report No. FHWA/IN/JTRP/10. West Lafayette, IN 47906.
Melvill, B. W. and Chiew, Y. M. 1999. Time scale for local scour at bridge piers. J. Hydraul. Eng. 125(1): 59-65.
Melville, B. W. and Dongol, D. M. 1992. Bridge pier scour with debris accumulation. J. Hydraul. Eng. 118(9): 1306-1310.
Melville, B. W. and Sutherland, A. J. 1988. Design method for local scour at bridge piers. J. Hydraul. Eng. 114(10): 1210-1226.
Moreno, M., Maia, R. and Couto, L. 2016. Prediction of equilibrium local scour depth at complex bridge piers. J. Hydraul. Eng. 142(11): doi.org/10.1061/(ASCE)HY.1943-7900.0001153.
Moshashaei, S. M., Asadi-Aghbalagi, M. and Samadi-Brojeni, H. 2015. Study the effect of accumulation of wood floating in front of the circle pier with pile. J. Water Soil. 25(2):
141-153. (in Persian)
Pagliara, S. and Carnacina, I. 2010. Scour and dune morphology in presence of large wood debris accumulation at bridge pier. Proceedings of the International Conference on Fluvial Hydraulics. Sep. 8-10. Braunschweig, Germany.
Pagliara, S. and Carnacina, L. 2011. Influence of wood debris accumulation on bridge pier scour. J. Hydraul. Eng. 137(2): 254-261.
Pasokhi-Dargah. Z., Esmaeili-Varaki, M. and Shafiei-Sabet, B. 2017. Experimental study of local scour around inclined bridge pier groups in presence of debris accumulation under various hydraulic conditions and installation of foundation level. Iranian J. Hydraul. 12(1): 59-75.
Raudkivi, A. J. and Ettema, R. 1983. Clear-water scour at cylindrical piers. J. Hydraul. Eng.
Sheppard, D. M., Odeh, M. and Glasser, T. 2004. Large-scale clear-water local pier scour experiments. J. Hydraul. Eng. 130(10): 957-963.