REDUCTION OF LOCAL SCOUR AROUND OBLONG BRIDGE PIERS USING SLOTS

H. Saleh, Hend; Abozeid, Gamal; S. Darweesh, Moustafa

doi:10.21608/jaet.2020.75171

	REDUCTION OF LOCAL SCOUR AROUND OBLONG BRIDGE PIERS USING SLOTS
Journal of Advanced Engineering Trends
Article 5, Volume 39, Issue 1, January 2020, Page 45-62 PDF (1.49 MB)
DOI: 10.21608/jaet.2020.75171
View on SCiNiTO
Authors
Hend H. Saleh^* ¹; Gamal Abozeid²; Moustafa S. Darweesh³
¹M. Sc. student, Eng. At Ministry of water resources and public work, Egypt
²Professors of hydraulics & water resources, Civil Eng. Dept., Assiut Univ., 71516
³Assistant Professor, Civil Engineering Dept., Assiut University, 71516 Assiut.
Abstract
This article presents an intensive experimental work for investigating the effect of rectangular slots and pier groups with various arrangements on the scour around bridge piers. Slots near the bed through an oblong pier with different arrangements and replacing the solid pier by two pier groups were provided to show their influence on the variation of scour dimensions under clear-water conditions. Water flow rate is varied four times (18, 15, 12.5 and 10.5 lit/s), while the water depth covers a range of Froude numberfrom 0.089 to 0.25 which is suitable for Egyptian canals. The scour hole dimensions and water depths are measured using calibrated point gages. The factors impacting the scour problem are normalized with the help of dimensional analysis theory. The experimental results show the efficient method that decreases the scour hole dimensions is the pier groups (pier type 7), where the scour depth, width and length reduced by 93, 73, and 79 % respectively. Slots within the oblong piers decrease the scour dimensions (depth, width and length) by 92, 53, and 69 %, respectively. These findings can easily safeguard the bridge piers and dramatically reduce the maintenance efforts and costs as well as improve the hydraulic performance of the water structures.
Keywords
Oblong Pier; Group Piles; Slots; Scour Depth


References
[1] Abozeid, G. "Scour at abutment of one-vent bridges.", J. of Eng. Scie., Assiut Univ., Vol. 32, pp. 1091-1105, July, (2004). [2] Abozeid , G. A., Hassan I. M., Shima, M. A., “3-D numerical simulation of flow and clear water scour by interaction between bridge piers” Proc. of the Tenth Water Tech. (IWTC) Conf., Alex., March 2006. [3] Ali, N. A., “A contribution to sediment transportation with reference to hydraulic resistance”, M. Sc. Thesis, Civil Eng. Dept. Assiut Univ., 1978. [4] Breusers, H. N. C., and A. J. Raudkivi. "Scouring. IAHR hydraulic structures design manual 2.", A. A. Balkema, Rotterdam, The Netherlands, (1991). [5] Chang, F., and Davis, S. "Maryland SHA Procedure for Estimating Scour at Bridge Abutments Part 2-Clear Water Scour.", Stream Stability and Scour at Highway Bridges: Compendium of Stream Stability and Scour Papers Presented at Conferences Sponsored by the Water Resources Engineering (Hydraulics) Division of the American Society of Civil Engineers, ASCE., (1998).‏ [6] Chatterjee, S. S., and Ghosh, S. N., “Submerged horizontal jet over erodible bed “, J. of Hyd. Div., ASCE, 106(HY), Nov. 1980. [7] Chiew, Y. M. "Scour protection at bridge piers.", J. of Hyd. Eng., Vol. 118, No. 9, pp. 1260-1269, Sept., (1992).‏ [8] Choi, S. U., and Choi, B. "Prediction of time‐dependent local scour around bridge piers.", Water and Environment Journal, Vol. 30., No. 1, pp. 14-21, (2016).‏ [9] Christensen, Z. M. "Reduction of local scour around bridge piers: Combined system of aerofoil and slot.", the Faculty of Eng., Southern Queensland Univ., pp. 1-150, October, (2009). [10] El-Razek, M., El-Motaleb, M. A., and Bayoumy, M. "Scour reduction around bridge piers using internal openings through the pier.", Alexandria Engineering Journal, Vol. 42., No. 2, pp. 241-248, (2003).‏ [11] Grimaldi, C., Gaudio, R., Calomino, F., and Cardoso, A. H. "Countermeasures against local scouring at bridge piers: slot and combined system of slot and bed sill.", J. of Hyd. Eng., Vol. 135., No. 5, pp. 425-431, (2009).‏ [12] Heidarnejad, M., M. Shafai Bajestan, and A. Masjedi. "The effect of slots on scouring around piers in different positions of 180-degrees bends.", World Applied Sciences Journal, Vol. 8., No. 7, pp. 892-899, (2010).‏ [13] Khodabakhshi, A., Mojtaba, S., and Abdolnabi A.K. "Experimental study on effect of slot level on local scour around bridge pier.", Int. J. of Res. in Eng. and Tech., Vol. 3., No. 2, pp. 103-108, (2014).‏ [14] Kumar, V., Raju, K. G. R., and Vittal, N. "Reduction of local scour around bridge piers using slots and collars.", J. of Hyd. Eng., Vol. 125., No. 12, pp. 1302-1305, (1999).‏ [15] Melville, B. W. "Local scour at bridge site", School of Eng., Univ. of Auckland, New Zeland, pp. 1-277, 1975.‏ [16] Melville, B. W., and Yee-Meng Chiew. "Time scale for local scour at bridge piers.", Journal of Hydraulic Engineering, Vol. 125., No. 1, pp. 59-65, (1999).‏ [17] Melville, B. W., and Coleman, S. E. "Bridge scour. ", Water Resources Publication, (2000).‏ [18] Moncada-M, A. T., Aguirre-Pe, J., Bolivar, J. C., & Flores, E. J. "Scour protection of circular bridge piers with collars and slots." J. of Hyd. Res., Vol. 47., No. 1, pp. 119-126, (2009). [19] Neill, C. R. "Guide to bridge hydraulics, Roads and Transportation Association of Canada. ", University of Toronto Press, Toronto, (1973).‏ [20] Setia, B., and Bhatia, K. "Sour protection by a slot through a model bridge pier." J Indian Water Res. Soc., Vol. 33., No. 1, pp. 9-15, (2013). [21] Siddiqui, N. A. and Elsebaie, I. H. "Experimental investigation of grain size effect on the temporal variation of local scour around bridge piers. ", J. of Water Res. and Pollution Studies, Vol. 2., No. 3, (2017). [22] Tseng, M. H., Yen, C. L., and Song, C. C. "Computation of three‐dimensional flow around square and circular piers.", Int. J. for numerical methods in fluids, Vol. 34., No. 3, pp. 207-227, (2000). [23] Vittal, N., Kothyari, U. C., and Haghighat, M. "Clear-water scour around bridge pier group." J.of Hyd. Eng., Vol. 120., No. 11, pp. 1309-1318, (1994). [24] Zarrati, Amir R., H. Gholami, and M. B. Mashahir. "Application of collar to control scouring around rectangular bridge piers.", J. of Hyd. Res., Vol. 42., No. 1, pp. 97-103, (2004).
Statistics Article View: 291 PDF Download: 479