Effect of Hydrograph Peak Time on Local Scour around Bridge Pier

Document Type : Research Article


1 PhD Graduate, Civil and Environmental Engineering, Amirkabir University of Technology, Tehran, Iran.

2 Professor, Civil and Environmental Engineering, Amirkabir University of Technology, Tehran, Iran.


In the present study effect of hydrograph peak time on local scour around bridge pier is studied. Hydrographs with one discharge peak as well as double discharge peaks were generated in the labaratory. The duration time for some of these hydrographs were so short that could be considered as flash flood occuring in arid or semi-arid zone rivers. In each experiment, development of scour depth with time was measured by small cameras. Results showed that for hydrogaphs with similar duration, parameter of peak time or sequence of peaks in double discharge peak has negligible effect on final scour depth but considerable effect on time development of scour depth. Furthermore, time developmet of scour depth for present hydrographs are calculated by stepped- hydrograph model and empirical equations presented in the literature for steady flow. Results also showed high descrepancy between calculated and measured data for time development of scour depth and all of the final calculated scour depths are larger than experimental ones. In the best case, the average error for final calculated scour depth is about 10%.


فاردی،آر. وی. و چالتون، اف. جی. (1381)، "نقش عوامل هیدرولیکی در طراحی پل­ها"، ترجمه دکتر امیر رضا زراتی، انتشارات دانشگاه صنعتی امیرکبیر.
سلامتیان، ا.، زراتی، ا. ر.، کریمایی، م. (1391)، "مطالعه انتقال رسوب بستر در جریان غیردائمی"، نهمین کنفرانس بین المللی مهندسی رودخانه، اهواز، دانشگاه شهید چمران.
سلامتیان، ا.، "بررسی میزان آبشستگی اطراف پایه­های پل در جریان­های غیر دائمی و تحلیل قابلیت اطمینان با و بدون طوق محافظ"، رساله دکتری، دانشگاه صنعتی امیرکبیر، 1392.
Breusers, H. N. C., Nicollet, G., and Shen, H. W. (1977). “Local scour around cylindrical bridge piers”, Journal of  Hydraulic Research, 15(3), pp. 211-252.
Briaud J. L.,  Chen H. C., Kwak K. W., Han S. W., and Ting F. C. K. (2001). “Multiflood and multilayer method for scour rate prediction at bridge piers”, Journal of Geotechnical and Geoenvirnmental Engneering, 127(2), pp. 114-125.
Chang, W. Y., Lai, J. S., and Yen, C. L. (2004). “Evaluation of scour depth at circular bridge piers”, Journal of  Hydraulic Engineering, 130(9), pp. 905-913.
Chow, V. T. (1959). Open-Channel Hydraulics. McGraw-Hill, New York.
De sutter, R., Verhoeven R., and Andreas Krein, A., (2001). “Simulation of sediment transport during flood events: laboratory work and field experiments”, Journal of Hydrological Science, 46(4), pp. 599-610.
Hager, W. H., and Unger, J. (2010), “Bridge pier scour under flood waves”, Journal of Hydraulic Engineering, 136(10), pp. 842-847.
Kothyary, U. C., Garde, R. J., and Ranga Raju, K. G. (1992). “Temporal variation of scour around circular bridge pier”, Journal of Hydraulic Engineering, 118(8), pp. 1091-1106.
Karimaee Tabarestani, M. and Zarrati, A. R., (2014),”Sediment transport during flood event, A review”, International Journal of Enviernmental Science and Tecnology, 12(2), pp. 775-788.
Lee, K.T., Liu, Y.L., and Cheng, K.H. (2004). “Experimental investigation of bed load transport processes under unsteady flow conditions”, Hydrological Processes, 18(13), pp. 2439-2454.
Lu, J. Y., Hong, J. H., Su, C. C., Wang, C. Y., and Lai, J. S. (2008). “Field measurements and simulation of bridge scour depth variations during floods”, Journal of  Hydraulic Engineering, 134(6), pp. 810-821.
Lu, J. Y., Shi, Z. Z., Hong, J. H., Lee, J. J. and Raikar, R. V. (2011). “Temporal variation of scour depth at nonuniform cylindrical piers”, Journal of Hydraulic Engineering, 137(1), pp. 45-56.
Melville, B. W. and Coleman, S. E. (1999). Bridge Scour, Water Resources Publications.
Melville, B. W. and Chiew, Y. M. (1999). “Time scale for local scour at bridge piers”, Journal of  Hydraulic Engineering, Vol. 125(1), pp. 59-65.
Mia, M. F., and Nago, H. (2003), “Design method of time-dependent local scour at circular bridge pier”, Journal of Hydraulic Engineering, 129(6), pp. 420– 427.
Oliveto G. and Hager W.H. (2002). “Temporal evolution of clear-water pier and abutment scour”, Journal of  Hydraulic Engineering , 128 (9), pp. 811-820.
Oliveto, G., and Hager, W. H. (2005). “Further results to time-dependent local scour at bridge elements”, Journal of  Hydraulic Engineering, 131(2), pp. 97-105.
Raudkivi, A. J. and Ettema, R. (1983). "Clear water scour at cylindrical piers", Journal of Hydraulic Engineering, 109(3), pp. 338-350.
Scott, S. H., (2006). “Predicting sediment transport dynamics in ephemeral channels: A review of literature”, ERDC/CHL CHETN-VII-6, U.S. Army Corps of Engineers.
Song, T. and Graf, W. H. (1996). “Velocity and turbulence distribution in unsteady open-channel flow”, Journal of Hydraulic Engineering, 122(3), pp. 141–154.