Acta Geophysica

, Volume 60, Issue 4, pp 1076–1097 | Cite as

Bridge pier scour mitigation under steady and unsteady flow conditions

  • Ali Tafarojnoruz
  • Roberto Gaudio
  • Francesco Calomino
Research Article


Watercourse morphology is affected by local scouring when the flow interferes with anthropic structures. Controlling the scour hole size is of predominant importance to guarantee bridge safety as well as to limit the variations of river morphology. A combined countermeasure against bridge pier scour is proposed and tested in order to reduce the maximum scour depth and deviate it away from the bridge foundation. In the first part of the laboratory campaign, combination of two countermeasures (bed-sill and collar) was evaluated for a circular pier under clear-water and live-bed steady flow conditions. The proposed combined countermeasure exhibited an efficiency of about 64% in terms of scour depth reduction. Afterwards, it was tested in unsteady flow conditions, first for a circular pier, then in the case of a rectangular pier with round nose and tail, two circular in-line piers and two rectangular in-line piers, under a hydrograph with a peak flow velocity slightly above the threshold condition of sediment motion. Results showed that the combined countermeasure had an efficiency of about 63% for a single circular pier; however, higher efficiency (about 75%) was obtained in applications to rectangular pier and two in-line circular or rectangular piers.

Key words

bridge pier scour bed-sill countermeasure collar unsteady flow 


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  1. Cardoso, A.H., and R. Bettess (1999), Effects of time and channel geometry on scour at bridge abutments, J. Hydraul. Eng. 125,4, 388–399, DOI: 10.1061/(ASCE)0733-9429(1999)125:4(388).CrossRefGoogle Scholar
  2. Cardoso, A.H., F. Calomino, R. Gaudio, R. Bettess, and M. Roca Collell (2010), Rischio idraulico ed erosivo in corrispondenza di punti singolari, POR Calabria 2000–2006. Università della Calabria, Dipartimento di Difesa del Suolo “V. Marone”, Rende (CS), Italy (in Italian).Google Scholar
  3. Chang, W.Y., J.S. Lai, and C.L. Yen (2004), Evolution of scour depth at circular bridge piers, J. Hydraul. Eng. 130,9, 905–913, DOI: 10.1061/(ASCE)0733-9429(2004)130:9(905).CrossRefGoogle Scholar
  4. Chiew, Y.M. (1992), Scour protection at bridge piers, J. Hydraul. Eng. 118,9, 1260–1269, DOI: 10.1061/(ASCE)0733-9429(1992)118:9(1260).CrossRefGoogle Scholar
  5. Chiew, Y.M. (1995), Mechanics of riprap failure at bridge piers, J. Hydraul. Eng. 121,9, 635–643, DOI: 10.1061/(ASCE)0733-9429(1995)121:9(635).CrossRefGoogle Scholar
  6. Chiew, Y.M., and F.H. Lim (2000), Failure behavior of riprap layer at bridge piers under live-bed conditions, J. Hydraul. Eng. 126,1, 43–55, DOI: 10.1061/(ASCE)0733-9429(2000)126:1(43).CrossRefGoogle Scholar
  7. Chiew, Y.M., and S.Y. Lim (2003), Protection of bridge piers using a sacrificial sill, P.I. Civil Eng. Mar. En. 156,1, 53–62, DOI: 10.1680/wame.2003.156.1.53.Google Scholar
  8. Chiew, Y.M., and B.W. Melville (1987), Local scour around bridge piers, J. Hydraul. Res. 25,1, 15–26, DOI: 10.1080/00221688709499285.CrossRefGoogle Scholar
  9. Ettema, R. (1980), Scour at Bridge Piers. Rep. No. 216, School of Engineering, University of Auckland, Auckland, New Zealand.Google Scholar
  10. Garde, R.J. (1970), Initiation of motion on a hydrodynamically rough surface. Critical velocity approach, Irrig. Power, 27,3, 271–282.Google Scholar
  11. Gaudio, R., A. Marion, and V. Bovolin (2000), Morphological effects of bed sills in degrading rivers, J. Hydraul. Res. 38,2, 89–96, DOI: 10.1080/00221680009498344.CrossRefGoogle Scholar
  12. Gaudio, R., A. Tafarojnoruz, and F. Calomino (2012), Combined flow-altering countermeasures against bridge pier scour, J. Hydraul. Res. 50,1, 35–43, DOI: 10.1080/00221686.2011.649548.CrossRefGoogle Scholar
  13. Goncharov, V.N. (1964), Dynamics of Channel Flow, Israel Programme for Scientific Translation, Moscow, 185.Google Scholar
  14. Grimaldi, C., R. Gaudio, F. Calomino, and A.H. Cardoso (2009a), Control of scour at bridge piers by a downstream bed sill, J. Hydraul. Eng. 135,1, 13–21, DOI: 10.1061/(ASCE)0733-9429(2009)135:1(13).CrossRefGoogle Scholar
  15. Grimaldi, C., R. Gaudio, F. Calomino, and A.H. Cardoso (2009b), Countermeasures against local scouring at bridge piers: slot and combined system of slot and bed sill, J. Hydraul. Eng. 135,5, 425–431, DOI: 10.1061/ (ASCE)HY.1943-7900.0000035.CrossRefGoogle Scholar
  16. Hamill, L. (1999), Bridge Hydraulics, E and FN Spon., Routledge, London.CrossRefGoogle Scholar
  17. Khosronejad, A., S. Kang, and F. Sotiropoulos (2012), Experimental and computational investigation of local scour around bridge piers, Adv. Water Resour. 37, 73–85, DOI: 10.1016/j.advwatres.2011.09.013.CrossRefGoogle Scholar
  18. Kothyari, U.C., R.J. Garde, and K.G. Ranga Raju (1992), Temporal variation of scour around circular bridge piers, J. Hydraul. Eng. 118,8, 1091–1106, DOI: 10.1061/(ASCE)0733-9429(1992)118:8(1091).CrossRefGoogle Scholar
  19. Lai, J.S., W.Y. Chang, and C.L. Yen (2009), Maximum local scour depth at bridge piers under unsteady flow, J. Hydraul. Eng. 135,7, 609–614, DOI: 10.1061/ (ASCE)HY.1943-7900.0000044.CrossRefGoogle Scholar
  20. Lenzi, M.A., A. Marion, and F. Comiti (2003), Interference processes on scouring at bed sills, Earth Surf. Proc. Land. 28, 99–110, DOI: 10.1002/esp.433.CrossRefGoogle Scholar
  21. Martín-Vide, J.P., and A. Andreatta (2009), Channel degradation and slope adjustment in steep streams controlled through bed sills, Earth Surf. Proc. Land. 34, 38–47, DOI: 10.1002/esp.1687.CrossRefGoogle Scholar
  22. Mashahir, M.B., A.R. Zarrati, and M.J. Rezayi (2004), Time development of scouring around a bridge pier protected by collar. In: Proc. 2nd Int. Conf. Scour and Erosion, Nanyang, Singapore, 14–17 November 2004, Stallion Press, Singapore.Google Scholar
  23. Mashahir, M.B., A.R. Zarrati, and E. Mokallaf (2010), Application of riprap and collar to prevent scouring around rectangular bridge piers, J. Hydraul. Eng. 136,3, 183–187, DOI: 10.1061/ (ASCE)HY.1943-7900.0000145.CrossRefGoogle Scholar
  24. Melville, B.W., and Y.M. Chiew (1999), Time Scale for local scour at bridge piers, J. Hydraul. Eng. 125,1, 59–65, DOI: 10.1061/(ASCE)0733-9429(1999) 125:1(59).CrossRefGoogle Scholar
  25. Melville, B.W., and S.E. Coleman (2000), Bridge Scour, Water Resources Publications, Littleton, CO.Google Scholar
  26. Moncada-M, A.T., J. Aguirre-PE, J.C. BolÍvar, and E.J. Flores (2009), Scour protection of circular bridge piers with collars and slots, J. Hydraul. Res. 47,1, 119–126, DOI: 10.3826/jhr.2009.3244.CrossRefGoogle Scholar
  27. Monti, R. (1994), Indagine sperimentale delle caratteristiche fluidodinamiche del campo di moto intorno ad una pila circolare, Tesi di Dottorato di Ricerca, Politecnico di Milano, Milan, Italy (in Italian).Google Scholar
  28. Tafarojnoruz, A. (2010), Flow-altering countermeasures against local scour at bridge piers, Ph.D. Thesis, Scuola di Dottorato “Pitagora” in Scienze Ingegneristiche, Università della Calabria, Rende (CS), Italy.Google Scholar
  29. Tafarojnoruz, A., R. Gaudio, and S. Dey (2010a), Flow-altering countermeasures against scour at bridge piers: a review, J. Hydraul. Res. 48,4, 441–452, DOI: 10.1080/00221686.2010.491645.CrossRefGoogle Scholar
  30. Tafarojnoruz, A., R. Gaudio, C. Grimaldi, and F. Calomino (2010b), Required conditions to achieve the maximum local scour depth at a circular pier. In: Proc. XXXII Convegno Nazionale di Idraulica e Costruzioni Idrauliche, 14–17 September 2010, Palermo, Italy, Farina, Palermo.Google Scholar
  31. Tafarojnoruz, A., R. Gaudio, and F. Calomino (2012), Evaluation of flow-altering countermeasures against bridge pier scour, J. Hydraul. Eng. 138,3, 297–305, DOI: 10.1061/ (ASCE)HY.1943-7900.0000512.CrossRefGoogle Scholar
  32. Tanaka, S., and M. Yano (1967), Local scour around a circular cylinder. In: Hydraulic Research: Proc. 12th IAHR Congress, Fort Collins, Colorado 3, IAHR, 193–201.Google Scholar
  33. Tregnaghi, M., A. Marion, and S. Coleman (2009), Scouring at bed sills as a response to flash floods, J. Hydraul. Eng. 135,6, 466–475, DOI: 10.1061/(ASCE)HY.1943-7900.0000033.CrossRefGoogle Scholar
  34. Unger, J., and W.H. Hager (2006), Riprap failure at circular bridge piers, J. Hydraul. Eng. 132,4, 354–362, DOI: 10.1061/(ASCE)0733-9429(2006)132:4(354).CrossRefGoogle Scholar
  35. Zarrati, A.R., H. Gholami, and M.B. Mashahir (2004), Application of collar to control scouring around rectangular bridge piers, J. Hydraul. Res. 42,1, 97–103, DOI: 10.1080/00221686.2004.9641188.CrossRefGoogle Scholar
  36. 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, J. Hydraul. Eng. 132,2, 154–162, DOI: 10.1061/(ASCE)0733-9429(2006)132:2(154).CrossRefGoogle Scholar
  37. Zarrati, A.R., M.R. Chamani, A. Shafaie, and M. Latifi (2010), Scour countermeasures for cylindrical piers using riprap and combination of collar and riprap, Int. J. Sediment Res. 25, 313–321, DOI: 10.1016/S1001-6279(10)60048-0.CrossRefGoogle Scholar

Copyright information

© Versita Warsaw and Springer-Verlag Wien 2012

Authors and Affiliations

  • Ali Tafarojnoruz
    • 1
  • Roberto Gaudio
    • 1
  • Francesco Calomino
    • 1
  1. 1.Dipartimento di Difesa del Suolo “V. Marone”Università della CalabriaRende (CS)Italy

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