Bridge pier scour mitigation under steady and unsteady flow conditions

• Autorzy: Tafarojnoruz A. , Gaudio R. , Calomino F.
• Języki publikacji: EN

Abstrakty

EN

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.

Słowa kluczowe

EN

bridge pier; scour; bed-sill; countermeasure; collar; unstedy flow

• Wydawca: Instytut Geofizyki PAN ; Springer
• Czasopismo: Acta Geophysica
• Rocznik: 2012
• Tom: Vol. 60, no. 4
• Strony: 1076--1097
• Opis fizyczny: Bibliogr. 37 poz.

Twórcy

autor

Tafarojnoruz A.

autor

Gaudio R.

autor

Calomino F.

• Dipartimento di Difesa del Suolo "V. Marone", Universita’ della Calabria, Rende (CS), Italy,

Bibliografia

• 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).
• 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).
• 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).
• 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).
• 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).
• 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).
• 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.
• Chiew, Y.M., and B.W. Melville (1987), Local scour around bridge piers, J. Hydraul. Res. 25, 1, 15-26, DOI: 10.1080/00221688709499285.
• Ettema, R. (1980), Scour at Bridge Piers. Rep. No. 216, School of Engineering, University of Auckland, Auckland, New Zealand.
• Garde, R.J. (1970), Initiation of motion on a hydrodynamically rough surface. Critical velocity approach, Irrig. Power, 27, 3, 271-282.
• 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.
• 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.
• Goncharov, V.N. (1964), Dynamics of Channel Flow, Israel Programme for Scientific Translation, Moscow, 185.
• 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).
• 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.
• Hamill, L. (1999), Bridge Hydraulics, E and FN Spon., Routledge, London.
• 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.
• 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).
• 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.
• 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.
• 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.
• 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.
• Mashahir, M.B., A.R. Zarrati, and E. Mokallaf (2010), Application of riprap and Colmar to prevent scouring around rectangular bridge piers, J. Hydraul. Eng. 136, 3, 183-187, DOI: 10.1061/(ASCE)HY.1943-7900.0000145.
• 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).
• Melville, B.W., and S.E. Coleman (2000), Bridge Scour, Water Resources Publications, Littleton, CO.
• 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.
• 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).
• 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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).
• 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.
• 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).
• 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.