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Experimental and Numerical Investigation of the Bed Erosion around Bridge Piers with Different Cross-Sections | ||
| تحقیقات مهندسی سازه های آبیاری و زهکشی | ||
| Article 3, Volume 19, Issue 71, August 2018, Pages 19-36 PDF (1.64 M) | ||
| Document Type: Original Article | ||
| DOI: 10.22092/aridse.2017.109453.1189 | ||
| Abstract | ||
| In present study, the effect of different cross-sections of bridge piers on reducing the bed erosion and the bed shear stress was experimentally and numerically evaluated. In experimental study, the bed erosion and the percentage of its resuction was calculated;also numerically, the flow around pier models was simulated three dimensionally, and the effect of each cross-section on reduction of bed shear stress was investigated. To determine the efficiency of suggested models, the circular model was selected as the reference model and the decreasing of maximum shear stresses in each model was compared with the decreased scour depth. Comparison of the velocity and water free surface profiles was conducted for verification of turbulence models and results showed that with model, more accuracy can be obtained. Among the presented models, the A2 model with decreasing scouring depth of 72 percent as copared to the refference model, was found to be best and most effective model. Also the B2 model lead to 8 percent reduction in scouring depth and can be suggested as a model that has the least effect on scouring. The D model causes the scouring depth increase by 7 percent relative to the reference model. Comparison of the numerical and experimental results was another objective of this study due to the complexities of experimental researches. The results showed that there are direct relationship between the bed shear stress and the equilibrium scour depths. | ||
| Keywords | ||
| Bridge Pier; Numerical Modelling; Scouring; Shear Stress; Turbulence Model | ||
| References | ||
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Ariyanfar, A., Shafaei-Bejestan, M. and Khosrojerdi, A. 2008. Investigation of shear stress distribution around slotted bridge piers by using Fluent. Proceeding of 7th Hydraulic Conference, Power & Water. 12-14 Nov. University of Technology (PWUT). Tehran, Iran. (in Persian)
Baraniya, S., Olsen, N. R. B., Stoesser, T. and Sturm, T. 2012. Three-dimensional RANS modeling of flow around circular piers using nested grids. Eng. Appl. Comput. Fluid Mech. 6, 648-662.
Breusers, H. N. C. and Raudkivi, A. J. 1991. Scouring-hydraulic structures design manual. IAHR, Rotterdam, Netherland.
Dargahi, B. 1990. Controlling mechanism of local scouring. J. Hydraul. Eng. ASCE. 116(10): 1197-1214.
Dey, S., Bose, S. K. and Sastry, G. L. N. 1995. Clear-water scour at circular piers: a model. J. Hydraul. Eng. ASCE. 121(12): 869-876.
Drysdale, D. M. 2008. The effectiveness of an aerofoil shaped pier in reducing downstream vortices and Turbulence. Ph. D. Thesis. University of Southern Queensland.
Ettema, R. 1980. Scour at bridge piers. Ph. D. Thesis. Auckland University, Auckland, New Zealand.
Frohlich, J. and Rodi, W. 2004. LES of the flow around a circular of finite height. Int. J. Heat Fluid Flow. 25, 537-548.
Grimaldi, C., Gaudio, R., Calomino, F. and Cardoso, A. H. 2009. Countermeasures against local scouring at bridge piers: slot and combined system of slot bed sill. J. Hydraul. Eng. ASCE.135(5): 425-431.
Hassanzadeh, Y., Hakimzadeh, H. and Ayari, S. 2012. Study the effects of bridge pier shape on the flow pattern using the Fluent software. Iran-Water Resour. Res. 7(4): 95-105 (in Persian)
Hassanzadeh, Y., Kardan, N. and Hakimzadeh, H. 2015. 3D numerical studying into combined models of pier shape and slot in reducing the bed shear stresses starter of scouring around the bridge pier. J. Civil Environ. Eng. 44(4): 39-50 (in Persian)
Kappler, M. 2002. Experimentelle untersuchung der umstromung von kreiszylinder mit ausgepragt dreidimensionalen effekten. Ph. D. Thesis. Institute for Hydromechanics, University of Karlsruhe. (in Germany)
Kardan, N., Hakimzadeh, H. and Hassanzadeh. Y. 2015. 3D numerical simulation of hydrodynamic parameters around the bridge piers using various turbulence models. J. Irrig. Sci. Eng. 37(4): 39-54. (in Persian)
Kumar, V., Rang-Raju, K. G. and Vittal, N. 1999. Reduction of local scour around bridge piers using slot and collars. J. Hydraul. Eng. ASCE. 125(12): 1302-1305.
Laursen, E. M. and Toch, A. 1956. Scour around bridge piers and abutments. Iowa Highway Research Board Bulletin, No. 4, Bureau of Public Roads, Iowa.
Melville, B. W. 1975. Local scour at bridge sites. Ph. D. Thesis. Department of Civil Engineering, University Auckland. Report No. 117.
Melville, B. W. and Sutherland, A. J. 1988. Design method for local scour at bridge piers. J. Hydraul. Eng. ASCE. 114(9): 1210-1226.
Melville, B. W. and Coleman, S. E. 2000. Bridge Scour. Water Resources Publication LLC, Highlands Ranch, Colorado, U.S.A.
Raudkivi, A. J. 1998. Loose Boundary Hydraulics. 3rd Ed. Rotterdam, Brookfield.
Raudkivi, A. J. and Ettema, R. 1983. Clear water scour at cylindrical piers. J. Hydraul. Eng. ASCE.
Rodi, W. 1997. Comparison of LES and RANS calculation of the flow around bluff bodies. J. Wind Eng. Ind. Aerod. 69(71): 55-75.
Roshangar, K. and Rouhparvar, B. 2012. Evaluation of artificial intelligence systems for simulation of bridge piers scouring in cohesive soils. Water Soil Sci. 23(3): 169-181. (in Persian)
Roulund, A., Sumer, B. M., Fredsoe, J. and Michelsen, J. 2005. Numerical and experimental investigation of flow and scour around a circular pile. J. Fluid Mech. 534, 351-401.
Salaheldin, T. M., Imran, J. and Chaudhry, H. 2004. Numerical modeling of three-dimensional flow field around circular piers. J. Hydraul. Eng. ASCE. 130(2): 91-99.
Schlichting, H. and Gersten, K. 2000. Boundary Layer Theory. 8th Revised and Enlarged Edition. Springer, Berlin.
Shen, H. W., Schneider, V. R. and Karaki, S. S. 1969. Local scour around bridge piers. J. Hydraul. Div. 95(6): 1991-1940.
Tseng, M. H., Yen, C. L. and Song, C. S. 2000. Computational three-dimensional flow around square and circular piers. Int. J. Numer. Meth. Fluids. 34, 207-227. | ||
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