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ARS Home » Southeast Area » Oxford, Mississippi » National Sedimentation Laboratory » Watershed Physical Processes Research » Research » Publications at this Location » Publication #350119

Research Project: Computational Tools and a Decision Support System for Management of Sediment and Water Quality in Agricultural Watersheds

Location: Watershed Physical Processes Research

Title: Three-dimensional numerical simulations of local scouring around bridge piers

Author
item Jia, Yafei - University Of Mississippi
item Altinakar, Mustafa - University Of Mississippi
item Guney, M Sukru - Ondokuz Mayis University

Submitted to: Journal of Hydraulic Research IAHR
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/10/2017
Publication Date: 12/8/2017
Citation: Jia, Y., Altinakar, M., Guney, M. 2017. Three-dimensional numerical simulations of local scouring around bridge piers. Journal of Hydraulic Research IAHR. DOI: https://doi.org/10.1080/00221686.2017.1356389.

Interpretive Summary: Local scouring is a common threat to in-stream structures, such as bridge piers and abutments that are constructed in alluvial rivers, as it often results in bridge damage or failures. Numerical simulations have greatly improved the understanding of the physical mechanisms of scouring and have resulted in development of semi-empirical equations and numerical models for predicting the depth of local scouring under a variety of flow, sediment and pier conditions. This paper presents a novel numerical method for simulating local scouring around bridge piers using a three-dimensional free-surface turbulent flow model. Strong turbulent fluctuations and the flows around the bridge pier are considered important factors in scouring the bed. The turbulent kinetic energy transported to the bed due to the strong vertical flow is approximated and converted to a shear stress to transport sediment particles from the bed in addition to the conventional bed shear stress. The model is validated using experimental data with a fixed flat bed and a scour hole, and four sets of experimental data of clear water scour and live-bed scour cases. Steady and unsteady flow conditions and uniform and non-uniform sediment conditions are included. Agreement between the simulations and the measured data is demonstrated. The results showed the applicability and robustness of the method to estimate scour around bridge piers that is important in the design of these structures.

Technical Abstract: This paper presents a novel numerical method for simulating local scouring around bridge piers using a three-dimensional free-surface RANS turbulent flow model. Strong turbulent fluctuations and the down-flows around the bridge pier are considered important factors in scouring the bed. The turbulent kinetic energy transported to the bed due to the strong vertical flow is approximated and converted to a shear stress to entrain sediment particles from the bed in addition to the conventional bed shear stress. A non-equilibrium bed load transport approach is used to model the erosion and sediment transport processes. The hydrodynamic model is validated using experimental data with a fixed flat bed and a scour hole. The local scour model is validated using four sets of experimental data of clear water scour and live-bed scour cases. Steady and unsteady flow conditions and uniform and non-uniform sediment conditions are included. Agreement between the simulations and the measured data is demonstrated.