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A theoretical analysis of the fluid–solid interactions governing the removal of woody debris jams from cylindrical bridge piers

Published online by Cambridge University Press:  14 January 2020

Diego Panici*
Affiliation:
Faculty of Engineering and Physical Sciences, University of Southampton, University Road, SouthamptonSO17 1BJ, UK College of Engineering, Mathematics and Physical Sciences, University of Exeter, North Park Road, ExeterEX4 4QF, UK
Gustavo A. M. de Almeida
Affiliation:
Faculty of Engineering and Physical Sciences, University of Southampton, University Road, SouthamptonSO17 1BJ, UK
*
Email address for correspondence: D.Panici@soton.ac.uk

Abstract

This paper proposes a theoretical model to describe previous laboratory observations of the dynamics of debris accumulations around bridge piers of cylindrical shape. The model is based on the assumption that the observed dynamics is mainly governed by dynamic changes of the point of application of the drag force exerted on a solid body formed by debris accumulated around a pier. A phase-plane analysis of the resulting nonlinear system of ordinary differential equations shows that the model captures the main patterns observed in previous laboratory experiments, including an oscillatory motion and the removal of debris from the pier by the flow. The model provides a theoretical basis for the analysis of the conditions required for debris jams to remain stable over long periods of exposure to impinging flow. Namely, the model indicates that the stability of debris accumulations primarily depends on geometrical asymmetry and on the length of the extension downstream of the pier. The former induces the torque required to rotate the jam about the pier, while the latter produces a stabilising effect after the body rotates.

Type
JFM Papers
Copyright
© The Author(s), 2020. Published by Cambridge University Press

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References

Abbe, T. B. & Montgomery, D. 1996 Large woody debris jams, channel hydraulics and habitat formation in large rivers. Regulated Rivers 12, 201221.3.0.CO;2-A>CrossRefGoogle Scholar
Bocchiola, D., Rulli, M. & Rosso, R. 2008 A flume experiment on the formation of wood jams in rivers. Water Resour. Res. 44, W02408.CrossRefGoogle Scholar
Diehl, T. H.1997 Potential drift accumulation at bridges. Tech. Rep. FHWA-RD-97-028. Federal Highway Administration, U.S. Department of Transportation, Washington D.C., USA.Google Scholar
Ebrahimi, M., Kripakaran, P., Prodanovic, D., Kahraman, R., Riella, M., Tabor, G., Arthur, S. & Djordević, S. 2018 Experimental study on scour at a sharp-nose bridge pier with debris blockage. J. Hydraul. Eng. 144, doi:10.1061/(ASCE)HY.1943-7900.0001516.CrossRefGoogle Scholar
Gschnitzer, T., Gems, B., Mazzorana, B. & Aufleger, M. 2017 Towards a robust assessment of bridge clogging processes in flood risk management. Geomorphology 279, 128140.CrossRefGoogle Scholar
Lagasse, P., Colopper, P., Zevenbergen, L., Spitz, W. & Girard, L.2010 Effects of debris on bridge pier scour. National Cooperative Highway Research Program, Transportation Research Board, Washington D.C., USA.Google Scholar
Manners, R. B. & Doyle, M. W. 2008 A mechanistic model of woody debris jam evolution and its application to wood-based restoration and management. River Res. Applic. 24, 11041123.CrossRefGoogle Scholar
Manners, R. B., Doyle, M. W. & Small, M. J. 2007 Structure and hydraulics of natural woody debris jams. Water Resour. Res. 43, W06432.CrossRefGoogle Scholar
Melville, B. W. & Dongol, D. 1992 Bridge pier scour with debris accumulation. J. Hydraul. Engng 118, 13061310.CrossRefGoogle Scholar
Pagliara, S. & Carnacina, I. 2011 Influence of wood debris accumulation on bridge pier scour. J. Hydraul. Engng 137, 254261.CrossRefGoogle Scholar
Panici, D. & de Almeida, G. A. M. 2018 Formation, growth and failure of debris jams at bridge piers. Water Resour. Res. 54, doi:10.1029/2017WR022177.CrossRefGoogle Scholar
Schmocker, L. & Hager, W. 2013 Scale modeling of wooden debris accumulation at a debris rack. J. Hydraul. Engng 139, 827836.CrossRefGoogle Scholar