Stability of Unstructured Block Ramps
Publication: Journal of Hydraulic Engineering
Volume 143, Issue 4
Abstract
Unstructured block ramps are fish-friendly structures to stabilize a riverbed, characterized by large macroroughness elements randomly placed on the riverbed. Physical model tests were conducted to investigate their stability and their behavior in case of overload. Different parameters describing the block and the base material were tested to find an optimal combination in terms of ramp stability with a maximum ramp slope typically in the range of 1–3%. A model for the determination of the ramp stability is presented, where the equilibrium slope of the ramp is related to a dimensionless specific discharge including information on the block size, the block placement density, and a characteristic grain size of the base material.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The project was partly funded by the Swiss Federal Office for the Environment (FOEN). Dr. Gian Reto Bezzola is gratefully acknowledged for his valuable input.
References
Aberle, J., and Smart, G. (2003). “The influence of roughness structure on flow resistance on steep slopes.” J. Hydraul. Res., 41(3), 259–269.
Alp, M., Karpati, T., Werth, S., Gostner, W., Scheidegger, C., and Peter, A. (2011). “Erhaltung und Förderung der Biodiversität von Fliessgewässern [Preservation and valorization of the biodiversity in rivers].” Wasser Energie Luft, 103(3), 216–223 (in German).
Bezzola, G. R., and Hegg, C. (2008). “Ereignisanalyse Hochwasser 2005, Teil 2—Analyse von Prozessen, Massnahmen und Gefahrengrundlagen [Analysis of flood event 2005. Part 2: Analysis of processes, measures and fundamentals of risks].”, Bundesamt für Umwelt BAFU, Eidgenössische Forschungsanstalt WLS, Bern, Switzerland (in German).
DWA (Deutsche Vereinigung für Wasserwirtschaft, Abwasser und Abfall). (2009). “Naturnahe Sohlengleiten (Natural block ramps).”, Hennef, Germany (in German).
Hunziker, Zarn & Partner. (2008). “Blockrampen Normalien: Manual zur Sanierung von Abstürzen [Block ramp guidelines: Manual to improve drops].”, Aarau, Switzerland (in German).
Janisch, T. (2007). “Aufgelöste blockrampen im modellversuch—Untersuchungen an der VAW [Model tests on unstructured block ramps—Investigation at the VAW].”, Laboratory of Hydraulics, Hydrology and Glaciology (VAW), ETH Zürich, Zurich, Switzerland (in German).
Janisch, T., Weichert, R., and Bezzola, G. R. (2007). “Verhalten von aufgelösten unstrukturierten Blockrampen [Behavior of unstructured block ramps].” Wasser Energie Luft, 99(2), 146–152 (in German).
Lange, D. (2007). “Blockrampen—ökologische Bauwerke zur Sohlstabilisierung [Block ramps—Ecological structures to stabilize the riverbed].”, Laboratory of Hydraulics, Hydrology and Glaciology (VAW), ETH Zürich, Zurich, Switzerland (in German).
Little, W. C., and Mayer, P. G. (1972). “The role of sediment gradation on channel armoring.”, Environmental Resources Center, Georgia Institute of Technology, Atlanta.
LUBW (Landesanstalt für Umwelt, Messungen und Naturschutz Baden-Württemberg). (2006). “Durchgängigkeit für Tiere in Fliessgewässern 2: Umgehungsgewässer und fischpassierbare Querwerke [Passage for animals in rivers 2: Nature-like bypasses and fish passages].” Karlsruhe, Germany (in German).
Meyer-Peter, E., and Müller, R. (1948). “Formulas for bed-load transport.” Proc., 2nd Meeting of the Int. Association for Hydraulic Structures Research, IAHR, Delft, Netherlands, 39–64.
Pagliara, S., and Chiavaccini, P. (2006). “Flow resistance of rock chute with protruding boulders.” J. Hydraul. Eng., 545–552.
Raudkivi, A. J., and Ettema, R. (1982). “Stability of armour layers in rivers.” J. Hydraul. Div., 108(HY9), 1047–1057.
Recking, A., Frey, P., Paquier, A., Belleudy, P., and Champagne, J. Y. (2008). “Bed-load transport flume experiments on steep slopes.” J. Hydraul. Eng., 1302–1310.
Requena, P. (2008). “Seitenerosion in kiesführenden Flüssen—Prozessverständnis und quantitative Beschreibung [Side erosion in gravel rivers—Process understanding and quantitative description].” Ph.D. thesis, Laboratory of Hydraulics, Hydrology and Glaciology (VAW), ETH Zürich, Zurich, Switzerland (in German).
Rouse, H. (1965). “Critical analysis of open-channel resistance.” J. Hydraul. Div., 91(HY4), 1–25.
Smart, G. M., and Jäggi, M. (1983). “Sedimenttransport in steilen Gerinnen [Sediment transport on steep slopes].”, Laboratory of Hydraulics, Hydrology and Glaciology (VAW), ETH Zürich, Zurich, Switzerland (in German).
Tamagni, S. (2013). “Unstructured block ramps.” Ph.D. thesis, Laboratory of Hydraulics, Hydrology and Glaciology (VAW), ETH Zürich, Zurich, Switzerland.
Tamagni, S., Weitbrecht, V., and Boes, R. M. (2014). “Experimental study on the flow characteristics of unstructured block ramps.” J. Hydraul. Res., 52(5), 600–613.
Weichert, R. (2006). “Bed morphology and stability of steep open channels.”, ETH Zürich, Zurich, Switzerland.
Werth, S., et al. (2011). “Lebensraumverbund Fliessgewässer: Die Bedeutung der Vernetzung [Habitat interconnection in rivers: The importance of the connectivity].” Wasser Energie Luft, 103(3), 224–234 (in German).
Zeh Weissman, H., Könitzer, C., and Bertiller, A. (2009). “Strukturen der Fliessgewässer in der Schweiz. Zustand von Sohle, Ufer und Umland (Ökomorphologie); Ergebnisse der ökomorphologischen Kartierung; Stand: April 2009 [Structures in Swiss rivers. Situation of riverbed, bank and environs (ecomorphology); results of the ecomorphological mapping; status: April 2009].”, Swiss Federal Office for the Environment (FOEN), Bern, Switzerland (in German).
Information & Authors
Information
Published In
Copyright
©2016 American Society of Civil Engineers.
History
Received: Feb 1, 2016
Accepted: Aug 9, 2016
Published online: Oct 27, 2016
Discussion open until: Mar 27, 2017
Published in print: Apr 1, 2017
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.