TY - CHAP A1 - Auel, C. T1 - Entlandung des Stausees Solis mit Hilfe eines Geschiebeumleitstollens – hydraulische Modellversuche T2 - Proc. 11. JuWi-Treffen, Communication No. 40, Laboratoire de Constructions Hydrauliques (LCH) N2 - Das Reservoir der Talsperre Solis in Graubünden wurde 1986 vom Elektrizitätswerk der Stadt Zürich (ewz) in Betrieb genommen. Bei Hochwasserereignissen werden grosse Sedimentmengen in den Stausee transportiert. Über 25 % des ursprünglichen Reservoirvolumens sind bereits verlandet. Aus diesem Grund plant ewz den Bau eines Geschiebeumleitstollens, der das bei Hochwasser ankommende Sediment um die Talsperre herum in Richtung Unterwasser leitet. Die Versuchsanstalt für Wasserbau, Hydrologie und Glaziologie (VAW) der ETH Zürich untersucht und optimiert in einem hydraulischen Modell den projektierten Umleitstollen. Bei Hochwasser wird der Stausee auf den minimalen Betriebswasserspiegel abgesenkt, der Verlandungskörper liegt grösstenteils frei, das Sediment erodiert. Mit Hilfe einer Leitkonstruktion wird die Strömung in Richtung Einlaufbauwerk des Stollens gelenkt und der Abfluss sowie das Geschiebe durch diesen geleitet. Bei Abflüssen, die die Ausbaukapazität des Stollens (HQ5) überschreiten, wird die überschüssige Strömung in den vorderen Bereich des Sees in Richtung Grundablass abgeführt. Das Geschiebe wird dennoch nahezu vollständig in den Stollen eingeleitet. Bei Hochwasser mit Schwemmholzaufkommen wird mit Hilfe einer Tauchwand sowie einer Teilablleitung des Hochwasserabflusses in den vorderen Seebereich verhindert, dass Schwemmholz in den Umleitstollen eingezogen wird. Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-151685 SP - 159 EP - 166 CY - Switzerland ER - TY - CHAP A1 - Auel, C. A1 - Berchtold, T. A1 - Boes, R.M. T1 - Sediment management in the Solis reservoir using a bypass tunnel T2 - 8th ICOLD European Club Symposium N2 - The Solis reservoir is located in the Alps in Grisons, Switzerland and is operated by the electric power company of Zurich (ewz). Since its construction in 1986, high sediment input during flood events has led to major aggradations in the reservoir. Up to date, nearly half of the original reservoir volume has been filled with sediments from upstream mountain torrents. The deltaic deposition starts extending into the active water volume. Therefore, ewz plans a sediment bypass tunnel to flush the incoming bedload around the dam to the downstream reach. In a first step the reservoir level during flood events is lowered to the minimum operation level. The delta is subjected to free surface flow and the bedload is transported over the delta and deposited further downstream. This sediment relocation decreases the delta volume within the active storage. During further flood events, the incoming sediment is led to the bypass tunnel intake using a guiding structure and flushed through the tunnel. If the flood exceeds the capacity of the bypass tunnel, the surplus flow passes the tunnel intake towards the bottom outlets with the bedload still being flushed through the tunnel. A skimming wall located upstream from the tunnel intake prevents driftwood blocking by leading it to the reservoir front where it can be safely removed. Both the sediment relocation due to water level drawdown and the flushing through the bypass tunnel are investigated and optimized in a hydraulic model at the Laboratory of Hydraulics, Hydrology and Glaciology (VAW) of ETH Zurich. Additionally, the sediment relocation process in the model is compared with a relocation test in the prototype. Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-151647 SP - 438 EP - 443 CY - Innsbruck, Austria ER - TY - JOUR A1 - Auel, C. A1 - Berchthold, T. A1 - Boes, R. T1 - Entlandung des Stausees Solis mittels Geschiebeumleitstollen JF - Wasserwirtschaft Y1 - 2010 SP - 117 EP - 119 ER - TY - JOUR A1 - Auel, C. A1 - Boes, R. A1 - Ziegler, T. A1 - Oertli, C. T1 - Design and construction of the sediment bypass tunnel at Solis JF - Int. Journal on Hydropower and Dams Y1 - 2011 SP - 62 EP - 66 ER - TY - CHAP A1 - Auel, C. A1 - Boes, R.M. T1 - Sediment bypass tunnel design – review and outlook T2 - Proc. ICOLD Symposium - Dams under changing challenges (Schleiss & Boes, eds.), 79th Annual Meeting of ICOLD, Lucerne, Switzerland N2 - Reservoir sedimentation is increasingly affecting the majority of reservoirs all over the world. As many dams are more than 50 years of age, this problem is becoming more and more seriou403s nowadays. Reservoir sedimentation leads to various severe problems such as a decisive decrease of the active reservoir volume leading to both loss of energy production and water available for water supply and irrigation. These problems will intensify in the very next future, because sediment supply tends to increase due to climate change. Therefore coun-termeasures have to be developed. They can be divided into the three main categories sediment yield reduction, sediment routing and sediment removal. This paper focuses on sediment routing by means of sediment bypass tunnels. Sediment bypass tunnels are an effective measure to stop or at least decrease the reservoir sedimentation process. By routing the sediments around the reservoir into the tailwater in case of flood events sediment accumulation of both bed load and suspended load is reduced significantly. However, the number of sediment bypass tunnels in the world is limited primarily due to high investment and above all maintenance costs. The state-of-the-art design criteria of constructing bypass tunnels are summarized herein; major problems such as tunnel invert abrasion are discussed. The need for further research regarding sediment transport in bypass tunnels and invert abrasion is highlighted. Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-151631 SN - 978-0-415-68267-1 SP - 403 EP - 412 PB - Taylor and Francis CY - London, UK ER - TY - CHAP A1 - Auel, C. A1 - Boes, R.M. T1 - Sediment bypass tunnel design - hydraulic model tests T2 - Proc. Hydro 2011 - Practical solutions for a sustainable future N2 - Reservoir sedimentation, a serious problem affecting the majority of reservoirs worldwide, was not systematically accounted for in the past. After 50 years of operation, a constantly decreasing reservoir volume becomes currently a serious challenge for reservoir owners, against which countermeasures have to be developed. This research focuses on sediment routing using a bypass tunnel to convey sediments past a dam. By transporting sediments into the tailwater past a dam, their accumulation in the reservoir is reduced significantly. However, the global number of sediment bypass tunnels is limited primarily due to high investment and maintenance cost. The main problem of all bypass tunnels is the massive invert abrasion due to high flow velocities combined with high sediment transport rates. Therefore, VAW started two research projects to counter this problem. The main goal of the first project Layout and design of sediment bypass tunnels is to investigate the invert abrasion process by conducting hydraulic laboratory tests and to establish general design criteria for optimal flow conditions in which both sediment depositions in the tunnel are avoided and the resulting abrasion damages are kept at a minimum. The second project Optimizing hydroabrasive-resistant materials at sediment bypass tunnels and hydraulic structures investigates the hydraulic resistance of different tunnel invert materials, such as high performance concrete or cast basalt plates in prototype tests at the Solis bypass tunnel. The sediment transport measurement technique used in this project was optimized during preliminary model tests. Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-151625 PB - Aqua-Media International Ltd CY - Prague, Czech Republic ER - TY - JOUR A1 - Auel, C. A1 - Albayrak, I. A1 - Boes, R.M. T1 - Hydraulische Modellierung der Hydroabrasion JF - VAW Mitteilungen N2 - Hydroabrasion tritt im alpinen Raum hauptsächlich bei Wasserbauwerken auf, die durch hohe Fließgeschwindigkeiten und große Sedimentfrachten belastet werden. Dies sind beispielswei-se Wehrschwellen in Flüssen, Wasserfassungen von Wasserkraftwerken und vor allem Sedi-mentumleitstollen. Letztere dienen dazu sedimentreiche Hochwasserspitzen um die Talsperre herum in den Unterlauf des Flusses zu leiten. Sie verhindern so eine fortschreitende Verlan-dung des Stauraums. Es gibt verschiedene Konzepte, dem Problem der Hydroabrasion entgegen zu wirken. Einer-seits kann der Umleitstollen hydraulisch optimiert werden, um die Einwirkung auf die Sohle zu minimieren. Auf der anderen Seite kann deren Widerstand verbessert werden. An der Ver-suchsanstalt für Wasserbau, Hydrologie und Glaziologie (VAW) der ETH Zürich werden zur Zeit zwei Forschungsarbeiten durchgeführt, die sich jeweils diesen Aspekten widmen. Dieser Beitrag befasst sich mit der hydraulischen Optimierung von Sedimentumleitstollen mit Hilfe von großskaligen Laborversuchen. In insgesamt drei Versuchsreihen werden die Mittelwert- und Turbulenz-Fließcharakteristik von schießendem Abfluss in einer Versuchsrinne mittels eines Laser-Doppler Anemometrie-Systems (LDA) aufgenommen, die Fortbewegungsart des Sediments mittels eines High-Speed Kamera-Systems analysiert sowie die Abrasion der Stollensohle untersucht. In Abhängigkeit des Sohlgefälles, des Durchflusses, der Größe und Menge der Sedimentfracht erfolgt die Fortbewegung des Sedimentkorns hüpfend, rollend oder gleitend und verursacht unterschied-liche Abrasionserscheinungen in der Stollensohle. Die Ergebnisse der LDA Experimente zei-gen, dass, abhängig vom Verhältnis Gerinnebreite zur Abflusstiefe, Sekundärströmungen auf-treten. Diese Sekundärströmungen beeinflussen im untersuchten Froude-Zahlenbereich 2, 4 und 8 das longitudinale Strömungsprofil sowie die Verteilung der Sohlen- bzw. Reynolds-Schubspannungen und der Turbulenzintensität und somit letztlich die Fortbewegungsart des Sedimentkorns in der Wassersäule. Mittels der drei Versuchsreihen sollen bestmögliche hydraulische Bedingungen für Sedimen-tumleitstollen gefunden werden, um die Hydroabrasion und somit die Unterhaltskosten signi-fikant zu minimieren. Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-151717 PB - ETH Zurich ER - TY - CHAP A1 - Auel, C. A1 - Boes, R.M. T1 - Sustainable reservoir management using sediment bypass tunnels T2 - Proc. 24th ICOLD Congress, Q92 R16, Kyoto, Japan N2 - Reservoir sedimentation is an increasing problem affecting the majority of reservoirs both in Switzerland and worldwide. As many dams are more than 50 years of age, this problem is becoming more and more serious nowadays. Res-ervoir sedimentation leads to various severe problems such as a decisive de-crease of the active reservoir volume leading to both loss of energy production and water available for water supply and irrigation. These problems will intensify in the near future, because sediment supply tends to increase due to climate change. Therefore, countermeasures have to be developed. They can be divided into the three main categories sediment yield reduction, sediment routing and sediment removal. This paper focuses on the sediment routing using sediment bypass tunnels. Sediment bypass tunnels are an effective means to decrease the reservoir sedimentation process. By routing the sediments around the reservoir into the tailwater, sediment accumulation is reduced significantly. However, the number of sediment bypass tunnels in the world is limited primarily due to high investment and maintenance costs. The main problem of all bypass tunnels is the invert abrasion due to high velocities in combination with high sediment transport. Three Swiss bypass tunnel examples suffering invert abrasion are presented in this paper. Furthermore, VAW started a research project to investigate the invert abrasion process by conducting hydraulic scale tests in the laboratory. The goal of this research project is to establish general design criteria for optimal flow con-ditions where both sediment depositions in the tunnel are avoided and the result-ing abrasion damages are kept at a minimum. Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-151605 SP - 224 EP - 241 PB - ICOLD ER - TY - CHAP A1 - Hagemann, M. A1 - Auel, C. A1 - Albayrak, I. A1 - Boes, R.M. T1 - Hydroabrasion in Sedimentumleitstollen T2 - Proc. 35. Dresdner Wasserbaukolloquium. "Staubauwerke - Planen, Bauen, Betreiben", Wasserbauliche Mitteilungen Heft 47 N2 - Sedimentumleitstollen leiten die sedimentreichen Hochwasserspitzen um die Tal-sperre herum in den Unterlauf des Flusses und verhindern so eine fortschreitende Verlandung des Stauraums. Aufgrund der hohen Fließgeschwindigkeiten und gro-ßen Sedimentfrachten in Umleitstollen weisen diese starke Verschleißerscheinun-gen auf, die zu hohen Unterhaltskosten führen. Es gibt verschiedene Konzepte um diesem Problem entgegen zu wirken. Einerseits kann der Umleitstollen hydrau-lisch optimiert werden, um die Belastung auf die Sohle zu minimieren. Auf der anderen Seite kann der Widerstand der Stollensohle verbessert werden. An der Versuchsanstalt für Wasserbau, Hydrologie und Glaziologie (VAW) der ETH Zü-rich werden zur Zeit zwei Forschungsarbeiten durchgeführt, die sich diesen zwei Aspekten widmen. In großskaligen Laborversuchen erfolgt eine systematische Untersuchung und Optimierung der maßgebenden Parameter wie Fortbewegungs-art des Sediments und Abrasionstiefe der Stollensohle. Anhand von Prototypver-suchen im neu errichteten Sedimentumleitstollen Solis in Graubünden (Schweiz) werden die Zusammenhänge zwischen Beanspruchung, Materialeigenschaften und Abrasion im Prototyp ermittelt. Darauf basierend können Empfehlungen be-züglich Materialwahl, konstruktiver Durchbildung und Dimensionierung abgege-ben und so zu einer nachhaltigen und wirtschaftlichen Wasserbewirtschaftung in Stauseen beigetragen werden. Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-151612 SP - 95 EP - 104 ER - TY - CHAP A1 - Albayrak, I. A1 - Auel, C. A1 - Boes, R.M. T1 - Supercritical flow in sediment bypass tunnels T2 - Proc. 12th Int. Symp. on River Sedimentation. Advances in River Sediment Research N2 - This paper deals with an experimental investigation of the mean and turbulence characteristics of supercritical quasi-uniform and gradually varied open-channel flows over a transitional rough bed. These conditions are typical for sediment bypass tunnels. The results show that the log-law holds well in the inner region across the channel. The roughness shifts the velocity profiles downward by an amount of ΔU+. The velocity-dip phenomenon and strong secondary currents exist in the channel for narrow open-channel flow. These currents cause the Reynolds shear stress distributions to deviate from the linear distribution and an undulation on the transversal distribution of the bed shear stress, which matches with the bed abrasion pattern. The streamwise turbulence intensity profiles deviate from the semi-empirical universal function whereas the vertical turbulence intensity profiles fit well with it only at the centerline of the channel. A strong wall effect exists on the turbulence intensities in the outer region. Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-151597 SN - 978-1-138-00062-9 SP - 1867 EP - 1875 PB - Taylor and Francis CY - London, UK ER -