TY - CHAP A1 - Oertli, C. A1 - Auel, C. T1 - Solis sediment bypass tunnel: First operation experiences T2 - Proc. 1st Int. Workshop on Sediment Bypass Tunnels, VAW Mitteilungen N2 - The Solis dam was built in 1986 by the Electric Power Company of Zurich (ewz). Ever since the construction, large amounts of sediments accumulated in the reservoir and led to severe sediment aggradation. As a consequence, the storage volume was reduced by about 50% till 2012 causing loss of energy production. Additionally, in the near future sediments may have caused severe damage at the dam due to blockage of the bottom outlets. Therefore, in 2011 and 2012 a sediment bypass tunnel was realized in order to redirect the incoming sediments into the tailwater to inhibit sediment aggradation. Since its inauguration, the tunnel was operated four times including a 100-year flood event in August 2014. First operational experiences are described herein. Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-151539 SP - 223 EP - 233 PB - ETH Zurich ER - TY - CHAP A1 - Müller-Hagemann, M. A1 - Auel, C. A1 - Albaryak, I. A1 - Boes, R.M. T1 - Bedload transport and hydro-abrasive erosion at steep bedrock rivers and hydraulic structures T2 - Riverflow, Lyon, France Y1 - 2018 ER - TY - JOUR A1 - Müller-Hagemann, M. A1 - Albayrak, I A1 - Auel, C A1 - Boes, RM T1 - Field Investigation on Hydroabrasion in High-Speed Sediment-Laden Flows at Sediment Bypass Tunnels JF - Water 12 (2) N2 - Wear due to sediment particles in fluid flows, also termed hydroabrasion’ or simply ‘abrasion’, is an omnipresent issue at hydraulic structures as well as in bedrock rivers. However, interactions between flow field, particle motion, channel topography, material properties and abrasion have rarely been investigated on a prototype scale, leaving many open questions as to their quantitative interrelations. Therefore, we investigated hydroabrasion in a multi‐year field study at two Swiss Sediment Bypass Tunnels (SBTs). Abrasion depths of various invert materials, hydraulics and sediment transport conditions were determined and used to compute the abrasion coefficients kv of different abrasion models for high‐strength concrete and granite. The results reveal that these models are useful to estimate spatially averaged abrasion rates. The kv‐value is about one order of magnitude higher for granite than for high‐strength concrete, hence, using material‐specific abrasion coefficients enhances the prediction accuracy. Three‐dimensional flow structures, i.e., secondary currents occurring both, in the straight and curved sections of the tunnels cause incision channels, while also longitudinally undulating abrasion patterns were observed. Furthermore, hydroabrasion concentrated along joints and protruding edges. The maximum abrasion depths were roughly twice the mean abrasion depths, irrespective of hydraulics, sediment transport conditions and invert material. Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-151268 PB - MDPI CY - Basel ER - TY - CHAP A1 - Koshiba, T. A1 - Sumi, T. A1 - Tsutsumi, D. A1 - Kantoush, S.A. A1 - Auel, C. T1 - Development of a bedload transport meas-uring system in sediment bypass tunnels T2 - 84th Annual Meeting of ICOLD, Johannesburg, South Africa 4-49−4-58 N2 - Sediment Bypass Tunnels are operated to divert sediment around reservoirs reducing reservoir sedimentation. A major drawback of these tunnels is severe invert abrasion due to high velocity and sediment flows. There is an urgent need to establish innovative measurement systems of sediment transport rates in SBTs. In this paper, three bedload measuring systems, namely hydrophones, geophones, and newly developed plate microphones are introduced and compared. The Koshibu SBT is planned to operate from 2016. Plate microphones combined with geophones and other planned systems are installed in the tunnel. Results of preliminary tests and installation plans of bedload measurement are presented. Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-151506 SN - 978-0-620-71042-8 PB - ICOLD ER - TY - CHAP A1 - Koshiba, T. A1 - Auel, C. A1 - Tsutsumi, D. A1 - Kantoush, S.A. A1 - Sumi, T. T1 - Improvement of a bedload transport rate measuring systems in sediment bypass tunnels T2 - River Sedimentation: Proc. 13th Int. Symposium on River Sedimentation N2 - For long term use of dams, it is required to develop methods of sediment management in reservoirs. As one method, Sediment BypassTunnels (SBT) are operated in Japan and Switzerland to prevent reservoir sedimentation. SBT reduces sedimentation in reservoirs by routing the incoming sediments around the dam. SBT, however, is prone to severe invert abrasion caused by high sediment flux. Therefore, it is necessary to establish a measurement system of sediment transport rates in the SBT. A geophone was experimentally investigated in a laboratory flume at ETH Zurich. The sediment transport rate is calculated based on the plate vibration caused by hitting of gravels. In this paper, in order to alleviate disadvantages of a geophone, two newly developed sensor systems, a plate microphone and plate vibration sensor, are suggested and the results of their calibration experiments are shown. Finally, they are compared with the existing methods. Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-151462 SN - 978-1-138-02945-3 SP - 1038 EP - 1045 PB - CRC Press CY - Stuttgart, Germany ER - TY - JOUR A1 - Koshiba, T. A1 - Auel, C. A1 - Tsutsumi, D. A1 - Kantoush, S.A. A1 - Sumi, T. T1 - Application of an impact plate - bedload transport measuring system for high-speed flows JF - International Journal of Sediment Research N2 - To achieve the sustainable use of dams, the development of methods for sediment management in reservoirs is required. One such method includes the use of Sediment Bypass Tunnels (SBTs) to divert sediment around a dam, thereby preventing sedimentation in the reservoir. However, SBTs are prone to severe invert abrasion caused by the high sediment flux. Therefore, it is necessary to establish a measurement system of the sediment transport rate in these tunnels. One system to measure sediment transport in rivers is the Swiss plate geophone, which can register plate vibrations caused by particle impact. In Japan, the Japanese pipe microphone is used, and sediment transport is measured based on the sound emitted by the particle impact. In this study an attempt was made to optimize the advantages of both systems by fixing a microphone and an acceleration sensor to a steel plate. The results of calibration experiments with this new system are presented and compared with the existing methods. It was found that the acceleration sensor can detect sediment particles larger than 2 mm in diameter. Moreover, a new parameter, referred to as the detection rate, was introduced to describe the correlation between the actual amount of sediment and the registered output. Finally, two parameters - the saturation rate and hit rate - are introduced and exhibit strong correlation with the detection rate. Y1 - 2018 U6 - http://dx.doi.org/10.1016/j.ijsrc.2017.12.003 SP - 35 EP - 46 ER - TY - CHAP A1 - Kobayashi, S. A1 - Auel, C. A1 - Sumi, T. A1 - Takemon, Y. T1 - Effects of sediment supply by bypass tunnels on bed to-pography, grain size, and invertebrate habitat T2 - Proc. 20th IAHR APD Congress, Colombo, Sri Lanka, 5B008 N2 - To understand the effects of sediment bypass on environmental recovery of the degraded channels below dams, bed topography and bed materials above and below dam reaches were surveyed by ground-based measurements and aerial photos using quadrocopter. Coarse bed materials such as boulders were more represented below than above the Koshibu dam, where the bypass tunnel had not been in operation yet. The coarse materials formed steps and protruded in the water column within riffles and runs, both of which can increase slow-flow areas, below the dam. On the other hand, sand, gravel, and cobbles were abundant below as much as above the Asahi dam, where the bypass tunnel had been operated for >17 years. The downstream environment in terms of bed topography and grain size seems to have almost been recovered for the Asahi dam. However, less representation of large cobbles and boulders below the dam suggested a possibility of a selective deposition of coarse materials at the upstream of the bypass tunnel inlet. Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-151473 PB - IAHR ER - TY - CHAP A1 - Kobayashi, S. A1 - Auel, C. A1 - Sumi, T. A1 - Takemon, Y. T1 - Recovery of riverbed features and invertebrate community in degraded channels by sediment supply through bypass tunnel T2 - Proc. 12th Int. Conference on Hydroscience and Engineering, Tainan, Taiwan N2 - Sediment, which deposits and damages the function of reservoirs, is an essential element of aquatic habitats in downstream ecosystems. We reviewed ecosystem features of degraded channels associated with sediment deficiency below dams and ecosystem responses to changes in sediment conditions after management practices in Japan. Sediment bypass tunnel (SBT) is an effective way to transport sufficient amount of sediment to downstream ecosystems. Based on a concept of suitable mass and size of sediment for ecosystem, some effects and limitations of SBT on downstream ecosystems were discussed. Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-151447 PB - ICHE 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 - JOUR A1 - Hagemann, M. A1 - Albayrak, I. A1 - Boes, R.M. A1 - Auel, C. A1 - Sumi, T. T1 - Reviewing research and experience on sediment bypass tunnels JF - Int. Journal on Hydropower and Dams Y1 - 2016 SP - 54 EP - 58 ER -