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 - CHAP A1 - Auel, C. A1 - Thene, J.R. A1 - Carroll, J. A1 - Holmes, C. A1 - Boes, R.M. T1 - Rehabilitation of the Mud Mountain bypass tunnel invert T2 - VINGT SIXIÈME CONGRÈS DES GRANDS BARRAGES Vienne, Juillet 2018 N2 - This paper describes the design of the new tunnel invert lining of the 9-foot tunnel at Mud Mountain Dam, Washington, USA. The tunnel diverts all bed load sediments into the tailwater. Major invert abrasion has been observed in the existing steel lining. The new invert design consists of 0.59 m2 and 0.79 m2 granite blocks that are 0.25 m thick and placed tightly together along the tunnel. Stability analysis showed factors of safety ranging from 1.2 to 2.6 against uplift. This will be achieved with strip drains placed in the bedding material along the tunnel. A service-design-life analysis was performed using abrasion prediction modelling. This model was based on abrasion measurement data acquired from granite field tests at Pfaffensprung sediment bypass tunnel, Switzerland. The estimated annual abrasion depths for the granite were approximately 0.50 mm/year for average sediment transport conditions. Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-151413 PB - COMMISSION INTERNATIONALE DES GRANDES BARRAGES ER - TY - CHAP A1 - Auel, C. A1 - Kobayashi, S. A1 - Sumi, T. A1 - Takemon, Y. T1 - Effects of sediment bypass tunnels on sediment grain size distribution and benthic habitats T2 - River Sedimentation: Proc. 13th Int. Symposium on River Sedimentation Y1 - 2016 SP - 825 EP - 832 PB - CRC Press CY - Stuttgart, Germany 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 - 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 - TY - JOUR A1 - Auel, C. A1 - Kobayashi, S. A1 - Takemon, Y. A1 - Sumi, T. T1 - Effects of sediment bypass tunnels on grain size distribu-tion and benthic habitats in regulated rivers JF - International Journal of River Basin Management N2 - Four dams in Japan and Switzerland with Sediment Bypass Tunnels (SBT) as a measure against reservoir sedimentation were monitored to analyse the effects of sediment supply on the downstream environment based on up- to downstream differences in geomorphological and biological characteristics. SBT operation times ranged from 93 years at Pfaffensprung and 17 at Asahi to only three years at Solis and no operation at Koshibu. Sediment grain size distribution was monitored, and microhabitats and invertebrates were analysed in terms of richness and composition. Results showed that grain sizes were coarser down- than upstream at dams with newly established SBTs, while they were similar or finer for dams with long SBT operation. Analysis of biotic data revealed that microhabitat and invertebrate richness was low directly below the dam but increased further downstream the longer the SBT operation. Sedentary species dominated at locations where bed conditions were stable, e.g. directly downstream of the dam at Koshibu. Recovery of downstream environment with increasing SBT operation time was disclosed by the Bray–Curtis similarity index, which evaluated an overlap between up- and downstream reaches for both microhabitat composition and invertebrate communities. With increasing operation time, both indices increased, revealing the positive effects of long-term SBT operation. Y1 - 2017 U6 - https://doi.org/10.1080/15715124.2017.1360320 SP - 433 EP - 444 ER - TY - JOUR A1 - Auel, C. A1 - Albayrak, I. A1 - Sumi, T. A1 - Boes, R.M. T1 - Sediment transport in high-speed flows over a fixed bed. 1: Particle dynamics JF - Earth Surface Processes and Landforms N2 - Particle dynamics are investigated experimentally in supercritical high-speed open channel flow over a fixed planar bed of low relative roughness height simulating flows in high-gradient non-alluvial mountain streams and hydraulic structures. Non-dimensional equations were developed for transport mode, particle velocity, hop length and hop height accounting for a wide range of literature data encompassing sub- and supercritical flow conditions as well as planar and alluvial bed configurations. Particles were dominantly transported in saltation and particle trajectories on planar beds were rather flat and long compared with alluvial bed data due to (1) increased lift forces by spinning motion, (2) strongly downward directed secondary currents, and (3) a planar flume bed where variation in particle reflection and damping effects were minor. The analysis of particle saltation trajectories revealed that the rising and falling limbs were almost symmetrical contradicting alluvial bed data. Furthermore, no or negligible effect of particle size and shape on particle dynamics were found. Implications of experimental findings for mechanistic saltation-abrasion models are briefly discussed. Y1 - 2017 U6 - https://doi.org/10.1002/esp.4128 SP - 1384 EP - 1396 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 - 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 -