TY - CONF A1 - Boes, R.M. A1 - Hagemann-Müller, M. A1 - Albaryak, I. A1 - Müller, B. A1 - Caspescha, L. A1 - Flepp, A. A1 - Jacobs, F. A1 - Auel, C. T1 - Sediment bypass tunnels: Swiss experiences with bypass efficiency and abrasion-resistant invert materials T2 - VINGT SIXIÈME CONGRÈS DES GRANDS BARRAGES, Vienne, Juillet 2018 N2 - In this paper typical bypass efficiencies of sediment bypass tunnels (SBTs) used to counter reservoir sedimentation are described, distinguishing between two layouts of the tunnel intake. It results that SBTs are an effective measure to reduce the sedimentation of dam reservoirs, particularly of type (A) with intake at the reservoir head. The hydroabrasive wear of tunnel inverts is significant and has to be mitigated by using adequate invert liners. The invert abrasion can be estimated based on an abrasion model where a correct input value of the bed material resistance coefficient is paramount to limit model uncertainties. Based on abrasion measurements at prototype SBTs typical values of the material resistance coefficient are recommended for high-strength concrete, natural stones and steel liners. The field experiences gathered so far and the comparison of various invert materials suggest granite pavers as a promising lining material for severe abrasion conditions. Y1 - 2022 UR - https://www.hb.fh-muenster.de/opus4/frontdoor/index/index/docId/15139 UR - https://nbn-resolving.org/urn:nbn:de:hbz:836-opus-151399 PB - COMMISSION INTERNATIONALE DES GRANDES BARRAGES ER -