HYDRAULICS OF DAMS AND RIVER STRUCTURES PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON HYDRAULICS OF DAMS AND RIVER STRUCTURES, 26–28 APRIL 2004, TEHRAN, IRAN Hydraulics of Dams and River Structures Edited by Dr. Farhad Yazdandoost K.N.Toosi University of Technology, Tehran, Iran Dr. Jalal Attari Power and Water University of Technology, Tehran, Iran A.A.BALKEMA PUBLISHERS Leiden/London/New York/Philadelphia/Singapore Copyright © 2004 Taylor & Francis Group plc, London, UK All rights reserved. No part of this publication or the information contained herein may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, by photocopying, recording or otherwise, without written prior permission from the publisher. Although all care is taken to ensure the integrity and quality of this publication and the information herein, no responsibility is assumed by the publishers nor the author for any damage to property or persons as a result of operation or use of this publication and/or the information contained herein. Published by: A.A.Balkema Publishers, a member of Taylor & Francis Group plc http://www.balkema.nl/ and http://www.tandf.co.uk/ This edition published in the Taylor & Francis e-Library, 2005. “To purchase your own copy of this or any of Taylor & Francis or Routledge’s collection of thousands of eBooks please go to http://www.ebookstore.tandf.co.uk/.” ISBN 0-203-02409-5 Master e-book ISBN ISBN Volume: 90 5809 632 7 (Print Edition) ISBN CD-ROM: 90 5809 673 4 (Print Edition) Table of contents Hydraulics of Dams and River Structures—Yazdandoost & Attari (eds) © 2004 Taylor & Francis Group, London, ISBN 90 5809 632 7 Preface x 1 Part 1: Hydraulic Structures 2 1. Air-water flow Air-water flows in water engineering and hydraulic structures. Basic 3 processes and metrology H.Chanson De-aeration of a diversion tunnel of a large-scale hydroelectric scheme 22 H.Sigg, U.Keller, P.U.Volkart & H.-E.Minor Free-surface aeration in dam break waves: an experimental study 34 H.Chanson New model investigations on two-phase chute flow 45 K.Kramer, W.H.Hager & H.-E.Minor Evaluation of incipient-aeration point on spillways 57 A.Najafi & M.Yasi 68 2. Intakes and outlets Air entrainment at Guri Dam intake operating at low heads 69 G.Montilla, A.Marcano & C.Castro 3-D CFD modeling-investigation of potential vortex formation at the intakes 79 of Caruachi Powerhouse A.Marcano, L.Rojas-Solórzano, M.Reyes & J.Marín Numerical unsteady flow model simulation during the sluice closure of 93 Caruachi Dam A.Marcano, C.Castro, I.Mendes & E.Martinez Yacyretá Dam: spillways modification to reduce total dissolved gases 104 concentrations downstream of the dam J.D.Bacchiega & C.A.Fattor Hydromatrix®: a new way to generate hydropower 118 H.Drobir & V.Keinberger 127 3. Hydrodynamic forces Impulse waves from laboratory scale to mega-tsunamis 128 W.H.Hager, H.M.Fritz & A.Zweifel Extreme wave transients in reservoirs, their characteristics and interaction 149 with dams T.L.Gvelesiani, A.Huber, Ch.Koutitas & G.T.Matcharadze Dynamic pressure fluctuations at real-life plunge pool bottoms 158 E.F.R.Bollaert, P.A.Manso & A.J.Schleiss A new procedure to evaluate dynamic uplift of concrete linings or rock blocks 169 in plunge pools E.F.R.Bollaert Instantaneous pressure field on a submerged jump stilling basin 181 R.A.Lopardo, C.A.Fattor, M.C.Lopardo & J.M.Casado Aspects of vibrations and fatigue of materials related to coherent structures of 189 macroturbulent flows R.A.Lopardo, C.A.Fattor, J.M.Casado & M.C.Lopardo Scale effect on pressure fluctuations over sills in stilling basins 199 D.Berzi, E.Larcan, S.Mambretti & E.Orsi Analysis of the air rubber dam using “ANSYS” 212 H.Musavi-Jahromi, A.H.Navabi & A.M.Horr 221 4. Energy dissipators Plunge pool scour in prototype and laboratory 222 S.Pagliara, W.H.Hager & H.-E.Minor Experimental investigations on high-velocity jet characteristics and its 233 influence on plunge pool rock scour P.A.Manso, E.F.R.Bollaert & A.J.Schleiss Effect of sill arrangement on maximum scour depth DS of abruptly enlarged 245 stilling basins A.M.Negm Energy dissipation and hydrodynamic forces of aerated flow over macro- 256 roughness linings for overtopped embankment dams S.André, J.Matos, J.-L.Boillat & A.J.Schleiss Experimental study of energy loss at drops 267 H.Musavi-Jahromi, F.Salmasi & M.Bina Dam safety: the use of guidance documents for the training of Inspecting 277 Engineers R.Freer 285 5. Reservoir sedimentation Impacts of Sanmenxia Dam and management strategies 286 B.S.Wu & Z.Y.Wang New approach in determining useful life of reservoirs 307 J.S.Yeoh, J.H.Loveless & A.M.Siyam The use of labyrinth weir in a reservoir flushing system 318 J.H.Loveless & J.S.Yeoh Numerical and physical modelling concerning the removal of sediment 328 deposits from reservoirs H.Scheuerlein, M.Tritthart & F.Nuñez Gonzalez Application of fine sediment behavior to sedimentation management in Miwa 342 Dam, Japan M.Umeda, M.Okano & G.Yokomori Management of reservoir sedimentation due to turbidity currents by technical 354 measures C.D.Oehy & A.J.Schleiss 365 6. Stepped spillways Energy dissipation along stepped spillways 366 G.Valentin, P.U.Volkart & H.-E.Minor Velocity and pressure field in skimming flow in stepped spillways 375 A.Amador, M.Sánchez Juny, J.Dolz, F.Sánchez-Tembleque & J.Puertas Stepped spillways for embankment dams. Review, progress and development 384 in overflow hydraulics H.Chanson & C.A.Gonzalez 395 Part 2: River Structures 396 7. Scouring and sedimentation around structures Recent views on the origin of river meandering and braiding 397 M.S.Yalin Time-dependent local scour at piled bridge foundations 407 G.Oliveto, A.Rossi & W.H.Hager Time evolution of scour at comparatively long abutments 416 C.M.S.Fael & A.H.Cardoso Local scour downstream of grade control structures 428 C.Adduce, M.La Rocca & P.Mele Scouring profile at channel junction 438 S.M.Borghei, A.Nazari & A.R.Daemi 8. Numerical approaches in hydrodynamics of river flow 445 An improved implicit solution for the two dimensional shallow water 446 equations using unstructured grids S.Komaie & W.Bechteler A fully mesh-less Lagrangian numerical method for prediction of free water 461 surface L.Farhadi & B.Ataie-Ashtiani Numerical study of flood routing in compound channels 471 S.A.Ayyoubzadeh & A.Zahiri A finite volume method for solving SWE in rivers on complex topographies 481 D.Farshi & H.-E.Minor Application of a Boussinesq-type equation to flow over trapezoidal profile 491 weirs Y.T.Zerihun & J.D.Fenton Hydrodynamics of three-dimensional density currents 502 B.Firoozabadi 510 9. River response to hydraulic structures Experimental analysis on the hydraulic efficiency of mudflow breakers 511 A.Armanini, C.Dalrì, F.Della Putta, M.Larcher, L.Rampanelli & M.Righetti Sub-critical flow in open channel junction 522 A.Behrangi, S.M.Borghei & A.R.Daemi Boundary shear stress distribution in a V-shaped channel 534 M.Mohammadi & D.W.Knight 547 10. Hydroinformatic applications Cardiff Bay barrage and managing the impounded water quality 548 R.A.Falconer & B.Lin River flow forecasting using artificial neural networks 563 M.Zakermoshfegh, M.Ghodsian & Gh.A.Montazer Evaluation of the application of neural networks on real-time river flood 571 prediction M.T.Dastorani Prediction of salinity intrusion in Arvand River 585 B.Sherkati-Azin, A.Etemad-Shahidi & E.Jabbari Author index 595