– Spillway Design Step by Step – Spillway Design Step by Step Geraldo Magela Pereira Coverphotodescription:frontcover:TucuruíSpillway(Brazil);MonticelloSpillway(Napa,USA);Bonfante Spillway(Brazil);backcover:MonjolinhoSpillway(Brazil). CRCPress/BalkemaisanimprintoftheTaylor&FrancisGroup,aninformabusiness ©2020Taylor&FrancisGroup,London,UK TypesetbyApexCoVantage,LLC Allrightsreserved.Nopartofthispublicationortheinformationcontainedherein maybereproduced,storedinaretrievalsystem,ortransmittedinanyformorbyanymeans,electronic, mechanical,byphotocopying,recordingorotherwise,withoutwrittenpriorpermissionfromthepublishers. Althoughallcareistakentoensureintegrityandthequalityofthispublicationand theinformationherein,noresponsibilityisassumedbythepublishersnortheauthorforanydamagetothe propertyorpersonsasaresultofoperationoruseofthispublicationand/ortheinformationcontained herein. LibraryofCongressCataloging-in-PublicationData Appliedfor Publishedby: CRCPress/Balkema Schipholweg107C,2316XC,Leiden,TheNetherlands e-mail:[email protected] www.crcpress.com–www.taylorandfrancis.com ISBN:978-0-367-41936-3(Hbk) ISBN:978-0-367-81690-2(eBook) DOI:https://doi.org/10.1201/9780367816902 This book is dedicated to my wife, Cristine, love of my life, for the constant and perennial support during my career in all my jobs; and to my daughters, Ligia and Marina, and to my granddaughter Luiza, the reason for my life. Contents Preface xiii Acknowledgments xvii About the author xix List of acronyms xxi List of symbols xxiii 1 Introduction 1 1.1 Initial considerations 1 1.2 Phases of studies of the basin. The cases of Banqiao (China), Mascarenhas de Moraes and Itá (Brazil) 4 1.3 Spillway and design flood 8 The case of the Mascarenhas de Moraes HPP 8 1.4 Layout and choice of spillway 15 1.5 Two notable cases: Theodore Roosevelt (USA) and Orós (Brazil) 18 1.6 Ruptures of dams due to insufficient discharge capacity of the spillway 25 1.7 Risks of dam ruptures – submersion waves 31 1.8 Case of rupture by earthquake 33 1.9 Operation and maintenance 34 2 Types of spillways 39 2.1 Classification of the spillways 39 2.2 Ogee spillway 40 2.3 Side spillway 41 2.4 Morning glory spillway 45 2.5 Tunnel spillway 47 2.6 Chute spillway 51 Barra Grande HPP, Pelotas river (Rio Grande do Sul/Santa Catarina States, Brazil) 53 Campos Novos HPP, Canoas river (Santa Catarina State, Brazil) 54 Corumbá HPP, Corumbá river (GO, Brazil) 56 viii Contents viii Serra da Mesa HPP, Tocantins river (GO, Brazil) 57 2.7 Culvert spillway (bottom outlet) 58 2.8 Orifice spillway 59 2.9 Labyrinth spillway 61 2.10 Siphon spillway 64 2.11 Stepped spillway 65 2.12 Horizontal apron spillway (spillway without ogee) 70 3 Spillway design 73 3.1 Initial considerations 73 3.2 Ogee shape 74 3.3 Hydraulic design 78 3.4 Practical rules for defining the type of spillway 85 3.4.1 Location of the spillway 86 A Plants located in wide plains 86 B Plants located in stretches of moderately embedded rivers 89 C Plants located in very embedded valley – “V” valley 89 3.4.2 Spillway main parameters: P, Ho, P/Ho and Co 89 3.5 Hydraulic design of the ogee spillway – example of Tucuruí 90 3.5.1 Design flood 90 3.5.2 Discharge coefficient and the number of gates 91 3.5.3 Culverts for the river diversion 94 3.5.4 Studies on hydraulic models 94 3.6 Hydraulic design of other types of spillway – notes 96 3.6.1 Culvert spillway – bottom outlet 96 3.6.2 Spillway in orifice 99 3.6.3 Labyrinth spillway 101 3.6.4 Stepped spillway 105 3.6.5 Morning glory spillway 108 Discharge 110 Crest profiles 113 Transition project 116 Conduit design 117 3.6.6 Side spillway design example 123 4 Hydrodynamics pressures 125 4.1 Initial considerations 126 4.2 Average pressures 126 4.3 Instant pressures – Shin-Nariwa (Japan) 131 Forces acting in the chute/powerhouse roof slab 136 Powerhouse roof slab oscillations 137 Variation of Ćp 137 ix Contents ix 4.4 Instant pressures – Karakaya 140 4.5 Instant pressures – Tucuruí (Brazil) 143 5 Energy dissipation 145 5.1 Classification of the dissipators 145 5.2 Ski jump dissipators 150 5.2.1 Summary of theory 150 5.2.2 Spillway of Jaguara 151 5.2.3 Spillways of Tarbela 154 5.2.4 Spillway of Grand Rapids 159 5.2.5 Spillway of Água Vermelha 162 5.2.6 Spillway of Itapebi 165 5.2.7 Spillway of Katse dam 167 5.2.8 Spillway of Kariba 170 5.2.9 Spillway of Cahora Bassa 174 5.2.10 Spillway of Itaipu 175 5.2.11 Spillway of Itá 181 5.2.12 Spillway of Fengtan 184 5.3 Hydraulic jump dissipators 186 5.3.1 Summary of theory 186 5.3.2 Stepped spillway of Dona Francisca 191 5.3.3 Spillway of Porto Primavera 192 5.3.4 Spillway of Ilha Solteira 192 5.3.5 Spillway of Estreito 193 5.3.6 Spillway of Coaracy Nunes 195 5.3.7 Spillway of Moxotó 197 5.3.8 Spillways of Sobradinho 200 5.3.9 Spillway of Grand Coulee 203 5.4 Cases 204 5.4.1 Spillway of Machadinho 205 5.4.2 Spillway of Marimbondo 208 5.4.3 Spillway of Nova Ponte 214 5.4.4 Spillway of Paulo Afonso IV 215 5.4.5 Spillway of Crestuma 216 5.4.6 Spillway of Lower Notch 221 5.4.7 Spillway of Sardar Sarovar 224 5.4.8 Spillways of Salto Grande 225 6 Pressure forces downstream of dissipators 229 6.1 Hydrodynamics pressures downstream of ski jumps 229 6.1.1 Important results for the project engineer 231 6.1.1.1 Thickness of water height to protect the rocky massif 231