Practical Guide to Rock Tunneling

266 Pages·2017·46.839 MB·English

by  Dean Brox

Practical Guide to Rock Tunneling
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Practical Guide to Rock Tunneling
Dean Brox
Brox Consulting, Vancouver, Canada
CRCPress/BalkemaisanimprintoftheTaylor&FrancisGroup,aninformabusiness
©2017Taylor&FrancisGroup,London,UK
TypesetbyIntegraSoftwareServicesPrivateLtd
PrintedandboundinGreatBritainbyCPIGroup(UK)Ltd,Croydon,CR04YY
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andtheinformationherein,noresponsibilityisassumedbythepublishersnor
theauthorforanydamagetothepropertyorpersonsasaresultofoperation
oruseofthispublicationand/ortheinformationcontainedherein.
LibraryofCongressCataloginginPublicationData
Appliedfor
Publishedby:CRCPress/Balkema
P.O.Box11320,2301EHLeiden,TheNetherlands
e-mail:[email protected]
www.crcpress.com–www.taylorandfrancis.com
ISBN:978-1-138-62998-1(Hardback)
ISBN:978-1-315-21011-7(eBook)
Contents
Foreword xiii
Abouttheauthor xv
Acknowledgements xvii
Dedication xix
Disclaimer xxi
Listoffiguresandtables xxiii
1 Introduction 1
2 Functionalusesofrocktunnels 3
2.1 General 3
2.2 Functionaluses 3
3 Tunnelprojectexecution 5
3.1 General 5
3.2 Projectdeliverymethod 5
3.3 Executionstages 6
3.4 Pre-planningbyclient 6
3.5 Projectengineeringbyconsultants 7
3.6 Engineeringeffortanddeliverablesduringexecution 8
3.7 Functionalrequirementsfordesignbuild 9
3.8 Earlycontractorengagementandinvolvement 9
3.9 Constructabilityreviews 10
3.10 IndependentTBMriskassessment 10
4 Siteinvestigations 13
4.1 General 13
4.2 Potentialconsequencesoflimitedsiteinvestigations 14
4.3 Reviewofexistinginformationandpreviousexperience 15
4.4 Planningandbudgetingforsiteinvestigations 15
4.5 Compilationofrelevantinformationandbasemap 17
vi Contents
4.6 Identificationofkeygeologicalrisksandpossibleconcerns 17
4.7 Planningofphasedinvestigations 18
4.8 Fieldmappingandgroundproofingofinferred
geologicalfaults 19
4.9 Geophysicalsurveys 20
4.10 Boreholedrilling 22
4.11 Insitutesting 24
4.12 Selectionandpreparationofsamples 28
4.13 Laboratoryandqualityassurancetesting 29
4.14 Fieldinstrumentationandmonitoringbeforeconstruction 31
4.15 Pilotortestexcavation/gallery 31
4.16 Reporting 32
4.17 Drillcorephotographs 32
4.18 Longtermstorageofdrillcore 33
5 Rockcharacterization 35
5.1 Regionalandsitegeology 35
5.2 Tunnelalignmentgeology 35
5.3 Faultsandfracturezones 36
5.4 Rockmassfractures 36
5.5 Rockstrength 37
5.6 Rockmineralogy 38
5.7 Rockalteration 39
5.8 Rockabrasivity 39
5.9 Rockdurabilityandswellingpotential 40
5.10 Groundwaterconditions,predictedinflows,andquality 44
5.11 Insitustresses 45
5.12 Rockmassquality 46
5.13 Tunnelalignmentandsectioncharacterization 49
6 Rocktunneldesign 51
6.1 Designcriteriaandbasis 51
6.2 Technicalstandardsandcodesofpractice 51
6.3 Tunnelcrosssectionandinternalgeometrical
requirements 52
6.4 Tunnelsizeandshape 53
6.5 Portallocationsandsupportdesign 54
6.6 Horizontalalignmentandseparation 55
6.7 Verticalalignment 56
6.8 Practicalgrade 56
6.9 Intermediateortemporaryaccessrequirements 56
6.10 Drainagerequirements 57
Contents vii
6.11 Invertrequirements 57
6.12 Operationaldesignrequirements 58
6.13 Accessrequirements 58
6.14 Designofhydraulicpressuretunnels 59
6.15 Seismicdesignconsiderationsforrocktunnels 64
6.16 Constructabilityofdesign 64
7 Tunnelstability 65
7.1 General 65
7.2 Probablemodesofinstability 65
7.3 Stabilityanalysesandselectionofparameters 66
7.4 Empiricalassessmentsofstability 67
7.5 Kinematicstabilityassessment 67
7.6 Rockmassstabilityassessment 68
7.7 Discreteelementrockmassstabilityassessment 69
7.8 Evaluationofoverstressingandcharacterization 70
7.9 Tunnelstabilityatfaultzones 76
7.10 Squeezingconditions 79
7.11 Stabilityofaginghydropowertunnels 81
7.12 Reviewofstabilityofexistingtunnelsinsimilargeology 84
8 Tunnelexcavation 85
8.1 Practicalconsiderations 85
8.2 Minimumconstructionsize 85
8.3 Overbreakconsiderations 86
8.4 Drillandblastexcavation 87
8.5 Blastingdesign 89
8.6 Chemicalrockbreakingwithoutvibrations 90
8.7 Scaling 90
8.8 Highspeeddrillandblastexcavationforlongtunnels 91
8.9 SequentialExcavationMethod(SEM)forweakrock 91
8.10 TunnelBoringMachine(TBM)excavation 93
8.11 AssessmentofTBMapplicability 99
8.12 TheuseofTBMsinsqueezinggroundconditions 100
8.13 TheuseofTBMsforminingprojects 101
8.14 MinimumtechnicalspecificationsforTBMs 102
8.15 Roadheaderexcavation 103
8.16 Methodsforinclinedexcavation 104
8.17 Shaftexcavation 105
8.18 Cavernexcavation 107
8.19 Newanddevelopingtechnologiesforexcavationinrock 108
8.20 Constructionmethodologyevaluationandrisks 109
viii Contents
9 Tunnelsupport 113
9.1 Generaldesignprinciples 113
9.2 Initialrocksupport 114
9.3 Finalrocksupport 115
9.4 Practicalinstallation 115
9.5 Portalsupport 116
9.6 Supportcomponentsandtypicalproducts 117
9.6.1 Rockbolts 117
9.6.2 Cables 118
9.6.3 Mesh 118
9.6.4 Shotcrete 119
9.6.5 Latticegirdersandsteelsets 120
9.7 Tunnelsupportforsevereoverstressingand
rockbursts 121
9.8 Tunnelsupportforsqueezingconditions 123
9.9 Corrosionpotentialassessment 124
9.10 Pre-supportrequirements 125
9.11 Groundfreezing 127
9.12 Tunnelstabilityandsupportdesignverification 128
10 Tunnelliningrequirements 131
10.1 Purposeoftunnelliningsinrock 131
10.2 Acceptabilityofunlinedtunnelsinrock 131
10.3 Shotcreteforfinallining 133
10.4 Shotcreteforfinalliningofhydraulictunnels 134
10.5 Cast-in-placeconcreteforfinallining 135
10.6 One-passconcretesegmentalliningwithTBMexcavation 137
10.7 Waterproofingrequirementsandapplications 139
10.8 Fireprotectionrequirements 140
11 Constructionconsiderations 143
11.1 Sitemobilization 143
11.2 Sitepreparationofcamps,stagingandlaydown
areas 143
11.3 Portalandshaftaccess 144
11.4 Ventilation 144
11.5 Constructionwatersupply 145
11.6 Electricalsupply 145
11.7 Constructionpumpsandsumps 145
11.8 Groundwaterandconstructionwatertreatment 146
11.9 Environmentalsamplingandtestingrequirements 147
11.10 Spoildisposal 148
11.11 Tunnelsupportdesignimplementation 149
Contents ix
11.12 Geologicalandgeotechnicalmappingrequirements 151
11.13 Qualityassuranceinspections 152
11.14 Geotechnicalinstrumentation 152
12 Constructionrisksandmitigationmeasures 155
12.1 Portalhazards 155
12.2 Tunnelinghazards 155
12.3 Stabilityinfluencebetweenadjacentandexisting
tunnels 157
12.4 Groundwatercontrolandmanagement 158
12.5 Tunnelconstructionimpactsanddisturbancestothe
community 159
12.6 TBMentrapmentandrelief 160
12.7 TBMspecialproblemsanddesignfeatures 161
12.8 GenerationoffinematerialsduringTBMexcavation 161
12.9 Probedrilling 161
12.10 Pre-drainage 162
12.11 Pre-excavationgrouting 164
12.12 Post-excavationgrouting 164
12.13 Pilottunnels 165
12.14 Investigativetechniquesduringconstruction 165
12.15 Additionaltunnelingequipmentandresourcesduring
construction 167
13 Constructioncostestimationforrocktunnels 169
13.1 General 169
13.2 Costingstandardsandrecommendedprocedures 170
13.3 Keyassumptionsforconstructioncostestimates 172
13.4 Directconstructioncosts 172
13.5 Indirectconstructioncosts 173
13.6 Constructioncostcontingenciesandprofits 173
13.7 Client'scosts 174
13.8 Totalanticipatedtunnelprojectcost 174
13.9 Probabilisticanalysisofconstructioncostsandgeological
uncertainty 175
13.10 Integratedcostandscheduleriskanalysis 175
13.11 Benchmarkcomparisonstosimilarprojects 176
14 Constructionschedulingforrocktunnels 177
14.1 Identificationofkeyconstructionactivitiesandgraphic
presentation 177
14.2 Procurementleadtimeforkeyequipment 178
x Contents
14.3 Evaluationofrealisticratesofproductivityand
workinghours 181
14.4 Schedulecontingenciesforriskevents 181
14.5 Criticalpathactivities 181
15 Tunnelcontractstrategyandimplementation 183
15.1 General 183
15.2 Contractdocumentationandtypesofcontracts 183
15.3 Pre-qualification 186
15.4 Formofpayment 187
15.5 Risksharingandcompensationfordifferingsite
conditions 188
15.6 Geotechnicalbaselinereportsandimplementation 189
15.7 Constructioncontractandschedulingmanagement 191
15.8 Partnering 192
15.9 Disputeresolution 193
15.10 Claimsmanagement 194
16 Riskmanagement 195
16.1 Riskmanagementandpractice 195
16.2 Qualitativeriskassessmentsandriskregisters 197
16.3 Riskallocation 199
16.4 Quantitativeriskassessments 200
17 Inspectionofrocktunnels 201
17.1 General 201
17.2 Manualinspections,datadocumentation,and
safetypractices 202
17.3 Unwateredinspectionsofhydraulictunnels
usingROVs 203
18 Renovation,repairs,anddecommissioning 207
18.1 Renovationofrocktunnels 207
18.2 Repairofrocktunnels 208
18.3 Decommissioningofrocktunnels 210
19 Casehistoriesandlessonslearned 213
19.1 General 213
19.2 LesothoHighlandsWaterProjectPhase1,Lesotho 213
19.3 PacificPlacePedestrianTunnel,HongKong 214
19.4 TaipeiRingRoadTunnels,Taiwan 215
19.5 BoluMountainRoadTunnel,Turkey 215
19.6 GotthardBaseRailTunnel.Switzerland 216