Specification for tunnelling

Contents
Foreword iii
1 General requirements 1
101. General notes 3
102. Definitions 5
103. References to Standards 6
103.1 Standards and alternative standards 6
103.2 Alternative materials and equipment 6
104. Eurocodes and European and British Standards 7
104.1 Eurocodes 7
104.2 European Standards 7
104.3 British Standards 10
105. Other standards and documents 13
105.1 Standards referred to in the text 13
105.2 Documents referred to in the text 13
106. General provisions 16
107. Occupational health, safety and welfare 17
108. Quality Management and records 19
108.1 Quality Management System 19
108.2 Engineer’s agreement 19
108.3 Site records 19
108.4 As-built records 19
2 Materials 21
201. Standards 23
202. Concrete 24
202.1 General 24
202.2 Constituent materials – cement 24
202.3 Constituent materials – aggregates 25
202.4 Constituent materials – water 26
202.5 Constituent materials – admixtures 26
202.6 Constituent materials – fibres 26
202.7 Constituent materials – additions 26
202.8 Concrete mixes 27
202.9 Ready-mixed concrete 27
202.10 Concrete batching 28
202.11 Quality control 28
203. Reinforcement 29
203.1 Bar reinforcement 29
203.2 Welded wire fabric 29
203.3 Fibre reinforcement 29
204. Precast concrete linings 31
204.1 General 31
204.2 Manufacturer of segments 31
204.3 Moulds 31
204.4 Tolerances for the manufacture of bolted
segments 32
204.5 Tolerances for the manufacture of
expanded segments 32
204.6 Opening sets 33
204.7 Marking of segments 33
204.8 Joint packing 33
204.9 Gasket grooves 33
204.10 Concrete cover 33
204.11 Grout holes 34
204.12 Curing 34
204.13 Handling stacking and transport 34
204.14 Segments reinforced with steel fibres 34
205. Spheroidal graphite cast iron (SGI) linings 36
205.1 General 36
205.2 Testing 37
205.3 Production testing 37
205.4 Marking segments 38
205.5 Machining and drilling 39
205.6 Dimensions and tolerances 39
205.7 Segment weights 40
205.8 Grout holes 41
205.9 Grout plugs 41
205.10 Casting details 41
205.11 Corrosion protection 41
205.12 Damaged segments 42
205.13 Ring removal 42
206.1 Structural steelwork and steel linings 43
206.1 General 43
206.2 Fatigue and dynamic loading 43
206.3 Connection design 43
206.4 Materials 43
206.5 Fabrication 43
206.6 Protective treatment 44
206.7 Steelwork erection 44
206.8 Bolt assembles 45
206.9 Fabricated steel segments 45
206.10 Cold-formed pressed steel segments 45
207. Jacking pipes 46
207.1 General 46
208. Support arches and lattice girders 47
208.1 General 47
208.2 Arches/ribs 47
208.3 Lattice girders 47
209. Spiles, dowels and rockbolts 50
209.1 Spiles 50
209.2 Rock dowels 50
209.3 Rockbolts 50
209.4 Rock anchors 51
210. Sprayed concrete constituent materials 53
210.1 Cement 53
210.2 Pulverised fuel ash (PFA) and ground
granulated blastfurnace slag (GGBS) 53
210.3 Silica fume 53
210.4 Aggregates 54
210.5 Water 55
210.6 Admixtures 55
210.7 Consistency 56
210.8 Strength and quality 56
210.9 Fibres 57
211. Sheet waterproof membranes 58
211.1 Sheet waterproofing membrane systems 58
211.2 Materials – geotextile fleece 58
211.3 Materials – fixing elements for sheet
waterproofing membrane 58
211.4 Materials – sheet waterproof membrane 58
211.5 Additional Items – sheet waterproofing
systems 59
212. Sprayed-applied waterproofing membrane 60
212.1 General 60
212.2 Materials 60
212.3 Materials – health and safety during
application 60
212.4 Selection of spray-applied membrane
systems – from track record or
appropriate trials 61
212.5 Quality assurance and requirements
during trials 61
212.6 Quality Assurance construction testing 63
213. Gaskets 64
213.1 Compression gaskets – general 64
213.2 Compression gaskets – testing 64
213.3 Hydrophilic gaskets 65
213.4 Elastomeric gaskets 65
213.5 Composite gaskets 65
213.6 Gaskets for pipejack joints 66
214. Cement grout for cavity grouting 67
214.1 General 67
214.2 Special grouts 67
214.3 Mixing 68
214.4 Storage and delivery 68
215. Packings 69
215.1 Packings for segmental linings 69
215.2 Packings for opening frames 69
215.3 Packings for jacking pipes 69
216. Grommets and bolts 70
216.1 Grommets 70
216.2 Bolts 70
217. Pointing and caulking material 71
217.1 Caulking 71
217.2 Pointing 71
218. Timber 72
218.1 General 72
3 Methods 73
301. Excavation for tunnels 75
301.1 General 75
301.2 Rock 76
301.3 Soft ground 76
302. Drilling 78
302.1 General 78
302.2 Blast hole drilling 78
302.3 Probe hole drilling 78
303. Temporary Works and ground support 79
303.1 General 79
304. Spilling, dowelling and rockbolting 80
304.1 Spiling 80
304.2 Rock dowelling 80
304.3 Rockbolting 81
304.4 Load testing 82
304.5 Records 82
305. Sprayed concrete 83
305.1 General 83
305.2 Proficiency 84
305.3 Batching and mixing 84
305.4 Application 84
305.5 Curing 86
305.6 Defects and repairs 86
305.7 Reinforcement 87
305.8 Tests for trial mixes 87
305.9 Test panels and acceptance tests 87
305.10 Production tests 88
306. Ground support with arches 91
306.1 Steel arches/ribs and lattice girders 91
307. Forepoling 92
307.1 General 92
308. Explosives 93
308.1 General 93
308.2 Blasting vibrations 94
309. Groundwater 96
309.1 General 96
310. Probing ahead 97
310.1 General 97
311. Break-outs from shafts and tunnels 98
311.1 General 98
312. Installation of sheeted waterproof membranes 99
312.1 Surface preparation 99
312.2 Geotextile fleece layer 99
312.3 Waterproof membrane 99
312.4 Construction joints: geotextile fleece 100
312.5 Construction joints: sheet waterproof
membrane 100
312.6 Quality Assurance and control – field
trials 100
312.7 Quality Assurance and control –
construction testing 100
312.8 Defective membrane 101
312.9 Inner lining concrete works 101
313. Installation of sprayed-applied waterproof
membrane 102
313.1 Substrate preparation 102
313.2 Application 102
313.3 Equipment 103
313.4 Construction joints 103
313.5 Defective membrane 103
313.6 Secondary lining construction 103
314. Tunnel boring machines (TBMs) and shields 104
314.1 General 104
314.2 Machine characteristics 104
314.3 Guidance 105
314.4 Fire protection 105
314.5 Contractor’s submission 106
314.6 Inspection and testing 106
314.7 Personnel and training 106
315. Slurry and earth pressure balance machines 107
315.1 General 107
315.2 Machine characteristics 107
315.3 Grouting 108
315.4 Spoil removal 108
315.5 Instrumentation 108
316. Open-faced tunnel boring machines 110
316.1 General 110
316.2 Unshielded tunnelling machines 110
316.3 Shielded tunnelling machines 110
317. Hand shields and mechanised open shields 111
317.1 General 111
317.2 Boom cutting machines 111
317.3 Backhoe machines 111
318. Tunnelling machines and shield operation 112
318.1 General 112
318.2 Excavation 112
319. Pipe jacking 114
319.1 General 114
319.2 Thrust and reception pits 114
319.3 Operation 114
319.4 Packing and sealing 115
319.5 Monitoring and instrumentation 115
319.6 Tolerances 116
319.7 Microtunnelling 116
320. Jacked box tunnelling 117
320.1 General 117
320.2 Design principles 117
320.3 Site investigation 118
320.4 Tunnelling shield 118
320.5 Jacking system 118
320.6 Anti-drag systems 118
320.7 Prediction of ground movements 119
320.8 Design 119
320.9 Construction 119
320.10 Tunnelling operations 119
321. Construction of segmental tunnel lining 121
321.1 General 121
321.2 Segmental lining: general 121
321.3 Erection of bolted lining 121
321.4 Tapered segmental lining 122
321.5 Grouting of bolted lining 122
321.6 Erection of expanded lining 122
321.7 Packing 122
321.8 Defective work 123
322. Segment gaskets 124
322.1 General 124
323. Grouting 125
323.1 Cavity grouting of segmental lining 125
323.2 Primary grouting 125
323.3 Secondary grouting 126
323.4 Cavity grouting of in situ lining 126
324. Pointing and caulking 128
324.1 Pointing 128
324.2 Caulking 128
324.3 Lead caulking 128
324.4 Cementitious cord caulking 128
325. In situ concrete linings other than sprayed
concrete 129
325.1 General 129
325.2 Temperature monitoring of the concrete 129
325.3 Transport of concrete 130
325.4 Concrete placing equipment 130
325.5 Placing concrete 130
325.6 Compaction 131
325.7 Curing and protection 131
325.8 Construction joints 132
325.9 Defective work 132
325.10 Formwork 132
325.11 Concrete finishes 133
325.12 Fixing bar and mesh reinforcement 134
325.13 Inspection of completed structure 135
326. Shafts 136
326.1 General 136
326.2 Safety 136
326.3 Temporary shafts 136
326.4 Construction 136
327. Timber headings 138
327.1 General 138
328. Tolerances for tunnels, shafts and underground
works 139
328.1 All tunnels and shafts 139
328.2 Segmental lined tunnels and shafts 139
328.3 Sprayed concrete lined tunnels and shafts 139
329. Monitoring recording and the control process of
underground works 141
329.1 General 141
329.2 Ground movement monitoring 141
329.3 Monitoring of tunnel excavation 142
329.4 Tunnel and shaft linings 143
329.5 Daily review meeting (DRM) 143
329.6 Key performance indicators 143
329.7 RESS – Required Excavation and
Support Sheet 145
329.8 Contingency measures and emergency
procedures 145
330. Survey and setting out 147
330.1 Datum for the Works 147
330.2 Survey bench marks 147
4 Ground stabilisation processes 151
401. Compressed air working 151
401.1 General 151
401.2 Submission of information 151
401.3 Initial pressurisation 151
401.4 Minimisation of leakage 151
401.5 Changes in working conditions 151
401.6 Submission of daily records 151
401.7 Exposure records 151
401.8 Decompression of working chamber 152
401.9 Settlement 152
401.10 Emergency procedures 152
401.11 Storage of materials 152
401.12 Burning and welding 152
402. Grouting for ground stabilisation and groundwater
control 153
402.1 General 153
402.2 Contractor’s proposals 153
402.33 Drilling 154
402.4 Plant 154
402.5 Disposal of waste 154
402.6 Records 154
403. Ground freezing 155
403.1 General 155
403.2 Process 155
403.3 Methods 155
403.4 Precautions 155
403.5 Method statement 156
403.6 Freeze pipes 156
403.7 Plant 156
403.8 Monitoring and records 156
404. Dewatering 158
404.1 General 158
404.2 Contractor’s proposals 158
404.3 Drilling and jetting 159
404.4 Plant 159
404.5 Operations 159
404.6 Monitoring and records 159
405. Compensation grouting 160
405.1 General 160
405.2 Execution 160
405.3 Monitoring 160
405.4 Assessment 160
5 Working environment 161
501. Temporary electrical installations 163
501.1 General 163
502. Ventilation during construction 164
502.1 General 164
502.2 Ventilation systems 164
502.3 Monitoring 165
502.4 Start-up ventilation 165
502.5 Checking and inspection 166
502.6 Ventilation failure 166
502.7 Ventilation after breakthrough 166
503. Lighting 167
503.1 General 167
504. Noise and vibration 168
504.1 General 168
504.2 Temporary fencings and barriers 168
504.3 Plant and equipment 169
504.4 Transport restrictions 169
504.5 Noise and vibration monitoring 169
504.6 Noise and vibration levels 169
505. Access and egress 170
505.1 General 170
505.2 Designated access routes 170
505.3 Maintenance of routes 170
505.4 Access for others 170
505.5 Traffic safety and management 171
505.6 Signing and signalling 171
505.7 Temporary lighting 172
505.8 Survey and reinstatement 172
505.9 Access within Works 172
506. Atmospheric testing 174
506.1 General 174
506.2 Temperature 174
507. Disposal of spoil and water 175
507.1 Spoil waste programme 175
507.2 Disposal of solid waste spoil 175
507.3 Monitoring spoil removal 175
507.4 Liquid waste disposal 175
508. Leakage and infiltration 176
508.1 General 176
508.2 Leakage criteria and classes of tunnel 176
508.3 Leakage tests 176
508.4 Watertightness of tunnels and shafts 176
Index 177