Handbook on Tunnels and Underground Works: Volume 2: Construction – Methods, Equipment, Tools and Materials

Cover
Half Title
Title Page
Copyright Page
Table of Contents
Preface
Foreword 1
Foreword 2
Contributors
1 Introduction: excavation techniques for conventional and full-face mechanised tunnelling. Reasons for the choice and differences
	1.1 Dimensions of the excavation
	1.2 Functions and/or internal functional profile
	1.3 Length of the excavation
	1.4 Logistic conditions
	1.5 Geological and geotechnical/geomechanical conditions
	1.6 Boundary conditions and consequently the response of the rock mass
	Authorship contribution statement
	References
2 Construction methods
	2.1 Introduction
	2.2 Overview on the main aspects of drill and blast in tunnelling
		2.2.1 The compliance with the outline of the project
		2.2.2 Types of blasts
			2.2.2.1 Average specific consumptions
			2.2.2.2 Rules for the layout and initiation sequence of the cut holes
			2.2.2.3 V-cuts: calculation of the charges
			2.2.2.4 Parallel hole cuts: calculation of the charges
	2.3 Drilling in tunnel excavation
		2.3.1 Jumbo for tunnel driving
		2.3.2 Equipment, personnel and their use for the excavation of a hard rock tunnel: an example
			2.3.2.1 General data on the work
			2.3.2.2 Personnel and equipment
		2.3.3 Robotizied Jumbo
	2.4 Punctual mechanical excavation
		2.4.1 Roadheader
			2.4.1.1 General principles of roadheader operation
			2.4.1.2 Continuous excavation with roadheaders
			2.4.1.3 Roadheader components
			2.4.1.4 Operating principles
			2.4.1.5 Application of roadheader
			2.4.1.6 Main operating data and their assessment
		2.4.2 High energy impact hammer
			2.4.2.1 Sizing the HEIH
			2.4.2.2 Drill and split
	2.5 Full-face TBMs for tunnelling through rock masses
		2.5.1 Main rock TBM types
			2.5.1.1 Open type TBMs
			2.5.1.2 Shielded type TBMs
			2.5.1.3 TBM main components
			2.5.1.4 Drilling process
		2.5.2 TBM performance prediction models
			2.5.2.1 Analytical performance prediction models
			2.5.2.2 Gehring model
			2.5.2.3 Empirical performance prediction models
			2.5.2.4 Comparative analysis of the various models
	2.6 Soil TBM (shielded TBM)
		2.6.1 Main types – description and trends
			2.6.1.1 Slurry Pressure Balance TBMs (SPB)
			2.6.1.2 Earth pressure balance TBMs
			2.6.1.3 Multimode/hybrid shields
			2.6.1.4 Multimode TBMs
			2.6.1.5 Variable density hybrid machines (VD)
			2.6.1.6 Boring cycle
			2.6.1.7 Soil TBM main components
		2.6.2 Limits of actual classification: the soil TBM as a process, hybridi- sation as the new normal
		2.6.3 Features of the new soil machines “on demand”
		2.6.4 How to define the specifications for the required machine?
		2.6.5 Soil conditioning and backfilling
			2.6.5.1 Soil conditioning
			2.6.5.2 Backfilling grouting
	2.7 Vertical and inclined excavation
		2.7.1 Vertical shaft-sinking machines
	2.8 Slurry walls and DIAPHRAGM
		2.8.1 Introduction
			2.8.1.1 Slurry wall technique
			2.8.1.2 Applications of slurry walls in tunnelling
			2.8.1.3 Characteristics, special features
			2.8.1.4 Limitations
			2.8.1.5 Quality assurance
		2.8.2 Drilled piles
			2.8.2.1 Piling with Kelly
			2.8.2.2 Drilling with single rotary drive
			2.8.2.3 Double rotary drilling
			2.8.2.4 Bored pile walls
			2.8.2.5 Secant bored pile walls
			2.8.2.6 Quality assurance
	Acknowledgements
	Authorship contribution statement
	Bibliography
3 Support technology
	3.1 Introduction
	3.2 Shotcrete (sprayed concrete or spritz beton)
		3.2.1 Introduction
		3.2.2 Shotcrete technology spraying processes
			3.2.2.1 Dry spraying
			3.2.2.2 Wet spraying
			3.2.2.3 Process flow
		3.2.3 Materials
			3.2.3.1 Cementitious materials
			3.2.3.2 Water
			3.2.3.3 Aggregates
			3.2.3.4 Additions
			3.2.3.5 Accelerators
			3.2.3.6 Steel reinforcement
			3.2.3.7 Fiber-reinforced shotcrete
		3.2.4 Rebound
		3.2.5 Concrete spraying equipment (dry technology)
		3.2.6 Concrete spraying equipment (wet technology)
		3.2.7 Range of sprayers and systems
			3.2.7.1 Manual application with concrete spraying pump and nozzle
			3.2.7.2 Mechanized application with concrete spraying pump
and manipulator
			3.2.7.3 Mechanized application with self-propelled mobile concrete sprayers
			3.2.7.4 Shotcrete systems for TBM machine
		3.2.8 Functions and performance
			3.2.8.1 Low-pulsation concrete pumping
			3.2.8.2 Integrated accelerator dosing
			3.2.8.3 Boom and Nozzle movements and positioning
			3.2.8.4 Real-time control and diagnostics of process
		3.2.9 Research and development
			3.2.9.1 Hybrid technology
			3.2.9.2 Laser scanner technology and automation
			3.2.9.3 Logging of spraying process data and data transfer
	3.3 Steel ribs and girders
		3.3.1 General overview and application field
		3.3.2 Steel ribs/steel arches
		3.3.3 Tubular arch
		3.3.4 Lattice girders
		3.3.5 Installation and associated timelines
	3.4 Anchors
		3.4.1 General overview
		3.4.2 End-point-anchored bolts
		3.4.3 Frictional bolts
		3.4.4 Fully grouted bolts (grouted dowel)
		3.4.5 Cement grout
		3.4.6 Resin grout
		3.4.7 Self- Drilling (SD) bolts
		3.4.8 Fiberglass bolts
		3.4.9 Energy-absorbing rock bolts
		3.4.10 Hybrid systems (also with corrosion protection)
		3.4.11 Drilling, equipment and performance
	3.5 Cast-in-place lining and formworks
		3.5.1 General overview and application field
		3.5.2 Criteria for the definition of the main geometrical features
		3.5.3 Casting geometries
		3.5.4 Materials
			3.5.4.1 Concrete
			3.5.4.2 Liner reinforcement
			3.5.4.3 Fibers
		3.5.5 Typology of formwork systems
		3.5.6 Schedule and norms
		3.5.7 Operations in concreting cycle, curing and timing
		3.5.8 Precast predalles slab
		3.5.9 Precast elements
	3.6 Segment lining
		3.6.1 General overview and application field
		3.6.2 Types of rings and segments
		3.6.3 Criteria for the definition of the main geometrical features
			3.6.3.1 Internal diameter
			3.6.3.2 Thickness
			3.6.3.3 Average length
			3.6.3.4 Number of segments
			3.6.3.5 Joint shape
		3.6.4 The accessories
			3.6.4.1 Handling into the TBM
			3.6.4.2 Connections
			3.6.4.3 Injection device
		3.6.5 Materials
	3.7 Waterproofing and water collection
		3.7.1 Synthetic membranes
		3.7.2 Sprayed membrane
		3.7.3 Segmental liner watertightness
	3.8 Other support types
		3.8.1 Liner plates and steel sheets
		3.8.2 Bullflex
		3.8.3 RRS support type
		3.8.4 Deformable or yielding elements
			3.8.4.1 Swelling behavior
			3.8.4.2 Compressible/yielding layer in squeezing condition
			3.8.4.3 Sliding elements: collapsible telescopic ribs (Ω steel section)
			3.8.4.4 Compression/yielding elements
		3.8.5 GFRP and other materials
			3.8.5.1 Soft-eye technique
			3.8.5.2 Applications in aggressive environments
			3.8.5.3 Basalt fibers: green with high performance
	3.9 Large excavation support and technology
		3.9.1 Large excavations in rock
		3.9.2 Large excavations in weak rocks
		3.9.3 Large excavation in soils
			3.9.3.1 Cellular arch
			3.9.3.2 Active vault and “Nazzano” method
	Authorship contribution statement
	References
4 Auxiliary methods technology: ground reinforcing, ground improving and pre-support technology
	4.1 Introduction
		4.1.1 General classification
	4.2 Steel pipes umbrella and spiling (pre-support intervention)
		4.2.1 Historical overview: the origin of the method
		4.2.2 Modern review of the umbrella system
			4.2.2.1 Examples of steel pipes umbrella applications
		4.2.3 Forepoling and spiling
		4.2.4 Summary
	4.3 Use of fibreglass elements for face reinforcement (preconfinement intervention)
		4.3.1 Face reinforcement and fibreglass element
		4.3.2 Work phases
		4.3.3 Quality control
			4.3.3.1 Laboratory test
			4.3.3.2 Job site pull-out tests
		4.3.4 Summary
	4.4 Grouting
		4.4.1 Introduction
		4.4.2 Construction methods
			4.4.2.1 Penetration grouting
			4.4.2.2 Hydro-fracture grouting
			4.4.2.3 Compaction grouting
			4.4.2.4 Bulk filling
		4.4.3 Grout mixtures
			4.4.3.1 Suspensions
			4.4.3.2 Solutions
			4.4.3.3 Mortars
	4.5 Jet-grouting
		4.5.1 Introduction
		4.5.2 Jet-grouting technology
			4.5.2.1 Executive systems
			4.5.2.2 Equipment
			4.5.2.3 Working parameters
			4.5.2.4 Control procedures
		4.5.3 Application’s context and soil’s improvement
		4.5.4 Design criteria
			4.5.4.1 Soil investigation and field tests
			4.5.4.2 Design approach and technical specifications
			4.5.4.3 Monitoring systems
		4.5.5 Projects’ applications
	4.6 Artificial ground freezing
		4.6.1 Freezing methods
		4.6.2 Freezing applications
		4.6.3 Monitoring artificial ground freezing
			4.6.3.1 Surveying the actual arrangement of the net of freeze-pipes and thermometric chains
			4.6.3.2 Temperature monitoring
			4.6.3.3 Water pressure monitoring
			4.6.3.4 Displacement monitoring
		4.6.4 Summary
	4.7 Precut and pretunnel
		4.7.1 Cavity preconfinement by means of full-face mechanical precutting
		4.7.2 Cavity preconfinement using pretunnel technology
		4.7.3 Precutting: the evolution for tunnel widening
			4.7.3.1 Working cycle
		4.7.4 Summary
	4.8 Drainage
		4.8.1 Cavity preconfinement by means of truncated cone “umbrellas”
of drainage pipes ahead of the face
			4.8.1.1 Operational stage
		4.8.2 Particular cases
		4.8.3 Summary
	Acknowledgements
	Authorship contribution statement
	References
5 Monitoring
	5.1 Introduction
	5.2 Measurement, technologies and type of instruments
		5.2.1 Displacement and rotation
			5.2.1.1 3D topographical methods
			5.2.1.2 Optical levels
			5.2.1.3 Laser scanner
			5.2.1.4 GPS/GNSS
			5.2.1.5 Laser distometers
			5.2.1.6 Hydrostatic levelling system
			5.2.1.7 In-SAR methods
			5.2.1.8 Inclinometers
			5.2.1.9 Surface extensometers
			5.2.1.10 Borehole extensometers
		5.2.2 Strain
			5.2.2.1 Electrical strain gauges
			5.2.2.2 Fiber optic strain gauges
		5.2.3 Force
			5.2.3.1 Load cells
		5.2.4 Stress
			5.2.4.1 Total pressure cells
			5.2.4.2 Stress meters
		5.2.5 Water pressure and flow
			5.2.5.1 Piezometers
			5.2.5.2 Flowmeters
		5.2.6 Temperature
			5.2.6.1 Electrical thermometers
			5.2.6.2 Fiber optics distributed strain/temperature sensors
		5.2.7 Velocity and acceleration
			5.2.7.1 Vibrometer system
		5.2.8 Data acquisition and transmission system
			5.2.8.1 Dataloggers
			5.2.8.2 Telemetry
	5.3 TBM performance monitoring
		5.3.1 Performance parameters (all TBMs type)
			5.3.1.1 Drilling length [DL: m/cycle]
			5.3.1.2 Penetration rate [PR1: mm/min; PR2: mm/rev.]
			5.3.1.3 Advance rate [m/h]
			5.3.1.4 Cutterhead rotational direction and speed
[clockwise/anticlockwise RPM: rev/min]
			5.3.1.5 Cutter head torque [T: kNm]
			5.3.1.6 Cutter head thrust [F: kN]
			5.3.1.7 Cutterhead power [P: kW]
		5.3.2 TBM position
		5.3.3 Tunnel face stability and support action control (EPB/SPB TBMs type)
			5.3.3.1 Excavated ground volume per advancing cycle [m[sup(3)]/m]
			5.3.3.2 Excavated ground weight per advancing cycle [kN/m]
			5.3.3.3 Pressure in the excavation chamber (EPB TBMs) [bar]
			5.3.3.4 (Apparent) density of the material in the excavation chamber (EPB TBMs) [kN/m[sup(3)]]
			5.3.3.5 Pressure in the screw conveyor (EPB TBMs) [bar]
			5.3.3.6 Screw conveyor rotation speed (EPB TBMs) [rev./min]
			5.3.3.7 Screw conveyor torque (EPB TBMs) [rev./min]
			5.3.3.8 Air pressure in the air bubble (SPB TBMs) [bar]
			5.3.3.9 Height of slurry in the excavation chamber (SPB TBMs) [m]
		5.3.4 Construction data (all TBMs type)
			5.3.4.1 Shift report (SR: Adim.)
			5.3.4.2 Produciton data
			5.3.4.3 Utilization [U: %]
			5.3.4.4 Specific energy [SE: MJ/m[sup(3)]]
		5.3.5 Other monitoring data
			5.3.5.1 Volumes and pressure of materials injected during excavation (all TBMs type) [m[sup(3)]; bar]
			5.3.5.2 Ground conditioning parameters: concentration,
FIR, FER (EPB TBMs) [bar]
			5.3.5.3 Slurry characteristics (SPB TBMs)
			5.3.5.4 Air pressure and volume losses in the hyperbaric chamber (counterpressyre TBMs) [bar, m[sup(3)]/h];
	Authorship contribution statement
	References
6 Plants and job site organization
	6.1 Introduction
	6.2 Material and muck handling
		6.2.1 Trucks
		6.2.2 Trains
			6.2.2.1 Traction unit
			6.2.2.2 Muck cars
			6.2.2.3 Transport cars
		6.2.3 Multi-Service Vehicle (MSV)
		6.2.4 Belt conveyors
			6.2.4.1 Conveyor systems’ effectiveness
			6.2.4.2 Construction types
			6.2.4.3 Belt types
			6.2.4.4 Control system for conveyor systems
			6.2.4.5 Conveyor systems’ advantages
	6.3 Excavators, loaders and special hauling equipment
		6.3.1 Excavators
			6.3.1.1 Special equipment for excavators
		6.3.2 Wheel loaders and load, haul, dump (LHD)
			6.3.2.1 Dumpers
		6.3.3 Rail-borne loading and transport in tunnels
			6.3.3.1 Shuttle cars
	6.4 Sliding and lifting platform logistic system
		6.4.1 Suspended platform system
			6.4.1.1 The Ceneri Base Tunnel
	6.5 Aggregate and cement plants, grout, concrete and formworks
		6.5.1 Concrete plants in underground
		6.5.2 Injection plants
		6.5.3 Concrete transportation machines and performance
		6.5.4 Concrete pumping; equipment and performance
			6.5.4.1 Feeding systems
		6.5.5 Mobile formworks
			6.5.5.1 Self-reacting formwork
			6.5.2.2 Turret-type formwork
			6.5.5.3 Cut and cover formwork
			6.5.5.4 Light and multi-section formwork
			6.5.5.5 Cycling time and job site organization
		6.5.6 Full round equipment
		6.5.7 Self-launching formwork: principles, cycling time and job site organization
	6.6 TBM segment plants
		6.6.1 Moulds and tolerances
		6.6.2 Segment precasting methods
		6.6.3 Cover opening/closing
		6.6.4 Mould cleaning
		6.6.5 Segment demoulding operation
		6.6.6 Robotics and automation
		6.6.7 Traceability system
		6.6.8 BIM design and tunnel modelling in the Industry 4.0 (I4.0) supply chain
	6.7 Ventilation systems design for tunnelling during its excavation
		6.7.1 Underground ventilation criteria
		6.7.2 Design flow rate
			6.7.2.1 References
			6.7.2.2 Airflow demand
			6.7.2.3 Ventilation scenarios analysis example
			6.7.2.4 Fan flow rate
			6.7.2.5 Design pressures calculation
			6.7.2.6 Fan losses
			6.7.2.7 Calculation parameters
			6.7.2.8 Lambda and duct leakage factors
		6.7.3 Equipment and material characteristics
			6.7.3.1 Fan characteristics
			6.7.3.2 Tunnel ducts
			6.7.3.3 Installation of ducts
		6.7.4 Energy consumption
			6.7.4.1 Sensitivity analysis: the importance of a correct duct sizing
		6.7.5 Calculation of pollutants and Health, Safety & Environment (HSE) requirements
			6.7.5.1 Pollutants
			6.7.5.2 Exposure limits
			6.7.5.3 Temperature and oxygen level
			6.7.5.4 Ventilation monitoring
			6.7.5.5 Gas monitoring
		6.7.6 Complex cases
			6.7.6.1 Brenner Base Tunnel experience
			6.7.6.2 Very long adits – use of plenum
			6.7.6.3 Specific areas of risk
	References consultation
	Acknowledgements
	Authorship contribution statement
	References
7 Tunnel refurbishment
	7.1 Introduction
	7.2 Investigating the lining condition
	7.3 Rehabilitation works for tunnel in the absence of traffic
		7.3.1 Shallow interventions
			7.3.1.1 Steel and FRP nets
			7.3.1.2 Treatment of shallow cavities
			7.3.1.3 Replacement of reinforcement bars
			7.3.1.4 Resins injection
			7.3.1.5 Leakage collection
		7.3.2 Deep interventions
			7.3.2.1 Interventions in the presence of deep detachments
(20–40 cm)
			7.3.2.2 Treatment of deep cavities in the lining (up to 40 cm)
			7.3.2.3 Treatment of cavities at the ground-lining interface: method statement
			7.3.2.4 Structural arches at the intrados
		7.3.3 Lining demolition and reconstruction
			7.3.3.1 Temporary pre-works strengthening
			7.3.3.2 Concrete cutting
			7.3.3.3 Milling, demolition and preparatory work for lining
			7.3.3.4 Concrete casting with prefabricated and mobile formworks
	7.4 Rehabilitation works in the presence of traffic
		7.4.1 Use of prefabricated protection shields
		7.4.2 Use of mobile protection
	7.5 Revamping of water tunnels
	Authorship contribution statement
	Futher reading
Index