Thames Water Utilities Ltd Major Projects

Thames Tideway Tunnel Programme

Lee Tunnel Main Contract Contract No 6LYG/A1

Section 4 PT – Particular Tunnelling Specification

Operating Division Waste Water Services

August 2008 Lee Tunnel, Contract No. 6LYG/A1 PT – Particular Tunnelling Specification - PT100

PT100 PARTICULAR TUNNELLING SPECIFICATION - INTRODUCTION PT100.1 So far as the Specification for Tunnelling may conflict, or be inconsistent, the specifications shall prevail in the following order of precedence: • Particular Tunnelling Specification • Specification for Tunnelling (BTS/ICE 2000) • Particular Civil Specification • CESWI PT100.2 Clause numbers for 'tunnelling' specifications are prefixed with a 'PT', i.e. PT112.1.4 etc. For consistency, the 'PT' prefix shall be deemed to apply also to all sections and clauses in the Specification for Tunnelling. PT100.3 Clauses for the main tunnel 7200mm diameter are prefixed PT2XX, the 3.05 ID Abbey Mills Connector Tunnel “TBM and Tunnelling” PT3XX, for the precast concrete segmental tunnel linings PT4XX, for the EPDM gaskets to the precast concrete segmental tunnel linings PT5XX and for the segmental shaft linnings PT6XX. PT100.4 This Specification for Tunnelling covers all Tunnelling Works and Segmentally lined Shafts within the scope of Works for this Project . PT100.5 Diaphragm Walls are specified in the Particular Civil Specification:-PC 3.15. PT100.6 The Contractor shall refer to the Particular Civil Specification for the requirements for all structures not specifically referenced in this specification. PT100.7 The Lee Tunnel is a long tunnel drive predominantly in flint laden chalk at high water pressures as described in the Geotechnical Baseline Report. The tunnel route prevents any direct access to the TBM from the surface. For this reason TW considers that the design, performance & operation of the TBM is one of the major risk mitigations on the Lee Tunnel.

This specification should be considered as a MINIMUM requirement.

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TABLE OF CONTENTS

PT200 SPECIFICATION FOR NEW TUNNEL BORING MACHINE AND TUNNEL CONSTRUCTION – 7200MM MINIMUM NOMINAL INTERNAL DIAMETER FOR TUNNEL BETWEEN BECKTON STW AND ABBEY MILLS PS...... 2 PT201 SUMMARY...... 2 PT202 REFERENCE STANDARDS ...... 2 PT203 DEFINITIONS ...... 2 PT204 SUBMITTALS ...... 3 PT205 GENERAL- TUNNEL BORING MACHINE ...... 5 PT206 MINIMUM REQUIREMENTS FOR TBM TUNNELLING EQUIPMENT...... 6 PT207 FINITE ELEMENT (F.E.) ANALYSIS...... 6 PT208 CUTTERS ...... 6 PT209 CUTTER HEAD ...... 7 PT210 CUTTER HEAD INTERVENTIONS ...... 8 PT211 FRONT SHIELD...... 8 PT212 THRUST SYSTEM AND STEERING ...... 9 PT213 DRIVE SYSTEM ...... 9 PT214 EXCAVATED MATERIAL MUCKING SYSTEM ...... 10 PT215 SEALS...... 12 PT216 GROUTING SYSTEM...... 13 PT217 SEGMENT ERECTOR...... 13 PT218 ERECTOR BRIDGE...... 14 PT219 SEGMENT MAGAZINE ...... 15 PT220 TBM – LINING INTERFACE...... 15 PT221 CONTROL AND INTERLOCKS...... 15 PT222 TBM OPERATION ...... 16 PT223 TBM ELECTRICAL REQUIREMENTS...... 17 PT224 GUIDANCE SYSTEMS...... 18 PT225 TAIL SEAL GREASE INJECTION ...... 21 PT226 OTHER FEATURES ...... 21 PT227 SPARE PARTS...... 22 PT228 FIRE PREVENTION – TBM AND BACK-UP...... 22 PT229 TBM FACTORY TESTING...... 23 PT230 QUALITY ASSURANCE ...... 23 PT231 QUALITY PLAN ...... 24 PT232 PERSONNEL AND TRAINING...... 24 PT233 TUNNEL HEALTH AND SAFETY ASSURANCE ...... 24 PT234 REGULATIONS...... 24 PT235 BORED TUNNEL TEMPORARY FACILITIES...... 26 PT236 TUNNEL BORING MACHINE MAINTENANCE...... 27 PT237 GENERAL TUNNELLING CONSTRUCTION REQUIREMENTS...... 27 PT238 ELECTRONIC DATA ACQUISITION, VISUALISATION AND REPORTING SYSTEM (DAVARS) ...... 27 PT239 GROUTING METHODOLOGY ...... 29 PT240 INSTALLATION, MONITORING AND CONTROL FOR SEGMENTAL LINING 30 PT241 SURFACE DISPLACEMENT MONITORING ...... 31 PT242 DEFECT AND CONDITION SURVEYS ...... 34 PT243 TEMPORARY ELECTRICITY SUPPLY FOR TUNNEL CONSTRUCTION ...... 34 PT244 TREATMENT OF ARISINGS...... 34 PT245 TBM LAUNCH FROM OVERFLOW SHAFT ...... 36 PT246 CONSTRUCTION TOLERANCES ...... 36 PT247 AS-BUILT TUNNEL SURVEY ...... 36 PT248 SECONDARY LINING DESIGN AND ISTALLATION ...... 37

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PT200 SPECIFICATION FOR NEW TUNNEL BORING MACHINE AND TUNNEL CONSTRUCTION – 7200mm MINIMUM NOMINAL INTERNAL DIAMETER FOR TUNNEL BETWEEN BECKTON STW AND ABBEY MILLS PS

PT201 SUMMARY PT201.1 The work in this Section includes, but is not limited to, providing all labour, materials, tools, equipment, and incidentals necessary to construct a 7200mm minimum nominal ID finished tunnel (including a primary and secondary lining) in accordance with the Works Information and Site Information. PT201.2 The work in this Section includes, but is not limited to, the following activities: • The provision of a new Tunnel Boring Machine includes, but is not limited to: design, manufacture, supply, maintain and testing of a tunnel boring machine for the express purpose of constructing TBM excavated tunnels between Beckton and Abbey Mills. • Boring Tunnel includes, but is not limited to: mining of tunnels, installation of pre-cast concrete segmental tunnel lining, temporary tunnel facilities, geotechnical monitoring, control of ground loss, settlement and heave, and removal and disposal of excavated material. • As-Built Tunnel Survey PT201.3 This is a performance specification. The Contractor shall be responsible for the selection and complete design of the new tunnel boring machine and tunnel construction systems. The Works Information, Site Information and GBR provides parameters and design criteria for this element of the works.

PT202 REFERENCE STANDARDS PT202.1 UK Health and Safety Regulations including but not limited to the Construction, Health, Safety and Welfare Regulation 1996, The Confined Spaces Regulations 1997 and the Approved Code of Practice H.S.E. Document L101. PT202.2 Joint Code of Practice for Risk Management of Tunnel Works in the UK published by the British Tunnelling Society/Association of British Insurers and the International Tunnelling Association/AITES Guidelines to Tunnelling Risk Management: ITA Working Group. PT202.3 BS6164: 2001 Code of Practice for Safety in Tunnelling in the Construction Industry. PT202.4 EFNARC (European Federation for Specialist Construction Chemicals and Concrete Systems) Specification and Guidelines for the use of Specialist Products for Soft Ground Tunnelling. This publication is located at the following internet address: http://www.efnarc.org/pdf/SGTSpec.pdf) PT202.5 BSEN 12336:2005 -Tunnel Machine Safety Requirements. PT202.6 The Groundwater Regulations 1998: “Protection of Groundwater Against Pollution Caused by Certain Substances” List One and List Two.

PT203 DEFINITIONS PT203.1 TBM excavation: The construction of underground tunnels by mechanical means using a tunnel boring machine PT203.2 Segmental tunnel lining: Pre-cast concrete segments that are bolted together inside the TBM tail shield to form a gasketed, watertight tunnel lining ring. The lining shall be designed to withstand both handling loads and all ground and external hydrostatic and internal storm water loads.

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PT203.3 TBM: As used in this Section, the term New TBM means the total system of the tunnel boring machine including trailing gear and relevant support equipment, materials and any items of plant which are necessary for the sustaining of TBM excavation operations all to be designed in accordance with the requirements of this Section, all elements of the above shall be new. The TBM shall have the ability to apply a sustained and controlled pressure on the tunnel face within a pressure bulkhead located behind the face, to form a plenum under pressure with the remainder of the tunnel maintained at atmospheric pressure. PT203.4 EPBM: An Earth Pressure Balanced TBM with a pressure bulkhead located behind the face to form a plenum under pressure. Conditioners can be injected through the cutter head and into the plenum to control the quality of the excavated material through a screw conveyor in closed or open mode. For the construction of this tunnel the EPBM will operate in closed mode at all times, unless expressly agreed by the Project Manager. PT203.5 SPBM: A Slurry Pressure Balanced TBM utilising a controlled slurry in a pressure chamber in the head of the machine to stabilize the face and minimize settlement. The resultant slurry, with excavated material, is removed to the Slurry Separation plant by pumping.

PT204 SUBMITTALS PT204.1 The following information shall be submitted to the Project Manager within 28 days of the award of Contract: a) TBM Manufacturer’s Name, Address, and Track Record in Production of similar TBMs. b) A detailed programme for the design, manufacture and assembly of the TBM including the place of manufacture and assembly. The Contractor shall arrange regular “Task Force” meetings with the Project Manager and the TBM Supplier to develop the TBM design, monitor the manufacture, ensure exchange of information, develop TBM transport and assembly requirements and meet programme dates. c) TBM Concept Plan and Drawings consisting of the following elements: i) General Arrangement Drawings from TBM manufacturer ii) Proposed TBM type including specifications to meet the minimum requirements set out in this document. iii) Statement on the technical assistance afforded by the TBM supplier to the Contractor during the assembly at the work site and during commissioning start up and learning curve until the TBM performance requirements have been achieved. iv) A statement setting out the training plan for the Contractors proposed TBM staff carried out by the in liaison with the Contractor. v) Statement of the technical assistance to be afforded by the TBM supplier during the assembly of the TBM. vi) Type of cutting tools, their wear resistance, expected wear rate and track record stating where they have been used on other projects. d) Preliminary Quality Plan The Preliminary Quality Plan shall indicate the approach and structure that the Quality Plan will take with respect to the design and supply of the TBM. e) All quality assurance and quality control procedures which are to be used in the design, manufacturing, commissioning and maintenance of the TBM. The preliminary plan shall cover such issues as, non-destructive testing plans, and of steel plate identification, weld testing and procedures.

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f) Quality assurance audit proposals i) A statement detailing the records that will be kept and supplied to the Project Manager. ii) Inspection and test plans for each activity requiring inspection and the level of that inspection. g) TBM Detail Plans showing: i) Cutters, cutter head and overcut ii) Conditioner generation and injection system iii) Integrated support pressure control system iv) Thrust, steering and drive systems, including main bearing v) Shield articulation details demonstrating compliance with the minimum radius requirements. h) Spoil Treatment i) For EPBM, provide details of type of conditioners to be used, mixing methods and proposed muck to conditioner ratios, and a description of the various conditioners used in anticipated ground conditions for the TBM. ii) For SPBM, provide details of the slurry treatment plant and operations, slurry and conditioner materials and additives to be used. This is to include the number of centrifuges that the Contractor proposes to provide and the assumptions made in the design of the Separation Plant. i) Product Data Provide data sheets for materials to be used for tunnel excavation including shelf life and handling and storage instructions particularly any polymers shall be submitted for acceptance by the Project Manager. j) Risk Assessments for the type of TBM selected and associated tunnelling method. The Contractor shall submit a comprehensive and detailed risk assessment for the above. This shall take into account the following: i) The strategy for interventions into the cutting head for planned and unplanned maintenance or monitoring in high water pressures. ii) The ability to undertake major repairs to the TBM. iii) The issues associated with transporting spoil within the tunnel and shaft. iv) The ability to achieve long term production rates. v) Wear resistance of the cutter head, tooling and other wear parts. vi) The risk of TBM rolling due to high cutter head torque. k) Ground Settlement Control i) The contractor shall submit to the Project manager within 28 days of the award of Contract, the operation and control features for the TBM to minimise subsurface and ground level settlement as described in PT206.2. ii) A TBM Hazard and Risk Assessment, to be submitted a minimum of 28 days after award of the Contract. The TBM Hazard and Risk Assessment is to include the following:

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• The TBM electrical system (electrical shock and fire, electrical equipment fault and damage, loss of power supplies, fire suppression systems etc). • The TBM Back-up system, leakage of high pressure fluids, close location to heat and electrical sources, occurrence of naked flame, danger of moving machinery etc). • The entry and exit points from the TBM and back-up systems ( To include as a minimum:- means of escape during an emergency, moving of tunnel lining segments through the TBM back-up on to the segment erector, moving of tunnel lining segment on the segment erector, dangers to personnel arising from the segment erector, and operation of cutter head etc). • Access for operation and maintenance for the TBM, including for surveying. • The slurry discharge circuit (SPBM). • The grouting system. • TBM assembly and dismantling. PT204.2 28 days prior to delivery of the TBM to the Contractor, As-constructed drawings, technical documentation and details of the TBM manufacturer’s recommended planned maintenance proposals shall be forwarded to the Project Manager. PT204.3 Within 28 days, a list of recommended consignment spares that the Contractor will retain on Site. The list shall be derived from a risk assessment undertaken by the Contractor and agreed with the Project Manager. The risk assessment shall identify which parts are likely to wear out, anticipated life-span of the parts and level of appropriate spares required on Site.

PT205 GENERAL- TUNNEL BORING MACHINE PT205.1 The work of this Section includes, but is not limited to, the following activities: supplying a new tunnel boring machine (TBM), as defined in this Section, for the express purpose of constructing TBM excavated tunnel in materials of soil types, densities, gradations(PSD), strength, abrasivity and hydrostatic pressures described in the GBR and Contract Documents. PT205.2 The TBM shall be designed to withstand all loads and forces occurring from the overburden and hydrostatic pressures and all loads and forces arising from operating the TBM, both in normal mode and in modes required to correct misalignment. PT205.3 The TBM shall be capable of applying a sustained and controlled pressure on the tunnel face to maintain surface settlements within the specified limits at all times. PT205.4 The bored tunnel lining shall be bolted pre-cast concrete segments fitted with EPDM gasket as specified in PT400. PT205.5 The selection of tunnel boring equipment and construction methods shall be compatible with the ultimate use of the tunnels, the ground and groundwater conditions, the depths of tunnels and the proximity of existing structures and services. PT205.6 TBM and supporting equipment shall be designed in accordance with the requirements of CEN standard BSEN 12336:2005 Tunnel Machine Safety Requirements. PT205.7 Design TBM and backup equipment to negotiate the curves in the alignment and meet the specified alignment tolerances as defined in the Contract Documents.

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PT205.8 Diameter of excavated tunnel: to be a minimum of 7200mm ID to match the Contractor’s design and to produce minimal over-excavation and least necessary clearance. Take into account horizontal and vertical grades to be negotiated. PT205.9 Equip TBM with integrated safety systems in accordance with applicable regulatory requirements for underground construction equipment and in accordance with BS6164 2001 “Safety in Tunnelling in the Construction Industry”. PT205.10 All soil conditioning materials, oils, greases, sealing compounds and any other material injected into or in contact with the soil, rock or ground water which is used during the mining operation shall be compliant with all relevant regulatory agencies and the requirements of the Works Information.

PT206 MINIMUM REQUIREMENTS FOR TBM TUNNELLING EQUIPMENT With particular reference to the Works Information and Site Information, the requirements as detailed in this Section will not modify or detract in any way whatsoever from the Contractor’s sole responsibility for the selection, design and operation of the tunnelling plant and equipment. PT206.1 The Contractor shall supply, assemble, maintain, operate and remove all tunnelling equipment necessary to construct and complete the tunnel in accordance with the Works Information and the ground conditions encountered. PT206.2 Ground Settlement: - The operation and control features of the TBM shall be designed to minimise sub-surface and ground level settlement. Ground loss from the TBM boring and tunnel construction shall be limited to a maximum of 1% of the excavated volume. The Contractor shall demonstrate in the form of a Method Statement the TBM operating principles that shall govern the use of the TBM in order to meet these requirements. PT206.3 The Contractor shall design the TBM to allow for the replacement of the main bearing, rearwards, from within the TBM.

PT207 FINITE ELEMENT (F.E.) ANALYSIS PT207.1 The shield shall be designed to withstand all loads and forces occurring from the overburden and hydrostatic pressures and all loads and forces arising from operating the TBM, both in normal mode and in modes required to correct misalignment. PT207.2 The design of the structure of the shield body and other important members shall be supported by FE method calculations under all loading conditions in graphical and numerical form. A Cat 3 check on all critical elements (to be agreed with the Project Manager) shall be carried out and the results forwarded to the Project Manager for acceptance.

PT208 CUTTERS PT208.1 The cutter head shall incorporate: Cutting tools appropriate for the expected geological conditions with replaceable wear protection. Pick cutters shall have substantial tungsten carbide inserts of grade E3 material equivalent to Sinter-HIP or grade B40 and have their exposed bodies wear protected with chromium carbide composite plate or similar material. Electrical cutter wear indicators shall be fitted to gauge, outer and face pick cutters. PT208.2 Disc cutters shall be a minimum of 17” dia of a type that will revolve in the mixed strata and avoid flats being worn on the tyres, double disc cutters shall be considered. Disc cutters shall lead the pick cutters by a minimum of 50mm at the face. a) Cutter design shall take into account the abrasivity of the ground conditions. The cutters shall be hard faced to a design giving best wear resistance.

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Cutters shall be back loaded such that access for repair and replacement can be carried out in safe working condition from within the TBM working chamber. b) Fixed gauge cutting shall be with disc cutters supported by pick cutters. The design shall incorporate a minimum of 6 passes of gauge & semi gauge disc cutters. c) Rescue tooling shall be incorporated in the outer section of cutter head arms. The rescue tools shall be held in reserve and only indexed into use upon failure of normal cutters. The rescue tools shall be used to reach a “safe haven” where free air conditions prevail to allow tool changing. PT208.3 All cutting tools shall be designed to be replaced from the rear face of the cutter head. Consideration shall be given to means of improving the work environment and reducing the duration of tool changing by use of mechanical aids and access ladders. PT208.4 The Contractor shall pay particular attention to protection of the moving (rotating) elements of the machine against the potentially abrasive nature of the ground. The TBM shall be equipped with Chromium Carbide abrasion resistant plating or other approved hard facing to all exposed moving surfaces of the TBM, for example cutting head and screw conveyor. PT208.5 Design components for maximum abrasion resistance and durability. Minimize disc cutter wear to the greatest extent possible when not currently in use to perform tunnel excavation by such means as designing hubs and bearings to allow discs to be readily rotated by hand.

PT209 CUTTER HEAD PT209.1 The TBM shall incorporate a soil conditioning system for injection directly onto the face. The screw conveyor (if EPBM closed mode) shall also incorporate a facility for soil conditioning. Soil conditioning agents shall be bio-degradable and acceptable for the excavated materials to be used as a fill. All ports shall be independent. PT209.2 The TBM shall be capable of excavating through the ground conditions indicated in the Works Information and Site Information and geological and geotechnical information available to the Contractor without interruption of the excavation operations. PT209.3 The cutter head structure and bearings shall be rated to absorb the maximum forces during tunnelling operations. PT209.4 The cutter head shall incorporate the following:- a) Rotary fluid coupling for transfer of hydraulic fluids. b) Provision to retract the cutter head from the face of the strata without rearward movement of the tail shield. c) An indexing facility to allow probe and ground treatment drilling through the cutter head. d) Bi-directional cutting. e) The cutter head aperture size shall be designed for all anticipated ground conditions as referred to is clause (b) of this section. The proposed aperture size shall be included in the tender information provided by the Contractor. It shall afford adequate ground support and spoil flow features. A cutter head of the open type with a minimum aperture size of 40% shall be provided. f) A method of pre-setting the cutter head to index into the desired tool change positions without the need to open the air lock entry door.

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g) An adjustable copy cutter with means of detecting the stroke and the arc through which it is selected. PT209.5 The Contractor shall consider in the design of the TBM a means of ensuring a safe method of work for the personnel carrying out all necessary work on the cutter head including mechanical aids for the transport of tools and equipment into the cutter head.

PT210 CUTTER HEAD INTERVENTIONS PT210.1 The Contractor shall submit within 28 days of the award of Contract a Method Statement detailing the proposed method for cutter head interventions for planned and unplanned maintenance, head inspections and other events. Should the use of the TBM compressed air system be considered the Method Statement shall demonstrate compliance with following compressed air documents: a) Work in Compressed Air Regulations (1996). b) Health and Safety Booklet “A Guide to the Work in Compressed Air Regulations 1996 – Guidance on Regulations (L96). c) Addendum “A guide to the Work in Compressed Air Regulations 1996 – Guidance on Oxygen Compression and use of Breathing Mixtures other than Compressed Natural Air in the Working Chamber” issued by the Health and Safety Executive. PT210.2 The Health and Safety Executive have advised the Employer that whilst the Regulations are not being revised, a new document combining references b) and c) above, along with a revision of the combined text is in preparation and it is hoped that this document will be issued by the HSE before the proposed start date of this Project. It is understood that the HSE document will set out procedures requirements on the Contractor seeking exemptions from the Regulations and for the approval by the HSE of the compressed air working practices which deviate from those required by the regulations. These could include interventions at pressures greater than the present legal pressure limit of 3.5Bar. With this understanding, it will be the intention of the Employer to hold discussions with the Contractor to assess and agree what impact these changes will have on the Contractors proposed methodology for interventions at high pressures, its impact on the proposed programmes and cost implications. The Contractor shall, in order to mitigate any potential delays to the Project and to ensure the cooperation and assistance in obtaining required approval from the Health and Safety Executive, invite a representative of the HSE to attend any discussions held on the issue of working in Hyperbaric Conditions. Preliminary discussions will be held between the Employer and the HSE in advance the award of Contract to try and secure HSE’s agreement in principle to interventions at pressure in excess of 3.5Bar. PT210.3 The Contractor will be responsible for obtaining all Regulatory exemptions and/or approvals for the proposed methodology and the Project Manager shall be invited to attend any meetings held with the Health and Safety Executive (with a minimum of two weeks notice). PT210.4 The design of airlocks shall conform to BSEN 12110:2002 Tunnelling Machines- Air-Locks Safety Requirements (currently being revised). PT210.5 The design shall include an effective means of testing for and purging the forward chamber of any hazardous gases and ventilating the TBM and back up before entry.

PT211 FRONT SHIELD PT211.1 The Front Shield shall incorporate a pressure bulkhead designed to withstand all operational pressures.

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PT211.2 A sufficient number of sleeves fitted with shut off valves spaced around the periphery for angular ground treatment shall be provided. The arrangement of the sleeves shall allow for the formation of a treated zone in the ground 20m diameter at a distance of 20m to 30m in front of the TBM cutter head face. This shall include the ability to insert freeze pipes through the angular holes to allow localised freezing of the ground. PT211.3 Provision for multiple probe / ground treatment drilling through the bulkhead to include glands and shut off valve shall be provided. This shall include the ability to insert freeze pipes through the angular holes to allow localised freezing of a ground. PT211.4 A collapse detecting device fitted to the front crown area for the detection of voids shall be provided.

PT212 THRUST SYSTEM AND STEERING PT212.1 Design TBM to provide forward propulsion by thrust cylinders that react against the installed segmental lining without damaging the lining and allow segment key insertion at pre-determined locations to suit tunnel curves. PT212.2 Equip the thrust cylinders with shoes or pads to distribute the jacking forces to the lining without damaging the lining. Design the thrust cylinder shoes to be consistent with segment and segment joint design while capable of individual and synchronized thrust cylinder actuation while limiting the maximum force that each thrust cylinder may exert so that linings are not damaged. Thrust cylinders shall resist displacements when idle. The control of the shove rams shall ensure that only those rams necessary shall be retracted to allow insertion of individual segments to prevent rearward movement of the TBM due to hydrostatic conditions. PT212.3 The TBM shall have a proven anti-roll system. PT212.4 The shield shall be articulated, subject to the following: a) Design and locate an articulation joint (or joints) as required, to assist constructing the tunnel to the theoretical alignment indicated in the Works Information and within the specified tunnel construction tolerances. Active articulation shall be rated to absorb a minimum of the maximum shove force. b) Equip the articulation joint with a seal replaceable from within the TBM to prevent the entry of slurry, grout, fines or other foreign material. Provide a means for cleaning the articulation joint from inside the TBM to maintain its full range of articulation.

PT213 DRIVE SYSTEM PT213.1 Provide a TBM having sufficient drive motor power so the machine is not torque limited while operating in earth pressure balance mode or slurry mode for any ground materials or conditions described in the Geotechnical Baseline Report. A torque / speed graph showing constant power characteristics shall be submitted to the Project Manager PT213.2 Provide capacity to start cutter head with not less than 1.25 times rated full load torque. Provide clutches or hydraulic assist for a variable frequency electric drive (VFD) or use a variable speed hydraulic drive system. PT213.3 The main bearing shall be designed such that it can be removed rearward from within the front bulkhead with the minimum of disturbance to other components PT213.4 The main bearing shall have a rating of not less than 10,000 hours B10 life based upon the assumed loadings defined by the TBM Supplier. The bearing shall be a 3- row axial, radial and counter axial roller bearing with integral drive gear. The Contractor shall submit lifecycle calculations for the main bearing and drive pinions against the given load cases for acceptance. As part of the proposal the

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Contractor shall nominate a recognised main bearing supplier and possible delivery time mitigation to meet TBM delivery requirements. PT213.5 Main drive gearboxes and motors shall have a rating of not less than 10,000 hours B10 life for the given load cases selected for the main bearing by the Contractor. PT213.6 To mitigate any risk of gearbox or drive pinion failure causing damage to the main bearing gear final drive pinions meshing with the main gear shall have bearing supports on each side of the pinion to remove bending moments. The Contractor shall submit the details of the gearbox drive pinions and support bearings to the Project Manager. PT213.7 Sampling points shall be provided for all lubricants in accessible points. PT213.8 TBM drive system shall be bi-directional.

PT214 EXCAVATED MATERIAL MUCKING SYSTEM PT214.1 If proposing an EPBM, fit and operate earth pressure balance tunnel boring machine with a screw conveyor in closed mode or in open mode to remove excavated material from the cutterhead chamber. Design the screw conveyor for operation in abrasive soil and for efficient replacement from within the tunnel. PT214.2 If proposing an EPBM, the screw conveyor shall be designed to maintain the required face pressure within the cutterhead chamber and the entrance to the screw conveyor. Pressure shall be reduced to atmospheric at the screw exit by control of the screw conveyor. The tunnel boring machine shall be capable of controlling face pressure to within ± 0.3Bar of the hydrostatic pressure. PT214.3 If proposing an EPBM, design the screw conveyor to be capable of being closed and sealed against earth pressure at each end. The front of screw conveyor shall be located at the base of the pressure chamber and shall project into chamber when operating. The screw shall be capable of being withdrawn in order to close front bulkhead door for maintenance and removal of obstructions. The design of the discharge shall include a system of flow dividers to prevent jamming. In the event of a power failure the discharge gate shall be closed by a stored power system. PT214.4 Fix the exit/outlet end of the EPBM screw conveyor with a pressure lock-out device to separate the pressurized ground water and muck from atmospheric pressure. PT214.5 For EPBM, provide mixing arms within the muck chamber to uniformly condition the material in the chamber. PT214.6 If proposing an EPBM provide and calibrate, as a minimum, six pressure cells in the mucking chamber and a minimum of four pressure cells on the screw conveyor all as recommended by manufacturer or as needed to assure accuracy of pressure measurements. Both EPBM and SPBM shall utilise the pressure gauges to detect water inflow into the mixing chamber to establish prevailing ground permeability. PT214.7 If proposing an SPBM provide a minimum of four agitator paddles in the suction zone of the Working chamber. PT214.8 The slurry circuit shall be designed to handle a minimum of: a) Solids volume per hour 300 cum. b) Total weight of solids volume removed 600 t/hour. c) Minimum slurry velocities of 4 m/s to ensure solids remain in suspension. PT214.9 The slurry system shall be equipped with: a) A means of measuring discharge slurry densities and velocities.

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b) A system which measures the excavated spoil mass and compares with the theoretical mass per ring of excavation, to prevent over excavation. c) A charge and discharge slurry pipe extension system including the necessary pipe handling machines. d) Non-return valve system to prevent slurry spillage into the tunnel when extending the pipes. e) Electrical programmable pump controllers to regulate and maintain the slurry circuit pressure. f) Bypass circuit and re-circulating controls. g) The Contractor shall design the slurry system to cater for anticipated spoil including the high strength flints, cobbles and associated abrasive materials. h) The Contractor shall carry out a risk assessment based on previous experience of similar systems in similar ground conditions to determine the location and which components will be subject to high wear and maintenance. i) The Contractor shall design the slurry main system to facilitate planned removal of high wear components with minimum down time. j) The Contractor shall have available appropriate spares for replacement of components including pumps and pipes. k) The Contractor shall prepare and submit his planned maintenance manual to the Project Manager. l) The Contractor shall provide the design of the proposed Rock Crusher to the Project Manager which shall then be tested with samples of flint to demonstrate its capability to crush them. m) A proven design of rock crusher or crushers shall be provided to reduce flint rock to a size of 100mm. The crusher or crushers shall be serviced from the rear face of the forward bulkhead in free air conditions. They shall form part of the slurry discharge system to ensure that all large rock pieces are reduced in size. The rock crushers shall be capable of crushing rocks (flints) as described in Contract Documents. The crusher or crushers shall be sized on an excavation solids volume of 300 cum/hour of which it can be expected 75cum/hour may consist of flint pieces. n) For SPBM, the TBM shall be designed to work under all conditions described in the Works Information and Site Information. This includes the complete slurry system required to stabilize the face and drive the tunnel. The slurry machine shall be capable of controlling the applied face pressure to within 0.3Bar of the hydrostatic head. o) If proposing SPBM the contractor shall provide a high pressure flushing system with the capability to direct flows to improve the agitation of the slurry and break up blockages in the area of the aperture of the submerged wall and in the area of the entrance to the suction pipes. p) If proposing a SPBM the TBM shall be capable of supporting hydrostatic pressures of up to 8Bar with an equivalent or greater slurry pressure q) Use a conveyor, rail or slurry system for muck transport in the tunnel. Design the system for the materials stated in the GBR, including abrasive flint chards, chalk fines and Thanet Sands. All proposed systems shall take into consideration the designed gradients of the tunnel and the safety of the underground personnel. r) For all conveyor belt systems, there shall be an audible alarm with a red flashing warning light giving the operatives advanced warning that the conveyor belt is about to start moving. Emergency stop buttons shall be

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provided at all working points and at frequent intervals along the conveyor belt system. Restarting the conveyor shall only be possible from a single position and under the control of one person s) For SPBM, the design of the slurry treatment plant shall accommodate the types and quantities of geological materials anticipated and to remove solids from the suspension at a rate such that the slurry treatment does not limit the TBM advance rate. The slurry shall be reconditioned or replaced with fresh slurry when the slurry properties are unsatisfactory. t) For SPBM, the TBM shall be fitted with flow, density and pressure meters in the inbound and outbound slurry pipes to: i) Monitor the progress of the TBM ii) Detect and control conditions in the excavation chamber iii) Ensure quality of slurry to the working chamber. iv) Detect slurry leakage in the system v) To check the actual volume of excavated material against the theoretical excavation per ring of advance. u) For SPBM the inbound and outbound pipes shall be provided with non-return valves to prevent slurry leakage into the tunnel during slurry pipe extensions.

PT215 SEALS PT215.1 The main bearing sealing system shall be of a proven design capable of protecting the bearing life of 10,000 working hours. Provide main bearing seals rated for tunnelling conditions and maximum pressure anticipated from the sum of all forces acting on the seals simultaneously and all machine operating characteristics related to the main bearings. Design the seals for the articulation joint, tail shield and probe ports for maximum hydrostatic and earth pressure. The sealing system shall be rated to withstand the maximum potential hydrostatic pressure as described in the GBR. PT215.2 The design shall provide for exchanging both inner and outer sealing systems from within the tunnel should failure of the seals occur. PT215.3 The main bearing sealing system shall have facilities to monitor its performance. Where total loss grease is used for lubrication, cooling and support of the seals a means of sampling shall be provided. Where oil is used to lubricate, cool and support the seals the TBM shall incorporate a circuit to filter, cool and sample the oil. PT215.4 The sealing system shall include the flushing of all component parts prior to assembly and flushing of the full system PT215.5 Shield tail seals shall incorporate a system of wire brushes to seal against maximum hydrostatic and cavity grout pressure with due consideration of the lining segment design and the influence of lining grouting in seal design. Provide a minimum of four rows of tail seals continuously fed with fibrous grease whenever the TBM advances. The first fill of the tail seal brushes shall be carried out by hand or pump stuffing using a grease of greater density than that used for the main tunnelling. PT215.6 Tail seals other than the rear seal shall be replaceable from within the tunnel during a drive. The Contractor shall provide a method statement before completion of TBM design detailing the proposed method for the replacement of the Tail seal brushes that shall be submitted for acceptance to the Project Manager.

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PT216 GROUTING SYSTEM PT216.1 The Contractor shall provide a computer operated grouting system linked to the TBM systems to calculate grout quantities and continuously adjust grout injection rate and pressure to ensure it does not exceed the hydrostatic or soil overburden pressure. All in accordance with the requirements as specified. PT216.2 There shall be provision for continuous pressure grouting the annulus of the tunnel linings utilising “A” retarded grout & “B” accelerator mixtures through ports in the tail skin. The design of the ports shall allow mixture “B” accelerator to join the cement slurry “A” mixture at the point of exit from the tail ports. PT216.3 The design shall facilitate their maintenance, ease of water flushing and cleaning and replacement by removable plates and pipes as a minimum. PT216.4 The TBM shall continuously grout the void behind the shield, as the TBM advances, through the tail shield using pipes or channels designed by the TBM manufacturer and embedded within the tail shield. For a Thixotropic Gel grout, a minimum of 4 delivery pipes shall be provided in the top of the shield from shoulder to shoulder. The Contractor shall provide means of clearing or replacing blocked pipes within the tail skin by water flushing. Grouting through grout holes in the segments will not be acceptable as the primary method of cavity grouting. PT216.5 The grouting system shall include a) 1-“A” mixture holding tank fitted with agitators with sufficient capacity for 2 rings. b) 1-“B” mixture holding tank with sufficient capacity for 2 rings. c) Peristaltic pumps for the supply of grout “A” to the tail skin injection ports. d) Peristaltic pumps for the supply of Grout “B” to the tail skin injection ports. e) Flow meters for liquid “A” grout. f) Flow meters for liquid “B” grout. g) Pressure meters for liquid “A” grout. h) Automatic injection units. PT216.6 Grouting Process a) The annulus void between the tunnel lining extrados and the excavated ground shall be grouted by means of injection ports located within the tail skin of the TBM using a constant pressure grout injection system. b) The lines shall be fitted with isolation valves to allow for safe maintenance.

PT217 SEGMENT ERECTOR PT217.1 The segment erector shall be compatible with the TBM and lining system to ensure safe and efficient segment installation and shall have an appropriate factor of safety for the anticipated loads. PT217.2 The erector head shall be provided with a vacuum pick up pad for the lifting of the segments with positive engagement interlock. A factor of safety 3:1 for lifting the heaviest segment shall be applied assuming 0.8 of absolute vacuum. This shall be applied to all vacuum devices. PT217.3 The erector shall be capable of actuation in the axial, radial, and circumferential directions and in the three articulation angles corresponding to the six degrees of freedom. Design the erector to grip and erect the segments so that they are positioned accurately, so that segments are aligned within the required tolerances, so that gaskets on the radial joint are fully compressed, and so that no damage or distortion of the segments occurs. PT217.4 The segment erector system shall include:

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a) Interlock to allow individual or group operation of shove rams for segment erection. This shall include safe switching between TBM operator and segment erector operator. b) Safe lifting alarms. c) Vacuum monitoring for segment lifting d) Return to pick up segment and automatic location and pick up of segments. PT217.5 Provide safe working areas as required to ensure for tunnelling personnel during the erection of the segments. PT217.6 The erector shall be fitted with a tapered single shear pin to locate into the central socket, within the segments. The pin shall be designed to impart the necessary cross joint closing force for the proposed gaskets, this shall be designed to transmit this force into the central section of the segment by a replaceable plastic sleeve to prevent damage to the segment. PT217.7 The erector shall be provided with 2 laser pencils that will align with dimples set into the segment intrados to ensure location of the shear pin into the segment. PT217.8 Operation of any functions using the erector remote control (pendant) shall be achieved only by simultaneous selection of an enabling button and the function button. PT217.9 The TBM segment erector shall be able to retrieve segments for replacement, if damage to a segment has been incurred whilst building the ring. PT217.10 The erector shall be provided with a means of safe transfer of power cables and hoses from static to rotation section by reel, or other approved system. PT217.11 The erector shall be provided with proportional control of main movements. PT217.12 The erector shall be provided with a pick up head with axial, rocking and slew movements. The rock movement shall be equal to about the “x” & “y” axis of the segments. PT217.13 All hand held electrical equipment, such as the pendant controls for the segment erector, shall be in a watertight enclosures and the control circuit protected by a Ground Fault Interrupter Circuit. PT217.14 The erector shall be equipped with an integral bearing and seal drive system rated for 10,000 hours. PT217.15 Vacuum erectors shall be tested prior to the commencement of every shift, by holding a segment plate for a minimum of 20 minutes without loss of suction. PT217.16 The vacuum system shall be fitted with a pressure sensing device that will detect loss of vacuum and prevent operation and lifting of segments, should vacuum fall below 0.8Bar. PT217.17 The Contractor shall provide a probe drill facility. PT217.18 The erector shall have mounting facilities to hold and direct a probe drill to align with angular ground treatment holes and probe holes within the TBM. PT217.19 The erector shall be provided with clockwise and anti clockwise rotational movements of ± 220º spaced equally about the invert of the tunnel.

PT218 ERECTOR BRIDGE PT218.1 The Contractor shall provide details of the erector bridge that demonstrates that the design is such that the support of the TBM ancillary equipment shall bridge the segment lining installation and grouting areas such that the first bearing on to the newly built lining takes account of the grouting time and the designed rate of gain of the grout strength. The bridge shall run on rail track supported by brackets fastened into the tunnelling.

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PT218.2 The erector bridge shall be provided with an articulated towing connection to the TBM with load indicating and interlocked features. These features shall include a link to the shove rams which will immediately stop the shove should excessive loads be transmitted to the towing connection. PT218.3 A platform shall be provided for proof grouting directly beyond the tailskin.

PT219 SEGMENT MAGAZINE PT219.1 The segment magazine shall include the following features:- a) A minimum capacity of one ring. b) Be reversible for removal of damaged segments from the ring building area. c) The base of the magazine shall be designed such that there is adequate access for grouting to the invert plates. d) Control of the magazine functions shall be by a trained driver who shall be positioned at a fixed station with clear site of movements. e) The base structure shall be designed such to allow a clear access walkway to the TBM tail area. f) There shall be sufficient clearance from the tunnel invert to maintain and take oil samples from the segment feeder.

PT220 TBM – LINING INTERFACE PT220.1 Concrete segments and associated items shall be designed for anticipated ground and water loads and environmental conditions on the completed tunnel. The Contractor shall ensure that the segments are compatible with its selected construction equipment, means, methods and procedures including, but not limited to alignment control, handling, erecting and grouting. PT220.2 Maximum ram thrust contact pressure at any point and any time on the lining system ram thrust shall not exceed 50% of the segment 28-day compressive strength. PT220.3 Thrust pads are to be designed such that they shall not damage gaskets or segments. PT220.4 Design thrust ram shoes to be consistent with the segment design and installation procedures, such that they do not introduce eccentric loads to the segments PT220.5 Design TBM system to allow complete backfill grouting of the annulus between the concrete segments and excavated surface, taking account of hydrostatic pressures and overburden loads.

PT221 CONTROL AND INTERLOCKS PT221.1 The TBM cutter head shall be prevented from moving at any point during any maintenance or entry. An interlock should be provided from the control cabin to allow remote inching operation of the cutter head. The Contractor shall establish safety procedures, for acceptance by the Project Manager, which will include, among other issues, a procedure to ensure that all personnel have evacuated the cutter head and front chamber before any movement is undertaken. This provision is intended to assist cutter tool changes with local indexing of the cutter head. The cutter head drive shall have fail-safe braking system to prevent inadvertent movement. PT221.2 The shove rams shall be controlled from the main control cabin during the excavation cycle and from remote stations during the ring building cycle. An interlock shall be provided to prevent duplicate operation of the shove rams. PT221.3 All erector load-holding functions shall have a fail safe alarm system. Rotational drives shall be fitted with fail safe brakes.

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PT221.4 The segment erector shall be fitted with visual and audibile safe lifting alarms. PT221.5 An interlock shall be provided that prevents extension of the shove rams should grout delivery through the tail skin be interrupted or blocked. The Contractor shall provide a method of automatic data logging and measuring volume and pressure of grout injected per tunnel lining ring. PT221.6 Condition monitoring of the main bearing the sealing system and main drive gearboxes to include oil flow, oil pressure, oil temperature including filter analysis and the measurement of metal parts per million on a regular basis to allow monitoring of the bearing, sealing system and main drive gearboxes to detect contamination and wear. An interlock with the cutter head movement shall be provided to prevent use should contamination occur. PT221.7 Provide power and torque monitoring. PT221.8 Interlocking of cutter head torque to shove rams. PT221.9 Provide Cutter tool electrical wear indicators & alarms. PT221.10 Monitoring of tail sealer grease delivery, indicating distribution, pressure and warnings. PT221.11 Monitoring and alarming of grout volume and pressure delivery interlocked with advance rate / shove rams – except for final 50mm of the shove

PT222 TBM OPERATION PT222.1 The Contractor shall provide an air-conditioned TBM control cabin. This shall contain all remote controls and warning indications for the safe operation of the TBM and its environment. The operation control cabin should have space for a minimum of 4 persons. The controls shall monitor and record the operational parameters of the TBM and its systems including the slurry inbound and outbound circuits. The cabin shall be equipped with closed circuit television that is able to observe the tunnel lining build area, the segment supply magazine and area of entry into the gantry of the locomotive and material delivery systems. PT222.2 A separate above ground monitoring station shall be provided, it shall duplicate the controls within the TBM Control Cabin. The station will have direct links with the TBM and will monitor and alarm all spoil volume checks and grout injection checks. It shall be supervised at all times during TBM operation by a trained dedicated Engineer with authority and means to stop the TBM. PT222.3 Performance Requirements The Contractor shall design that the TBM is capable of complying with the minimum performance factors described in this section. PT222.4 Boring Rates of Advance The instantaneous rate of advance corresponds to the boring of 1-stroke or width of the tunnel lining in 15 minutes. PT222.5 Shove Ram Retraction Provision shall be made to fast retract and extend individual or groups of rams, to allow the starting of tunnel ring erection within 1 minute of completing the shove stroke PT222.6 Tunnel Lining Supply and Erection The duration for the building of one ring of segments is defined as the period from engagement of the first segment by the erector to release of the key segment and the tightening of bolts. Time = Not greater than 15 minutes PT222.7 Rates of Advance - Performance

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Monitoring the average rates of advance shall be calculated by measuring the duration of time to advance twelve successive strokes. The time shall be measured from the beginning of the first boring stroke to the placement of the final segment. All auxiliary operations, including tunnel segment grouting, tail seal greasing, segment feeding and unloading shall be included within the performance monitoring. A cyclogramme of tunnelling operations, including all operations connected with the tunnelling advance shall be submitted to Project Manager. PT222.8 Machine Availability The TBM shall be designed to achieve a minimum of 95% machine availability including planned maintenance periods. Availability shall be the time when the TBM and all its associated systems are ready for use and shall be expressed as: Availability A= [100 (T-P)] / T. Where T = the time period measured. P = the time the machine is unable to work. To maximise TBM availability and performance the Contractor ensures that the TBM Supplier provides the following: a) Maintenance advice and supervision to the Contractor. b) Daily monitoring of equipment and early warning of maintenance requirements. c) Training of Contractors operatives and maintenance personnel. d) A maintenance manual detailing the design life of major components in order to establish a spare parts provision regime and to implement a preventative maintenance regime.

PT223 TBM ELECTRICAL REQUIREMENTS PT223.1 All TBM electrical installations shall comply with the safety and legislative requirements in place at the time of the Project duration. a) Control equipment shall conform to BSEN 60529 IP65 and, where possible all control components should be of the same manufacturer. Any MCB,s (Miniature circuit breakers) or MCCB’s (Moulded case circuit breakers) shall conform to BSEN60898 with the appropriate fault level rating. b) Motors shall be totally enclosed, fan cooled to BS5000 and shall be equipped with conventional overload protection and thermisters embedded in the motor windings to be used for trip and alarm via the operators console. Electrical main drive motors shall be water cooled. c) The motor starting methods shall be selected so as to ensure that large starting currents are avoided. d) All electrical power, control and safety systems shall have a minimum moisture ingress protection rating of NEMA 12. All cables in the tunnel shall be LSF (Low Smoke and Fume) or LSOH (Low Smoke Zero Halogen) sheathed and have the characteristics of a High Oxygen Index, good resistance to oil, abrasion and heat. e) If the TBM has a high voltage transformer this shall have an over temperature alarm and shall include all safety devices as required by the regulatory authorities. All electrical power, control and safety systems shall have a minimum moisture ingress protection rating of NEMA 12. All cables in the tunnel shall be LSF (Low Smoke and Fume) or LSOH (Low Smoke Zero Halogen) sheathed. If the TBM has a high voltage transformer this shall have an over temperature alarm and shall include all safety devices as required by the regulatory authorities. f) The TBM and its components shall meet all applicable codes and regulations, and all requirements posed by the electric power suppliers and any other agencies that have jurisdiction.

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g) Emissions. h) The Contractor shall arrange for the complete TBM and back up systems to be tested for electrical emissions in conformance with “The Amended Consolidated EMC Directive reference EMC89/336/EEC” and issued with CE conformance certification.

PT224 GUIDANCE SYSTEMS PT224.1 This Section provides guidance on the technical and procedural aspects of an integrated, laser-based guidance system for tunnel shields and TBMs. The Contractor shall provide a global coordinate TBM Guidance and Control System with laser theodolite. This shall be a proprietary manufactured system. PT224.2 Technical Aspects a) Reference should be made to Works Information for required accuracy and tolerance and other matters affecting the operation of the system. b) The tunnelling system shall be designed to maintain a clear space for the guidance system and laser beam, irrespective of shield or TBM orientation. c) The data shall be presented on displays at the underground Machine Operators position and at the offices on surface of the Contractor. Facilities to download data electronically (for further transmission) and for paper printout, independently of the current display, shall be provided. PT224.3 Procedural Aspects The operation of the guidance system shall be a specific feature of the Contractor’s Quality Assurance Plan. This should clearly address: a) Definition of responsibility and authority of personnel maintaining and operating the guidance system. b) Intervals between manual checking of data produced by the guidance system (lengthened intervals may be adopted as experience is gained) c) Intervals, at which survey control points are to be established, based upon tunnel geometry and guidance system characteristics. d) The guidance system shall be fully operational whenever the TBM is advancing. The guidance system shall assist in this by: i) Computing the alignment of this plane for the last lining built. ii) Computing the corrections required to achieve this plane in the next lining to be built. iii) For tapered lining rings, the guidance system shall compute the best fitting type and orientation of taper lining ring to be built next. The guidance system shall be configured to accept data from a minimum of four taper ring designs. PT224.4 Technical Aspects

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a) The guidance system shall incorporate a non-manual check of the correct position the reference laser line at hourly interval. An additional non-manual check should be initiated at the commencement of each shift. b) The guidance system, including cabling and connectors, shall be capable of a sustained, safe operation within the onerous environmental conditions of a tunnel under construction, where dust, water, high humidity, varying quality of power supply, sustained vibration and repeated shocks are to be expected. c) The guidance system shall be self-checking, with redundancy in essential components, and shall generate and record appropriate status messages for delivery when remotely or locally interrogated and to alert the operator to fault conditions immediately as they occur. d) Loss of primary power to the guidance system in the tunnel shall not result in data loss which would prevent the system self-starting on resumption or primary power supply.

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e) During forward movement of the TBM, the guidance system shall provide as a minimum the following real-time data for the TBM, with reference to the designed tunnel alignment at the machine head: i) Station (chainage) ii) Horizontal/line displacement iii) Vertical/level/grade displacement iv) Left or right lead/yaw at axis level v) Overhand or look-up/pitch at axis level PT224.5 Main axis rotation This information shall be presented in numerical and graphical form, refreshed every 20 seconds or faster. PT224.6 The accuracy and the limits of each measurement shall be as stated in Table 1 Accuracy and Limits of Position Measurements. Table 1 Accuracy and Limits of Position Measurements Data Accuracy (+/-) Limit (+/-) Station (chainage) (6mm) (12mm) Horizontal displacement (6mm) (6mm) Vertical displacement (6mm) (6mm) Left or right lead (3mm) (6mm) Overhang or look-up (3mm) (6mm) Main axis rotation (3mm) (12mm)

PT224.7 The data shall be presented on displays at the underground Machine Operators position and at the offices on surface of the Contractor and the Project Manager (three displays in all). Facilities to download data electronically (for further transmission) and for paper printout, independently of the current display, shall be provided at both offices. PT224.8 Data shall be recorded in a medium unaffected by primary power loss in a store of sufficient capacity to hold the entire tunnels production records. PT224.9 The guidance system shall, throughout the forward movement of the TBM, compute the correct curve which returns the TBM tangentially to the designed tunnel alignment and compute and display the necessary corrections to attitude to be applied during the course of the forward movement. This computed data may be used directly as input into the control mechanism of the TBM body and the excavation and between the tail skin and lining. PT224.10 The guidance system should also facilitate construction of the tunnel lining so that it follows, and does not bind onto, the TBM. The system shall provide data defining the plane of the circumferential joint of the leading edge of the tunnel lining with respect to Designed Tunnel Alignment and TBM axis. PT224.11 Procedural Aspects The operation of the guidance system shall be a specific feature of the Contractor’s Quality Assurance Plan. This should clearly address: a) Definition of responsibility and authority of personnel maintaining and operating the guidance system.

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b) Intervals between manual checking of data produced by the guidance system (lengthened intervals may be adopted as experience is gained) c) Intervals at which survey control points are to be established, based upon tunnel geometry and guidance system characteristics. d) Detection and correction of trends to non-conformance (requiring long-term data storage). e) Detection and disposal of non-conforming items. f) The guidance system must be fully operational whenever the TBM is advancing. The guidance system shall assist in this by: i) Computing the alignment of this plane for the last lining built ii) Computing the corrections required to achieve this plane in the next lining to be built. PT224.12 For tapered lining rings, the guidance system shall compute the best fitting type and orientation of taper lining ring to be built next. The guidance system shall be configured to accept data from a minimum of four taper ring designs. PT224.13 In making these computations and recommendations, the guidance system shall take into account and display clearances between the lining and the TBM tailskin and how they will change with the next forward movement. Manual input of original clearance data as specified. Locations should be accepted for this purpose, provided that the accuracy of measurement is within approximately 3mm. PT224.14 Provide a computer operated grouting system linked to the TBM systems to calculate grout quantities and continuously adjust grout injection rate and pressure to ensure it does not exceed the hydrostatic or soil overburden pressure. All in accordance with the requirements as specified.

PT225 TAIL SEAL GREASE INJECTION PT225.1 Tail Seal grease injections shall be automatic and continuous to ensure effective filling between the brushes. Injection of grease shall be in accordance with the TBM manufacturer’s written requirements, and shall be a positive distribution system to ensure even distribution of grease, details of which shall be made available to the Project Manager. Tail seal grease shall be fire resistant. PT225.2 Tail seal grease shall be compatible with the lining system gaskets and materials, shall be inert and fireproof, and shall not contaminate the surrounding ground or groundwater and shall not in any way cause the long term deterioration of the lining concrete, the joint connector, the gaskets, seals or joint packers. The design shall facilitate their maintenance and replacement.

PT226 OTHER FEATURES PT226.1 Provide method to test for the presence of hazardous or explosive gas in accordance with Health and Safety regulations requirements. PT226.2 Provide an environmental monitoring system that detects levels of potentially hazardous gases. Systems shall be arranged with adjustable limits and shall have a first level warning signal and a second level with automatic shut off of tunnelling equipment in accordance with Health and Safety Regulations requirements. Gases to be monitored shall include methane, oxygen, hydrogen sulphide, carbon dioxide and carbon monoxide. PT226.3 The Contractor shall supply Calibration Test Certificates for gas detection system, pressure cells in excavation chamber and screw conveyor, TBM guidance system

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and grout pressure gauges. Certificates to be updated in accordance with the manufacturers recommendations. PT226.4 In order to provide a clean environment for placing of the invert segment plate, the Contractor shall take appropriate measures to keep the shield area free from water and spoil material. Pumping facilities in the shield area of the TBM shall be designed to allow sufficient space for the equipment proposed. PT226.5 Only TBM synthetic hydraulic oils HFDU (biodegradable, fire resistant, polyesters) shall be used. All oils shall be approved by the TBM manufacturer. PT226.6 The Contractor shall provide foams, polymers, bentonite or other conditioners as required for stabilizing the tunnel face and maintaining the required pressure until discharge from the screw conveyor/slurry discharge pipes under all conditions described in the Works Information and Site Information. All conditioners shall be biodegradable, inert and conform with Environment Agency requirements in List 1 and 2 of the Groundwater Regulation 1998, unless otherwise agreed with the Project Manager.

PT227 SPARE PARTS PT227.1 Spare parts or maintenance materials to be stored on site shall include all items with lead in times greater than two days including: a) Parts and materials listed in the TBM manufacturer’s recommended spares list and maintenance plan. b) One complete set of excavation tools (discs, rippers and other cutters. One set consists of a complete replacement of all tools on the cutter head. c) Hydraulic rams, hydraulic hoses and components. d) Seals, o-rings and gaskets. e) Electrical and Mechanical components. PT227.2 Major spare parts to be stored off-site. PT227.3 Have one spare main bearing assembly, seals(bull gear), and one spare main drive motor stored off-site and vested to Thames Water and available from the TBM manufacturer for prompt replacement of the corresponding parts provided with the TBM. These spares shall be identified and available for the duration of the TBM excavation.

PT228 FIRE PREVENTION – TBM AND BACK-UP PT228.1 Subject to the conclusions of the hazard assessment, the TBM and back up systems shall be provided with: a) A fire hazard assessment, which will address all potential fire sources, shall be carried out to the acceptance of the Project Manager. b) The fire suppression system shall be compatible with the hazard assessment. c) Electrical cabinets shall be fitted with a manually operated fire suppression system. d) Emergency plunger buttons at suitable locations to activate a fire alarm. e) Hand held extinguishers provided with colour coded covers in suitable locations. f) A means of rapidly shutting off fresh air ventilation to the tunnel face, after the area has been evacuated. g) Permanent notices giving emergency procedures, in the event of fire, placed in suitable locations. h) Operators and training manuals for use by the Contractor.

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i) Hydraulic hoses shall comply with BS EN 853. / ISO 1436. The hose covers to be flame retardant and to conform to the requirements of USMSHA. j) Gas monitoring for oxygen deficiency, CO2, CO, H2S, NO2, SO2 and CH4 . k) Water mist screen to be positioned at the rear of the Back-Up System. l) Low density foam generators to be sited at high fire risk areas with automatic operation in the event of fire. m) Essential services shall be protected so that they remain operable during all tunnelling operations for a period of 1 hour. These essential Services are: i) Emergency power supplies. ii) All fire suppression systems. iii) TBM emergency lighting. iv) Environmental monitoring systems v) All controls and tunnel communications. vi) The security of the air supply and control systems to the man lock shall remain operable in all emergencies, particularly in the case of fire.

PT229 TBM FACTORY TESTING PT229.1 The Contractor shall submit, at least 30 days prior to the commencement of any factory tests, a test schedule and programme for the TBM and back-up system. The Contractor shall allow in his bid for the direct expenses, travel, and accommodation for the attendance by the Project Manager at the factory tests. PT229.2 The TBM shall be tested in accordance with the manufacturers recommendations and a certificate of confirmation of compliance with the requirements of this Section, together with a copy of the test results, shall be signed by the Contractor and the TBM manufacturer and shall be forwarded to the Project Manager prior to the TBM being delivered to the Site. PT229.3 The test shall include a demonstration mock up of the concrete segment erection system, using the precast concrete segments as proposed for the project.

PT230 QUALITY ASSURANCE PT230.1 The Contractor shall operate a Quality Management system in accordance with of ISO9001, 9002 & 9003 Quality Assurance Requirements. The Quality Management system shall include procedures for design, manufacturing, testing, commissioning and maintenance of the TBM. It shall provide the results of all specified tests and inspections to the Project Manager. Periodically during the manufacturer of the TBM the Employer may conduct compliance audits relating to the design and supply of the TBM. The Contractor shall provide suitably qualified staff to assist the audit team PT230.2 TBM Manufacturer: The proposed TBM manufacturer shall be a recognised commercial TBM manufacturer with no less than 5 years of successful experience in the design and manufacture of TBMs of the type proposed by the Contractor. PT230.3 For his works the Contractor shall use only qualified and suitably experienced persons in the following key positions:- Contract Manager, Construction Agent, TBM Mechanical Foreman and Electrical Foreman and TBM Operators. The Contractor shall submit the names and CVs of those key persons he proposes to use on this project. PT230.4 The Contractor shall arrange for a Technical Representative from the TBM manufacturer or an approved independent specialist, who is experienced in the assembly, operation and repair of TBMs, to be present for the duration of the

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assembly of the TBM in the Launch shaft, as well as for start-up and operation of the TBM for the first 1000mtrs of the tunnel drive. The technical representative shall certify in writing to the Project Manager that the TBM, as assembled, meets the Specified requirements.

PT231 QUALITY PLAN PT231.1 Within 4 weeks from award of Contract the Contractor shall submit a detailed Quality Plan based upon the Preliminary Quality Plan provided as a submittal under PT204. PT231.2 The Quality Plan shall be regularly updated to reflect any changes made to the procedures.

PT232 PERSONNEL AND TRAINING PT232.1 The Contractor shall ensure that all key personnel who are responsible for driving, maintenance and controlling the TBM, including any specialist for the TBM computer systems, have received the necessary training in the duties that they are required to perform. Such training shall include emergency procedures. PT232.2 The Contractor shall provide and maintain a complete register of the names of persons, and their duties, responsible for the operation of the TBM, who have completed the appropriate training to an accepted standard. PT232.3 The Contractor shall provide a foreman fitter on site for the duration of the tunnelling works. A fitter and electrician shall be provided for every shift. The Contractor shall provide the Project Manager with copies of the curriculum vitae for all fitters and electricians.

PT233 TUNNEL HEALTH AND SAFETY ASSURANCE As part of the Contractor’s Safety programme the Contractor shall produce a Tunnel Specific Safety Statement within 3 months of contract award detailing the precautions to be implemented to protect personnel working in the tunnel from the construction methodology risks associated with tunnelling at the designed gradients and long section. These shall include but not limited to: • Risk of runaway trains and derailments. • Tunnel inundations. • Control of water and standby provisions. • Temporary Tunnel Ventilation System. • Emergency evacuation of tunnel. • Fire precautions including the role of the appropriate fighting authority in the event of a tunnel fire. The procedure shall need to address all possible fire location and tunnel length scenarios. • Management of rail and pedestrian movements in the tunnel.

PT234 REGULATIONS The design and manufacture of the TBM and back up systems shall comply with all relevant regulations and codes of practice including, but not limited to those described below. The Contractor shall ensure he always uses the latest published version of any standard that relates to safety. These shall include but are not limited to: • Section 6: Health and Safety at Work Act. • A Guide to working in Compressed Air 1996 guidance on oxygen decompression.

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• Ventilation COSHH • Acoustics Noise emitted by machinery ISO/DP 9244:1986. • The Construction (Design and Management) Regulations 2007. • The Management of Health and Safety at Work Regulations 1992. • The Construction Health, Safety and Welfare Regulations 1996. • The Personal Protective Equipment at Work Regulations 1992. • The Control of Substances Hazardous to Health Regulations 1994. • The HSE Occupational Exposure Limits EH40/1996 (Updated Annually). • BS 5750 (BSEN ISO 9001, 9002 & 9003) Quality management and quality assurance standards. • BS EN 50073 Selection, installation, use and maintenance of apparatus for the detection and measurement of industrial gases. • BS 5345 Parts 1 to 8 inclusive, Selection, installation and maintenance of electrical e in potentially explosive atmospheres, where applicable. • BS EN 50054 to 50058 1991. Electrical apparatus for the detection and measurement of combustible gases general requirements and test methods. (This series of British and European unified standards replaces BS 6020 parts 1 to 5. “Instruments for the detection of combustible gases.” • BS EN 60079-25:2004 Electrical apparatus for potentially explosive atmospheres, where applicable. • Supply of Machinery (Safety) Regulations 1992-Schedule 3, clauses 1.5.8, 1.5.9, 1.7.4, 2.2 and 3.6.3; • Supporting [“C” Type Safety] Standards-Noise and Vibration Test Codes information required by manufacturers claim of “CE” Conformity. • BSEN 457 Safety of Machinery - Auditory danger signals - general requirements, design, design and testing. • BSEN 60034-9 Rotating Electrical Machines -Noise Limits. • BSEN 45014 General criteria for supplier’s declaration of conformity. • BS EN 981 Safety of machinery-System of Danger and Non Danger signals with sound and light. • BSEN 61310-1 Safety of Machinery-Indicating, marking and actuating principles; part 1 Visual, audible and tactile signals. • BS EN 1012 Compressors and vacuum pumps; Safety requirements. • ISO 4871 Acoustics-Noise labelling of machinery and equipment. • ISO 4872 Acoustics-Measurement of airborne noise emitted by construction equipment intended for outdoor use-Method of determining compliance with noise limits. • ISO 6394 Acoustics -Measurement of airborne noise emitted by earth moving machinery-Operators position-stationary test condition. • ISO 6395 Acoustics-Measurement of exterior noise emitted by earth moving machinery-Dynamic test conditions. • ISO/TR 11688; Parts 1 & 2: acoustics-Guidelines for the design of low noise machinery and equipment.

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• ISO/DRT 11690; Parts 1,2 & 3: Acoustics-Recommended practice for the design of low noise workplaces containing machinery. • Noise at Work Regulations 1989 (refer to regulation12). • Section 2 HSW/HS (G) 88, Hand-arm vibration; • BS 6841:1987; Measurement and evaluation of human exposure to whole body mechanical vibration and repeated shock. • BS 6842: 1987; Measurement and evaluation of human exposure to vibration transmitted to the hand.

PT235 BORED TUNNEL TEMPORARY FACILITIES PT234.1 The Contractor shall provide, operate and maintain for the duration of tunnelling construction a temporary ventilation system, which conforms to the Health and Safety requirements. The equipment shall be adequate to maintain sufficient supply of fresh air in underground work areas. a) Mechanical ventilation systems shall not be removed without the acceptance of the Project Manager. b) As a minimum, when the excavations are occupied by workers, the ventilation system shall be designed to deliver fresh air at a volumetric flow rate equal to 20mtrs per minute times the cross-sectional area of the tunnel. A higher volumetric flow rate shall be provided if necessary c) Power to the main ventilation system shall not be interrupted in the event of an alarm of the air monitoring system. d) Advance of the ventilation system shall be made a regular part of the normal tunnel excavation cycle. e) Temporary Tunnel Lighting System: The Contractor shall provide a temporary lighting system in the tunnel which conforms to the requirements of BS6164:2001“Code of practice for safety in tunnelling in the construction industry”. Lighting in the tunnel shall extend the full length of the tunnel and not be less than that required for safe working and access. An alternative source of power and emergency lighting system shall be provided to allow emergency securing operations and safe evacuation in the event of a primary power failure. An adequate number of hand lamps shall be located at key points underground. f) Temporary Personnel Walkway: The Contractor shall provide walking access in the tunnel at all times. This shall have a firm, level, slip- resistant and continuous surface and shall be suitable for use in emergencies. g) Temporary Locomotive Track: The track should be properly supported and secured against displacement in the tunnel. The entire length of the track shall be examined not less than once a week and the results of this inspection shall be forwarded to the Project Manager. Defects shall be recorded and remedial action will be promptly implemented when identified. h) Temporary Pumping: Provide intermediate pumping stations and reserve pumping capacity at the any point of the tunnel as required to remove groundwater inflows and construction water. i) Fire Extinguishers: Fire extinguishers shall be provided at a minimum every 500 metres of the running tunnels. They shall be maintained in accordance with the manufacturer’s recommendations. PT234.2 Smoking Policy There shall be no smoking in the tunnel. PT234.3 Breathing Sets

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Approved emergency breathing apparatus or approved oxygen self-rescuers as appropriate shall be provided and kept with all persons visiting or working in the tunnel for the duration of their time in the tunnel. All such equipment shall be regularly maintained in accordance with the manufacturers recommendations, records shall be kept in the Contractors site office and made available for inspection by the Project Manager.

PT236 TUNNEL BORING MACHINE MAINTENANCE. PT236.1 The Contractor shall monitor and analyse lubricants in critical areas of the tunnelling equipment on a weekly basis. This shall be performed by an Independent Laboratory to identify the presence of any pollutants. Critical areas shall include all major sealing systems, main bearing, final drive gear, hydraulic systems and motor gear boxes. The results of the analysis shall be forwarded to the Project Manager upon receipt together with any proposals for remedial action where pollutants have been identified. PT236.2 The Contractor shall forward to the Project Manager within 3 months of contract award details of proposals for the routine periodic preventative maintenance programme that shall be adopted during the tunnelling operation. A nominated person shall be responsible for ensuring compliance with all preventative maintenance procedures.

PT237 GENERAL TUNNELLING CONSTRUCTION REQUIREMENTS PT237.1 Perform tunnel construction to minimize movement of ground in advance of, around and above the tunnel; to control water and water inflow and attendant soil transport; and to minimize settlement, subsidence and heave of the ground surface, structures, and utilities above and close to the tunnel for ground conditions that are to be encountered as described in the Works Information and Site Information. Conduct tunnelling operations in a controlled manner so that settlement action levels are not reached. PT237.2 Unstable Conditions Procedures: Whenever there is a condition likely to endanger the excavation or adjacent structures, notify the Project Manager immediately and perform work on a 24-hour a day basis, including weekends and holidays, until such condition is resolved and eliminated. Briefings are to be given to mining gangs prior to tunnelling on the procedure for dealing with unstable conditions. PT237.3 Maintain clean working conditions inside the tunnel by continuously and promptly performing housekeeping to remove muck and grout spills, rubbish and other debris. PT237.4 A driving parameters check sheet shall be provided daily to the mining crews to allow the drive to be controlled and monitored.

PT238 ELECTRONIC DATA ACQUISITION, VISUALISATION AND REPORTING SYSTEM (DAVARS) The Contractor shall supply a computer-based Data Acquisition and Visualisation System’ DAVARS which can be used for the preparation and distribution of reports, This system shall fulfil the following main specifications. PT238.1 Extent and scope of DAVARS The DAVARS shall handle data and digital pictures, as minimum but not limited to, of: • The Tunnel Boring Machine (TBM), • The tunnel mucking system, • The reporting system, as agreed with the Project manager for Ring Reports and Shift Reports

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• The Quality Management / Quality Assurance (QM/QC) for the tunnelling process, including its reporting system (Non-Conformance Reports and Remedial Work Reports, etc.), • The ring erection data, • Ground surface, ground settlements, • The alignment data, • Display of the geology along the alignment, and statistic evaluations. PT238.2 The data shall be transferred automatically, into the DAVARS. PT238.3 The DAVARS shall allow the Employer and his representatives to execute by themselves, visualisation in any display combination of sensors and data labels. PT238.4 Real time data input a) One set of all data generated by the TBM, the mucking systems, tunnel guidance system and, if applicable, automated surveillance systems, shall be read into the data base at least every ten seconds. b) This data shall be transferred directly by the equipment’s PLC and must not be handled through a secondary data system. c) Procedures, which are controlled and recorded in intervals longer then one hour, shall be introduced into the data base manually by the Contractor on the same day. PT238.5 Accessibility of DAVARS a) The data shall be stored into a project data base, accessible through Internet by the Employer and his authorised representatives at any time. b) The DAVARS shall be kept operational for the Employer from TBM installation in the launch position throughout the project until final acceptance and financial closure of the Project. c) The Employer will receive one electronic copy of the database at the end of the Project. PT238.6 Further Functions of DAVARS a) The DAVARS shall allow printing and emailing of the graphs and reports at any work place while being logged-in. b) The DAVARS shall allow for applying active triggers to arbitrary parameters and connecting the triggers with message functions. Passing the set trigger level shall initiate a notification by email to selected individuals. PT238.7 Real Time Data Management The Contractor shall provide Shift Records using semi- automatic Real Time Data Loggers software for on-line display and in hard copy to the Project Manager, detailing work performed except where otherwise allowed or accepted herein, and integrated with requirements specified elsewhere for erection of precast segments, cavity grouting, and permeation grouting including: a) Date, location, shift and beginning and ending face station. A manual check of the TBM face location shall be conducted on a weekly basis. b) List of personnel by name, classification, and function working that shift. c) List of the number and type of equipment, including amount of and reason for any idle or down time. d) List of all materials used in the work. PT238.8 For every TBM shove or stroke:

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a) Description of soil or bedrock materials being excavated, including boulders and volume of excavated materials using methods as mutually agreed when not otherwise specified. b) Description of delays and down time longer than 10 minutes, including reason for delay. Include maintenance records identifying the component, component position or number and reason for replacement. c) Description and locations of water inflows, ground loss and other events. d) Cutter, pick teeth and muck system component changes, including time and date of replacement, cutter or component position or number, and reason for change. e) Rates of advance for each hour. f) Hours of actual machine operating time for each shift. g) Max thrust pressure for each shove. h) Ring number at start and end of each shift. i) Type, manufacturer and producer name and number of all ground conditioners used on each shift. j) Volume and pressure of grout pumped behind precast segments on each ring. PT238.9 Results of quality control tests including: a) Volume of conditioner used as applicable for EPBM operations b) Volume of slurry and slurry density, as applicable for SPBM operations

PT239 GROUTING METHODOLOGY PT239.1 Submittals a) Contractor shall submit to the Project Manager, within 28 days of award of Contract, for review and acceptance, a programme showing the methods and sequencing of placing primary and proof grouting b) The Contractor shall submit to the Project Manager for acceptance within 60 days of the award of Contract a detailed Method Statement of the grouting procedures to be followed during the construction of the tunnel. These details shall include:-mix design, constituents and testing procedures, pumping rates and pressures, means of gauging pressures at the point of injection, proof drilling pattern to be adopted. PT239.2 General a) The Contractor shall design a non-shrink Thixotropic Gel 2 part chemical grout system for Cavity Grouting. b) “Primary Grouting” refers to the initial cavity grouting which takes place during shield shove using a pressure grout system. c) During the first 100m of the tunnel drive, the Contractor shall demonstrate (by proof drilling) the effectiveness of the primary grouting system. d) A leachability test on the set grout shall be performed by the Contractor within 6 months of Contract Award in order to gain approval from the Environmental Agency for its use. PT239.3 Grout Delivery The entire grouting system shall be designed to constantly deliver 1 cum/min throughout the complete ring grouting cycle. PT239.4 Primary Grout Injection

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a) Primary grout shall be injected by positive displacement. Consideration shall be given to providing a ring main system with the incorporation of approved retarders and accelerators to control the setting of the grout. The grout pump system shall incorporate a safety pressure by-pass arrangement, with means of reading the grout pressure at the point of injection. b) Primary Grouting shall commence in a manner such the cavity is completely filled with grout and all excess air and water is displaced and the grout is retained under pressure until the first set takes place. PT239.5 Records Records at each stage of the grouting process shall be kept, to include quantity and pressure applied at each injection point. These records shall be submitted to the Project Manager daily. PT239.6 Grout Performance The minimum compressive strength requirement of all grouts as measured from testing cubes shall be:-1.5N/mm² at 24 hours and have an initial set within 10 seconds with Marsh Flows between 45 and 60 seconds at a base temperature of 20°C. PT239.7 Testing Three sample cubes of the grout shall be taken daily to an approved testing facility to verify the minimum strength requirement. The results of these tests shall be forwarded to the Project Manager. Tests shown in Table below to be carried out on the grout. item Specification Test method Frequency Remark On In ground each tunnel Bleeding Less Bleeding test Every Every Solution 3%(1hour) day week -A Consistency 8 to 11 sec Flow test Every Every Solution day week -A Gel time 5 to 12 sec Mix test Every Every A+B day week 1 hour Compressive Every Every Referen test with 4cm month month ce only 24 hour 1.5 N/mm2 cube sample Every Every day week 7 day Every Every Referen month month ce only 28 day Every Every Referen month month ce only PT240 INSTALLATION, MONITORING AND CONTROL FOR SEGMENTAL LINING PT240.1 Installation of Tunnel Lining a) Construct rings to correct line and level, in true circular form to preserve the circularity of the tunnel. b) Select combinations of tapered segment rings to provide specific tunnel geometry, and for making corrections as necessary during construction. c) Inspect concrete segments and gaskets before transport into the tunnel nd the building of the segments in the tailskin. No damaged segments are to be taken in to the tunnel and prior to build.

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d) The Contractor shall tighten bolts across the joints to ensure gasket compression in accordance with gasket manufacturer recommendations. e) Do not add packings or materials to circumferential joints to adjust line and grade unless accepted by the Project Manager. f) Stagger radial joints in adjacent rings. Rings may be rotated one or two equidistant bolt locations to meet line and grade and curve requirements, provided that only T joints result between adjacent rings. g) Hangers for utility lines necessary for construction of the tunnel may be connected to concrete segments with the Project Manager’s acceptance. PT240.2 Monitoring of Segments a) The Contractor shall take measurements of the horizontal and vertical diameters for each tunnel ring following installation within the tail skin. Measurements shall be forwarded to the Project Manager on a daily basis. b) Installation tolerances to be as per BTS specification. c) The deviation from the true inside diameter of the completed ring shall not exceed ± 15mm.

PT241 SURFACE DISPLACEMENT MONITORING PT241.1 Preliminary assessments have been made of the settlement resulting from the construction of the Works and are shown on drawings 6LYG-A1-02131 to 6LYG- A1-02141. These are provided for information only, with no warranty given by the Employer. to its accuracy or completeness, and the Contractor shall provide his own assessment of the settlement as required under Section 4 Schedule 2 of the Works Information. PT241.2 The Contractor shall carry out a detailed settlement assessment based on the proposed methods of working, proposed alignment, ground conditions and ground support details and submit detailed supporting calculations and a full set of revised settlement contour drawings for the Project Manager’s acceptance. PT241.3 The Contractor shall monitor the effects of tunnel construction, ground treatment or dewatering at the surface, including all ground movements and the effects on all structures, including the Works. For the purposes of this clause structures include buildings at Abbey Mills Pumping Station and Beckton STW, utility services including the Northern Outfall Sewer(See Clause PT242.a), railway tracks, bridges, railway furniture and all other structures identified as at risk of settlement damage by the construction of the Works. PT241.4 The Contractor shall submit to the Project Manager, within 60 days of award of Contract, a Method Statement detailing his proposal for the monitoring and control of surface displacement in accordance with the contract. The Contractor shall incorporate, where applicable, the requirements in the clauses below for agreement by the Project Manager and interested third parties where appropriate. PT241.5 The Employer shall serve notice where required by statute and provide letters detailing the Works to third parties which may be affected by the construction but do not require formal issue of Statutory notices. PT241.6 Monitoring shall be referenced to stable survey stations located outside the zone of influence of the works and not subject to ground movement. Such benchmarks and co-ordinated stations shall be established and agreed with the Project Manager before any ground is excavated and before any ground treatment or dewatering takes place. They shall be checked at intervals during the duration of the works. PT241.7 Surface displacement monitoring for the construction of the bored tunnel shall be carried out to ensure that the maximum allowable surface (vertical) settlement is

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limited to <8.5mm above the centreline of the tunnel or the predicted surface (vertical) settlement, whichever is the lesser value. PT241.8 Monitoring points above the centreline of the tunnel shall be established at ground level at a maximum of 50 metre centres along the full length of the tunnel, where practicable. Records of all readings taken by the Contractor shall be submitted to the Project Manager within 24 hours of the readings being taken. PT241.9 Prior to the commencement of the construction of each shaft, the Contractor shall submit a method statement detailing their proposals for the settlement monitoring and demonstrating that their proposed method of construction will not generate settlements of >5mm at the nearest Structure or identified Utility at Risk PT241.10 Settlement monitoring points are to be established for the lengths of the tunnel. Settlements monitoring reference arrays comprising three reference points, centred on, and perpendicular to the tunnel line, are to be placed at 50m maximum centres along the route of the tunnel. The transverse arrangement should be matched to the predicted settlement trough. Monitoring is to be undertaken to ensure the stability of readings prior to and after tunnelling has been completed, and at intervals to identify any trends in readings that demonstrate that ground movements are in accordance with predictions and control of the stability of works. Monitoring shall be in the form of precise levelling unless otherwise instructed by the Project Manager. Monitoring points shall be established at least 200m in advance of the face and at least 3 No. measurements undertaken to establish base readings. When the face has passed the array readings shall be undertaken on a daily basis for 7 days. Thereafter readings shall continue on a weekly basis for 4 weeks or until ground movements have ceased or as directed by the Project Manager. PT241.11 Settlement monitoring reference points shall comprise 50mm long masonry nails in road pavements cast in protective concrete, or 10mm diameter 50mm long stainless steel round head bolts with stainless steel washers with steel tamp in anchors with lead sleeves in structures (Ref. to BRE Digest 386 Monitoring building and ground movement by precise levelling). Settlement monitoring reference points in verges and other non paved areas shall comprise >1.0m long 20mm diameter deformed steel bar driven into the ground encased in protective concrete. If these systems are not acceptable to the owners of the land, other systems are to be proposed by the Contractor for agreement by the Project Manager and the relevant third parties. PT241.12 Monitoring measurements are to be undertaken to an accuracy of +/-0.5mm. PT241.13 All monitoring systems shall be removed at the end of the monitoring requirement subject to the agreement of the Project Manager and relevant third party or their agent. PT241.14 Monitoring of settlement of the Network Rail running rails and other infrastructure will be carried out by a surveyor approved by Network Rail. The arrangement of the installation of the targets on the tracks and ancillary structures is being agreed with Network Rail by the Employer as will the frequency of monitoring and reporting. The Contractor shall appoint a Network Rail approved surveyor to prepare a detailed method statement for the survey work to be approved by Network Rail. PT241.15 Monitoring of settlement of the LUL running rails and other infrastructure is expected to be carried out by LUL’s in-house surveyors. If the Contractor is subsequently required to carry out this work he shall employ a surveyor approved by LUL under LUL entry procedures. The arrangement of the installation of the targets on the tracks and ancillary structures shall be agreed with LUL as will the frequency of monitoring and reporting. The agreed monitoring works will not form part of the Price and cost relating to this will be dealt with as a Compensation Event.

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PT241.16 The Contractor shall observe, record and analyse the readings to establish trends in movement and shall provide a copy of all recorded results to the Project Manager. He shall make available results to the Project Manager in accordance with an agreed programme. PT241.17 Trigger values and actions shall be established for all the monitoring locations including settlement arrays, buildings, rail tracks, bridges, railway furniture, structures and services monitoring systems. These shall be based on the criteria given in the table below or as otherwise specified in Monitoring Plans for individual structures and agreed with the Project Manager and Third Parties before work commences: Trigger Level Rate of Reading Action / Reporting Condition / Limiting Change Frequency Value GREEN Movement < Increasing, Defined in Monitoring Report to be 75% of Constant or 18.1.6 provided to Project predicted Reducing (typically 24 Manager within 24 hrs hrs) AMBER Movement Increasing, Each shift or Monitoring Report to be 75% to 100% Constant or a min. of one provided to Project of predicted Reducing per 12 hours Manager within 6 hours.

Contractor to review construction operations and take action to reduce ground losses if required.

Prepare to implement contingency plan for additional measures to control ground movement as agreed with the Project Manager. Contingency plan to be submitted to the Project Manager for acceptance within 12 hours. RED Movement > Increasing, Twice per Stop work, secure face 100% of Constant or shift or a min. and immediately inform predicted Reducing of one per 3 the Project Manager. hours Implement contingency plan and additional measures to control ground movement as agreed with the Project Manager.

Tunnelling works may only recommence with the acceptance of the Project Manager.

PT241.18 Monitoring of reference arrays is to be undertaken to ensure the stability of readings prior to and after tunnelling has been completed, and at intervals to

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identify any trends in readings that demonstrate that ground movements are in accordance with predictions and control of the stability of Works. PT241.19 The Contractor shall observe, record and analyse the readings in a monitoring report to establish trends in movement and shall provide a copy of all recorded results to the Project Manager. He shall make available results to the Project Manager in accordance with an agreed programme. PT241.20 The format of reporting of monitoring results is to be agreed with the Project Manager prior to commencing construction activities. Typically it is to contain: a) Graphical representation of settlement of buildings/ground over time and annotated with tunnel / excavation progress. b) Excavation data including material excavated. c) Settlement and excavation data trends. PT241.21 Hard copy results of the settlement arrays or monitoring points are to be made available to the Project Manager on a daily basis when the tunnel face is within 25m of the array and weekly thereafter in excel and pdf format. PT241.22 Monitoring of settlement, scheduled defects and defects arising during the course of the Works shall continue at agreed intervals for a period at least until the end of the defects date or other such time as agreed by the Project Manager.

PT242 DEFECT AND CONDITION SURVEYS PT242.1 Pre and post construction defect surveys shall be carried out to a programme and methodology as submitted to and agreed with the Project Manager for all structures and key utilities identified as being within the 5mm settlement contour as shown on drawings 6LYG-A1-02131 to 02141. PT242.2 The Northern Outfall Sewer (NOS) The Lee Tunnel alignment follows the route of the existing Northern Outfall Sewer (NOS) for approx 4.5kms. The Contractor shall carry out a visual Condition survey of the sewer as soon as practical after the award of Contract. Record drawings of the sewer are included in the Contract for information (Section 6). The survey shall be organised by the Project Manager in liaison with the Thames Water Operations Division who will provide all safety cover and review Method Statements for the survey as required by the Thames Water procedures for Entry into Confined Spaces and Live Sewers. The Contractor shall provide a Northern Outfall Sewer Condition Survey Report which shall be submitted to the Project Manager who, in liaison with the Contractor, will agree any protective measures to the NOS that will have to be carried out.

PT243 TEMPORARY ELECTRICITY SUPPLY FOR TUNNEL CONSTRUCTION PT243.1 The Employer has agreed to make available a supply of electricity to the Contractor for the Construction of the Works. Details of the proposed supply are described in Schedule 3 Clause 4 of the Works Information. The Contractor shall confirm that the supply will be in accordance with his specific requirements. If the supply is insufficient the Contractor shall make his own arrangements for the provision of alternative additional power requirements. PT243.2 Emergency Generator: Supply an emergency standby generator of such capacity and configuration as to automatically and instantly come on line in the event of a power failure, without interruption, and to operate ventilation, lighting, pumping, communications and other critical systems.

PT244 TREATMENT OF ARISINGS PT244.1 Spoil Processing requirements for Slurry TBM

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a) The Contractor is responsible for the design of the slurry separation plant, and shall comply with the MINIMUM requirements as set out below. The Contractor shall take account in the design of his plant the materials to be excavated in the Graben structure as defined in the Geotechnical Baseline Report (GBR). Details of the design shall be submitted to the Project Manager for acceptance within 28 days of contract award. b) The Separation Plant shall have the capacity of processing 300 cu.m. of solid excavation material per hour. The centrifuges shall have the capacity for processing 200 cu.m. per hour of chalk fines and the removal of all particles above 5 microns in size. c) The moisture content of the slurry paste for disposal shall not exceed 45% unless agreed otherwise with the Project Manager.

PT244.2 Spoil Processing requirements for EPB a) The moisture content of the material for disposal shall not exceed 45% unless agreed otherwise with the Project Manager PT244.3 Wastewater can be disposed of as follows: a) The wastewater from the slurry separation plant can be discharged into the chamber, adjacent to the Work Site, as shown on Drg 6LYG-A1-02208A from which it will discharge to the to the Head of the works in Beckton STW. The Contractor shall be responsible for maintaining the discharge pipe in good working order. The wastewater shall not exceed the following criteria, and testing samples shall be submitted weekly to the Project Manager, for analysis by Thames Waters’ Operations team:- i) Suspended Solids - 750 mg/l ii) COD - 375 mg/l iii) Ammonia - 25 mg/l iv) Sulphate - 1400 mg/l b) For water not meeting the criteria in (a) above, the water will be disposed of offsite, in agreement with the Project Manager. PT244.4 The Contractor shall allow for processed spoil for disposal to be delivered by conveyor to the start of the jetty bridge as shown on Drg 6LGY-A1-02208. The conveyor shall be capable of transporting a minimum of 400 cu.m.of spoil per hour. The location for barge loading is identified on Drg 6LGY-A1-02208. The Contractor shall manage the logistics of river transportation of other materials to be delivered to the jetty bridge. (refer to ITT). PT244.5 The Separation Plant shall be new and purchased for the Project. PT244.6 The Contractor shall, using similar materials to those identified in the GBR for the tunnel alignment, conduct trials to demonstrate to the satisfaction of the Project Manager prior to purchasing the separation plant that it can meet the requirements above. PT244.7 Storage of Excavated Material, both EPBM and SPBM 2 no. existing sludge tanks (approximately 4000m3 storage volume each) as shown on Drg 6LYG-A1-02208A can be made available to the contractor for storage of excavated material, if required by the Contractor. These tanks currently store sludge and the initial emptying and cleaning of these tanks shall be under a Provisional Sum

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PT245 TBM LAUNCH FROM OVERFLOW SHAFT The TBM will be launched from the 25m ID Overflow Shaft at Beckton STW. From the Site Information and GBR, the launch of the TBM will be within the Greenwich Fault Zone of the chalk, the Employer views this as one of the highest risks to the success of this Project and the Contractor shall, within 28 days of the award of Contract, submit to the Project Manager a detailed Method Statement of his Means and Methods for the launch of the TBM, including ground treatment and temporary works proposals. A Risk Assessment shall also be provided.

PT246 CONSTRUCTION TOLERANCES PT246.1 Bored Tunnel Tolerances a) Tunnel shall be constructed to the alignment as defined in the Works Information. b) Maximum tolerances allowed in respect of the departure of any point on the bored tunnel alignment from its designed centreline shall not exceed 50mm horizontally and 50mm vertically. d) No ponding anywhere in the tunnel shall be deeper than 25mm. e) The maximum and minimum measured diameter in any one ring shall be within 0.5% of the theoretical design diameter of the ring. f) The maximum lipping between the edges of the adjacent segments shall not exceed 5mm. PT246.2 Inner Lining Tolerances a) At no point shall the lining thickness be less than that recommended by the designer. b) As stated in PT246.1 the maximum departure of any point on the inner lining shall not exceed 50mm from its designed position. c) No ponding anywhere in the tunnel shall be deeper than 25mm d) The internal diameter of the inner lining measured at any point around the circumference shall depart no more than 10mm from the designed diameter. e) If cast in sections there shall be no lipping between the panel joints. PT246.3 Groundwater Ingress Primary Lining a) The infiltration volume of water for the total length of tunnel shall not exceed 0.1 litre per hour per linear metre of nominal bore. b) Sealing of leaks in the segmental lined tunnel shall be carried out prior to the secondary lining installation PT246.4 Groundwater Ingress Inner Lining There shall be no visible damp patches or running water present on the finished surface of the lining.

PT247 AS-BUILT TUNNEL SURVEY PT247.1 On completion of the tunnel construction the Contractor shall carry out an As-Built Tunnel Survey in the bored tunnel. The accuracy of the survey shall be to ±20mm for vertical and horizontal alignment. PT247.2 The As-Built Tunnel Survey shall be completed as soon as practical following the completion of the tunnel, the As- Built Survey data is to be finalized and submitted to the Project Manager prior to the final acceptance of the tunnel.

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PT248 SECONDARY LINING DESIGN AND INSTALLATION PT248.1 The Contractor shall be responsible for the design and installation of a Reinforced Concrete Inner Lining in accordance with the Works Information. The design must allow for the build tolerances in the primary lining. PT248.2 The design life of the Inner Lining shall be 120 years. PT248.3 The Specification for the design and construction will be the British Tunnel Society Specification for Tunnelling and the References as detailed in PT402 Special Clauses are detailed in this Section PT248.4 The Contractor shall submit to the Project Manager for his acceptance in accordance the timescales of Schedule 4 and the requirements of Schedule 6 of the Works Information. This includes, but is not limited to, design calculations and drawings of the proposed Reinforced Concrete Inner Lining. The design submissions shall include as a minimum details of design standards used, loading conditions, design assumptions, design parameters, method of analysis, references and proposals as to how they will meet the water ingress specification PT246.4 and detailed drawings and installation methodology. PT248.5 The Contractor shall submit to the Project Manager for his approval within 90 days of award of Contract a detailed Method Statement of the proposed methodology for the construction of the Inner Lining. This is to include but not limited to details of the location of the Concrete Production, transportation of the concrete to the location of the placement, detailed drawings of the proposed arrangement of the internal formwork, method and timing of the fixing of reinforcement if proposed. PT248.6 The Contractor can work from Beckton and/or Abbey Mills on the installing of the Inner Lining should he so decide as part of the Construction methodology. Account should be taken of any restrictions imposed by the Planning Agreements at either site as described in the Works Information. PT248.7 Concrete Mixes shall be designed and mixed in accordance with the requirements of PT400. PT248.8 Concrete mixes shall be designed to minimise cracking of the lining and to ensure that crack widths do not exceed the permitted width specified in Eurocode 2-part 3:2006 and the National Application Document PT248.9 Concrete shall be compacted by high frequency mechanical vibrators. type shall be used, supplemented in the case of steel formwork by heavy duty formwork vibrators where necessary. Vibrators shall not be used to distribute concrete from the point on placing PT248.10 The Contractor shall submit to the Project Manager for acceptance within 90 days of the award of Contract a concrete placement Method Statement. This shall include the proposed construction joint detail and locations. This shall also include proposals for the testing of the inner lining concrete to ensure that the minimum concrete strength, as specified in the Contractor’s design submission, has been achieved prior to removal of the formwork, and any testing procedures the Contractor proposes to carry out to ensure that there are no voids in the concrete inner lining. The submission shall include a detailed methodology to eliminate air entrapment and voids between the inner lining and the primary lining when placing the concrete and pressure grouting procedures and his proposed method for ensuring the completed lining is free from voids PT248.11 Where encountered the Contractor shall grout any cavities and voids between the inner lining and the primary lining. Grouting will not be allowed until the concrete has been demonstrated as achieving the designed 28 day strength. Temporary grout pipes can be provided in the crown of the lining and used for the elimination of air entrapment and voids, these shall not remain within 40mm of the surface of the finished concrete.

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PT248.12 Design Loadings a) The internal lining shall be designed to resist the full internal hydrostatic pressure imposed when the tunnel and shaft systems fill to shaft roof soffit level. b) The internal lining shall be designed to resist the full external hydrostatic pressure imposed from the groundwater level as defined in the GBR. The loadings defined in a) and b) above shall be applied both simultaneously and separately.

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TABLE OF CONTENTS

PT300 CONSTRUCTION OF THE 3.05m DIAMETER STATION “A” CONNECTOR TUNNEL AT ABBEY MILLS : SPECIFICATION FOR THE TUNNEL BORING MACHINE AND TUNNEL CONSTRUCTION...... 2 PT301 SUMMARY...... 2 PT302 REFERENCE STANDARDS ...... 2 PT303 DEFINITIONS ...... 2 PT304 SUBMITTALS ...... 3 PT305 GENERAL – TUNNEL BORING MACHINE ...... 3 PT306 MINIMUM REQUIREMENTS FOR TBM TUNNELLING EQUIPMENT...... 4 PT307 CUTTERS ...... 4 PT308 CUTTER HEAD ...... 4 PT309 EXCAVATED MATERIAL MUCKING SYSTEM ...... 5 PT310 SEALS...... 6 PT311 GROUTING...... 6 PT312 SEGMENT ERECTOR...... 6 PT313 TBM/SEGMENTAL LINING INTERFACE...... 6 PT314 CONTROL AND INTERLOCKS...... 7 PT315 GUIDANCE SYSTEM ...... 7 PT316 APPLICABLE CODES AND REGULATIONS...... 8 PT317 TAIL SEAL GREASE INJECTION ...... 8 PT318 OTHER FEATURES ...... 8 PT319 FIRE PREVENTION – TBM AND BACKUP ...... 8 PT320 TBM FACTORY TESTING...... 9 PT321 QUALITY ASSURANCE ...... 9 PT322 TUNNEL HEALTH AND SAFETY ASSURANCE ...... 9 PT323 TUNNELLING CONSTRUCTION ...... 11 PT324 GENERAL TUNNELLING CONSTRUCTION REQUIREMENTS...... 11 PT325 GROUTING...... 12 PT326 INSTALLION, MONITORING AND CONTROL FOR SEGMENTAL LINING.... 13 PT327 SURFACE DISPLACEMENT MONITORING ...... 14 PT328 BUILDING DISPLACEMENT MONITORING ...... 14 PT329 TEMPORARY ELECTRICAL SUPPLY FOR TUNNEL CONSTRUCTION ...... 15 PT330 CONSTRUCTION TOLERANCES ...... 15

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Lee Tunnel, Contract No. 6LYG/A1 PT – Particular Tunnelling Specification - PT300

PT300 CONSTRUCTION OF THE 3.05m DIAMETER CONNECTOR TUNNEL AT ABBEY MILLS : SPECIFICATION FOR THE TUNNEL BORING MACHINE AND TUNNEL CONSTRUCTION

PT301 SUMMARY PT301.1 The work of this Section includes, but is not limited to, providing all labour, materials, tools, equipment, and incidentals necessary for a tunnel boring machine and tunnel construction, in accordance with the Contract Documents. PT301.2 The work of this Section includes, but is not limited to, the following activities: a) Tunnel Boring Machine includes, but is not limited to: design, manufacture, furnish, maintain and testing of a tunnel boring machine for the express purpose of constructing TBM excavated tunnels. b) Boring Tunnel includes, but is not limited to: mining of tunnels, installation of precast segment tunnel lining, temporary tunnel facilities, geotechnical monitoring, control of ground loss, settlement and heave, and removal and disposal of excavated material. c) As-Built Tunnel Survey PT301.3 This is a performance specification. The Contractor shall be responsible for the selection and complete design of the tunnel boring machine and tunnel construction systems. The Contract Documents provide parameters and design criteria for this portion of the Work.

PT302 REFERENCE STANDARDS See PT204 in “Specification for New Tunnel Boring Machine and Tunnel Construction”.

PT303 DEFINITIONS PT303.1 TBM excavation: The construction of underground tunnels by mechanical means using a tunnel boring machine. PT303.2 Segmental tunnel lining: Precast concrete segments that are bolted together inside the TBM tail shield to form a gasketed, watertight tunnel lining ring. The lining shall be designed to withstand both handling loads and all ground and water loads. Refer to PT400 for the detailed Specification requirements the design and supply of the Tunnel Linings. PT303.3 TBM: As used in this Section, the term TBM means the total system of the tunnel boring machine including trailing gear and appurtenant support equipment, materials and any items of plant which are necessary for the sustaining of TBM excavation operations all to be designed in accordance with the requirements of this Section. The TBM shall have the ability to apply a sustained and controlled pressure on the tunnel face within a pressure bulkhead located behind the face to form a plenum under pressure with the remainder of the tunnel maintained at atmospheric pressure. PT303.4 EPBM: An Earth Pressure Balanced TBM with a pressure bulkhead located behind the face to form a plenum under pressure. Conditioners can be injected into the plenum to control the quality of the excavated material through a screw conveyor in closed mode and belt conveyor in open mode. PT303.5 SPBM: A Slurry Pressure Balanced TBM utilizing a controlled dense slurry in a pressure chamber in the head of the machine to stabilize the face and minimize settlement. The resultant slurry, with excavated material, is removed to the Slurry Separation plant by pumping.

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PT304 SUBMITTALS PT304.1 To be submitted within 21 days from award of Contract. All submittals will be reviewed and returned within 14 days of Engineer’s receipt. See PT204 in “Specification for new Tunnel Boring Machine and Tunnel Construction” PT304.2 The Contractor shall state whether the tunnelling equipment proposed is to be new or refurbished. If refurbished elements are proposed the Contractor shall provide a detailed history of the use of the major components with the original calculated design life of the element together with supporting calculations, specifications and design. These components shall include but are not limited to: • Main Bearing • Muck excavation and handling systems (including slurry treatment facility if applicable). • Guidance system. • Segment transport and erector systems. • Tail seals and primary grouting system. • Gas detection system. • Services including ventilation, water management systems, utilities support and fire suppression systems. PT304.3 The following submittal is to be made a minimum of 90 days before the programmed date of TBM Start-Up: a) Tunnel Specific Safety Statement.

PT305 GENERAL – TUNNEL BORING MACHINE PT305.1 The work of this Section includes, but is not limited to, the following activities: furnishing a tunnel boring machine (TBM), as defined in this Section, for the express purpose of constructing a 3.05m ID TBM in materials of soil types, densities, gradations (PSD), strength, abrasivity and hydrostatic pressures described in the GBR and Contract Documents. PT305.2 The TBM shall be capable of applying a sustained and controlled pressure on the tunnel face to comply with the surface settlement limitations as required by this Specification. PT305.3 The bored tunnel lining shall be bolted precast concrete segments, with an EPDM gasket as specified in PT500 PT305.4 The selection of tunnel boring equipment and construction methods shall be compatible with the ultimate use of the tunnels, the ground and groundwater conditions, the depths of tunnels and the proximity of existing structures and services. PT305.5 Design TBM and backup equipment to negotiate the curves in the alignment and meet the specified alignment tolerances. PT305.6 Diameter of finished tunnel: to be a minimum of 3.05m ID to match the Contractor’s design and to produce minimal over-excavation and least necessary clearance. PT305.7 Equip TBM with integrated safety systems in accordance with applicable regulatory requirements for underground construction equipment and in accordance with BS6164 2001 “Safety in Tunnelling in the Construction Industry”.

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PT305.8 All soil conditioning materials, oils, greases, sealing compounds and any other material injected into or in contact with the soil, rock or ground water which is used during the mining operation shall be compliant with all relevant regulatory agencies and the requirements of the Contract.

PT306 MINIMUM REQUIREMENTS FOR TBM TUNNELLING EQUIPMENT PT306.1 With particular reference to this Contract Document, the requirements as detailed in this Section will not modify or detract in any way whatsoever from the Contractor’s sole responsibility for the selection, design and operation of the tunnelling plant and equipment. PT306.2 The Contractor shall assemble, maintain, operate and remove all tunnelling equipment necessary to construct and complete the tunnel in accordance with the Contract Documents and the ground conditions encountered. The Contractor shall also ensure that the design, manufacture and operation of the tunnel mining equipment, including the TBM, are carried out in such a manner that the tunnel can be constructed and completed in accordance with the time of completion requirements of the Contract.

PT307 CUTTERS PT307.1 Cutter design shall take into account the abrasivity of the ground conditions. The cutters shall be hard faced to a design giving best wear resistance. Cutters shall be backloaded such that access for repair and replacement can be carried out in safe working conditions. PT307.2 The Contractor shall pay particular attention to protection of the moving (rotating) elements of the machine against the potentially abrasive nature of the ground. The TBM shall be equipped with Chromium Carbide abrasion resistant plating or other approved hard facing to all exposed moving surfaces of the TBM, for example cutting head and screw conveyor. PT307.3 Design components for maximum abrasion resistance and durability. Minimize disc cutter wear to the greatest extent possible when not currently in use to perform tunnel excavation by such means as designing hubs and bearings to allow discs to be readily rotated by hand, and by limiting disc cutter projection beyond the cutter head face.

PT308 CUTTER HEAD PT308.1 The TBM shall incorporate a soil conditioning system for injection directly onto the face. The screw conveyor (if EPBM closed mode) shall also incorporate a facility for soil conditioning. Soil conditioning agents shall be bio-degradable and acceptable for the excavated materials to be used as a fill. All ports shall be independent. PT308.2 The TBM shall be capable of excavating through the ground conditions indicated in the Contract Documents and geological and geotechnical information available to the Contractor without interruption of the excavation operations PT308.3 Provide capacity to start cutter head with not less than 1.25 times rated full load torque. Provide clutches or hydraulic assist for a variable frequency electric drive (VFD) or use a variable speed hydraulic drive system. Thrust System and Steering a) Design TBM to provide forward propulsion by thrust cylinders that react against the installed segmental liner without damaging the liner. b) Equip the thrust cylinders with shoes or pads to distribute the jacking forces to the liner without damaging the liner. Design the thrust cylinder shoes to be consistent with segment and segment joint design while capable of individual and synchronized thrust cylinder actuation while limiting the

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maximum force that each thrust cylinder may exert so that liners are not damaged. Thrust cylinders shall resist displacements when idle. c) The TBM shall have a proven anti-roll system. PT308.4 The shield shall be articulated, subject to the following: a) Design and locate an articulation joint (or joints) as required, to assist constructing the tunnel to the theoretical alignment indicated in the Contract Documents and within the specified tunnel construction tolerances. b) Equip the articulation joint with a seal replaceable from within the TBM to prevent the entry of slurry, grout, fines or other foreign material. Provide a means for cleaning the articulation joint from inside the TBM to maintain its full range of articulation. PT308.5 Drive System a) Provide a TBM having sufficient drive motor power so the machine is not torque limited while operating in open earth pressure balance mode or slurry mode for any ground materials or conditions described in the Contract Documents. b) TBM drive system shall be bi-directional.

PT309 EXCAVATED MATERIAL MUCKING SYSTEM PT309.1 If proposing an EPBM, fit and operate earth pressure balance tunnel boring machine with a screw conveyor in closed mode and a conveyor belt in open mode to remove excavated material from the cutter head chamber. Design the screw conveyor for operation in abrasive soil and for efficient replacement from within the tunnel. PT309.2 If proposing an EPBM, the screw conveyor shall be designed to maintain the required face pressure within the cutterhead chamber and the entrance to the screw conveyor. Pressure shall be reduced to atmospheric at the screw exit by control of the screw conveyor. The tunnel boring machine shall be capable of controlling face pressure to within ± 0.3Bar of the desired pressure. PT309.3 If proposing an EPBM, design the screw conveyor to be capable of being closed and sealed against earth pressure at each end. The front of screw conveyor shall be located at the base of the pressure chamber and shall project into chamber when operating. The screw shall be capable of being withdrawn in order to close front bulkhead door for maintenance and removal of obstructions. PT309.4 Fix the exit/outlet end of the EPBM screw conveyor with a pressure lock-out device to separate the pressurized ground water and muck from atmospheric pressure. PT309.5 Provide and Calibrate, as a minimum, two TBM pressure cells in the mucking chamber and a minimum of two pressure cells on the screw conveyor all as recommended by manufacturer or as needed to assure accuracy of pressure measurements. PT309.6 Use a conveyor, rail or slurry system for muck transport in the tunnel. Design the system selected for materials with abrasive fines and high water content. All proposed systems shall take into consideration the designed gradients of the tunnel and the safety of the underground personnel. PT309.7 For all conveyor belt systems, there shall be an audible alarm with a red flashing warning light giving the operatives advanced warning that the conveyor belt is about to start moving. Emergency stop buttons shall be provided at all working points and at frequent intervals along the conveyor belt. Restarting of the conveyor shall only be possible from a single position and under the control of a single person.

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PT309.8 For SPBM, the TBM shall be designed to work under all conditions described in the Contract Documents. This includes the complete slurry system required to stabilize the face and drive the tunnel. The slurry machine shall be capable of controlling the applied face pressure to within 0.3Bar of the hydrostatic head. PT309.9 For SPBM, the design of the slurry treatment plant shall accommodate the types and quantities of geological materials anticipated and to remove solids from the suspension at a sufficiently fast rate so that the slurry treatment does not limit the TBM advance rate. The slurry shall be reconditioned or replaced with fresh slurry when the slurry properties are unsatisfactory.

PT310 SEALS PT310.1 Provide main bearing seals rated for tunnelling conditions and maximum pressure anticipated from the sum of all forces acting on the seals simultaneously and all machine operating characteristics related to the main bearings. Design the seals for the articulation joint, tail shield and probe ports for maximum hydrostatic and earth pressure. PT310.2 Shield tail seals shall incorporate a redundant system of wire brushes to seal against maximum hydrostatic and cavity grout pressure with due consideration of the liner segment design and the influence of liner grouting in seal design. Provide a minimum of three seals continuously fed with fibrous grease whenever the TBM advances. PT310.3 Tail seals other than the rear seal shall be replaceable from within the tunnel during a drive.

PT311 GROUTING PT311.1 Cavity Grouting: Provide a computer operated grouting system linked to TBM systems to calculate grout quantities and continuously adjust grout injection rate and pressure on the basis of the TBM advance rate and other data. PT311.2 The annulus void between the tunnel lining extrados and the excavated ground shall be fully grouted with a grouting system and mix approved by the Project Manager

PT312 SEGMENT ERECTOR PT312.1 The segment erector shall be compatible with the TBM and liner system to ensure safe and efficient segment installation and shall have an appropriate factor of safety for the anticipated loads. PT312.2 The erector shall be capable of actuation in the axial, radial, and circumferential directions and in the three articulation angles corresponding to the six degrees of freedom. Design the erector to grip and erect the segments so that they are positioned accurately, so that segments are aligned within the required tolerances, so that gaskets are fully compressed, and so that no damage or distortion of the segments occurs. PT312.3 All hand held electrical equipment, such as the pendant controls for the segment erector, shall be in a watertight enclosures and the control circuit protected by a Ground Fault Interrupter Circuit.

PT313 TBM/SEGMENTAL LINING INTERFACE PT313.1 Concrete segments and associated items shall be designed for anticipated ground and water loads and environmental conditions on the completed tunnel. The Contractor shall ensure that the segments are compatible with its selected construction equipment, means, methods and procedures including, but not limited to alignment control, handling, erecting, jacking and grouting.

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PT313.2 Maximum ram thrust contact pressure at any point and any time on the liner system ram thrust shall not exceed 50% of the segment 28-day compressive strength. PT313.3 Thrust pads are to be designed such that they shall not damage gaskets or segments. PT313.4 Equip TBM to allow continuous, complete backfill grouting of the annulus between the concrete segments and excavated surface. PT313.5 Tail seal grease shall be compatible with the liner system gaskets and materials, shall be inert, shall not contaminate the surrounding ground or groundwater and shall not in any way cause the long term deterioration of the liner concrete, the joint connector, the gaskets, seals or joint packers.

PT314 CONTROL AND INTERLOCKS PT314.1 The TBM cutter head shall be prevented from moving at any point during any maintenance or entry. An interlock should be provided from the control cabin to allow remote inching operation of the cutter head. Contractor to establish safety procedures, for approval by the Engineer, which will include, among other issues, a procedure to ensure that all personnel have evacuated the cutter head and front chamber before any movement is undertaken. This provision is intended to assist cutter tool changes with local indexing of the cutter head. The cutter head drive shall have fail-safe braking system to prevent inadvertent movement. PT314.2 All erector load-holding functions shall have a fail safe alarm system. Rotational drives shall be fitted with fail safe brakes. PT314.3 The segment erector shall be fitted with the selection and audibility of safe lifting alarms. PT314.4 An interlock shall be provided that prevents extension of the shove rams should grout delivery through the tail skin be interrupted or blocked. The Contractor shall provide a method of automatic data logging and measuring volume and pressure of grout injected per tunnel lining ring.

PT315 GUIDANCE SYSTEM PT315.1 The Contractor shall provide a TBM Guidance and Control System with laser theodolite. This shall be a commercially manufactured system. PT315.2 Technical Aspects a) Reference should be made to Contract Documents for required accuracy and tolerance and other matters affecting the operation of the system. b) The tunnelling system shall be designed to maintain a clear space for the guidance system and laser beam, irrespective of shield or TBM orientation. c) The data shall be presented on displays at the underground Machine PT315.3 Procedural Aspects The operation of the guidance system shall be a specific feature of the Contractor’s Quality Assurance Plan. This should clearly address: a) Definition of responsibility and authority of personnel maintaining and operating the guidance system. b) Intervals between manual checking of data produced by the guidance system (lengthened intervals may be adopted as experience is gained) c) Intervals at which survey control points are to be established, based upon tunnel geometry and guidance system characteristics.

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d) The guidance system must be fully operational whenever the TBM is advancing.

PT316 APPLICABLE CODES AND REGULATIONS The TBM and its components shall meet all applicable codes and regulations, and all requirements posed by the electric power suppliers and any other agency that has jurisdiction.

PT317 TAIL SEAL GREASE INJECTION Tail Seal grease injections shall be automatic and continuous to ensure effective filling between the brushes. Injection of grease shall be in accordance with the TBM manufacturer’s written requirements, and shall be a positive distribution system to ensure even distribution of grease, details of which shall be made available to the Engineer. Tail Seal grease shall be fireproof.

PT318 OTHER FEATURES PT318.1 Provide the TBM with probe hole and grouting drilling capability such that the probe and grout holes can be maintained a minimum of 20 metres ahead of the TBM cutterhead. The probing ports shall be fitted with suitable glands and valves to withstand the pressures envisioned. PT318.2 Provide method to test for the presence of hazardous or explosive gas in accordance with Health and Safety regulations requirements. Particular attention should be taken for the potential for migration of contaminated material from the Abbey Mills Site details of are given in Schedule 6 of the Works Information and the Factual Site Investigation Reports issued as part of the Contract PT318.3 All electrical power, control and safety systems shall have a minimum moisture ingress protection rating of NEMA 12. All cables in the tunnel shall be LSF (Low Smoke and Fume) or LSOH (Low Smoke Zero Halogen) sheathed. If the TBM has a high voltage transformer this shall have an over temperature alarm and shall include all safety devices as required by the regulatory authorities. PT318.4 Provide an environmental monitoring system that detects levels of potentially hazardous gases. Systems shall be arranged with adjustable limits and shall have a first level warning signal and a second level with automatic shut off of tunnelling equipment in accordance with Health and Safety Regulations requirements. Gases to be monitored shall include methane, oxygen, hydrogen sulphide, carbon dioxide and carbon monoxide and other gases, mists and fumes. PT318.5 The Contractor shall supply Calibration Test Certificates for gas detection system, pressure cells in excavation chamber and screw conveyor, TBM guidance system and grout pressure gauges. Certificates to be updated in accordance with the manufacturers recommendations. PT318.6 In order to provide a clean environment for placing of the invert segment plate, the Contractor shall take appropriate measures to keep the shield area free from water and spoil material. Pumping facilities in the shield area of the TBM shall be designed to allow sufficient space for the equipment proposed. PT318.7 The TBM shall be designed to withstand the full overburden pressure and anticipated hydrostatic pressures. PT318.8 Only TBM synthetic hydraulic oils HFDU (biodegradable, fire resistant, polyesters) shall be used. All oils must be approved by the TBM manufacturer.

PT319 FIRE PREVENTION – TBM AND BACKUP The TBM shall be provided with the following minimum systems of fire prevention but not limited to:

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a) Emergency Plunger buttons at suitable locations to activate a fire alarm. b) Hand held extinguishers provided with colour coded covers in suitable locations. c) A means of rapidly shutting off fresh air ventilation to the tunnel face, after the area has been evacuated. d) Conveyor belting, rubber covered rollers and other similar parts to be manufactured in materials that reduce the fire and toxic fume risk (Health and Safety regulations approved). e) Fire suppression system –manually operated

PT320 TBM FACTORY TESTING PT320.1 The Contractor shall submit, at least 30 days prior to the commencement of any factory tests, a test schedule and program for the TBM and back-up system. The Contractor shall allow for attendance by the Engineer at the factory tests. PT320.2 The TBM shall be tested in accordance with the manufacturers recommendations and a certificate of confirmation of compliance with the requirements of this Section, together with a copy of the test results, shall be signed by the Contractor and the TBM manufacturer and shall be forwarded to the Engineer prior to the TBM being delivered to the Worksite. PT320.3 The test shall include a demonstration mock up of the concrete segment erection system, using the precast concrete segments as proposed for the project.

PT321 QUALITY ASSURANCE PT321.1 TBM Manufacturer: The proposed TBM manufacturer shall be a recognised commercial TBM manufacturer with no less than 5 years of successful experience in the design and manufacture of TBMs of the type proposed by the Contractor. PT321.2 For this project the Contractor shall use only qualified and experienced person in the following key positions:- Contract Manager, Construction Agent, TBM Mechanical Foreman and Electrical Foreman and TBM Operators. The Contractor shall submit with his tender return the names and CVs of those key persons he proposes to use on this project.

PT322 TUNNEL HEALTH AND SAFETY ASSURANCE PT322.1 As part of the Contractor’s Safety program the Contractor shall produce a Tunnel Specific Safety Statement detailing the precautions to be implemented to protect personnel working in the tunnel from the construction methodology risks associated with tunnelling at the designed gradients and long section. These shall include: a) Risk of runaway trains and derailments b) Tunnel inundations c) Control of water and standby provisions d) Temporary Tunnel Ventilation System e) Emergency evacuation of tunnel f) Fire precautions. g) Management of rail and pedestrian movements in the tunnel. h) Tunnel Interventions for routine maintenance and unplanned events PT322.2 Bored Tunnel Temporary Facilities

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a) The Contractor shall design, provide, operate and maintain for duration of tunnelling construction a temporary ventilation system, which conforms to the Health and Safety requirements. The equipment shall be adequate to maintain sufficient supply of fresh air in underground work areas. b) The design of the ventilation system shall take into account any mitigation measures the Contractor may deem necessary having regard to the potential for the migration of any gases and contaminated material into the tunnel or shafts from the contaminated materials as detailed in the Reports and Site Information at Abbey Mills to be found in Schedule 6 of the Works Information i) Mechanical ventilation systems shall not be removed without the approval of the Project Manager. ii) As a minimum, in good air quality, when the excavations are occupied by workers, the ventilation system shall be designed to deliver fresh air at a volumetric flow rate equal to 20mtrs per minute times the cross- sectional area of the tunnel. A higher volumetric flow rate shall be provided if necessary iii) Power to the main ventilation system shall not be interrupted in the event of an alarm of the air monitoring system. iv) Advance of the ventilation system shall be made a regular part of the normal tunnel excavation cycle. PT322.3 Temporary Tunnel Lighting System The Contractor shall provide a temporary lighting system in the tunnel which conforms to the requirements of BS6164:2001“Code of practice for safety in tunnelling in the construction industry”. Lighting in the tunnel shall extend the full length of the tunnel and not be less than that required for safe working and access. An alternative source of power and emergency lighting system shall be provided to allow emergency securing operations and safe evacuation in the event of a primary power failure. An adequate number of hand lamps shall be located at key points underground. PT322.4 Temporary Personnel Walkway The Contractor shall provide walking access in the tunnel at all times. This shall have a firm, level, slip-resistant and continuous surface and shall be suitable for use in emergencies. PT322.5 Hop ups for pedestrian safety shall be provided in the tunnel at a minimum of 100mtr centres. PT322.6 Temporary Locomotive Track The track should be properly supported and secured against displacement in the tunnel. The entire length of the track shall be examined not less than once a week and the results of this inspection shall be forwarded to the Engineer. Defects shall be recorded and remedial action will be promptly implemented when identified. PT322.7 Temporary Pumping Provide intermediate pumping stations and reserve pumping capacity at the any point of the tunnel as required to remove groundwater inflows and construction water. PT322.8 Fire Extinguishers Fire extinguishers shall be provided at a minimum every 500 metres of the running tunnels. They shall be maintained in accordance with the manufacturer’s recommendations.

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PT322.9 Smoking Policy There shall be no smoking in the tunnel. PT322.10 Breathing Sets Approved emergency breathing apparatus or approved oxygen self-rescuers as appropriate shall be provided and kept with all persons visiting or working in the tunnel for the duration of their time in the tunnel. All such equipment shall be regularly maintained in accordance with the manufacturers recommendations, records shall be kept in the Contractors site office and made available for inspection by the Engineer.

PT323 TUNNELLING CONSTRUCTION PT323.1 The construction of the Connector Tunnel shall be carried out from Shaft F, which is the 25m internal diameter Reception shaft for the Lee Tunnel, and shall be driven at an upward grade to Shaft A, all as shown on the Contract Drawings. Tunnel driving from Shaft A will not be permitted due to the restricted available working space at that shaft. The Contractor shall ensure that sufficient float has been allowed in his Construction Programme to ensure that any delay in the construction of the Station A Connection Tunnel and Shaft F itself should not delay the completion of the Works. PT323.2 The Contractor shall monitor and analyze lubricants in critical areas of the tunnelling equipment on a weekly basis. This shall be performed by an independent specialist to identify the presence of any pollutants. Critical areas shall include all major sealing systems, main bearing, final drive gear, hydraulic systems and motor gear boxes. The results of the analysis shall be forwarded to the Engineer upon receipt together with any proposals for remedial action where pollutants have been identified. PT323.3 The Contractor shall forward to the Engineer details of proposals for the routine periodic preventative maintenance program that shall be adopted during the tunnelling operation. A nominated person shall be responsible for ensuring compliance with all preventative maintenance procedures. PT323.4 The Contractor shall provide foams, polymers, bentonite or other conditioners as required stabilizing the tunnel face and maintaining earth pressure until discharge from the screw conveyor under all conditions described in the Contract Documents,. All conditioners shall be biodegradable and inert.

PT324 GENERAL TUNNELLING CONSTRUCTION REQUIREMENTS PT324.1 Perform tunnel construction to minimize movement of ground in advance of, around and above the tunnel; to control water and water inflow and attendant soil transport; and to minimize settlement, subsidence and heave of the ground surface, structures, and utilities above and close to the tunnel for ground conditions that are to be encountered as described in the Contract Documents. Conduct tunnelling operations in a controlled manner so that settlement action levels are not reached. PT324.2 Unstable Conditions Procedures Whenever there is a condition likely to endanger the excavation or adjacent structures, notify the Engineer immediately and perform work on a 24-hour a day basis, including weekends and holidays, until such condition is resolved and eliminated. PT324.3 Maintain clean working conditions inside the tunnel by continuously and promptly performing housekeeping to remove muck and grout spills, trash and other debris. PT324.4 Daily records

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The Contractor shall provide Shift Reports to the Engineer, no later than 24 hours following the shift worked, detailing work performed except where otherwise allowed or approved herein, and integrated with requirements specified elsewhere for erection of precast segments, cavity grouting, and permeation grouting including: a) Date, location, shift and beginning and ending face station. A manual check of the TBM face location shall be conducted on a weekly basis. b) List of personnel by name, classification, and function working that shift. c) List of the number and type of equipment, including amount of and reason for any idle or down time. d) List of all materials used in the work. e) For every TBM shove or stroke: i) Description of soil or bedrock materials being excavated, including boulders and volume of excavated materials using methods as mutually agreed when not otherwise specified. ii) Description of delays and down time longer than 10 minutes, including reason for delay. Include maintenance records identifying the component, component position or number and reason for replacement. iii) Description and locations of water inflows, ground loss and other events. iv) Cutter, pick teeth and muck system component changes, including time and date of replacement, cutter or component position or number, and reason for change. v) Rates of advance for each hour. vi) Hours of actual machine operating time for each shift. vii) Max thrust pressure for each shove. viii) Ring number at start and end of each shift. ix) Type, manufacturer and produce name and number of all ground conditioners used on each shift. x) Volume and pressure of grout pumped behind precast segments on each shift. PT324.5 Results of quality control tests including: a) Volume of conditioner used as applicable for EPBM operations b) Volume of slurry and slurry density, as applicable for SPBM operations

PT325 GROUTING PT325.1 General “Primary Grouting” refers to the initial cavity grouting which takes place during shield shove using a constant pressure grout system. This shall be to a pressure that equates to the earth and hydrostatic pressure. PT325.2 Method Statement – Grouting The contractor shall submit to the Engineer for acceptance within 56 days of the award of contract a detailed Method Statement of the grouting procedures to be followed during the construction of the tunnel. These details shall include: mix design, constituents and testing procedures, pumping rates and pressures, means of gauging pressures at the point of injection, proof drilling pattern to be adopted.

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PT325.3 Primary Grout Injection Primary grout shall be injected by positive displacement .Consideration shall be given to providing a ring main system with the incorporation of approved retarders and accelerators to control the setting of the grout. The grout pump system shall incorporate a safety pressure by-pass arrangement, with means of reading the grout pressure at the point of injection. PT325.4 Records Records at each stage of the grouting process shall be kept, to include quantity and pressure applied at each injection point. These records shall be submitted to the Engineer daily.

PT325.5 Grout Performance The minimum compressive strength requirement of the grout as measured from testing cylinders shall be: 1.5N/mm² at 24 hours.

PT326 INSTALLION, MONITORING AND CONTROL FOR SEGMENTAL LINING PT326.1 Installation of Tunnel Lining a) Construct rings to correct line and grade, in true circular form to preserve the circularity of the tunnel. b) Select combinations of tapered segment rings to provide specific tunnel geometry, and for making corrections as necessary during construction. c) Inspect concrete segments and gaskets before transport into the tunnel. No damaged segments are to be taken in to the tunnel. d) Tighten bolts across the joints to ensure gasket compression in accordance with gasket manufacturer recommendations. e) Do not add packings or materials to circumferential joints to adjust line and grade unless approved by the Project Manager. f) Stagger radial joints in adjacent rings. Rings may be rotated one or two equidistant bolt locations to meet line and grade and curve requirements, provided that only T joints result between adjacent rings. g) Hangers for utility lines necessary for construction of the tunnel may be connected to concrete segments with the Designer’s approval and on completion of the driving of the tunnel shall fill the holes with a non-shrink cement mortar. h) The Contractor shall fill all the caulking grooves of the segments with a non- shrink sand/cement mortar to the satisfaction of the Project Manager i) The Contractor shall fill all bolt pockets and exposed lifting holes and grout holes with a non-shrink sand/cement mortar to the satisfaction of the Project Manager PT326.2 Monitoring of Segments The Contractor shall take measurements of the horizontal and vertical diameters for each tunnel ring following installation within the tailskin. Measurements shall be forwarded to the Project Managerr on a daily basis. PT326.3 Installation Tolerances a) Projection or lipping of a segment with respect to the adjoining segment shall not exceed 12mm on the inside face. b) The deviation from the true inside diameter of the completed ring shall not exceed ± 15mm.

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PT327 SURFACE DISPLACEMENT MONITORING PT327.1 The contractor shall submit to the Project Manager, at least 28 days prior to the commencement of tunnelling a method statement detailing his proposal for the monitoring and control of surface displacement in accordance with the contract. PT327.2 The Contractor shall carry out settlement assessments and submit these to the Project Manager for acceptance. Any facilities predicted to settle >5mm shall be subject to pre and post-construction condition surveys. PT327.3 Surface displacement monitoring for the construction of the bored tunnel shall be carried out to ensure that surface (vertical) settlement is limited to <10mm above the centreline of the tunnel. PT327.4 Monitoring points above the centreline of the tunnel shall be established at ground level every 50 metres along the full length of the tunnel, where practicable. Records of all readings taken by the contractor will be submitted to the Project Manager within 24 hours of the readings being taken. PT327.5 Settlement monitoring reference arrays comprising 3 reference points, centred on, and perpendicular to the tunnel line are to be placed at centres to be agreed with the Project Manager. Monitoring is to be undertaken to ensure the stability of readings prior to and after tunnelling has been completed, and at intervals to identify any trends in readings that demonstrate that ground movements are in accordance with predictions and control of the stability of works. Monitoring shall be in the form of precise levelling unless otherwise instructed by the Project Manager. Monitoring points hall be established at least 40m in advance of the face and measurements undertaken to establish base readings. When the face has passed the array readings shall be undertaken on a daily basis for 7 days. Thereafter readings shall continue on a weekly basis for 4 weeks or until ground movements have ceased or as directed by the Project Manager. Settlement monitoring reference points shall comprise 50mm long masonry nails in road pavements, or 10mm diameter 50mm long stainless steel round head bolts with stainless steel washers in steel tamp in anchors with lead sleeves in structures. Settlement monitoring reference points in verges and other non paved areas shall comprise 1.5m long 20mm diameter deformed steel bar driven into the ground. If these systems are not acceptable to the owners of the structure, other systems are to be proposed by the Contractor for acceptance by the Project Manager. PT327.6 Allowable Limiting Values (Vertical Settlement) for the construction of the bored tunnel is 10mm. PT327.7 Definition of Limiting Values: Limiting Values for allowable displacements are levels at which no further displacement will be acceptable. Displacements exceeding the Limiting Values specified shall require the immediate implementation of the following procedures: a) Cease work. b) Immediately notify the Engineer that work has ceased as a result of exceeding the Limiting Values. c) Submittal, of a modified Action Plan defining the additional corrective measures to assure no further displacement will occur. d) Tunnelling can only recommence with the approval of the Engineer.

PT328 BUILDING DISPLACEMENT MONITORING Building displacement instrumentation and monitoring for the construction of the bored tunnel shall be carried out as required by the Project Manager.

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PT329 TEMPORARY ELECTRICAL SUPPLY FOR TUNNEL CONSTRUCTION PT329.1 The Employer has agreed to make available a supply of electricity to the Contractor for the Construction of the Works. Details of the proposed supply are described in Schedule 3 Clause 4 of the Works Information. The Contractor shall confirm that the supply will be in accordance with his requirements. If the supply is insufficient the Contractor shall make his own arrangements for the provision of alternative additional power requirements at his own cost. PT329.2 Emergency Generator: Furnish an emergency standby generator of such capacity and configuration as to automatically and instantly come on line in the event of a power failure, without interruption, and to operate ventilation, lighting, pumping, communications and other critical systems.

PT330 CONSTRUCTION TOLERANCES PT330.1 Tunnel Tolerances a) Tunnel shall be constructed to the alignment as defined in the Contract Document. b) Maximum tolerances allowed in respect of the departure of any point on the bored tunnel alignment from its designed centerline shall not exceed 100mm horizontally and 50mm vertically. c) No ponding anywhere in the tunnel shall be deeper than 25mm. d) The maximum lipping between the edges of adjacent segments shall not be greater than 12mm e) The plane of each segmental ring shall not depart any point from the plane surface normal to the longitudinal axis by more than 12mm. f) The maximum and minimum measured diameter in any one ring shall be within 0.5% of the theoretical design diameter of the ring. PT330.2 Groundwater Ingress The water infiltration criteria is set out below. This criteria applies for the bored tunnel: a) The infiltration volume of water for the total length of tunnel shall not exceed 0.1 litre per hour per linear metre of nominal bore. PT330.3 As-Built Tunnel survey On completion of the tunnel construction the Contractor shall carry out an As- Built Tunnel Survey in the bored tunnel. The accuracy of the survey shall be to ± 20mm for vertical and horizontal alignment.

PT330.4 Timings of Surveys The As-Built Tunnel Survey shall be completed as soon as practical following the completion of the tunnel, the As- Built Survey data is to be finalized and submitted to the Project Manager prior to the final acceptance of the tunnel.

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TABLE OF CONTENTS

PT400 SPECIFICATION DESIGN AND SUPPLY OF PRECAST CONCRETE SEGMENTAL TUNNEL LININGS FOR THE LEE TUNNEL AND THE ABBEY MILLS CONNECTOR TUNNEL ...... 2 PT401 SUMMARY...... 2 PT402 REFERENCE STANDARDS ...... 2 PT403 SUBMISSIONS TO BE MADE FOLLOWING THE AWARD OF CONTRACT .... 2 PT404 PRODUCTS...... 3 PT405 DESIGN ...... 6 PT406 CONCRETE FOR SEGMENTAL TUNNEL LINING ...... 9 PT407 TESTING CONCRETE FOR SEGMENTAL LININGS...... 9 PT408 QUALITY...... 11 PT409 GENERAL CONSTRUCTION REQUIREMENTS...... 13 PT410 SEGMENT CASTING ...... 17 PT411 SITE QUALITY CONTROL...... 18 PT412 TOLERANCES...... 19 PT413 ADJUSTMENTS AND REPAIR PROCEDURES...... 20 PT414 INSPECTION OF PRECAST CONCRETE SEGMENTS ...... 20 PT415 DEMONSTRATION RINGS...... 20 PT416 PRODUCT DELIVERY, STORAGE, AND HANDLING ...... 21 PT417 SEQUENCING AND PROGRAMMING...... 22 PT418 QUALITY ASSURANCE ...... 22

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Lee Tunnel, Contract No. 6LYG/A1 PT - Particular Tunnelling Specification - PT400

PT400 SPECIFICATION DESIGN AND SUPPLY OF PRECAST CONCRETE SEGMENTAL TUNNEL LININGS FOR THE LEE TUNNEL AND THE ABBEY MILLS CONNECTOR TUNNEL

PT401 SUMMARY The work of this Section includes, but is not limited to, providing all labour, materials, tools, equipment and incidentals necessary for the design, manufacture and supply of the precast concrete segmental tunnel lining for the bored tunnels as in accordance with the Works Information and Site Information.

PT402 REFERENCE STANDARDS PT402.1 BS EN 1992: 2004. Eurocode 2 : Design of Concrete Structures PT402.2 BS EN 14889-1:2006 Steel Fibres – Definitions, Specifications and Conformity. PT402.3 BS EN 206-1: 2000 Concrete, Specification, Performance 8500-1:2006. Production and Conformity PT402.4 BS EN 8500-2: 2006 Specification for Constituent Materials and Concrete PT402.5 BS EN 934 parts 2 and 6. Admixtures for Concrete PT402.6 BS8666 Reinforcement, Dimensioning Bending and Cutting of Steel Reinforcement for Concrete PT402.7 BS 8110-Parts 1, 2 &3. Structural Use of Concrete PT402.8 BS8007:1987 Design of Concrete Structures for Retaining Aqueous Liquids PT402.9 British Tunnelling Society Specification for tunnelling 2000 PT402.10 Concrete Society Technical Report No. 63 Guidance for the Design of Steel Fibre Reinforced Concrete PT402.11 EN 14651 2005 Test Method for Metallic Fibred Concrete- Measuring the Flexural Tensile Strength (Limit of Proportionality (LOP), residual) PT402.12 EN 14721 2005 Test Method for Metallic Fibre Concrete – Measuring the fibre content in fresh and hardened concrete PT402.13 EN 14845-2 2006 Test Methods for Fibres in Concrete – Part 2: Effect on Concrete PT402.14 EN 14650 2005 Pre-Cast Concrete Products – General rules for factory production control of metallic fibred concrete

PT403 SUBMISSIONS TO BE MADE FOLLOWING THE AWARD OF CONTRACT PT403.1 Product data At least 60 days prior to the beginning of segment production, the Contractor shall submit to the Project Manager the following information: a) Concrete mix proportions including the ingredients, water tests, trial mixes, and the results of all concrete tests.

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b) Methods for testing and data to show that the proposed consolidation and curing process shall result in pre-cast concrete segments with the specified strengths and water permeability properties. c) Material specifications for components of the joint connection system and specifications describing the pullout capacity, material properties of the assemblies, and methods to verify proper assembly during installation in tunnel. d) Repair Mortar: Certificates of compliance with the properties listed herein and certifying the single source manufacturer for all compounds. PT403.2 Segment Design Submission The Contractor shall submit to the Project Manager for his acceptance within 28 days of the award of contract calculations and drawings of the proposed segmental lining. The design submissions shall include as a minimum details of design standards used, loading conditions, design assumptions, design of the proposed radial and circumferential joint connection detail (including any alignment locating dowel), design parameters, method of analysis, geotechnical parameters, references and detailed drawings. PT403.3 Installation and inspection data At least 30 days prior to the beginning of segment casting operations, submit the following: a) Segment repair and rejection criteria. b) Submit a quality control programme which shall establish a comprehensive inspection and testing programme, including proposals for the 3D laser dimensional checking of cast segments and moulds to ensure compliance with the specification. This programme shall be described in detail in a quality assurance plan. PT403.4 Performance reports and test data a) Joint Connection Test Assemblies: Perform three certified tests by a suitably qualified UKAS certified independent laboratory to demonstrate the pullout capacity of the individual joint connector assemblies. These tests shall include the actual joint connector assemblies and shall be performed in the embedded condition using concrete of the design strength. b) Submit details and results of joint connection pull-out capacity testing at least 30 days prior to the beginning of segment casting. c) During segment casting operations, submit on a weekly basis, methods and results of concrete testing for review and approval as specified herein. d) Product certifications On completion of the design of the TBM and the precast concrete segments, the Contractor shall provide written certification that the precast concrete segments are compatible with the proposed TBM. This shall include written certification by the precast concrete segment manufacturer, the Designer and the TBM manufacturer affirming the compatibility of the TBM and the liner system.

PT404 PRODUCTS PT404. 1 General All materials supplied to the Works shall conform to one or more of the following in the order of priority as detailed below a) This Specification

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b) The appropriate European or British Standard. Where a BSI Kite Mark certification is available, material supplied shall be marked with the BSI Certification trade mark(kite mark) c) Materials where no standard readily applies shall be supplied as far as practically possible from a Quality Assured source and documentation to indicate compliance with the Specification shall be provided to the Project Manager d) All materials shall be handled and stored in a way to maintain their integrity and to avoid damage and degradation PT404. 2 Concrete for Precast Concrete Tunnel Lining a) The Contractor shall provide for acceptance by the Project Manager all details of the mix design, source, details of materials and methods of production in advance of production. b) The production control of the factory producing pre-cast concrete segments shall be in accordance with EN 14650. c) The maximum size of aggregates shall be chosen to suit the proposed reinforcement together with the bolt pockets and grout hole inserts. d) Admixtures containing calcium chloride shall not be allowed. Unless otherwise agreed with the Project Manager any admixtures shall comply with the following:- i) BS EN 934-2. Admixtures for concrete, mortars and grouts – Part 2; Concrete admixtures – Definitions, Specifications and Conformity Criteria. ii) BS EN 934 – 6 - Quality Control. e) Admixtures shall be used in accordance with the manufacturer’s recommendations. PT404. 3 Reinforcing Steel a) Bar Reinforcement i) Reinforcement shall comply with BS4449 and BS8110. ii) Reinforcement shall be obtained from a certified supplier and the Contractor shall provide copies of the manufacturer’s certificates of test results relating to the steel reinforcement to be supplied. iii) Steel reinforcement shall be cut and bent in accordance with BS8666. iv) Steel Fibre reinforcement shall comply with BS EN 148899-1:2006 Fibres for concrete steel fibres – Definitions, Specifications and Conformity, or as agreed by the Project Manager. b) Steel Fibre Reinforcement i) Steel Fibre shall be deformed steel fibre Group 1 in accordance with BS EN 14889-1. Fibre shall be produced from cold drawn wire. ii) Fibres may be collated with a fast-acting water-soluble glue, or may be uncollated individual fibres. iii) Fibres shall be stored in dry sealed containers until required for use and shall be free from corrosion, oil, grease, chlorides and deleterious materials which may reduce the bond between the fibres and the concrete. iv) Fibres shall be hook ended or deformed of minimum diameter 0.45mm and minimum tensile strength 1000 N/mm2. v) Fibres shall be of low carbon content conforming to BS EN 14889-1

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vi) Fibres shall have an aspect ratio in the range of 40 to 80 for lengths of 30 to 90mm. Tolerances shall be in accordance with BS EN 14889-1 vii) Fibre type shall be selected on the basis of compliance with this Specification and on suitability and ease of use in the batching, mixing and concrete placement processes proposed, as demonstrated by site trials viii) Fibres which tend to form fibre balls during batching and mixing shall not be used. ix) Minimum fibre dosage rates for the concrete mix design shall be based upon the following table c) Minimum Steel Fibre Dosage Aspect Ratio 40 45 50 55 60 65 70 75 80 Minimum Dosage (kg/m3) 65 50 40 35 30 25 20 20 20

d) Tests on steel fibre shall be in accordance with BS EN 14721 and EN 14845-2 PT404. 4 Grommets for precast concrete linings shall be PTFE unless otherwise approved by the Project Manager. PT404. 5 Threaded Lifting Inserts shall be corrosion resistant. Type and size to be determined by Contractor based on handling and placing requirements. PT404. 6 Grout holes shall be threaded and fitted with non-return valves designed and installed to resist twice the maximum grouting pressure. The maximum grouting pressure for design purposes shall be 8Bar or to the maximum hydrostatic pressure. Grout holes will be provided with threaded caps designed and tested to the maximum hydrostatic pressure. PT404. 7 Gaskets Segments shall be supplied with waterproofing EPDM gaskets, or similar approved on all mating faces, complying with the requirements of this Contract as specified in Section PT500 PT404. 8 Dowels a) Alignment dowels shall be polyethylene material with shore hardness ASTM D785.D Scale 85 to 95. b) Circumferential Joint Dowel Connector The Circumferential joint dowel connectors, if proposed by the Contractor, shall be chosen to ensure the installed system is compatible with maintaining the gasket fully compressed. The Contractor shall provide the Project manager with load elongation test data to demonstrate the capacity of the dowel. PT404. 9 Compression Packing Bituminous fibre-board compression joint packers or other material accepted by the Project Manager shall be provided to produce a maximum 3mm joint gap thickness. The gaskets shall be designed to allow full closure of gaskets with compression packing in place. The compression packing shall extend no closer than 6mm from inside edge of gasket groove, no closer than 50mm from corner of segments, and shall be the same width as the flat surface of the joint (less the 6mm clearance). The compression packing shall cover a minimum of 90% of the area of the flat joint surface. PT404. 10 Radial and Circle Mechanical Joint Connector Systems

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The design of the radial and circle mechanical joint connector system shall take into consideration the Contractor’s method of working, procedure for the erection of the segments and the provision of any required locator system to assist in the a) Bolts shall conform to grade 8.8 to BS 3692:2001. b) Galvanised bolts shall be hot dip spun to BS729 c) Minimum bolt size shall be 20mm diameter. d) Nuts and sockets shall conform to BS4320:1968 unless noted. e) Structural washers shall conform to BS4395:1969. f) Galvanize ferrous parts of bolting system to minimum coating designation in accordance with BS4291:1988. g) Minimum 200kN/m² embedded pullout capacity yield on circumferential joint and radial joint connector assemblies. PT404. 11 Mortar for Segment Repair Provide a proprietary cementitious repair mortar for the repair of concretes. a) Suitable for use on vertical and overhead areas. The mortar is to be suitable for vertical applications having thicknesses greater than 50 mm b) The mortar shall have properties (compressive strength, indirect tensile strength, E-Modulus, shrinkage and coefficient of thermal expansion, etc) that are compatible with the segment concrete.. c) Components. The cementitious mortar shall consist of factory proportioned and pre-bagged materials whose components conform to the following properties: d) Mortar shall not contain chlorides, nitrates, added gypsum, added lime, or high alumina cements. Application time (working time) for horizontal and vertical repairs shall be 45 minutes after mixing and shall have set times suitable for the repair work in hand. Colour of the finished material shall be concrete grey.

PT405 DESIGN PT405. 1 The Contractor shall be responsible for the design of the segments. PT405. 2 All designs shall be carried out in accordance those Reference Standards as specified in this section and PT402 a) All Technical Submissions have to be checked and approved by a qualified Chartered Engineer experienced in the design of tunnel segments. b) The design life of Tunnels shall be 120 years. c) Bolted linings shall be provided with a caulking groove to all sides of the segment. All bolts shall be grommeted or as accepted by the Project Manager. d) Segments shall be provided with recesses to accommodate a gasket in accordance with the Particular Specifications. Alternatively, gaskets may be fitted into a groove in the segment mould walls and cast into the segment with the freshly placed concrete e) Lining design shall take into consideration measures to maximise the resistance to spalling in fires of the lining during the construction phase. Such measures may include the use of monofilament polypropylene fibres with a mean diameter <30 microns. f) The Contractor shall appoint a Design Consultant, approved by the Project Manager, to carry out an independent CAT3 design check in accordance

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with BD/2/05 of the Highways Agency DMRB for Technical Approval of Highway Structures. A Check Certificate will be submitted to the Project Manager, prior to any segments being cast, confirming that the proposed design has been carried out in accordance with the Contract requirements. g) Precast segmental lining systems shall be designed in accordance with Eurocode and environmental exposure conditions as defined in BS EN 8500-1 2006 are as stated below. It should be noted that BS EN 8500-1 does not provide guidance in the durability of steel fibre reinforced concrete, nor specifically for structures with a design life in excess of 100 years. The mix design shall comply with the following requirement:- • Water Permeability of concrete at 8Bar pressure 1 x 10⎯¹² m/s h) Summary of Exposure classes Location Exposure class Comment Internal XC3/4 Moderate humidity or cyclic wetting and drying External XD2 Wet rarely dry

i) Summary Design Sulfate and ACEC Classes. Location Design Sulfate ACEC class Comment Class Internal DS-3 AC-5 Brownfield site with mobile (worst ground water assumed case) Internal DS-2 AC-4z Brownfield site with mobile (best case) ground water assumed External DS-2 AC-2 Brownfield site with mobile ground water assumed

j) Summary of DC Classes Location DC class/ no. of APMs Comment Internal DC-4z / 1 Only APM3 – surface (worst case) protection is recommended Internal DC-4z / 0 - (best case) External DC-2 / 1 Additional APM applied due to potentially high hydrostatic head.

k) Summary of code requirements for steel fibre reinforced lining The following table present the summary of the durability requirements to BS 8500 and BRE Special Digest 1:2005 Parameter Requirements Exposure Case Internal Internal External (worst case) (best case)

Strength Class C50/60 C50/60 C50/60 (from design

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assumptions) Max w/c ratio 0.45 0.45 0.40 Cement type Groups 1, 2 or Groups 1, 2 or Groups 2 or 3 3* 3* Minimum 380 380 380 cementitious content (kg/m3) Max aggregate 20 20 20 size (mm) Minimum CFBO n/a n/a n/a cover (mm) RC Required 25kg/m3 steel 25kg/m3 steel 25kg/m3 steel minimum fibre fibres fibres fibres dosage Testing Fibre content, Fibre content, Fibre content, Requirements Residual flexural Residual flexural Residual strength, strength, flexural compressive compressive strength, strength, strength, compressive strength, Indirect tensile Indirect tensile strength strength Indirect tensile strength Notes: For cement types refer to Table A.17 in BS 8500 * Excluding Portland-limestone cement PT405. 3 Concrete segments and associated items shall be designed for anticipated ground and water loads and environmental conditions on the completed tunnel. The Contractor shall ensure that the segments are compatible with its selected construction equipment, means, methods and procedures including, but not limited to, handling, erecting, jacking, and grouting. PT405. 4 The Contractor shall confirm in writing that the tunnel rings are designed to negotiate the Contract alignment. a) The Contractor shall design and select lifting inserts for the segments that shall be compatible with the Contractor’s proposed segment lifting, handling, and erection equipment. PT405. 5 The Contractor shall design for all construction-imposed, operational and testing loads, including, but not limited to the following: a) Loads across joint connections and along the circumference, to maintain joint and installation performance. b) Invert loads along the longitudinal axis of tunnel derived from transport of equipment and materials. c) Loads generated by grouting, handling and erection and the tunnel boring machine. d) Lifting devices shall be designed to handle the segment weight, including dynamic and impact stresses induced during the lifting, transport and placement of segments. e) Maximum internal loading generated when the tunnel is being used for storage of surcharge flows, including chemical attack.

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f) Maximum internal loading generated when the tunnel is being tested as part of the pre-acceptance tests.

PT406 CONCRETE FOR SEGMENTAL TUNNEL LINING PT406. 1 General Concrete shall be produced and assessed for conformity in accordance with BS EN206 and BS8500. Further testing required for fibre reinforced concrete shall be undertaken in accordance with EN 14651 2005 or other equivalent standards approved by the Project Manager. PT406. 2 Cements a) Constituent materials shall be obtained from a supplier operating quality systems in accordance with BS EN ISO 9002. b) Cementitious materials shall be of the following designations to Table 6 of BS8500-1: i) IIB-V+SR(cement combinations with 25-35% pfa) ii) IIIA+SR (cement combination with 36-65%ggbs) PT406. 3 Aggregates a) Aggregates shall conform to BS EN 12620 and PD6682. b) The moisture content of the aggregate shall be accurately and continuously monitored throughout the concrete production process by the use of moisture probes in the aggregates storage bins. Appropriate adjustment shall be made to the added water and batching weight for the aggregate. PT406. 4 Water Mixing water shall comply with BS EN 1008 PT406. 5 Admixtures a) Admixtures containing chlorides or other corrosive agents shall not be used b) High Range Water Reducing (superplasticiser) and accelerating admixtures shall be employed to achieve the consistence and early strength development characteristics required. These admixtures shall comply with BS EN 934-2 and BS EN 934-6.

PT407 TESTING CONCRETE FOR SEGMENTAL LININGS PT407. 1 Concrete Mixes a) The design and quality control of mixes shall be carried out by the Contractor. b) If existing data on materials and properties of trial concrete mixes are not available, preliminary laboratory tests shall be carried out to establish the mixes to satisfy the specification with the available materials. c) Laboratory trial mixes shall be tested to determine the following properties of mixes proposed: i) Compressive strength ii) Indirect tensile strength iii) Free water/cement ratio iv) Consistency v) Plastic density vi) Water permeability

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vii) Residual flexural strength d) Unless otherwise agreed with the Project Manager, field trial mixes shall be prepared under full-scale site conditions at least 35 days before the commencement of concreting and tested in accordance with BS 1881. e) The mixes shall be tested to determine the following properties: i) Compressive strength ii) Indirect tensile strength iii) Free water/cement ratio iv) Consistency v) Water permeability vi) Plastic density vii) Residual Flexural Strength Acceptable value for the limits of these properties shall be established during the trials which shall therefore be used to monitor the quality control of the mixes and set the standard of compliance. PT407. 2 Evidence of Suitability a) For each mix, before making concrete for use in the works and whenever a change in the materials or mix proportions is proposed, suitability of the mix shall be established from historic records and/or laboratory trials. The supplier shall provide the following information: i) cement certificates ii) admixture data sheets iii) total chloride, sulphate and alkali values for mixes iv) target proportions of constituents v) results of relevant previous tests for the concrete vi) consistence loss with temperature and time vii) strength development curves at 20°C between 12 hours and 28 days and at the curing temperature of the concrete between 4 hours and 3 days b) Trials will be undertaken and approved prior to concrete being placed in the permanent works PT407. 3 Site Trials a) For each trial mix the following set of test specimens shall be made from each of 3 consecutive batches: i) cubes for compression testing at 28 days to BS EN 12390 b) For fibre reinforced concrete trial mixes the following set of additional test specimens shall also be made from each of 3 consecutive batches: i) 3 beams for flexural testing at 28 days to EN 14651 ii) 3 cubes/cylinders for indirect tensile strength testing at 28 day to BS EN 12390-6 c) For one batch an additional 2 samples shall be made to permit water permeability to be tested at 28 days in accordance with BS EN 12390-8 PT407. 4 Control of Chloride and Sulphate Content of Mixes

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The chloride content class of the concrete shall be CI 0,20 in accordance with BS EN 206-1. The total estimated sulphate (SO3) content of the concrete mixes shall not exceed 3.7% by mass of cement. PT407. 5 Control of alkali-aggregate reactivity Precautions against alkali reactivity shall be taken in accordance with BRE Digest 330. PT407. 6 Concrete batching a) The concrete batching plant shall be of a wet-batch, planetary pan mixer type, or similar approved, with moisture monitoring probes (Hydronix or similar) installed in the pan mixer b) Batching shall be by weigh-batching equipment with measuring devices (e.g. load cells) for the weighing mechanism. The machines shall be checked and calibrated regularly, every 3 months. Calibration certificates shall be made available to the Project Manager. c) The batching plant shall be controlled by a computerised batching system that is capable of recording the as-batched weights and moisture contents of all constituent materials for each individual batch of concrete d) The water supply to the concrete mixers shall have a metering system to control and record the amount of water used. e) Admixtures shall only be introduced using purpose made dosing equipment accurately calibrated. f) Water shall not be added to concrete after it has left the mixer. g) Provisions for the heating of water and aggregates in cold weather shall be included in the concrete batching plant h) Where steel fibre reinforcement is added to the concrete mix, this shall only be introduced using purpose made and calibrated weighing and dosing equipment.

PT408 QUALITY PT408. 1 Quality Control a) The Contractor shall plan all quality management procedures in accordance with BS EN ISO9001 and carry out all quality control testing as required herein within laboratories accredited by UKAS or operating to an equivalent standard for such testing. Method statements shall be submitted for the following concreting operations: i) production and transport - to demonstrate adequate control of constituent materials, consistence, temperature and early strength development characteristics ii) placing and compaction - to demonstrate adequate precautions to avoid honeycombing, excessive blowholes and segregation iii) curing and protection - to promote early strength development and long-term durability, including the avoidance of thermal and plastic cracking iv) concrete testing - to confirm the required properties of the fresh and hardened concrete have been obtained, including in situ temperature and strength monitoring v) segment handling – to demonstrate adequate planning to minimise the risk of accidental damage and overstressing during, striking, moving and lifting

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vi) remedial actions – to confirm that each non-conformity can be addressed and serviceability restored. b) Test specimens shall be compacted by vibration. The shape, manufacture and curing for each specimen type shall be in accordance with BS EN 12390-1 and BS EN 12390-2 as follows: i) cubes 150mm ii) beams 150 x 150 x 550mm iii) cylinders 150mm in diameter and 300mm in length PT408. 2 Testing of fresh concrete a) The consistence of every batch of concrete shall be determined at delivery and assessed according to the Identity criteria in BS 8500-1 b) Weekly monitoring of the plastic density of the concrete shall be carried out in accordance with BS EN 12350-6 c) For steel fibre reinforced concrete the fibre content shall be demonstrated by taking random samples of 5 litres of the concrete mix and separating out the fibres. The frequency of testing shall be 1 set of 3 samples per mixing unit per production shift. The fibres shall be collected, dried and weighed. The fibre content shall be deemed acceptable if the following are satisfied: i) The average fibre content from a set of 3 samples is greater than the design fibre content; and ii) No individual sample has a fibre content less than 80% of the design fibre content. PT408. 3 Testing of hardened concrete a) Cubes i) One set of cube test specimens shall be made for each work shift or every 100m3 of concrete used (whichever is more frequent) for identity. ii) For fibre reinforced concrete, one set of cube test specimens shall be made for each work shift or every 100m3 of concrete used (whichever is more frequent). iii) For fibre reinforced concrete, one set of beam test specimens shall be made for each 1000 m3 of production. b) One set of test specimens shall, comprise: i) For cubes: 3 cube for compressive strength testing at 7 days and 3 cubes for compressive strength testing at 28 days to BS EN 12390-3 ii) For beams: 3 beams for flexural strength testing at 28 days to EN 14651. iii) For cylinders: 3 cylinders for indirect tensile strength testing at 28 days to BS EN 12390-6. c) Additional cubes shall be made to confirm the compressive strength prior to demoulding and handling. Alternatively, a maturity monitoring system, utilising thermocouples, laboratory calibrated concrete maturity curves at the anticipated hydration and curing temperatures and analytical computer software may be used to accurately determine actual in-situ concrete maturity (and, consequently, compressive strength) of cast segments prior to demoulding. d) Cubes results shall be assessed using the Identity criteria in BS EN 206. e) The beam results comply with the specified flexural strength at first crack as defined in EN 14651 if the minimum flexural strength at first crack is greater

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or equal to 5.8 N/mm2 for all specimens and the toughness factor, Re3 is greater or equal to 63%. f) Alternative testing standards may be used with the agreement of the segment designer. g) The beam results comply with the specified residual flexural strength as defined in EN 14651 if the following is satisfied: i) The average residual flexural strength obtained from any 4 consecutive tests exceeds the characteristic residual flexural strength by 0.3 N/mm2. ii) The residual flexural strength obtained from any individual test is not less than the characteristic residual flexural strength less 0.3 N/mm2. iii) The characteristic residual flexural strength is not less than 63%. h) The cube results comply with the specified tensile splitting strength if the following are satisfied: i) The average tensile splitting strength obtained from any 4 consecutive tests exceeds the characteristic tensile splitting strength by 0.3 N/mm² ii) The tensile splitting strength obtained from any individual test is not less than the characteristic tensile splitting strength less 0.3 N/mm² iii) The characteristic tensile splitting strength is not less than 3.9 N/mm². i) The failed specimens shall be checked to ensure the random distribution and alignment of the steel fibres to the satisfaction of the Project Manager. Should the fibre alignment or distribution be noticeably non-random so as to improve the results from the testing above, the tests shall be repeated. PT408. 4 Durability Test Where required concrete shall be tested for durability properties at a nominal age of 28 days as described below. a) Absorption tests shall be carried out in the testing laboratory on 75mm diameter cores cut at an age of 24 to 28 days to enable the absorption tests to be carried between 28 to 32 days in accordance with BSI881 Part 122. where appropriate, tests may be carried out on 75mm x 75mm prisms cast for the purpose. The upper acceptance limit for absorption after 30 min shall be 3%. b) Tests to determine the penetration of water under pressure (“effective permeability tests”) shall be carried out in accordance with BS EN 12390-8. the average depth of penetration of two determinations shall not exceed 20mm. The coefficient of water permeability shall be calculated and corrected to provide a water permeability at 8Bar pressure.

PT409 GENERAL CONSTRUCTION REQUIREMENTS PT409. 1 Workmanship a) Furnish segments to be mechanically connected across joint faces. Provide joint connection assemblies to facilitate structural performance, achieve and maintain maximum joint closure and required gasket compression, and assist in ring stabilization and ring circularity. b) Provide gasket grooves as on designer approved drawings. Design joint to prevent lipping, which forms outside of edge of gasket groove, from contact with opposing lip during erection and thrusting of adjoining ring to prevent damage and spalling. Joint surface upon or against which gasket may bear shall be smooth, free of spalling, fractures and imperfections that would

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adversely affect performance of joint. Provide written verification that specified gasket groove load shall not be exceeded. c) Each segment shall include no less than one grout/lifting hole, with lifting insert and non-return valves. PT409. 2 Identification of Segments a) Provide a positive means of identifying each segment, such as a bar code system or similar approved that is accepted by the Project Manager. Segment identification should indicate the following information i) Internal diameter of liners ii) Concrete specification iii) Segment type designation iv) Manufacturer’s name or initials, if made off-site v) Date of manufacture vi) Mould number b) Indicated joint designation on inside face of liner. c) Markings such as logos, trademarks and proprietary information, except panel identification markings, are prohibited on surfaces of tunnel liner segments. PT409. 3 Surface Finishes a) Ensure that the maximum local irregularity on formed surfaces does not exceed rounded protrusion of 1mm. above the general concrete surface. b) If the extrados surface is not formed, it shall be finished with a steel trowel such that the maximum local irregularity does not exceed a rounded protrusion 3mm above the general concrete surface. PT409. 4 Segment Moulds a) Fabricate steel moulds with machined steel mating surfaces to conform to the dimensions and tolerances indicated, ensure segments of common design and cast in different moulds are interchangeable. Joints are to be watertight and form surfaces shall be prepared to provide segments with finished surfaces free from irregularities. b) Provide moulds of special sizes and cross sections with metal thickness, reinforcement, stiffness and surface finish as required to form concrete surfaces smooth, free from irregularities and conforming to the required dimensions. c) Construct moulds for precast segment with smooth casting faces such that a true, sound concrete surface is formed. i) Mould Bottom • The bottom formwork shall be composed of a 10mm bent steel plate (skin), two side plates with laser cut radius, two front plates and frame supports for side and head walls. • The bottom shall be high precision machined on one length and one side to guarantee the tolerance of the angle of the longitudinal joint. • The whole bottom formwork is to be assembled or manufactured in a pre-made gauge or template, in order to guarantee the given tolerances, and to avoid torsions during welding works.

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• Additional stiffeners will be included at any connection point of the machined sidewalls and heads of the mould. • Each mould shall be equipped, if required, with 4 electric vibrators, each (2 for the key); force calculated according the mould and concrete weight.

ii) Side Walls The side walls exist of strong, machined steel plates with supports and stiffeners to avoid torsion. Production procedure: • Cutting of the rolled plate • Welding the supports and stiffeners • Stress release by heat treatment 590 - 620°C • Machining - machining shall be conducted on computer controlled turning and milling machines. • Assembly iii) Mechanical Supports to the Side Walls The mechanical supports to open and close the side walls shall include: • Legs made of U or H profiles • Closing spindle with round or trapezoidal threads, secured by pre- stressed springs • To be operated easily by hand. • Geometrical adjustment with strong threads and double nuts, secured by additional nuts iv) Heads Shall comprise of: • Strong machined steel plates with supports and stiffeners to avoid torsion. • Opening and closing with mechanic toggle lever. • Self centring with cones to the side walls. v) Connections of Side Walls to Heads Shall comprise of: • Conical bush with threaded centre hole • Centring cone with fixing bolt to avoid deformation of the head during mould closing and fixing vi) Covers Shall comprise of: • 2 no. mould covers with supports to the mould bottom • For easy handling the covers shall be equipped with pull back springs.

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• If the covers are closed, the concrete can be filled into the mould through the remaining gap of approx. 400 mm. • To guarantee a perfect outer radius, the lateral parts of the covers shall be laser cut and the seal shall be integrated in an additional groove-profile, welded to the cover. • Closing and fixing of the covers to be by heavy bolts, to be closed by hand or with hydraulic wrench

vii) Seals • Rubber seals shall be integrated in the side walls and the heads to seal the gap to the mould bottom. • Additional rubber profile shall be integrated into the side wall to seal any possible gap to the heads. • Integrated rubber seals shall be provided in the radius of the covers to seal the cover and the outer radius of the side wall and head during concrete placement and compaction. viii) Manufacturing Tolerances • The moulds shall adjusted to the required tolerances according to the segment design. • The steel segment moulds shall be manufactured to the following tolerances: Flatness of surface of machined side walls: +/- 0.3mm Flatness of surface of machined heads: +/- 0.3mm Outer radius: +/- 1.5mm Arc length: +/- 1.0mm • Mould width shall be adjusted by using a digital micrometer. Width: ± 0.5mm Thickness: ± 1.0mm d) Segments of common dimensions and cast in different moulds shall be interchangeable. e) Provide moulds with individual identifications to ensure that all segments cast are marked and fully traceable. f) Form mould joint surfaces to provide flat planes at the orientations shown in the Works Information. g) Make all inserts to mould bolt pockets, holes, grout holes, etc. of approved steel or material having a coefficient of thermal expansion similar to that of concrete. h) Provide steel templates, gauges, and 3D laser checking apparatus, as required, to enable the measurement of tolerances to ensure that each segment falls the maximum and minimum dimensions allowed. Keep suitably protected from damage and distortion, free from dirt and corrosion and ready for use in checking the segments as described hereinafter. i) Clean and coat mould with non-staining release agent before each reuse. j) Securely anchor mould inserts and embedded items to formwork. k) Check each mould prior to each production pour to ensure that the dimensional tolerances of each form are being maintained. The Contractor

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shall submit details of the proposed methods to achieve this, such as matched line markings on the mould walls, prior to the commencement of production l) Keep a record of all the units cast in each form. Any mould that becomes distorted or which casts faulty units shall be withdrawn from service until it is proved to the satisfaction of the Project Manager to be corrected. m) Formed surfaces – Smooth form finish. n) Extrados face – Segment shall be finished by a steel trowel. Provide a finish smooth and free from blemishes and surface undulations greater than 3mm to ensure an adequate seal is achieved with the tail skin seal of tunnelling machine.

PT410 SEGMENT CASTING PT410. 1 Segment Casting Preparation a) The maximum variation in the position of the reinforcing bars shall be +5mm. Except for internally at joint connectors, grout holes, and as otherwise shown, the minimum concrete cover over the reinforcement shall be 35mm. Cages shall be sufficiently rigid to prevent deformation during the manufacturing process. b) Reinforcement cages shall be kept clean and dry and stored in such a manner that no distortion occurs. c) Clean reinforcement of loose rust, mill scale, and other foreign material. d) Fix concrete spacers so that the reinforcement is held firmly in the correct position within the formwork with all the cover specified. The spacers shall be rigidly fixed to the reinforcement to prevent displacement. If the spacers are wired on, the ends of the wires shall be turned into the unit. e) Furnish concrete spacers made from the approved concrete mix for the segments, compacted and cured to the same standard as the segments, or from concrete of an equal or higher strength to that identified in this Section. Plastic spacers are not to be used. f) Saturate all spacers with clean water prior to use. Spacers shall not be allowed to dry out after being fixed to reinforcement cages before the concrete is cast. g) Check reinforcement cages and other embedments within each mould. PT410. 2 Segment Casting a) Produce segments under enclosed plant controlled conditions with production areas protected against wind, rain, snow, dust and direct sunlight. b) The initial concrete placement temperature shall be less than 25°C and shall be no less than10°C. Thermocouples shall be cast into freshly cast segments to check maximum temperatures reached within the cast concrete. This shall be performed on at least two occasions per production shift. At no time should the maximum concrete temperature exceed 60 deg C. c) Protect all concrete from hot and cold weather at all times during production. d) Consolidate and work concrete into complete contact with forms and embedded items. Consolidate and work concrete into complete contact with forms and embedded items. Consolidate concrete adjacent to side forms and along the entire length of forms to ensure a smooth surface finish after stripping of formwork. Alternatively, the use of self compacting concrete (SCC) may be employed in the casting of the segments.

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e) Check the first segment cast in any form to confirm that the segment conforms to the required dimensions and tolerances. Thereafter as a minimum, two percent of the segments cast on each shift, not less than one segment per shift, shall be checked on a rotating form/mould basis to ensure that the dimensions and tolerances of the segments are maintained. 3D laser checking equipment shall be used for this process and shall be carried out at a designated laser checking station within the segment factory. f) All units of the same type shall be interchangeable and the dimensions for each unit shown in the Works Information shall be accurately reproduced within the tolerances indicated in the Works Information. g) If an out-of-tolerance segment is found, do not use that segment in the work or any other segments from the form found to be out-of-tolerance. The segment mould shall be removed from the production line and checked for dimensions with a 3D laser checking system and then adjusted and re- engineered until it is within tolerances. h) Verify that the segments have attained the characteristic strength prior to shipping by comparison with strength gain-maturity curves. Verify the results with cube test from concrete cured with the segments. i) The segments shall be delivered to the tunnel excavation sites in undamaged condition. No segment may be installed in the permanent works until it has attained its characteristic compressive strength. PT410. 3 Curing Segments shall be cured in accordance with the provisions of Eurocode 2. a) If proposing heat curing, immediately after segments have been cast, place the forms in a sealed, curing chamber. b) Do not attempt to remove segments from forms until compressive strength as required by the design of the segments is attained, as determined by temperature matched curing of cubes or a maturity monitoring system. c) When the compressive strength required for demoulding is attained, allow the segments to cool slowly. Segments shall be pre-stored internally within the casting factory for a minimum of 24 hours after demoulding in order to mitigate the risk of cracking from thermal shock. The use of thermal blankets may be required to minimise the rate of heat loss from the stored segments in cold weather conditions d) Segments shall be taken directly to outside storage stockpiles after the 24 hours pre-storage e) Any heat curing cycle to be used shall be designed to minimise the consumption of energy and maintain the peak temperature of hydration to below 60 deg C. The segments shall be examined immediately after striking for evidence of cracking or other damage. Cracks greater than 0.15mm shall be treated as a non-conformance.

PT411 SITE QUALITY CONTROL PT411. 1 Acceptance Tests a) Source Quality Control – Factory Tests i) Provide a written notice at least 30 days before starting manufacture of segments, to allow the Project Manager to inspect place of fabrication. Inspection by the Project Manager shall not relieve the Contractor of responsibility of furnishing material and workmanship meeting specified quality requirements.

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ii) When directed by the Project Manager as a check for manufacture, assemble and bolt up randomly selected segments for at least two quality control rings, per one hundred rings manufactured, to prove that outside surfaces of rings are coplanar and that tolerances of the completed rings meet specified requirements. iii) Allow the Project Manager access to work areas, and provide sufficient office space, workers, and equipment for performing the inspections. iv) Provide equipment including master working templates, gauges and callipers adequate to determine accuracies and tolerances in manufacture. b) Test concrete in accordance with the following requirements: i) Mix Design and Curing Strength Test. ii) Before start of manufacture, establish concrete mix that shall produce concrete of specified characteristic compressive strength. iii) After approval of the initial mix design has been obtained, make six cubes from a single batch of concrete. iv) Obtain prior written acceptance from the Project Manager for change in mix design during manufacture of segments. v) Prepare cubes before start of manufacture. Remove in pairs at appropriate time intervals during curing, and test for compressive strength immediately upon removal to establish correct curing duration. vi) For cubes prepared because of change in mix design, and as required by the Project Manager. c) Follow same procedures specified for cubes prepared before start of manufacture. d) Obtain acceptance of test results from the Project Manager before manufacture of segments using a new mix design. e) Production Test Cubes i) Prepare three cubes and cure as specified for each work shift or for every 100 mtrs³ of concrete used, whichever is more frequent. ii) Test cubes for compressive strength as follows: one cube after 7 days and the remaining 2 cubes after 28 days. iii) During segment manufacture, prepare two cubes per week from a concrete batch utilized to cast segments and test the cubes to demonstrate minimum strength for form removal is being attained. Alternatively, an approved maturity measurement system shall be used to determine the actual in-situ strength of the concrete immediately prior to demoulding. Procedures for monitoring demoulding strength by this method shall be submitted to and approved by the Project Manager.

PT412 TOLERANCES PT412. 1 Dimensional Tolerances of segments Dimensions of individual precast concrete segments shall be within the following tolerances:- a) circumferential length: ± 1.0mm b) thickness: ± 1.5mm c) width: ± 1.0mm

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d) bolt holes: size +1.0mm, -2.0mm e) bolt holes and dowel position ± 0.5mm f) sealing gasket grooves: depth ± 1.0mm g) sealing gaskets grooves: width ± 0.5mm h) longitudinal joints: in a ±- 0.3mm with a rate of deviation plane along the axis of the not exceeding 0.6mm/m i) tunnel (longitudinal) j) In a radial plane: 0.1mm with a rate of deviation not exceeding 1mm/m k) Circumferential faces 0.3mm from theoretical plane with rate of deviation not exceeding 0.6mm/m l) Smoothness of other faces extrados face:- ± 1.5mm intrados face:- ±1.0mm m) mismatch of sealing groove ± 0.5mm at corners PT412. 2 Demonstration Ring Tolerances a) Internal diameter : ± 0.2% ID or 6.0mm whichever is the greater b) lip between adjacent segments <5.0mm on internal diameter: c) gap between longitudinal segment 1.0mm feeler gauge not passing joints (packing removed and bolts tightened):

PT413 ADJUSTMENTS AND REPAIR PROCEDURES Repair of Segment Defects a) Repair or replace structurally damaged segments in accordance with this Section and to the satisfaction of the Project Manager; and to maintain the structural integrity, durability and water tightness of the segmental tunnel lining system. b) Prior to lining installation, repair minor damage to a concrete segment before erection by removing defective damaged area to sound concrete and patching with materials and procedures accepted by the Project Manager. c) Damage or irregularities to a concrete segment, which may impair structural integrity or performance, shall be cause for rejection of the segment by the Project Manager.

PT414 INSPECTION OF PRECAST CONCRETE SEGMENTS The Project Manager shall have the right to inspect, check and reject a finished segment not found to be in accordance with the Works Information. To measure and determine accuracy of manufacture, the Contractor shall provide and make available at all times master templates and working templates, gauges, callipers, 3D laser and other equipment as may be required by the Project Manager to inspect the segments.

PT415 DEMONSTRATION RINGS PT415. 1 Prior to full scale segment production, prepare one demonstration liner mock-up to demonstrate the accuracy and compatibility of the segments within the allowable tolerances. The mock-up shall consist of three complete precast

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concrete segmented rings erected vertically, without gaskets and packers, on a flat level base. a) Furnish to the Project Manager a 15-day written advance notice of start of assembly of demonstration liners. b) Assemble entire demonstration liner rings at the Site or another approved location above ground, with longitudinal axis vertical to demonstrate the accuracy of segments within the allowable tolerances. c) Furnish all tools and equipment to measure the required dimensions at no additional cost to the Project Manager. d) If demonstration liners are not acceptable, dismantle liners, adjust forms, cast new segments if necessary, and erect (at no additional cost) new demonstration liners for approval. Discard all segments that are determined to be unacceptable. e) Maintain demonstration liners intact for use as master rings in tolerance measurement until tolerances of completed rings are verified and the Project Manager authorizes removal of liners. Use dismantled segments for lining tunnel, if accepted by the Project Manager. PT415. 2 Second Demonstration Ring A second full scale demonstration mock-up shall be erected at the place of manufacture of the TBM. The purpose of the mock-up is to verify compatibility between the TBM and the segments. a) Furnish to the Project Manager a 15-day written advance notice of start of assembly of demonstration liners at the TBM manufacturer’s plant. b) Erect one complete ring, with the longitudinal axis horizontal, utilizing the erector arm of the TBM. c) Provide supplemental framing and bracing as required to enable the erection of the lining. d) Disassemble ring once the demonstration assembly is complete and the Project Manager is satisfied with the compatibility of the erector arm and the segments. e) Undamaged segments of the demonstration liner may be utilized for the tunnel lining. f) Transport segments between the segment manufacturer’s plant and TBM manufacturer’s plant. PT415. 3 Demonstration rings are to be erected on a flat and level base with the top ring rotated 180 degrees from the bottom ring with bolts inserted. All designed longitudinal packings shall be included in both rings. The test ring dimensions shall be checked to ensure that the tolerances are within the specification.

PT416 PRODUCT DELIVERY, STORAGE, AND HANDLING PT416. 1 Transportation Transport, store, and handle units to avoid damage and prevent excessive stresses from developing within segments. Follow all instructions from manufacturer of precast concrete segmental tunnel lining regarding transportation, storage, and handling of segments. PT416. 2 Segment Support Use supports for storing and handling segments to avoid damage; do not subject segments to undue strains.

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PT416. 3 Prevent damage to segment surfaces during handling and storage. Keep wire ropes, chains and hooks from direct contact with segment surfaces, joint assemblies, gaskets and joint compression packings. PT416. 4 Do not store segments with gaskets out-of-doors more than 90 days, unless the gaskets are proven to be resistant to ultra violet light and weather. PT416. 5 During cold weather, prevent water from filling the pockets and recesses of the segments and freezing. PT416. 6 Ensure segments have attained the specified 28-day characteristic strength prior to shipment. Segments to be loaded and shipped shall be a minimum 7 days old. Unless otherwise agreed with the Project Manager PT416. 7 Inspect the segments, remove defective or damaged segments, and repair any minor damage, in accordance with specified procedures prior to loading segments. PT416. 8 Arrange deliveries to the site from either the plant or stockpile. PT416. 9 Pre-bagged Repair Mortar Products: a) Deliver materials to the site in original packages or containers bearing the manufacturer’s labels and identification. b) Store and handle materials to prevent inclusion of foreign matter and water deteriorating effects of hot and cold temperatures as prescribed by the manufacturer of the materials to prevent inclusion of foreign matter and water and deteriorating effects of hot and cold temperatures as prescribed by the manufacturer of the materials. c) Any material stored past the expiration date shall be disposed of properly.

PT417 SEQUENCING AND PROGRAMMING PT417. 1 The Contractor shall ensure availability of demonstration lining rings in the appropriate time frame to allow supplying completed rings to the manufacturer of the tunnel boring machine (TBM) for use in performance testing of the TBM as specified in PT200.

PT418 QUALITY ASSURANCE PT418. 1 Contractor Qualifications For the manufacture of the segments employ a qualified firm or personnel regularly engaged in the manufacture of high precision precast concrete units of similar dimensions and tolerances to those specified, and who has manufactured precision precast concrete units to the quality as specified in this Section and shall demonstrate at least 5 years experience in manufacture and distribution of high precision products.

PT418. 2 Personnel Qualifications Employ supervising personnel experienced in the manufacturing and installation of mechanically connected precast concrete segmented linings, to the satisfaction of the Project Manager. The supervising personnel shall have at least 2 years experience in the manufacturing and installation mechanically connected precast concrete segmented linings. PT418. 3 Designer Qualifications All calculations shall be signed by a qualified Chartered Engineer in accordance with Schedule 6 of the Works Information. PT418. 4 Test Agency Qualifications

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Employ a Testing Laboratory, accepted by the Project Manager, to provide specified inspection and testing. The Testing Laboratory shall be UKAS Accredited and accepted by the Project Manager, unless otherwise instructed by the Project Manager.

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TABLE OF CONTENTS

PT500 SPECIFICATION FOR EPDM GASKETS FOR PRECAST CONCRETE TUNNEL SEGMENTAL LININGS ...... 2 PT501 SUMMARY ...... 2 PT502 REFERENCE STANDARDS ...... 2 PT503 SUBMITTALS ...... 2 PT504 MATERIALS ...... 2 PT505 GENERAL...... 5 PT506 INSTALLATION ...... 5

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Lee Tunnel, Contract No. 6LYG/A1 PT - Particular Tunnelling Specification - PT500

PT500 SPECIFICATION FOR EPDM GASKETS FOR PRECAST CONCRETE TUNNEL SEGMENTAL LININGS

PT501 SUMMARY The work of this Section includes, but is not limited to providing all labour, materials, tools, equipment, and incidentals necessary for EPDM gaskets for precast concrete tunnel linings for the Thames Lee Tunnel and the Abbey Mills Connection Tunnel, in accordance with the Works Information.

PT502 REFERENCE STANDARDS BS2494 Type D

PT503 SUBMITTALS PT503.1 The Contractor shall submit the following to the Project Manager for acceptance. a) Details of proposed gasket b) Manufacturer’s name, address etc. c) Name of proposed proprietary system d) Details of proposed gasket e) Details of gasket adhesive if used f) Details of gasket lubrication. g) Case Studies detailing previous relevant applications of the system PT503.2 Manufacturer’s Qualifications The manufacturer of the EPDM gaskets shall have been regularly engaged in the manufacture of such products for tunnels with hydrostatic heads equal to or greater than that of this scheme for a period of no less than 5 years and shall submit documentation to verify this. PT503.3 Manufacturer’s Installation Recommendations for: a) Storage b) Handling c) Installation d) Testing e) Repair Instructions f) Special instructions for corners and intersections. g) Installation equipment if any h) Health and safety data PT503.4 Shop Drawings, including as a minimum: a) Layout of EPDM gasket detailing joint locations. b) Details of joints and other construction details.

PT504 MATERIALS PT504. 1 Elastomeric Gaskets – General a) ‘Ethylene-Propylene-Diene-Monomer’ materials are referred to using the acronym EPDM.

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b) Elastomeric gaskets shall be from approved manufacturers and shall be tested in accordance with the Works Information, to the acceptance of the Project Manager. Gaskets shall be dense elastomeric synthetic rubber type, free of pittings, porosity, blisters and other imperfections, manufactured as a continuous frame, with moulded gasket corners mitred on each side and vulcanized to provide uniform gasket thickness along the entire length of mating surfaces. c) The extruded section shall be joined to form a rectangular gasket that is stretch fit into the grooves of the concrete segments. The corner joint shall be shot moulded and the corner pieces shall be of a different section from the extruded lengths in order that the water tightness characteristics described in this Section may be achieved and to avoid excessive load on the corners of the concrete segments. d) Gaskets shall be manufactured from extruded solid sections with appropriate spaces within the section to enable the gasket to be fully compressible within the groove formed in the concrete segments. e) The material from which gaskets are to be manufactured shall withstand any chemical attack from the ground or groundwater and shall not be subject to any biological degradation, to such an extent that the gasket fails to function properly during the specified warranty period for the gaskets as specified in this Section. f) The material shall consist of a compound based on EPDM able to withstand the long term stresses and strains without detriment to the specified performance. g) The gasket cross-section shall be dimensioned to suit the groove as detailed for the mating faces of the segmental tunnel linings in accordance with the Works Information and shall be approved by the tunnel segment designer. Manufacturing tolerances shall be in accordance with DIN ISO 3302-2, tolerance class E2. h) The supplier shall confirm in writing that the gasket groove as dimensioned in the Works Information is correct for the proposed gasket. As a minimum the gasket shall be designed to withstand under full compression the maximum hydrostatic pressure with a factor of safety of 1.5. i) The supplier shall ensure that the performance of the gasket shall comply with all the requirements of the Contract. PT504. 2 Elastomeric Gaskets - Testing and Material a) Gaskets shall be tested as follows. The test rig shall simulate a range of conditions of displacement and joint gap, including the worst combination to be encountered in the completed structure. In each test the water pressure shall be increased in increments of 1.0Bar and held at each value for 5 minutes. The final pressure shall be at least two times in excess of the in- situ maximum hydrostatic pressure to which the tunnel may be subjected. This pressure shall be maintained for 24 hours during which no leakage shall occur at the gasketed faces. Tests shall be carried out at normal ambient (surrounding) temperature. b) EPDM gaskets shall be in accordance with the following specified minimum requirements Value Standard Requirement Tensile strength ISO 30 > 9mPa (ASTM D412) Elongation ISO 30 > 175%

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Value Standard Requirement (ASTM D412) Hardness ISO 48 80 ± 5 Short Term (22hrs 70°C) (ASTM D2240), International Rubber 15% compression Hardness Degree Durometer A (IRHD) Long Term (70hrs 23°C) 20% compression Ozone resistance ISO 1431-1 No surface cracking of untensioned (ASTM D1149, specimen under x7 ASTM D518 Proc A). magnification Accelerated ageing: ISO 188 • change of 168 hours, 70°C (ASTM D573) hardness less than -5 to +8 (IRHD) • change of tensile strength less than -20% to +10% • change of elongation less than -30% to +10% Stress relaxation Test. ISO 11346 Minimum residual load to be better than WLF Equation Elevated temperature at 70°C 55% after 3 months of for 3 months. continuous testing Constant vertical deflection to uncompleted gap closure of 3mm. 60 minute measured load set equal to 100% Water absorption ASTM D471 Change in weight less than 10% 48 hours at 70 °C Use distilled water for standard test Use distilled water for standard test Oil absorption ASTM D471 Change in weight less than 110% 70 hours at 70 °C (IRM903)

PT504. 3 Warrantees and Guarantees a) Materials furnished and supplied under this Section shall be guaranteed to perform according to the Works Information and to the manufacturer’s published specifications whichever is greater or more stringent. b) The materials shall be warranted for a minimum of 50 years on-site against failures and defects in materials.

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PT505 GENERAL PT505.1 Technical Assistance A representative of the EPDM manufacturer shall be available at the Site, or at the segment manufacturing facilities, to provide installation and testing instructions to the Contractor’s or the Segment Manufacturer’s personnel if and when required. The EPDM manufacturer’s representative shall also provide training to the Contractor’s or the Segment Manufacturer’s personnel before the beginning the EPDM installation. PT505.2 General Competence and Workmanship The Contractor shall demonstrate to the satisfaction of the Project Manager, proven ability and competence to install the approved EPDM gasket in accordance with the manufacturer’s instructions.

PT506 INSTALLATION PT506.1 Surface Inspection Surfaces to receive EPDM gaskets shall be inspected for defects which could result in poor performance of the gasket. Defects shall be corrected prior to the installation of the EPDM gasket. PT506.2 Preparation Surfaces to receive EPDM gaskets shall be cleaned and free of oil, water, laitance and other deleterious substances in accordance with the EPDM gasket manufacturer’s instructions. PT506.3 Adhesive The gasket shall be fixed into the groove cast in the segmental tunnel linings prior to erection using only adhesives recommended by the EPDM gasket manufacturer. The adhesive shall be non-toxic and non-flammable at temperatures up to 200°C PT506.4 Lubricant Gasket faces to the key segment radial joints shall be lubricated prior to segment erection with a product recommended by the EPDM gasket manufacturer and accepted by the Project Manager. The lubricant shall be an organic soap based and applied by brush. PT506.5 Fitting Fitting shall be in accordance with the EPDM gasket manufacturer’s instructions.

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TABLE OF CONTENTS

PT600 SPECIFICATION DESIGN AND SUPPLY OF PRECAST CONCRETE SHAFT SEGMENTAL LININGS FOR THE LEE TUNNEL PROJECT...... 2 PT601 SUMMARY ...... 2 PT602 REFERENCE STANDARDS ...... 2 PT603 SUBMISSIONS TO BE MADE FOLLOWING THE AWARD OF CONTRACT...... 2 PT604 PRODUCTS...... 3 PT605 DESIGN...... 5 PT606 CONCRETE FOR SEGMENTAL SHAFT LINING...... 6 PT607 CONCRETE MIXES ...... 7 PT608 QUALITY ...... 7 PT609 SEGMENT CASTING...... 10 PT610 SITE QUALITY CONTROL...... 11 PT611 TOLERANCES ...... 11 PT612 ADJUSTMENTS AND REPAIR PROCEDURES ...... 12 PT613 PRODUCT DELIVERY, STORAGE, AND HANDLING...... 12 PT614 QUALITY ASSURANCE...... 13

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Lee Tunnel, Contract No. 6LYG/A1 PT - Particular Tunnelling Specification - PT600

PT600 SPECIFICATION DESIGN AND SUPPLY OF PRECAST CONCRETE SHAFT SEGMENTAL LININGS FOR THE LEE TUNNEL PROJECT

PT601 SUMMARY The work of this Section includes, but is not limited to, providing all labour, materials, tools, equipment and incidentals necessary for the design and supply of the precast concrete segmental shaft linings for the Lee Tunnel Project in accordance with the Contractor’s design of the Permanent Works

PT602 REFERENCE STANDARDS PT602.1 ABS EN 1992: 2004 Eurocode 2 : Design of Concrete Structures PT602.2 ASTM 820/820M-04 A Standard Specification for Steel Fibres for Fibre Reinforced Concrete PT602.3 BS EN 206-1: 2000 Concrete, Specification, Performance, 8500-1. Production and Conformity PT602.4 BS EN 8500-2: 2002 Specification for Constituent Materials and Concrete PT602.5 BS EN 934 parts 2 and 6 Admixtures for Concrete PT602.6 BS8666 Reinforcement, Dimensioning Bending and Cutting of Steel Reinforcement for Concrete PT602.7 BS 8110-Parts 1, 2 &3 Structural Use of Concrete PT602.8 BS8007:1987 Design of Concrete Structures for Retaining Aqueous Liquids PT602.9 British Tunnelling Society Specification for Tunnelling 2000 PT602.10 Technical Report No. 63 Guidance for the Design of Steel Fibre- Reinforced Concrete

PT603 SUBMISSIONS TO BE MADE FOLLOWING THE AWARD OF CONTRACT PT603.1 Product data At least 60 days prior to the beginning of segment production, the Contractor shall submit to the Project Manager the following information: a) Concrete mix proportions including the ingredients, water tests, trial mixes, and the results of all concrete tests. b) Methods for testing and data to show that the proposed consolidation and curing process shall result in uncracked segments with the specified strength and permeability properties. c) Polymer Repair Mortar: Certificates of compliance with the properties listed herein and certifying the single source manufacturer for all compounds. PT603.2 Shaft Segment Design Submission a) The Contractor shall submit to the Project Manager for his acceptance in accordance with the timings as defined in Schedule 2 of the Works Information calculations and drawings of the proposed shaft segmental lining. The design submissions shall include as a minimum details of design standards used, loading conditions, design assumptions, design of the proposed radial and circumferential joint connection detail (including any alignment locating dowel), design parameters, method of analysis, geotechnical parameters, references and detailed drawings.

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b) Joint Connection: If the proposed Shaft Segment joint connection design is an existing system the Contractor shall provide details of at least 3 projects where this system has been successfully used previously. Contact names and telephone contact numbers for a Reference for each project shall also be included c) During segment casting operations, submit methods and results of concrete testing for review and approval as specified herein. d) Product certifications Following the acceptance by the Project Manager of the Contractors proposed methods of construction, the Contractor shall provide written certification that the precast concrete segments are compatible with the proposed methods of Shaft construction. This shall include written certification by the precast concrete segment manufacturer and the Designer

PT604 PRODUCTS PT604. 1 General All materials supplied to the Works shall conform to one or more of the following in the order of priority as detailed below: a) This Specification b) The appropriate European or British Standard. Where a BSI Kite Mark certification is available, material supplied shall be marked with the BSI Certification trade mark(kite mark) c) Materials where no standard readily applies shall be supplied as far as practically possible from a Quality Assured source and documentation to indicate compliance with the Specification shall be provided to the Project Manager d) All materials shall be handled and stored in a way to maintain their integrity and to avoid damage and degradation PT604. 2 Concrete for Precast Concrete Shaft Lining a) Admixtures containing calcium chloride shall not be allowed. Unless otherwise agreed with the Project Manager any admixtures shall comply with the following: i) BS EN 934-2. Admixtures for concrete, mortars and grouts – Part 2; Concrete admixtures – Definitions, Specifications and Conformity Criteria. ii) BS EN 934 – 6 - Quality Control. b) Admixtures shall be used in accordance with the manufacturer’s recommendations. PT604. 3 Reinforcing Steel a) Bar Reinforcement i) Reinforcement shall comply with BS4449 and BS EN 10080:2005. ii) Reinforcement shall be obtained from a certified supplier and the Contractor shall provide copies of the manufacturer’s certificates of test results relating to the steel reinforcement to be supplied. iii) Steel reinforcement shall be cut and bent in accordance with BS8666. iv) Steel Fibre reinforcement shall comply with BS EN 148899-1:2006 Fibres for concrete steel fibres – Definitions, Specifications and Conformity, or as agreed by the Project Manager.

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b) Steel Fibre Reinforcement i) Steel Fibre shall be deformed steel fibre Group 1, 2 or 3 in accordance with BS EN 14889-1 except that Group 1 fibre may be either circular or rectangular in section. Fibre shall be produced from mild steel or cold drawn wire. ii) Fibres may be collated with a fast-acting water-soluble glue, or may be uncollated individual fibres. iii) Fibres shall be stored in dry sealed containers until required for use and shall be free from corrosion, oil, grease, chlorides and deleterious materials which may reduce the bond between the fibres and the concrete. iv) Fibres shall be hook ended or deformed of minimum diameter 0.45mm and minimum strength 1000 N/mm2. v) Fibres shall be of low carbon content conforming to BS EN 14889 or EN 10016-2-C9D vi) Fibres shall have an aspect ratio in the range of 40 to 80 for lengths of 30 to 90mm. Tolerances shall be in accordance with BS EN 14889-1. vii) Fibre type shall be selected on the basis of compliance with this Specification and on suitability and ease of use in the batching, mixing and concrete placement processes proposed, as demonstrated by site trials viii) Fibres which tend to form fibre balls during batching and mixing shall not be used. c) Tests on steel fibre shall be in accordance with BS EN 14721 or ASTM A820-04) except that: i) The cross sectional area used to compute the tensile strength shall be carried out to four decimal places, in units of square millimetres, and shall be: “for drawn wire fibres, the area calculated from the actual diameter”. ii) For cut sheet fibres, the area calculated from the actual thickness and width, or if fibres are tested, the area of each individual fibre calculated from the measured length and weight of the fibre, weighed to the nearest 0.0001g, based on a density of 7850 kg/m³. iii) For melt-extraction fibres, the area calculated from the equivalent diameter of the fibres, computed from measured average length and the weight of a known quantity of fibres, based on a density 7850 kg/m³. PT604. 4 Spacers shall be concrete with a compressive strength similar to that of the segments. Plastic spacers may not be used PT604. 5 Grommets for precast concrete linings shall be PTFE unless otherwise approved by the Project Manager. PT604. 6 Threaded Lifting Inserts shall be corrosion resistant. Type and size to be determined by Contractor based on handling and placing requirements. Test certificates required. PT604. 7 Grout holes shall be threaded and fitted with non-return valves designed and installed to resist twice the maximum grouting pressure. The maximum grouting pressure for design purposes shall the maximum hydrostatic pressure. Grout holes will be provided with threaded caps designed and tested to the maximum hydrostatic pressure.

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PT604. 8 Gaskets Segments shall be supplied with EPDM gaskets on all mating faces complying with the requirements of this Contract as specified in Section PT500 PT604. 9 Dowels Circumferential Joint Dowel Connector The Circumferential joint dowel connectors, if proposed by the Contractor, shall be chosen to ensure the installed system is compatible with maintaining the gasket fully compressed. The Contractor shall provide the Project manager with load elongation test data to demonstrate the capacity of the dowel. PT604. 10 Compression Packing Bituminous fibre-board compression joint packers or other material accepted by the Project Manager shall be provided to produce a maximum 3mm joint gap thickness. The gaskets shall be designed to allow full closure of gaskets with compression packing in place. The compression packing shall extend no closer than 6mm from inside edge of gasket groove, no closer than 50mm from corner of segments, and shall be the same width as the flat surface of the joint (less the 6mm clearance). The compression packing shall cover a minimum of 90% of the area of the flat joint surface. PT604. 11 Radial and Circle Mechanical Joint Connector Systems The design of the radial and circle mechanical joint connector system shall take into consideration the Contractor’s method of working, procedure for the building of the segments and the provision of any required locator system to assist in the process. a) Bolts shall conform to grade 8.8 to BS 3692:2001 and BS EN ISO 898-1 b) Galvanised bolts shall be hot dip spun to BS EN ISO 1461:1999 c) Minimum bolt size shall be 20mm diameter. d) Nuts and sockets shall conform to BS4320:1968 unless noted. e) Structural washers shall conform to BS EN 14399-1:2005 f) Galvanize ferrous parts of bolting system to minimum coating designation in accordance with BS EN ISO 1461:1999 g) Minimum 200kn/m² embedded pullout capacity yield on circumferential joint and radial joint connector assemblies. PT604. 12 Mortar for Segment Repair An approved proprietary system shall be proposed by the Contractor for acceptance by the Project Manager

PT605 DESIGN PT605.1 The Contractor shall be responsible for the design of the shaft segments. PT605.2 All designs shall be carried out in accordance those Reference Standards as specified in this Section and PT400. a) All Technical Submissions have to be checked and approved by a Chartered Engineer experienced in the design of shaft segments. b) The design life of Shafts shall be 120 years. c) Bolted linings shall be provided with a caulking groove to all sides of the segment. All bolts shall be grommeted or as accepted by the Project Manager. d) Segments shall be provided with recesses to accommodate a gasket in accordance with the Particular Specifications.

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e) The Contractor shall appoint an Design Consultant, approved by the Project Manager, to carry out an independent CAT3 design check in accordance with BD/2/05 of the Highways Agency DMRB for Technical Approval of Highway Structures. A Check Certificate will be submitted to the Project Manager, prior to any segments being cast, confirming that the proposed design has been carried out in accordance with the Contract requirements. PT605.3 Precast segmental lining systems shall be designed in accordance with Eurocode and environmental exposure conditions as defined in BS EN 8500-1 2006. It should be noted that BS EN 8500-1 does not provide guidance in the durability of steel fibre reinforced concrete. PT605.4 Concrete segments and associated items shall be designed for anticipated ground, water loads and environmental conditions on the completed tunnel. The Contractor shall ensure that the segments are compatible with its selected construction equipment, means, methods and procedures including, but not limited to, handling, erecting, jacking, and grouting. PT605.5 The Contractor shall design for all construction-imposed, operational and testing loads, including, but not limited to the following: a) Loads across joint connections and along the circumference, to maintain joint and installation performance. b) Loads generated by grouting, handling and erection and the tunnel boring machine. c) Lifting devices shall be designed to handle the segment weight, including dynamic and impact stresses induced during the lifting, transport and placement of segments. d) Maximum internal loading generated when the shaft is being used for storage of surcharge flows e) Maximum internal loading generated when the shaft is being tested as part of the pre-acceptance tests. PT605.6 At Abbey Mills the Contractor shall take due notice in his design of the shaft segments for the potential of contaminated ground at the Shaft A and Shaft F locations, details of which can be found in Schedule 6 of the Works Information and the Site investigation as included in the Contract.

PT606 CONCRETE FOR SEGMENTAL SHAFT LINING. PT606.1 General Concrete shall be produced and assessed for conformity in accordance with BS EN206 and BS8500. Further testing required for fibre reinforced concrete shall be undertaken in accordance with Japan Concrete Institute Standard JC1 SF4 or other equivalent standards approved by the Project Manager. PT606.2 Water Mixing water shall comply with BS EN 1008 PT606.3 Admixtures a) Admixtures containing chlorides or other corrosive agents shall not be used b) Water reducing and accelerating admixtures shall be employed to achieve the consistence and early strength development characteristics required. These admixtures shall comply with BS EN 934-2 and BS EN 934-6.

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PT607 CONCRETE MIXES AND CONCRETE TESTING PT607.1 Concrete Mixes and Testing. The design, testing and quality control of mixes shall be carried out by the Contractor in accordance with the requirements of PT400. PT607.2 Evidence of Suitability For each mix, before making concrete for use in the works and whenever a change in the materials or mix proportions is proposed, suitability of the mix shall be established from historic records and/or laboratory trials. PT607.3 Control of Chloride and Sulphate Content of Mixes The chloride content class of the concrete shall be CI 0,20 in accordance with BS EN 206-1. The total estimated sulphate (SO3) content of the concrete mixes shall not exceed 3.7% by mass of cement. PT607.4 Control of alkali-aggregate reactivity Precautions against alkali reactivity shall be taken in accordance with BRE Digest 330. PT607.5 Concrete batching a) Batching shall be by weigh-batching machines equipped with measuring devices for the weighing mechanism. The machines shall be cleaned, checked and adjusted regularly. Calibration records shall be made available to the Project Manager. b) The water supply to the concrete mixers shall have a metering system to control and record the amount of water used. c) Admixtures shall only be introduced using purpose made equipment accurately calibrated. d) Water shall not be added to concrete after it has left the mixer. e) Materials shall not be heated unless agreed with the Project Manager. f) Where steel fibre reinforcement is added to the concrete mix, this shall only be introduced using purpose made equipment.

PT608 QUALITY PT608.1 Quality Control The Contractor shall plan all quality management procedures in accordance with BS EN ISO9001 and carry out all quality control testing as required herein within laboratories accredited by UKAS or operating to an equivalent standard for such testing. Method statements shall be submitted to the Project Manager for the all concreting operations: PT608.2 Testing of hardened concrete a) Cubes i) One set of cube test specimens shall be made for each work shift or every 100m3 of concrete used (whichever is more frequent) for identity. ii) For fibre reinforced concrete, one set of cube test specimens shall be made for each work shift of every 100m3 of concrete used (whichever is more frequent). iii) For fibre reinforced concrete, one set of beam test specimens shall be made for each week’s production. iv) Additional cubes shall be made to confirm the strength prior to demoulding and handling.

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v) Cubes results shall be assessed using the Identity criteria in BS EN 206. vi) Beam results shall comply with the specified flexural strength at first crack as defined in JCI SF4 if the minimum flexural strength at first crack is greater or equal to 4.2 N/mm² for all specimens. vii) Alternative testing standards may be used with the agreement of the Project Manager. b) The beam results comply with the specified residual flexural strength as defined in EN14651 if the minimum flexural at first crack is greater or equal to 5.8N/mm² if the following is satisfied: i) The average residual flexural strength obtained from any 4 consecutive tests exceeds the characteristic residual flexural strength by 0.3 N/mm². ii) The residual flexural strength obtained from any individual test is not less than the characteristic residual flexural strength less 0.3 N/mm². iii) The characteristic residual flexural strength is not less than 3.0 N/mm². c) The cube results comply with the specified tensile splitting strength if the following are satisfied: i) The average tensile splitting strength obtained from any 4 consecutive tests exceeds the characteristic tensile splitting strength by 0.3 N/mm² ii) The tensile splitting strength obtained from any individual test is not less than the characteristic tensile splitting strength less 0.3 N/mm² iii) The characteristic tensile splitting strength is not less than 3.9 N/mm². d) The failed specimens shall be checked to ensure the random distribution and alignment of the steel fibres to the satisfaction of the Project Manager. Should the fibre alignment or distribution be noticeably non-random so as to improve the results from the testing above, the tests shall be repeated. PT608.3 Durability Test Concrete shall be tested for durability properties at a nominal age of 28 days. PT608.4 Workmanship a) Furnish segments to be mechanically connected across joint faces. Provide joint connection assemblies to facilitate structural performance, achieve and maintain maximum joint closure and required gasket compression, and assist in ring stabilization and ring circularity. b) Provide gasket grooves as on designer approved drawings. Design joint to prevent lipping, which forms outside of edge of gasket groove, from contact with opposing lip during erection and thrusting of adjoining ring to prevent damage and spalling. Joint surface upon or against which gasket may bear shall be smooth, free of spalling, fractures and imperfections that would adversely affect performance of joint. Each segment shall include no less than one grout/lifting hole, with lifting insert and non-return valves. PT608.5 Identification of Segments a) Provide a positive means of identifying each segment that is accepted by the Project Manager. Segment identification should indicate the following information: i) Internal diameter of lining ii) Concrete specification iii) Segment type designation

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iv) Manufacturer’s name or initials v) Date of manufacture vi) Mould number b) Markings such as logos, trademarks and proprietary information, except panel identification markings, are prohibited on surfaces of tunnel liner segments. PT608.6 Surface Finishes a) Ensure that the maximum local irregularity on formed surfaces does not exceed rounded protrusion of 1mm. above the general concrete surface. b) If the extrados surface is not formed, it shall be finished with a steel trowel such that the maximum local irregularity does not exceed a rounded protrusion 3mm above the general concrete surface. PT608.7 Formwork and Finishing a) Conform to the dimensions and tolerances indicated, ensure segments of Fabricate steel and concrete moulds with machined steel mating surfaces to common design and cast in different moulds are interchangeable. Joints are to be watertight and form surfaces shall be prepared to provide segments with finished surfaces free from irregularities. b) Provide moulds of special sizes and cross sections with metal thickness, reinforcement, stiffness and surface finish as required to form concrete surfaces smooth, free from irregularities and conforming to the required dimensions. c) Construct moulds for precast segment with smooth casting faces such that a true, sound concrete surface is formed. d) Segments of common dimensions and cast in different moulds shall be interchangeable. e) Provide moulds with individual identifications to ensure that all segments cast are marked and fully traceable. f) Form mould joint surfaces to provide flat planes at the orientations shown in the Works Information. g) Make all inserts to mould bolt pockets, holes, grout holes, etc. of approved steel or material having a coefficient of thermal expansion similar to that of concrete. h) Provide steel templates, gauges, and testing apparatus, as required to enable the measurement of tolerances to ensure that each segment falls within two concentric volumes in space represented as the maximum and minimum dimensions allowed. Keep suitably protected from damage and distortion, free from dirt and corrosion and ready for use in checking the segments as described hereinafter. i) Clean and coat mould with non-staining release agent before each reuse. j) Securely anchor mould inserts and embedded items to formwork. k) Check each mould prior to each production pour to ensure tolerances of each form are being maintained. Each mould shall be rechecked after every production pour to ensure that no changes occurred in the form during casting (under vibration). l) Keep a record of all the units cast in each form. Any mould that becomes distorted or which casts faulty units shall be withdrawn from service until it is proved to the satisfaction of the Project Manager to be corrected. m) Formed surfaces – Smooth form finish.

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n) Back face – Segment shall be finished by a steel trowel. Provide a finish smooth and free from blemishes to ensure an adequate seal is achieved with the tail skin seal of tunnelling machine.

PT609 SEGMENT CASTING PT609.1 Segment Casting Preparation a) The maximum variation in the position of the reinforcing bars shall be +5mm. Except for internally at joint connectors, grout holes, and as otherwise shown, the minimum concrete cover over the reinforcement shall be 35mm. Cages shall be sufficiently rigid to prevent deformation during the manufacturing process. b) Reinforcement cages shall be kept clean and dry and stored in such a manner that no distortion occurs. c) Clean reinforcement of loose rust, mill scale, and other foreign material. d) Fix concrete spacers so that the reinforcement is held firmly in the correct position within the formwork with all the cover specified. The spacers shall be rigidly fixed to the reinforcement to prevent displacement. If the spacers are wired on, the ends of the wires shall be turned into the unit. e) Do not use spacers in the circumferential or radial joint regions. The joint regions are the areas up to a distance of 100mm from the joint surface. f) Furnish concrete spacers made from the approved concrete mix for the segments, compacted and cured to the same standard as the segments, or from concrete of an equal or higher strength to that identified in this Section. Plastic spacers are not to be used. g) Saturate all spacers with clean water prior to use. Spacers shall not be allowed to dry out after being fixed to reinforcement cages before the concrete is cast. h) Check reinforcement cages and other embedments within each mould. PT609.2 Segment Casting a) Produce segments under enclosed plant controlled conditions with production areas protected against wind, rain, snow, dust and direct sunlight. b) The initial concrete placement temperature shall be less than 25°C and shall be no less than10°C. c) Protect all concrete from hot and cold weather at all times during production. d) Consolidate and work concrete into complete contact with forms and embedded items. Consolidate and work concrete into complete contact with forms and embedded items. Consolidate concrete adjacent to side forms and along the entire length of forms to ensure a smooth surface finish after stripping of formwork. e) Check the first segment cast in any form to confirm that the segment conforms to the required dimensions and tolerances. Thereafter as a minimum, two percent of the segments cast on each shift, not less than one segment per shift, shall be checked on a rotating form/mould basis to ensure that the dimensions and tolerances of the segments are maintained. f) All units of the same type shall be interchangeable and the dimensions for each unit shown in the Works Information shall be accurately reproduced within the tolerances indicated in the Works Information. g) If an out-of-tolerance segment is found, do not use that segment in the work or any other segments from the form found to be out-of-tolerance.

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h) Verify that the segments have attained the design strength prior to shipping by comparison with strength gain-maturity curves. Verify results with cube test from concrete cured with the segments. i) The segments shall be delivered to the tunnel excavation sites in undamaged condition. PT609.3 Curing Segments shall be cured in accordance with the provisions of Eurocode 2 a) If proposing heat curing, immediately after segments have been cast, place the forms in a sealed, vapour-tight enclosure or chamber large enough to allow complete circulation of heat b) Do not attempt to remove segments from forms until compressive strength as required by the design of the segments, as determined by test cubes. c) When specified strength is attained, allow segments to cool slowly, do not exceed rate of temperature change specified in this Section. d) Segments shall be moist cured for a minimum of five days after manufacture. The moist curing shall be achieved by placing the segments in a special area where water shall be continuously sprayed or atomized, after the steam curing to ensure a 100% relative humidity environment. e) Protect the segments from thermal shock. Utilize thermal blankets to minimize thermal shock. Do not allow rate of change of temperature to exceed 18°C per hour. f) The curing cycle shall follow the recommendations of AC1517.2R. The segments shall be examined immediately after striking for evidence of cracking. Cracks greater than 0.15mm shall be treated as a non- conformance.

PT610 SITE QUALITY CONTROL PT610.1 Acceptance Tests a) Source Quality Control – Factory Tests i) Allow the Project Manager access to work areas, equipment for performing the inspections. ii) Provide equipment including master working templates, gauges and callipers adequate to determine accuracies and tolerances in manufacture. b) Production Test Cubes i) Prepare three cubes and cure as specified for each work shift or for every 100 mtrs³ of concrete used, whichever is more frequent. ii) Test cubes for compressive strength as follows: one cube after 7 days and the remaining 2 cubes after 28 days.

PT611 TOLERANCES Dimensional Tolerances of segments Dimensions of individual precast concrete segments shall be within the following tolerances:- a) circumferential length: ±1mm b) thickness: ±1.5mm c) width: ±1 mm d) bolt holes: size+1mm,-2mm

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e) bolt holes and dowel: positions1mm f) sealing gasket grooves: depth ±1mm g) sealing gaskets grooves: width ± 0.5mm h) longitudinal joints: in a 0.3mm with a rate of deviation plane along the axis of the not exceeding 0.6mm/m tunnel (longitudinal) i) In a radial plane: 0.1mm with a rate of deviation not exceeding 1mm/m j) Circumferential faces: 0.5mm from theoretical plane with rate of deviation k) Smoothness of other faces: back face:- ±1.5mm front face:- ±1mm l) mismatch of sealing groove at corners: >0.5mm

PT612 ADJUSTMENTS AND REPAIR PROCEDURES PT612.1 Repair of Segment Defects a) Repair or replace structurally damaged and misaligned segments in accordance with this Section and to the satisfaction of the Project Manager; and to maintain the structural integrity, durability and water tightness of the segmental tunnel lining system. b) Prior to lining installation, repair minor damage to a concrete segment before erection by removing defective damaged area to sound concrete and patching with materials and procedures accepted by the Project Manager. c) Damage or irregularities to a concrete segment, which may impair structural integrity or performance, shall be cause for rejection of the segment by the Project Manager. d) The Project Manager shall have the right to inspect, check and reject a finished segment not found to be in accordance with the Works Information. To measure and determine accuracy of manufacture, the Contractor shall provide and make available at all times master templates and working templates, gauges, callipers and other equipment as may be required by the Project Manager to inspect the segments.

PT613 PRODUCT DELIVERY, STORAGE, AND HANDLING PT613.1 Transportation Transport, store, and handle units to avoid damage and prevent excessive stresses from developing within segments. Follow all instructions from manufacturer of precast concrete segmental tunnel lining regarding transportation, storage, and handling of segments. PT613.2 Segment Support Use supports for storing and handling segments to avoid damage; do not subject segments to undue strains. PT613.3 Prevent damage to segment surfaces during handling and storage. Keep wire ropes, chains and hooks from direct contact with segment surfaces, joint assemblies, gaskets and joint compression packings. PT613.4 Do not store segments with joint compression packing and/or gaskets out-of- doors more than 30 days, unless the gaskets and packers are protected from sunlight and weather.

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PT613.5 During cold weather, prevent water from filling the pockets and recesses of the segments and freezing. PT613.6 Ensure segments have attained the specified 28-day design strength prior to shipment. Segments to be loaded and shipped shall be a minimum 14 days old. Unless otherwise agreed with the Project Manager PT613.7 Inspect the segments, remove defective or damaged segments, and repair any minor damage, in accordance with specified procedures prior to loading segments. PT613.8 Arrange deliveries to the site from either the plant or stockpile. PT613.9 Polymer Repair Mortar Products: a) Deliver materials to the site in original packages or containers bearing the manufacturer’s labels and identification. b) Store and handle materials to prevent inclusion of foreign matter and water deteriorating effects of hot and cold temperatures as prescribed by the manufacturer of the materials to prevent inclusion of foreign matter and water and deteriorating effects of hot and cold temperatures as prescribed by the manufacturer of the materials. c) Any material stored past the expiration date shall be disposed of properly.

PT614 QUALITY ASSURANCE PT614.1 Contractor Qualifications For the manufacture of the segments employ a qualified firm regularly engaged in the manufacture of high precision precast concrete units of similar dimensions and tolerances to those specified, and who has provided precision precast concrete units to the quality as specified in this Section and shall demonstrate at least 5 years experience in manufacture and distribution of high precision segments.

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