080731 6LYG A1 Particular Tunnelling Specification ... - SCATnow

Lee Tunnel, Contract No. 6LYG/A1
PT – Particular Tunnelling Specification - PT300
PT305.8
PT306
PT306.1
PT306.2
PT307
PT307.1
PT307.2
PT307.3
PT308
PT308.1
PT308.2
PT308.3
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.
MINIMUM REQUIREMENTS FOR TBM TUNNELLING EQUIPMENT
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.
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.
CUTTERS
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.
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.
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.
CUTTER HEAD
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.
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
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
Thames Water Utilities Limited August 2008
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