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

Lee Tunnel, Contract No. 6LYG/A1
PT – Particular Tunnelling Specification - PT200
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
PT224.1
PT224.2
PT224.3
PT224.4
GUIDANCE SYSTEMS
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.
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.
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.
Technical Aspects
Thames Water Utilities Limited August 2008
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