Page 468 - Trenchless Technology Piping Installation and Inspection

418 App endix D

console. Electronic information is transmitted to the control console from
the heading of the machine. This information includes head position,
steering angle, jacking force, progression rates, machine face torque,
slurry and feed line pressures, and laser position. Some control consoles
are equipped with a computer that tracks the data for a real-time analysis
of the tunnel drive.

Control lever: A handle that activates or deactivates a boring machine
function.
Conventional pipe jacking: Jacking pipe sections simultaneously as tunnel
excavation proceeds using various forms of TBMs or hand mining (not
microtunneling or pilot tube microtunneling).
Conventional trenching: See open-cut.
Corrugated pipe: Pipe with ridges (corrugations) going around it to make
it stiffer and stronger. The corrugations are usually in the form of a sine
wave a+B181nd are usually made of galvanized steel or aluminum.
Cradle machine: A boring machine typically carried by another machine
that uses winches to advance the casing.

Creep: The dimensional change, with time, of a material, such as plastic,
under continuously applied stress after the initial elastic deformation.
Crossing: Pipeline installation in which the primary purpose is to
provide a passage beneath a surface obstruction, such as a road, railroad
track, lake or river.
Crown: (1) Top of pipe segment, or (2) The highest elevation within a
pipe.
Cured-in-place pipe (CIPP): A lining system in which a thin flexible tube
of polymer or glass fiber fabric is impregnated with thermoset resin and
expanded by means of fluid pressure into position on the inner wall of a
defective pipeline before curing the resin to harden the material. The
uncured material may be installed by winch or inverted by water or air
pressure, with or without the aid of a turning belt.
Cut and cover: See open-cut.
Cutterhead: Any rotating tool or system of tools on a common support
that excavates at the face of a bore; usually applies to the mechanical
methods of excavation.
Cutter bit (cutter head): The actual teeth and supporting structure that is
attached to the front of the lead auger, drill stem, or front face of the
tunnel-boring machine. It is used to reduce the material that is being
drilled or bored to sand or loose dirt so that it can be conveyed out of the
hole. Usually applies to mechanical methods of excavation, but may also
include fluid jet cutting.
Dead man: A fixed anchor point used in advancing a saddle or cradle-
type boring machine.