Page 463 - Trenchless Technology Piping Installation and Inspection

APPENDIX D

Glossary of Terms

ABS: Acrylonitrile-butadiene-styrene; a form of thermoplastic.
AC: Asbestos cement; a composite material used in pipe construction.

AMP: Asset management plan; a structured approach for utilities to
achieve long-term defined service standards or an external bearing used
to isolate the final drive from the thrusting force of the machine.

ASTM: American Society of Testing Materials.
Auger: A flighted drive tube having hex couplings at each end to
transmit torque to the cutting head and transfer the spoil back to the
machine.
Auger boring: Also horizontal auger boring, a technique for forming a
bore from a drive pit to a reception pit, by means of a rotating cutting
head. Spoil is removed back to the drive shaft by helically wound auger
flights rotating in a steel casing. The equipment may have limited steering
capability. See guided auger boring.
Auger machine: A machine to drill earth horizontally by means of a
cutting head and auger or other functionally similar device. The machine
may be either cradle or track type.
Auger MTBM: A type of microtunnel boring machine, which uses auger
flights to remove the spoil through a separate casing placed through the
product pipeline.
Auger TBM: Tunnel boring machine in which the excavated soil is
removed to the drive shaft by auger flights passing through the product
pipeline pushed in behind the TBM.
Back reamer: A cutting head attached to the leading end of a drill string
to enlarge the pilot bore during a pullback operation to enable the carrier,
sleeve, or casing to be installed.
Backstop: Also thrust block, a reinforced area of the entrance pit wall
directly behind the track or where the jacking loads will be resisted.
Band: A ring of steel welded at or near the front of the lead section of
casing to cut relief and strengthen the casing (used in horizontal auger
boring).

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