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Precision Utility Locating is a rapid and cost
effective way to detect and track subsurface utilities and is an important
element of the Utility Designation phase of Subsurface Utility Engineering
(SUE) projects. The locations of utilities can be marked quickly at a site
without extensive data processing, and in some circumstances, the depths of the
utilities can be determined.
The PUL method is commonly used in conjunction
with complementary geophysical methods such as magnetics,
EM, and GPR. One advantage of the
PUL method is that it can be used successfully in urban areas where surface
features such as buildings and overhead utilities prevent the effective use of
other geophysical methods. A second is that it works in areas of conductive
ground where GPR does not. The most common type of PUL equipment detects the
electromagnetic field produced by the current flowing along a buried conductor,
such as a pipe of cable, and uses that field to locate the utility.
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General Applications |
Specific Applications |
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transportation construction projects: highways,
airports, rail facilities
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construction projects in urban areas
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locate potential contamination pathways from floor
drains, dry wells, cesspools, and septic systems
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clear locations of proposed borings and test pits
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PUL equipment can be
used either in an active mode or in a passive mode. In active
mode, a PUL transmitter is either directly connected to a known
utility at a surface point or it is used to induce a current on a
buried known utility. The PUL receiver is used to trace the
signals along the utility. In passive mode, the PUL receiver is
used alone to trace signals carried by a utility from local power
lines or distant radio transmitters. The passive mode is used
to explore areas where no surface evidence of utilities is present.
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PUL
equipment cannot be used to detect non-metallic pipes, such as
concrete, vitrified clay, plastic, PVC, or masonry, except in cases
where surface access permits insertion of an accessory device to
transmit signals. |
Our diverse experience--we
have successfully located active and abandoned utilities on large and
small sites, in dense urban settings, along highway rights of way, at
airports, at military facilities, and at a variety of industrial and
commercial facilities--is available to help design a utility location
program to meet your objectives and circumstances. We have the trained
staff and a full complement of state-of-the-art PUL equipment, as well as
magnetic, EM, and GPR equipment.
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PUL Case Study |
Problem:
An 80-acre railroad yard, located in
the center of a northeastern city, was to be redeveloped. Dozens of
historic and newer buildings, razed buildings, and support
structures were present. Available information on location of
subsurface utilities was severely outdated. Over the long history of
use at the site, subsurface utilities had been added, altered,
removed, and some had been abandoned in place. Our objectives were
to detect and locate all utilities. The results would be used for
the planning and construction phases of the redevelopment project.
Solution:
Hager-Richter sent two
field teams to the site. One team used PUL equipment in active mode
to map the locations of utilities with surface connections (gas,
water, electric, telephone, and sewers). The other team used PUL
equipment in passive mode and supplementary EM and GPR methods to
explore for subsurface utilities without surface connections.
Hager-Richter's work was completed two weeks ahead of schedule and
under budget. |
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