Courtesy BHMM/C TE. Photo Mark Vogler.
To hit its target at the end of 2,016 ft of drilling, precise alignment of the 9-ft-diameter, 50-ft long,
207,000-lb tunnel-boring machine was critical. Shown is the fully assembled machine just prior to its
4-1/2-month journey across the airfield.
the tunnel until the trailing end was
adjacent to the leading end of the second
pipe. The carrier pipes and casings were
field-welded and sealed and pulled as a
single 2,000-ft length until the trailing
end of the second pipe was adjacent to
the third pipe. Pipes and casings at this
joint were temporarily joined, and pulling
resumed (with 3,000 ft of pipe connected)
until the first 2,000-ft length was in place.
The second and third pipes were then
disconnected and the third pipe was
repositioned; it then became the “lead”
pipe for the next 2,000-ft length. Once
the hot-water system piping was in-place,
a similar process was repeated for the
chilled-water piping. This installation
method ultimately saved the project several
months and better than $1.0 million.
could only change as result of mutually
agreed changes in the scope of the project.
The target price concept also provided
a mechanism for acquiring long-lead items
(e.g., sheet piling, prefabricated piping,
tunnel-boring machine, etc.), which
required a significant outlay of cash.
As the project progressed, actual accumulated costs were tracked and compared
against the target. If, at project completion, the actual cost exceeded the target,
the contractor would share in a percentage
of the cost overrun; however, the contractor’s exposure was limited to a predetermined amount. If the actual cost
was less than the target, the owner would
share a percentage of the savings with the
contractor; however, the amount the contractor could gain was also limited by a
predetermined amount. Periodic ‘true-ups’
were performed as the project proceeded
to track overall financial performance.
it was felt that proper completion of
hydrostatic testing would be nearly
impossible.
The decision – an innovative one –
was made to preassemble the high-temperature hot water and chilled-water
piping above ground. With adequate layout space available, the thought was to
make use of the inherent flexibility of
long lengths of pipe by fully assembling
and testing all of the temporary-opening
pipe above ground, and then pull the
long lengths into position beneath the
runway and taxiways. That being the
case, the project team, working in conjunction with the manufacturer, Perma-Pipe Inc., developed a working plan for
‘Operation Noodle.’
Several months before the temporary
opening was available, the above-ground
assembly of eight 1,000-ft lengths of
thermal piping began. After completion
of the temporary opening and installation of electric and communications
duct banks, the preassembled thermal
piping was pulled into place. This was
accomplished by use of heavy steel cable
and a pneumatic tugger, which was firmly
anchored at the tunnel machine’s receiving
pit on the opposite side of the airfield.
A pipe support and guidance system was
designed using a combination of concrete
barriers, structural steel, specialty pipe
rollers and house trailer axles.
For the high-temperature hot water
system, the lead pipe was pulled onto
rollers located in the upper portion of
While construction of under-
ground, direct-buried thermal
utility systems is quite common,
expediting this work beneath
a runway and taxiways was
unique – and a challenge.
‘Operation Noodle’
While construction of underground,
direct-buried thermal utility systems is
quite common, expediting this work
beneath a runway and taxiways was
unique – and a challenge. Because of the
limited space available within the temporary 108-inch-diameter opening, traditional construction for thermal piping
would require piece-by-piece assembly
of the pipe and casing. This process was
estimated to take at least five months, and
it could not commence until the 2,016-ft-
long opening was complete. Additionally,
Central Energy Plant
Modifications
Phase 2 of BHMM’s work involved
modifying the Central Energy Plant.
Distinctly separate from the utility connector project, the design for plant
modifications was already completed
by December 2005. Since connector
construction would extend well into fall
2007, and since construction drawings
and specifications were ready for bid,
BHMM/CTE, with IAA concurrence, decided
to pursue this work with a traditional
design-bid approach. As with the connector, BHMM/CTE provided project management and construction financing, and
worked directly with Aviation Capital
Management, the owner’s technical representative. Working for BHMM/CTE
were Frank E. Irish Inc., mechanical contractor; Miller-Eads Inc., electrical contractor; ConServ Inc., instrumentation
and controls contractor; and Shiel-Sexton,
construction manager. The project engineer, Applied Engineering, Indianapolis,
was retained by the IAA.
