PORTLAND, OR --Portland International Airport,
commonly referred to as “PDX” and one of America’s best airports, anticipates
substantial growth over the next two decades.
PDX
is scaling up in preparation to better serve 35 million passengers annually by
undergoing a main terminal expansion project – nearly doubling its size.
A key component of this
expansion is the construction of a new, seismically isolated roof structure
over the central area of the airport. Mammoet was contracted to jack up,
transport, and install 20 panels of five distinct types at the airport in
Portland, Oregon, USA - all while avoiding passenger disruption.
The roof, crafted mainly from regionally and sustainably sourced wood, was
fully prefabricated between the active runways of the airport over the course
of a year.
Prior to being moved, the roof panels were
disconnected into approximately football field sized pieces to be transported
to the new terminal expansion. This allowed the airport to carry-on as usual
while minimizing disruption to airport operations.
Depending on the type
of panel, each was launched, rolled into place, set directly with self-propelled modular
transporters (SPMTs), or lifted with a crane into its final position.
The panels vary in weight between 40t and 632t, with dimensions up to 72m x 50m
x 6m. Mammoet used four towers of Mega Jack 800 to
jack up the roof panels to approximately 17m to allow SPMTs with falsework to
be driven underneath each roof section.
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Portland, OR International Airport
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At midnight on the day
of each move, the runways were closed for the one-mile transport of the panel
from laydown yard to terminal. The roof sections were moved with care at a
speed of about 1.6 kilometers, or one mile, per hour.
Most panels needed to be installed over the top of populated areas of the
existing terminal building. With safety at the forefront of the entire project,
work was done during strict overnight closures when the public could be kept
clear of the work area.
Once the area was
verified to be clear of all pedestrians, the installation of the roof panels
could begin. Each panel, referred to as a super cassette, was installed using
stationary skidding propelled by strand jacks and lowered with the skidding
jacks onto column isolators.
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| Portland Airport runway |
The next set of panels
were then rolled into position down the bottom flanges of the previously set
panels.
The panels were safely
secured with consideration for potential elevated wind and project specific
seismic requirements before the public was allowed to reoccupy the area below.
A major complexity of the project was the wood material used in the roof
panels’ construction.
Deflection of the roof
panels was a major concern of the client and the roof designers, so at each
point in the jacking, transport, and installation process deflection of the
roof was monitored and kept within stringent criteria.
Only the super cassette
pieces had steel girders in the longitudinal direction to support the 25m
wooden arches and to allow the panels to be “launched” using stationary
skidding equipment.
Also, the supports for
the launching jacks were temporary towers supported by wooden piles which were
installed in the 1950s.
To mitigate any issues,
Mammoet performed extensive friction testing in its Rosharon, Texas yard prior
to execution to ensure no structural damage occurred to a mockup roof panel,
and that the design values presented to the client for strand jack anchoring
were realistic. When executing the job on site, Mammoet closely monitored the
loads and deflections to ensure that they were in line with the tested values.
To date, Mammoet has successfully placed sixteen panels to wrap up phase one of
the project. Four additional panels will be installed in 2024 during phase two
- once the interior of the new terminal expansion has been built out by the
client for general occupancy.
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Mammoet Rosharon, TX testing yard
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Mammoet’s airport-related
expertise includes examples such as Seattle-Tacoma International Airport's
elevated pedestrian walkway, the
world's longest airside bridge in Hong
Kong, and the
transport of airport buildings in Texas.
CONTACT:
Amanda Lunsford
Marketing, Communications & Events Manager
Mammoet Americas
Phone +1 281 650 1286
amanda.lunsford@mammoet.com
www.mammoet.com
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