Extradosed bridge design is relatively new, and the
first bridge of this type was built in Japan. The
design combines elements of a cable-stayed bridge
(where cables support the roadway anchored in the
tower) and a box-girder bridge (where the bridge
structure is in the shape of a hollow box).
The Pearl Harbor Memorial Bridge features 10
lanes crossing the Quinnipiac River.
battleship-inspired bridge is the first extradosed, prestressed concrete bridge
built in the United States and stands as the centerpiece of the highway
that replaced a structure that returned World War II veterans built in the late
One of the unique features of an extradosed bridge is
that the towers are lower than those found on a traditional cable-stayed
bridge, which means it’s easier and more cost-efficient to replace or maintain
stay cables. Plus, a lower height means they won’t interfere with air traffic
from the nearby airport.
The new cast-in-place, segmental concrete, box-girder
bridge (built in sections) features 10 lanes crossing the Quinnipiac River
in New Haven.
SHIFTING FOR SAFETY
PCL constructed the bridge in two main stages and one
transitional stage. The project team recognized early on that the schedule was
compressed for the third stage, and that to stay on schedule, they had to do
some creative rethinking. The original contract detailed the demolition of the
existing northbound bridge during stage two, the transitional stage, while
traffic was still on the existing southbound bridge. The plan needed a revision
because it was possible to reach the northbound bridge only over live traffic,
which meant multiple lane closures that would impact the traveling public,
ultimately resulting in additional cost and schedule delays.
The project team developed a concept that introduced the
“chicane” method, an artificial feature that creates extra turns in a road to
slow traffic safely. The use of this feature shifted the existing southbound
lanes to the (old) northbound lanes on the existing bridge. The shift allowed
demolition to begin early on the southbound structure first, where crane access
COORDINATION OF CONTRACTS
Another key challenge in the overall construction was
coordinating the schedule for the two construction teams that needed to
complete work on anchor pier one, the final piece of the bridge. This bridge
support is the shared transition point of PCL’s segmental bridge to the
structural steel approach built adjacent by another contractor.
The concern was that the original contract didn’t have
an interim date for completion of anchor pier one, only a final date for the
entire bridge structure. Without an early turnover on the bridge, the
structural steel contractor would have a significant wait time before they
could “land” their steel girders on the shared support and complete the
The PCL team developed a plan to begin construction of
anchor pier one early, adjusting the schedule and resources. This solution led
to an early turnover of anchor pier one, which enabled the structural steel
contractor to speed up their schedule for the final phase and turn over the
project to the traveling public. It was a win for all parties involved.
Completed on July 20, 2015, the bridge opened to traffic
after Labor Day, keeping the Pearl Harbor memory alive in Connecticut.
“The Walsh/PCL Joint Venture Team continually
worked to solve problems and keep the project on schedule. The staff was always
professional, knowledgeable, and showed a strong desire to work as a team. It
was truly a pleasure working on this project."
— John Dunham, PE, assistant district engineer, ConnDOT