Cost: $144 million
In 1997, the Metropolitan Transportation Authority began
a 16-year, $1 billion project to reconstruct all three portions
of the Triborough Bridge. It is the greatest repair job the
bridge has seen since it opened in 1936 and is the single
largest rehabilitation ever taken by the MTA.
During the current phase, a project that began in December
2002 and completed March 2003, the 60-40 joint venture between
Koch Skanska, of Carteret, N.J. and American Bridge Co., of
Coraopolis, Penn. involved replacing all 368 suspender ropes
and roadway decks on the East River span, as well as the complete
re-decking of the existing 2,723-ft. suspension bridge with
orthotropic deck panels and the 1,568-ft. Queens Viaduct approach
spans with precast concrete deck panels.
The Triborough Bridge is not a single span, but a complex
comprised of three long-span bridges, a number of smaller
bridges and viaducts, 14 mi. of approach highways and parkways,
parks and recreational facilities, and administrative offices
for the Triborough Bridge and Tunnel Authority.
The bridge's three branches meet on Randall's Island, where
an interchange and two toll plazas sort out traffic flowing
in 12 directions and provide access to the island itself.
The project was divided into three phases. The first involved
replacing the roadway deck and barriers from the Randall's
Island toll plaza to the Queens approach and included the
Hell Gate suspension span, the Randall's Island-Ward's viaduct
and the Queens viaduct. The suspender ropes on the main span
were also replaced.
The second phase involved replacing the roadway deck and
barriers from the Randall's Island toll plaza to the Bronx
approach and included the Bronx Kills truss span and connecting
ramps in the Bronx.
The third phase of the project involved replacing the roadway
deck and barriers from the Randall's Island toll plaza to
the Manhattan approach and included the Harlem River lift
span and connecting ramps in Manhattan.
The replacement systems were pre-formed in 10-ft. by 4-in.-wide
panels (the width of one road lane) so that the work would
affect traffic flow as little as possible.
After completing the analysis, the team determined that the
most efficient alternative was to utilize different types
of designs for different deck sections. That included orthotropic
panels for suspended spans, precast concrete panels for viaduct/approach
sections and precast deck for the truss spans.
In total, more than 1.6 million sq. ft. of deck was replaced.
The project included replacement and rehabilitation designs
for the Queens and Bronx approach ramps and viaducts, including
steel and concrete structures. Work also included the rehabilitation
of pedestrian walkways and ramps to comply with Americans
with Disabilities Act requirements and seismic retrofit requirements.
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