By: Allen Zeyher
The cool new way to get to the beaches of Daytona is across
the Broadway Bridge. In fact, the route has been requested by the children of
several local dignitaries who spoke at the dedication of the new bridge. The
children want to see the mosaics of wildlife that adorn the pedestrian walkway
along the 3,008-ft length of the dual segmental concrete structure.
When the Florida DOT put the new bridge up for bids, the
agency expected to get a fast, efficient way of getting along State Route 92
from the city of Daytona Beach over the Halifax River, also known as the
Intracoastal Waterway, to the famous beaches. It did not expect to get a linear
art gallery featuring wildlife native to the area.
The Figg Engineering Group, which won the job over four
other international firms, is definitely not an average bridge design and
engineering firm. Instead of having a mundane public relations manager or
communications director, the company has a Director of Lasting Impressions.
And instead of engineering run-of-the-mill bridges, no
matter how structurally excellent, Figg creates works of art that are
integrated into the surrounding environment and community. The job title encapsulates
Figg's mission.
The new Broadway Bridge replaces a 50-year-old bascule
bridge. "The bridge was functionally obsolete," Charlie Silcox,
Figg's project manager, told Roads & Bridges. "It had 11-ft lanes and
no shoulders. It was an expensive maintenance item for the department."
Figg, based in Tallahassee, Fla., proceeded with a design
charette process, in which members of the community voted on the design of the
bridge. Construction started in January 1999. The result is an award winner.
The Engineers' Society of Western Pennsylvania, in
association with Bayer Corp., awarded the Broadway Bridge the Gustav Lindenthal
Medal, presented at the International Bridge Conference in Pittsburgh on June
10. The Lindenthal Medal is given for a single, recent, outstanding achievement
in bridge engineering. The winning project must exhibit an improvement in
bridge technology through technical or material innovation, achievement of high
aesthetic merit, harmony with the environment or successful community
participation in planning and design.
"We started with a blank canvas without any
preconceived ideas and we looked at a multitude of different types of bridge
shapes and span lengths and arrangements and ideas that would fit within the
customer's budget," Linda Figg, president and CEO of Figg Engineering
Group, told Roads & Bridges. "We brought these to the first community
design charette to get input from the community on their preferences on things
they thought would best suit the visual image they wanted to project for their
bridge."
The design charettes were led by Linda Figg, the daughter of
Gene Figg, the founder of the company, who passed away recently.
FDOT invited area residents, business owners and people from
city and county agencies, business groups and the media. About 40 of them
attended, and the first order of business was to pick an overall theme for the
bridge. By a consensus vote of 8 out of 10, they selected "Timeless
Ecology." The priority was to integrate the bridge into the local ecosystem
as innocuously as possible.
Each person in the charette voted on each item on a scale of
1 to 10. The stronger they felt about the item, the higher they scored it.
During the first charette, the group also chose long spans
(8.1) over moderate spans (6.0) and submerged footings (7.8) over waterline
footings (6.0). In the second charette, the participants got a look at the
bridge design they had assembled and voted on aesthetic elements, such as
color, deck lighting, accent lighting and artistic elements. Figg delivered a
design that incorporated all the aesthetic elements chosen and fit them all
within FDOT's budget.
Music of the tiles
Broadway bridge serves as a learning experience as well as a
roadway. One of the aesthetic features voted for by the design charette was a
group of glass-tile mosaics that depict animals that inhabit the area around
Daytona Beach. Eighteen wildlife mosaics are arranged along the bridge's
separated sidewalk, about 262 ft apart, one for each of the span segments. The
mosaics are repeated along the walkway on the other side of the bridge deck,
making a total of 36.
The mosaics near the bridge landings feature sea creatures,
such as sailfish, sharks and turtles. Land animals, such as the Florida
panther, are depicted farther up the bridge. The mosaic at the highest point of
the bridge features a pair of bald eagles, with pictures of other birds nearby,
such as ospreys and egrets. On the opposite side of the mosaics, facing the
water, are 7-ft-tall concrete medallions in a shell design cast in relief.
For boaters passing by on the water, the wildlife theme is
incorporated into the bridge's piers. Dolphins, manatees and other water life
frolic in 10-ft-tall mosaics that encircle the bridge piers above the water
line. The image is the same on each pier but shifted in such a way that the
animals appear to be swimming around the pier base—another example of the
attention to detail that went into the Broadway Bridge design.
As part of the dedication ceremony, on July 20, 2001,
children were invited to participate in "Stars on Broadway" and learn
a little about the indigenous wildlife. Each of the 36 mosaics along the bridge
walkway is "signed" by the installer with a star-shaped tile. The
children were challenged to find all 36 star tiles and name the species
pictured in the mosaics.
No more ups and downs
The reason FDOT wanted a new bridge was to replace the old
one and to help revitalize downtown Daytona Beach.
The original bascule span bridge had to be raised to let
boat traffic through, and the process caused problems and congestion for both
water and land vehicle traffic.
The new bridge has a vertical clearance of 65 ft to allow
unimpeded boat traffic under and land vehicle traffic on the bridge. It is a
twin structure with less than a foot of space in between. The total length of
the precast segmental structure is 3,008 ft.
The primary contractor chosen to construct the bridge to
Figg's plans was Misener Marine Contractors Inc., Tampa, Fla.
The bridge was erected using the balanced cantilever method.
Barge-mounted cranes and shoring towers around the piers took the
out-of-balance moments.
The structure consists of 352 segments that are 48 ft wide
and vary in depth from 13 ft to 7 ft 9 in. The heaviest segment weighed 120
tons. The deck has a total area of 260,152 sq ft. The bridge contains 1,704,786
lb of post-tensioning tendons and more than 4 million lb of reinforcing steel.
High-performance concrete including fly ash and calcium
nitrate was used to increase the durability of the bridge. A 1?2-in.
sacrificial layer of concrete was provided as a wearing surface and milled to
profilograph tolerances for a smooth ride. Also contributing to ride smoothness
is the fact that the bridge has only two expansion joints.
The bridge segments were cast in Flagler, Fla., about 20
miles north of the bridge location and floated by barge to the construction
site.
The elliptically shaped piers were cast in place. The upper
portion of each pier contains voids to reduce the pier's overall weight. The
lower part is solid to minimize potential damage in an impact from a boat.
The piers should be tough enough to survive a collision.
"The bridge was designed to withstand a vessel
impact," said Silcox. "That was part of the original design criteria.
We studied the local vessel traffic in that area and determined their average
speed. We transformed that to a static force that would be applied to the
piers, and we designed for that force. The actual design vessel was a
barge."
Pier heights very from 12 ft 8 in. to 77 ft.
A single foundation is used for each pair of piers in the
dual-pier configuration. Cofferdams were employed to pour the mud-line
footings. Five-ft shafts were drilled into the river bed. A reinforcing cage
was then lowered into the shaft, and the concrete was poured.
Conveying vitality
For a budget of $37 million in public funds, Daytona Beach
got a link in the redevelopment of the city, especially on the beach side of
the bridge.
"The bridge has become a major feature in attracting
and convincing players to be involved in the redevelopment efforts," said
Suzanne Kuehn, economic development administrator for Daytona Beach.
Locating the new bridge slightly south of the old bridge
opened up 10 acres of land for the city to redevelop into a new riverfront park
on the west end of the bridge. The western landing of the bridge also is near
the Beach Street area, which is a National Register Historic District, and City
Island, a thriving complex with a rowing club, a ball park and a library.
The participants in the bridge construction hope the
wildlife in the area also thrives. The contractor designated a full-time
manatee lookout, whose job was to watch for approaching manatees during their
migration season. If the lookout spotted a manatee, the requirement was to stop
work until the manatee left the area.