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Interstate 10 Bridges Don't Stay Down Long
Rapid Repair Projects Keep Vital
Link Open
By Debra Wood
During back-to-back killer hurricane seasons, Interstate
10 bridges from Florida to Louisiana suffered serious damage,
forcing states to cobble together rapid repairs to reopen
the spans and begin constructing replacement bridges.
I-10, one of only three transcontinental highways reaching
from coast-to-coast, is one of the longest interstate routes
in the country, totaling 2,460 mi. from Jacksonville, Fla.,
to Santa Monica, Calif., and traversing eight states. The
Gulf Coast region considers it a lifeline for commerce and
visitors.
"I-10 is a major east-west thoroughfare through the state
of Florida," said Tommie Speights, spokesman for the
Florida Department of Transportation, district three. "It's
the main artery from Alabama across to Jacksonville and connects
with I-75 and I-95."
Florida
In September 2004, Hurricane Ivan plowed into Pensacola, Fla.,
as a category three storm. Air trapped under the bridges during
the resulting 20-ft.-high storm surge lifted segments of the
1960s-era Escambia Bay Bridge's deck off its piers and dropped
58 spans, more than 3,400-ft. of decking, into the water.
Another 66 spans were knocked out of alignment.
A joint venture team of Gilbert Southern Corp. of Atlanta
and Massman Construction Co. of Kansas City, Mo., completed
the $26 million repair ahead of schedule, allowing the state
to open two lanes on the westbound bridge within 17 days and
one lane of the eastbound span 66 days after the storm. Volkert
& Associates of Mobile, Ala., consulted.
The team moved salvageable sections from the more severely
damaged eastbound bridge to the westbound bridge, straightened
misaligned spans and replaced bents and pilings as needed.
To compensate for the missing segments on the eastbound bridge,
contractors placed prefabricated, modular-steel Acrow panels,
which the FDOT had in inventory.
In April 2005, FDOT awarded a design-build team led by Tidewater
Skanska of Virginia Beach, Va.; Flatiron Construction Corp.
of Longmont, Colo.; and Parsons Brinckerhoff Quade & Douglas
of Tampa a $243 million contract to build higher and wider
replacement structures.
"Design-build is an excellent way to deliver an emergency
project," said David Bogan, FDOT's I-10 project manager.
"It streamlines the process and allows you to get the
product you need."
The new 3-mi.-long bridges combine Florida Bulb-T 78-in. beam
construction with a post-tensioned girder segment over the
navigational channel. About 1,300 36-in. square, voided concrete
piles, driven up to 147 ft., support the bridges. As of mid-April,
Tidewater/Flatiron had driven 560 piles. The design-build
team selected the larger-than-typical piles due to their lateral
stability.
"Not only do you drive less of them, the 36-in. piles
are just more stout," Bogan said.
After starting construction, the design-build team modified
the plan to use precast pile caps and footings, rather than
cast-in-place, in order to speed construction.
Low-member elements on the new bridges will be more than twice
as high as the existing structures' 12-ft. clearance. Height
in the navigational channel will increase from 45 ft. to 65
ft. In addition to the added height, the new bridges include
deck venting to release trapped air and are more robustly
secured, tying together four spans.
"If you get any lift on the girder caused by a storm
surge, they are designed to vent themselves out," said
Bill Eskins, project manager for Tidewater/Flatiron. "[A
surge] would have to lift a continuous four-span unit, which
is much longer, much heavier, and get it off place. It would
be more difficult for a storm surge to pick up a four-span
unit and move it."
The replacement bridges will have three lanes of traffic in
each direction, as well as inside and outside emergency shoulders
and a bicycle lane. The joint venture team stands to earn
a $10 million bonus if it gets the first, eastbound bridge
open before Dec. 29 and a $133,000-per-day penalty, up to
$10 million, if it does not.
While Tidewater/Flatiron officials stay focused on finishing
the eastbound bridge this year, crews are driving piles for
the westbound bridge and doing some construction on it. The
completion target for the second span is now November 2007,
pushed back from August 2007 due to delays related to 2005
hurricanes and tropical storms.
Tidewater/Flatiron changed sequencing to make up time after
the storm delays. Modifications include putting all traffic
on the new eastbound bridge, two lanes in each direction,
as soon as it is finished and taking down both existing structures,
rather than waiting until the westbound bridge is open. That
necessitated widening a portion of the bridge on the west
side of the bay, taking some slope protection out and putting
in a retaining wall.
The entire project was 35 percent complete in April. Pile-driving
crews are working two shifts, seven days a week, and high-level
positions are working two shifts, five days per week.
"Work is progressing," FDOT spokesman Speights said.
"They are on target to open it by the end of the year."
Louisiana
A year later, the very similar I-10 bridges across Lake Pontchartrain,
east of New Orleans, suffered a similar fate when Hurricane
Katrina's storm surge plunged these structures under water.
Air trapped under the spans lifted them up and allowed wave
action to drop about 60 sections of the 5.4-mi.-long bridges
into the water and misalign more than 400 additional spans.
Soon after the storm passed, FDOT engineers headed to Louisiana
to share their expertise and experiences.
"They certainly did go out of their way," Artur
D'Andrea, project manager and assistant bridge design administrator
for the Louisiana Department of Transportation and Development,
said in an e-mailed statement. "William Nickas (FDOT
state structures design engineer) was aware of trouble they
had with Escambia and the Florida coast, so he knew we'd need
their help."
As in Florida, the Louisiana DOTD decided to cannibalize intact
deck on one span to more quickly repair and open at least
one structure. Crews then filled in missing segments with
Acrow panels. DOTD also hired Volkert for inspection and consulting.
Volkert's John Horn served as project manager on both jobs.
"There were a lot of lessons he learned that he was able
to help us with," said Al Flettrich, bridge division
manager for Boh Bros. Construction Co. of New Orleans, which
began repairs two weeks after Katrina hit. "There were
some [things] we came up with on our own, but we got some
tips on what not to do and that certainly helped."
HNTB Corp. of Baton Rouge served as consulting engineer to
Boh Bros. Dennis Gowins, HNTB's department manager for structures,
said the general scheme of repairs was patterned after Escambia
Bay but the actual repairs and retrofits were different, including
the type of Acrow used.
Gowins said most engineering was done onsite after determining
what materials were available in Boh Bros. yard. The team
purchased jacks off the Internet.
"The people you're [normally] getting your materials
from were no longer in business or operational," Gowins
said. "You were left to your own imagination."
Boh Bros. used the jacks to slide shifted spans back into
place. Those sections more than half off required a Goldhofer
hydraulic trailer on a barge to move them back into the proper
position. The team repaired holes in some of the hollow cylinder
piles and left some structurally sound damaged piles.
Boh Bros. finished the eastbound lanes in October and completed
the westbound span in January, eight days ahead of schedule.
The company's $35 million contract includes annual maintenance
and repair or replacement of the temporary elements.
DOTD will replace the existing twin spans with two new, higher
bridges, estimated to take five years to build. Rather than
members as low as 8.5 ft., the new bridge will be at least
30 ft. above sea level.
"Even though we are building the bridges at higher elevations,
we are taking additional storm precautions," D'Andrea
said. "A positive anchor system, including keeper walls,
should prevent the girders from falling off the caps."
The new design also calls for the substructure to withstand
forces determined by a post-Katrina storm-surge analysis and
sheer keys on the bent caps to catch and hold the deck in
place, said Amy Kohls Buehler, vice president and director
of the Texas office of Figg Engineering Group of Tallahassee,
designer of one of two possible replacement options.
DOTD divided the project into two parts, a 1-mi. section above
the navigational channel at the north end and the balance
of the bridge, which will be constructed first. The department
designed an I-beam girder bridge and hired Figg to design
a post-tension segmental bridge.
"The options allow for a better competitive bid and contractor
flexibility," D'Andrea said. "This gives the contractor
real choices and tries to keep costs within our budgets."
Louisiana opened contractor bids for the first section in
mid-April and expected to make a decision within 45 days.
Boh Bros. was the low bidder at $379 million to build the
DOTD-designed girder bridge. No bids were submitted for the
segmental design, according to Cheryl Maze, spokesperson for
Figg. The navigational channel section will not open for bidding
until summer.
Useful sources:
Replacement of I-10 Bridges Over Escambia Bay
http://www.escambiabaybridge.com/
Louisiana Department of Transportation and Development
http://www.dotd.state.la.us/
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