Bridge Builders
Milton-Madison
Bridge
construction in full swing
Despite
flood delay,
workers aim to finish project on time
By
Don Ward
Editor
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July
2011 |
(July 2011) – After nearly two months of spring
flooding delays, Walsh Construction is finally making progress on building
the new $103 million Milton-Madison Bridge, spanning the Ohio River
between Milton, Ky., and Madison, Ind. Walsh’s Project Manager
Charlie Gannon oversees the work of more than 100 employees and subcontractors.
That number is expected to grow as the project continues. Gannon led
a media tour of the project June 23 of the site on both sides of the
river.
“This project is not only unique in its approach but also its scope,
and it is attracting a lot of attention in the engineering community,”
said Gannon, 58, a native of Anderson, Ind. The project also has fascinated
the general public, especially those who live and work in the region
and drive across the bridge each day.
With the Madison Regatta coming this month, to be followed by two more
riverfront festivals later this summer, Gannon said, “We are doing
everything we can to keep the project on schedule and prevent the work
from interfering with people’s lives here in the area. “
For instance, work will be halted July 1-4 during the Madison Regatta
weekend and resume after the Fourth of July.
The project began in earnest in January, just a few months after Laporte,
Ind.-based Walsh Construction was awarded the construction contract
for the ambitious effort. But weeks of flooding in April and May set
the project back six weeks. The company was recently granted an extra
60 days to complete the project, but Gannon says his company hopes to
make up for lost time by working longer days and weekends to try and
make the September 2012 targeted completion date.
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Milton-Madison 1. Existing
bridge pier strengthening: January - September 2011. Other Project
Facts Source: Interviews with project team and INDOT officials\ |
As a result flooding, the first of two previously announced
five-day bridge closures has been delayed from July until sometime this
fall. The closure is necessary to reroute traffic onto the existing
bridge using two yet-to-be-built temporary ramps while the new bridge
is being built just a few feet immediately downriver from it. Construction
on the temporary ramps will take place in July, Gannon said.
The second bridge closure will take place near the end of the project
when the newly constructed bridge will be slid onto the strengthened
existing piers.
Gannon emphasized that the closure would be scheduled around the Madison
Chautauqua Festival of Art in late September, to avoid causing problems
for the city’s other major festival.
So far the work has concentrated on building the “causeway,”
or river access ramp, in Madison and “tressel” loading dock
in Milton, plus a storage barn in Milton to receive and distribute construction
materials. Work is also under way to construct “cofferdams”
around the existing concrete piers to conduct extensive pier strengthening
to support the new bridge. A cofferdam is a temporary enclosure built
within a body of water and constructed to allow the enclosed area to
be pumped out, creating a dry work environment for the work to proceed.
Work also is beginning to take shape to build temporary access ramps
to the existing bridge on both sides of the river to eventually re-route
traffic onto it while the new bridge and new ramps are being built.
The causeway on the Madison side allows access to the river to deliver
via barges concrete and steel materials to workers who are building
the cofferdams out in the river. When the time comes, concrete will
be delivered on several rotating barges, each carrying four large buckets
that can hold up to four yards of concrete per trip.
Soon the 130-foot tressel, or dock, on the Milton side will be expanded
into a T-shape so the 700-foot, steel truss sections of the new bridge
can be pre-assembled aboard six barges to be moored there. The bridge
trusses will be painted in the shop and then touched up after they are
installed and connected. When finished, the two longest spans of the
truss will be floated out into the river and hoisted into place atop
temporary steel piers to be installed along the west side of the existing
bridge. The other spans will be assembled right onto the temporary piers
on each side of the bridge nearer the shorelines. Once complete, traffic
will be routed onto the new bridge while the old bridge is dismantled
using small explosives. Then, near the end of the two-year project,
the new bridge – including the deck, lights and rails – will
be slid over a matter of hours from the temporary support structures
onto the newly strengthened concrete piers that now hold the existing
bridge. Traffic will open on the new bridge and the temporary steel
piers will be removed. The pedestrian walkway will be installed much
later to the west side of the new bridge.
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The new bridge will have a five-foot less vertical clearance
than the existing one. It will feature a 40-foot deck containing two
12-foot lanes with eight-foot shoulders and a five-foot pedestrian walkway.
The current bridge is only 20 feet wide, with two 10-foot lanes and
no shoulder or walkway.
“The temporary bridge piers will be constructed to the same specifications
as if it were new construction and were going to stay there for years
to come,” Gannon said. “They are only temporary in that they
will be removed once the new bridge is built and slid over onto the
reinforced, concrete piers.”
He emphasized that the temporary bridge piers, which essentially will
be vertical steel structures driven into the bed of the river, will
be able to withstand weather and even barge impact.
The new bridge truss will be slightly longer than the existing one,
and one concrete pier nearest to the Indiana side will be completely
removed.
The first cofferdam is already in place around Pier 2 on the Kentucky
side and workers are busy pumping out water. Meantime, concrete reinforcement
work is under way around Pier 1, which sits on land in Milton.
“To build the cofferdam in the river, it involves driving steel
sheet piles into the river bottom to form an air-tight seal, and then
pumping out the water to let workers get down to the bottom of the caissons
to do the pier strengthening,” explained Aaron Stover, the project
manager for Michael Baker Jr. Inc., an engineering firm hired to conduct
design review and site inspection as the project moves forward.
The piers are being cleaned from years of debris. Holes are being drilled
as deep as 70 feet into the bedrock to pour the bonding material to
further strengthen the piers. It takes up to two days to drill one hole
that deep, Gannon said.
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Rendering
provided The
new bridge will feature a |
Thousands of reinforcement bars, or rebar, are being installed
into the concrete stems and caissons to strengthen them since the new
bridge will be twice as wide and also feature a walkway on the southern
side, when complete. The rebar is being added, both horizontally and
vertically into the existing piers. A concrete “jacket” is
being poured around the base of the piers, adding to their strength.
This concrete jacket is being poured as thick as six feet in some places.
In addition to pier strengthening, the top 15 feet of the existing piers
will be removed and wider pier caps will be installed to support the
wider bridge deck. These caps will have a tapered design that will flare
out at the top instead of curve in, like the current piers (See graphics,
Page 22).
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Photos
by Don Ward Water
is being pumped out of the |
The temporary approach ramps will connect on the east
side of the existing bridge on both sides of the river. The Madison
approach will be built using dirt and steel girders, starting along
Vaughn Drive from Ferry Street and up and onto the bridge. It will have
four inches of asphalt on the surface of the two 12-foot lanes.
Traffic will approach the bridge from Hwy. 56, head down Ferry Street
to the river, then turn onto the temporary ramp and up onto the bridge.
On the Milton side, traffic will approach the bridge from Hwy. 36, turn
into the Milton boat ramp area and make two 90-degree turns to approach
the bridge.
“We’ll build everything right before we shut down traffic
for the first five-day closure to attach the temporary approach spans,”
Gannon said.
The current 15-ton weight limit that was placed on the existing bridge
in 2009 will be strictly enforced during this time, since semi-trucks
will be unable to negotiate the 90-degree turns on the Milton side,
said Andy Barber, the project manager for the Kentucky Transportation
Cabinet. He said enforcement will be stepped up by the state police
agencies in both states. There will also be a 35-foot length restriction
on vehicles and the speed limit, now at 35 mph, will be reduced to 20
mph, Barber said.
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Photos
by Don Ward Walsh
Construction |
During the project, a group of Purdue University students,
led by professor Robert J. Connor, are studying the stress of the existing
bridge using gauges and wires to monitor it. This “fracture behavior”
study is expected to provide valuable information for future bridge
builders and “allow us to learn how much additional load the bridge
can handle before it would fracture and fall,” Stover said. “This
is a great opportunity for the old bridge to teach us something about
the load stress and fracture critical nature of the steel. It is very
rare to have a bridge like this to study, and this is the perfect candidate.”
Stover said a newer, stronger steel material is being used in the construction
of the new Milton-Madison Bridge that is designed to be more fracture
resistant.
Replacing the 80-year-old structure has been a long-awaited event in
the lives of residents and commuters who live and work here. Bridge
inspectors two years ago declared the Milton-Madison Bridge structurally
deficient and functionally obsolete, thus prompting the 15-ton weight
limit. It was given less than 10 years of remaining life.
The unique “Design-Build” approach being used to replace the
bridge allows the contractor and the design team to make changes along
the way, if necessary. Burgess & Niple of Columbus, Ohio, is the
lead designer of the steel trusses, while Buckland & Taylor Ltd.
of Seattle is also a design team partner on the project.
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Photo by Don Ward Purdue
University students |
Walsh’s bid to do the job was not only the lowest
but also the only one that proposed closing the existing bridge for
only 10 total days during construction. The other bidders planned to
shut down the bridge for a year.
“This company is not afraid of big projects and taking risks, and
I think this project demonstrates that,” Gannon said his employer,
Walsh. “To try and replace a bridge like this in the short amount
of time we plan to do it and in the way we plan to do it, with only
10 total days of closure requires a company to be smart and innovated
and determined – and not be afraid of it.”
The companies teamed up to submit a unique bridge-sliding concept that
is considered to be the longest truss slide ever undertaken in the United
States.
The transportation departments from both Kentucky and Indiana teamed
up to coordinate the project. Kentucky technically owns the river and
bridge, but the Indiana Department of Transportation is taking the lead
on the construction. A federal stimulus grant totaling $20 million was
provided to help pay for project, with the two states splitting the
balance.
• To learn more about the project or view the live web cam, visit: www.MiltonMadisonBridge.com.