Building the Bridge
Closure
allows Walsh
to attach temporary approach ramps
Traffic
will continue to use
existing bridge through 2012
By
Don Ward
Editor
(May 2012) – Walsh Construction Co. officials,
along with transportation officials in Kentucky and Indiana, re-opened
the Milton-Madison Bridge at 11:59 p.m. Saturday, April 28, ahead of
schedule, following work to demolish the old ramps and attach temporary
ones on both sides of the Ohio River.
The planned five-day closure was the first of two such closures to be
made during the two-year, $103 million project to replace the 83-year-old
structure. During the closure, Walsh Construction Co. worked around
the clock to complete the task in a timely fashion.
 |
|
Photo
courtesy of Aaron Stover, Explosives
were used April 25 |
Heavy equipment was used to demolish the ramps and explosives
were used to sever steel girders and remove a short section of ramp
on the Madison side. The event drew a large crowd of spectators to the
riverfront on Wednesday, April 25, along with TV news crews from several
Louisville stations.
The removal of the bridge approaches – including the concrete road
deck and supporting steel structure – required the use of a heavy
hydraulic demolition hammer and controlled explosives.
Work continued on the ramps throughout the week, including setting beams,
bracing, timbers and concrete barrier railing. Load testing experiments
were conducted by Purdue University students on a 150-foot approach
span at the north end of the bridge.
Workers then paved the remaining ramp sections leading up onto the existing
bridge platform. Signage was installed to direct traffic to the new
approach locations on each side of the river.
 |
|
Photo
courtesy of Debbie Crawford Walsh
Construction workers |
In Madison, traffic now approaches the bridge from Ferry
Street and Vaughn Drive to a steel ramp rising up to the bridge platform.
In Milton, traffic has been diverted to the Milton Boat Ramp where a
temporary earthen and steel ramp was built.
Both approaches require a 90-degree turn and no large trucks will be
allowed on to the bridge. The 3-ton weight limit will remain in place
and the speed limit has been lowered from 35 mph to 25 mph. A 36-foot
vehicle length restriction will be in place as well due to the turn
radius of the temporary ramps.
The next major construction event will take place in June when workers
lift the first of two steel bridge trusses onto temporary supports being
installed just west of the existing bridge. Two trusses will be lifted
into place using large hydraulic strand jacks. The rest of the new bridge
truss will be assembled in air, as opposed to being constructed aboard
the barges parked along the Milton riverfront.
Traffic will continue to use the existing bridge through December, when
it will then be diverted onto the new bridge truss that is being constructed
just downstream from the existing bridge.
Then the old bridge truss will be demolished to make way for the sliding
into place of the new truss onto the existing, rehabilitated concrete
piers.
The sliding is expected to take place in 2013 during the second planned
five-day bridge closure. Once the new bridge is opened to traffic, there
will be no weight restrictions.
The pedestrian walkway will be attached to the downstream side of the
new bridge several weeks after the new bridge has re-opened to traffic,
officials say.
The replacement of the narrow and deteriorating Milton-Madison Bridge
originally entailed a year-long bridge closure. But due to innovative
design and construction methods, the bridge remains open during construction
for all but a total of 10 days. Once complete, the new wider bridge
will lie within the existing footprint.
Using a method called “truss sliding,” the new 2,400-foot-long
steel truss bridge will be built on temporary piers and slid into place
on top of the existing piers which are being strengthened to meet modern
standards. Construction began in early 2011 and is expected to
be complete in 2013.
Named one of the Top 10 bridge projects in the country by Roads &
Bridges Magazine, and the recipient of several state and national engineering
awards, the Milton-Madison Bridge Project is a bi-state effort between
INDOT and KYTC. For more information, visit www.MiltonMadisonBridge.com.