Bridge slide projected for mid-summer

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By Dave Taylor

The much-anticipated “slide” of the new, wider Milton-Madison Bridge is scheduled to take place this summer, marking near-completion of the bridge replacement project. While the event is currently expected to occur in mid-July, the schedule is dependent on weather and subject to change.

Meanwhile, work continues when weather permits on installation of the stay-in-place decking materials preparatory to pouring the concrete decking on the new bridge truss and the Milton approach ramp.

“You’ve seen those stay in place forms that go in between the concrete beams,” engineer Aaron Stover said during a recent interview. “A similar system will be used on the truss between the steel stringers that are out there now. They’ll get that same stay in place decking with rebar across the deck and an eight-inch-thick concrete deck on top.”

Stover is an engineer with Michael Baker, Jr., Inc., the company in charge of bridge inspection during the construction project.

Work has slowed in recent weeks because of recent rains and sub-freezing temperatures. High water impairs the crews from safely working on the barge impact frames and installation of the boulders used for scour protection around the piers in the river, a project spokesperson said. Scour is caused by swiftly moving water past the piers and can cause erosion. Work had resumed on scour protection yesterday.

The high river levels also had an impact on the ongoing bolt up of the new truss because the water was too high for the accompanying safety boat to be in the river.

In July, with the help of hydraulic jacks, the new 2,427-foot-long steel truss bridge - currently sitting on temporary piers - will move along sliding girder beams to its permanent home on top of the existing piers which are being rehabbed and reused.

As it has for all but a few days during construction, the existing bridge remains open to traffic, with a 3-ton weight limit and 36-foot vehicle length restriction.

Project officials considered sliding the bridge this spring, but that would have made it necessary to pour the concrete bridge deck in the winter, which is a more complex process. Instead, they plan to pour the deck this spring and slide the truss this summer.

Several crucial steps must take place before the slide can occur, including:

*Completion of the new bridge road deck, expected to take place this spring when concrete pouring conditions are best.

*The shift of traffic from the existing bridge to the new bridge, which is sitting on temporary piers.

*Removal of the old truss - or upper steel portion of the existing bridge.

*Completion of pier rehabilitation with the addition of wider pier caps to accommodate the new 40-foot-wide bridge - twice the width of the old bridge.

Walsh Construction’s complex, multistep method of replacing the bridge has allowed the bridge to remain open during construction, avoiding the originally expected year-long closure. The bridge will be closed for several days while the slide and approach connections are completed this summer.

The Milton-Madison Bridge Project is a joint effort between the INDOT and the Kentucky Transportation Cabinet.