Bridge over Chenango St. was supposed to be fixed months ago. Why is it taking so long?

A New York state Department of Transportation project to stop the bridge in Binghamton from sinking was expected to take about 90 days but has gone on for about eight months with no firm completion date established.

State officials note that work continued non-stop during the winter but tricky logistics and subpar results from a concrete application method have pushed the project's finish past previous estimates.

The I-81/Route 17 bridge was built during Phase 1 of the $290 million Prospect Mountain Construction Project in Binghamton.

The state announced last June that DOT engineers detected an "uncharacteristic settlement" in the roadway above the Chenango Street arch.

A $3.5 million effort to strengthen the structure got underway in September 2021. The DOT said the project was undertaken "out of an abundance of caution" and to preserve the structure’s 75-year design life.

“We didn’t want to spend millions and millions and millions down the road, prior to that 75 years. So we are going to spend a few million now and get it back to its 75-year life span,” said Scott Cook, DOT Region 9 public information specialist.

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With engineers determining the bridge deck is completely safe for travel, construction workers set up on the underside of the highway. This strategy has kept bridge traffic flowing as usual but resulted in a pair of detours on the section of Chenango Street that runs beneath the overpass.

Since Sept. 11, 2021 motor vehicle traffic has been diverted at Frederick Street on the south end of the arch and at Bevier Street on the north side.

The road under the arch remains accessible to pedestrians and bicyclists, while local motorized traffic retains access to destinations between the diversions and the overpass on Chenango Street.

Project continued during winter months

In February, the DOT said the work exceeded its time estimate due to the "logistic challenges" of the project.

“DOT remains committed to re-open Chenango Street as soon as possible while ensuring the safety of the traveling public and durability of the arch as originally designed,“ Brian Kelly, DOT Region 9 acting regional director, said earlier this year.

Kelly pledged crews would work through the cold weather months with the goal of reopening Chenango Street to vehicular traffic before spring.

Crews set up heaters under the arch and continued to work every day, Cook said.

Still, spring came and the work continued.

The DOT has not released an updated cost for the project since its original $3.5 million estimate.

Cast-in-place concrete is testing well

The essence of the project is enlarging and strengthening the structure from the underside, Cook said.

Two concrete walls and shoulders, one for each side, were pre-formed and then slid into place.

"And then you have to fill in the crown or ceiling," Cook said.

This is where things slowed down. Cook said the DOT did not initially get the results it expected for the crown.

“We were using a method called shotcrete which is essentially spray-on concrete," he said. "You do it layer by layer by layer until you have it thick enough layer to do the reinforcement. For some reason, it wasn’t performing up to our standards as we thought it would.”

The project then switched to a different method of concrete application called "cast-in-place."

"Essentially you put forms there, then you pump in the concrete in. What we are finding with that is we are getting better coverage," Cook said. "With the shotcrete we were getting some open spaces. With the cast-in-place the testing is going well and we are getting full coverage.

"As we are testing we are also moving along. If the testing is good, we move to the next section and so far that has been the case."

After two prior time estimates proved to be wrong, the DOT is not releasing a new estimate of when the project will be finished.

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This article originally appeared on Binghamton Press & Sun-Bulletin: Bridge over Chenango Street in Binghamton still not fixed