How do state workers determine if any structural damage was done to the Gold Star Memorial Bridge?

GROTON, Conn. (WFSB) - As the southbound side of the Gold Star Memorial Bridge remains closed, state workers will be investigating the structural integrity, making sure the bridge is safe to drive on again.

But how do they determine that?

The Gold Star Memorial Bridge has long been a vital connection for people and goods traveling between New York and New England.

The state will have to look at multiple things to determine whether it will be safe to drive over again.

When trying to determine if the Gold Star Memorial Bridge sustained long-term structural damage, engineering professors from the University of Connecticut and Quinnipiac University say state engineers and inspectors will look at a few things.

The amount of combustible material involved, in this case, home heating fuel, the maximum temperature the oil reached, and how long the bridge was exposed to those temperatures.

“Nothing can be said until they have more information about those two specific things,” says Dr. Arash Zaghi, Professor of Civil and Environmental Engineering at the University of Connecticut. “Unfortunately fuel tankers are the worst because it brings both of the, a lot of fuel that will be burnt and typically it can elevate to very high temperatures. It’s not a good situation.”

Inspectors will use things like imaging, x-rays and concrete or steel samples to test material strength.

“This is a steel truss bridge and because steel is a metal, if you heat it up too much, the actual property, at the microscopic atomic level can change and make the interior weaker,” says Ari Perez, Associate Professor of Civil Engineering at Quinnipiac University. “As long as the strength of the material is higher than the demands, the bridge is stable.”

Because the fire also went under the bridge, that will need to be looked at too.

“What happened to the areas that were exposed underneath?,” says Dr. Lexi Hain, Assistant Professor of Civil and Environmental Engineering.

The Northbound side of the Gold Star Memorial Bridge was built in the 1940s, the southbound, the 1970s.

“This is an older bridge and depending on what spans were damaged, that will make a huge difference. If it’s an original span from the 1940s, the steel technology back then was not as advanced and so steel was not as strong as the steel produced today. Newer section, the damage won’t be as bad,” says Perez.

The state recently received 158 million dollars in federal funds to repair the bridge. The bridge received a “poor” rating in 2019.

“One of the benefits of having a bridge that’s undergoing repairs right now is the data the DOT is going to have in terms of the recent inspections is going to be very thorough,” says Dr. Hain.

Fixing the steel trusses on the bridge was already underway when federal funding was announced.

There is no word yet on if that will be delayed or when the bridge could fully reopen.

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