New ways to monitor bridge safety

Videography by Jeanne Galatzer-Levy

No matter how well we design and build our roads and bridges, the stresses of traffic, weather and age take a toll. Maintenance and repair of infrastructure is expensive and too often delayed until conditions become unsafe.

The ideal would be monitoring that could pinpoint problems as they arise. A number of different sensors have been developed, but the equipment is expensive, difficult to place and hard to read.

Farhad Ansari, professor and head of civil and materials engineering, leads research that incorporates telecommunications, sophisticated software and fiber optic technology to create new bridge monitoring systems.

“What we have tried to do is that is use the latest technology so that we could make it fast, accurate and very affordable,” Ansari said.

One thin optical fiber can be placed along a bridge, replacing dozens — even thousands — of individual sensors, Ansari said. The cable sends signals to the lab, where computers can read information on bridge stresses in real time.

In one current project, Ansari and his research team are working with the Illinois Department of Transportation to identify and weigh trucks as they cross a bridge on the Stevenson Expressway, an overpass at the intersection of Archer Avenue and Lock Street.

“We are hoping that many of the highway agencies use these sensors to make our bridges more safe,” Ansari said.