INFRATRUCTURE Wireless Sensor System for Continuous Monitoring of Bridge Deformation

Researchers in Drexel University’s College of Engineering have developed a solar-powered, wireless sensor system that can continually monitor bridge deformation and could be used to alert authorities when the bridge performance deteriorates significantly. With more than 46,000 bridges across the country considered to be in poor condition, according to the American Society of Civil Engineers, a system like this could be both an important safety measure, as well as helping to triage repair and maintenance efforts.

The system, which measures bridge deformation and runs continuously on photovoltaic power, was unveiled in a recent edition of the IEEE Journal of Emerging and Selected Topics in Industrial Electronics in a paper authored by Drexel College of Engineering researchers, Ivan Bartoli, PhD, Mustafa Furkan, PhD, Fei Lu, PhD, and Yao Wang, a doctoral student in the College.

“With as much aging infrastructure as there is in the U.S. we need a way to keep a close eye on these critical assets 24-7,” said Bartoli, who leads the Intelligent Infrastructure Alliance in the College of Engineering. “This is an urgent need, not just to prevent calamitous and often tragic failures, but to understand which bridges should take priority for maintenance and replacement, so that we can efficiently and sustainably approach the preservation and improvement of our infrastructure.”

More than 40% of America’s 617,000 bridges are more than 50 years old. While they are built to last, they must also be inspected regularly – every two years, according to Bartoli, who is a professor in the College’s Department of Civil, Architectural and Environmental Engineering. The current practice is to make a visual inspection and, in rare cases, to monitor only the bridges deemed “problematic structures,” he said.

But the number of bridges that require attention is growing, according to the ASCE’s “Report Card for America’s infrastructure.” A system like Drexel’s could help federal agencies and inspectors get their arms around the challenge and reduce the overall need for inspections as new bridges are built.

Their wireless displacement sensor consists of a solar photovoltaic cell, a deformation measuring device — called a displacement potentiometer — and a monitoring interface transceiver. All three are mounted on the bridge to take continuous measurements of its deformation as traffic moves across it and transmit that information to a remote monitoring station.