Research: Sensors Will Read Mackinac Bridge
Researchers based out of Michigan State University will be adding more data-tracking sensors to the Mackinac Bridge this summer—sensors that will read data that can contribute to maintenance of the Mighty Mac’s structural components.
Deployment of the sensors began in 2016, funded by the Federal Highway Administration, when MSU associate professor of civil and environmental engineering, Nizar Lajnef, and Washington University in St. Louis professor, Shantanu Chakrabartty, started placing the sensors beneath the bridge.
Bridge Sensor Research
According to the Mackinac Bridge Authority, the Mighty Mac, which opened to traffic in 1957, is currently the fifth longest suspension bridge in the world, and is the longest suspension bridge in the western hemisphere. The Mighty Mac’s total length runs 26,372 feet, with a 3,800-foot-long main span. The initial testing phase passed muster, and demonstrated that it was ready to move on to further testing.
The first 20 prototype infrastructure sensors, originally installed in the beginning of 2016, were powered solely by traffic vibrations. Now, for the next phase of testing, 2,000 sensors will be installed to investigate large-scale deployment and provide useful monitoring data to the Mackinac Bridge Authority.
"The successful large-scale deployment of this novel low-cost sensing technology will dramatically transform the economics of bridge preservation/management and ultimately improve the serviceability of bridges," Lajnef said.
"We also will explore how the collected data could be used for improved cost-effective, condition-based maintenance of the Mackinac Bridge structural components. We are very excited that this will be the first fully instrumented bridge in the country using advanced wireless and self-powered monitoring technology."
The sensors have no external power source, which eliminates the need for battery chargers or wiring to power sources. Staff will also be able to access data from the sensors wirelessly.
"In addition to being a statewide need, the development of effective methods for preserving our transportation infrastructure systems is a critical national need," Lajnef said.
"Through this largescale deployment, we would show that the system can autonomously monitor the loading experienced by the bridge components, and that the information from the sensors can be collected without significant human intervention and at significantly low cost."
Bridge Authority staff will assist with the installation of the sensors. The agency will also retain ownership of the data, and WUSTL will provide the sensor prototypes. MSU will oversee providing tools to analyze the data for bridge staff to use in making structure engineering and maintenance decisions.