ICT Researchers Help Ensure Secure Bridges in Illinois

Since its inception, the ICT has been conducting research related to bridge safety. From monitoring specific bridges to developing and implementing innovative technologies to improve bridge monitoring, the ICT has an ongoing role in assuring the safety of Illinois bridges.

The ICT recently received additional funding to evaluate low-volume, older bridges in Illinois to ensure their structural integrity. Because most of the damage to these bridges is likely to be near the bottom or internal, the ICT will evaluate the bridges using innovative nondestructive testing technology. Professor Imad Al-Qadi, director of ICT, and Professor John Popovics are currently conducting a feasibility study and devising a work plan for these nondestructive evaluations.

In addition to long-term bridge evaluation and monitoring projects, the ICT has rapidly responded to the Illinois Department of Transportation's urgent requests on issues related to bridge integrity.

For example, when a highway bridge girder suddenly collapsed on the suburban Chicago Kingery Expressway construction site (ramp "J" interchange between Interstate 80 eastbound and Illinois route 394 northbound) killing one person and injuring others, the ICT was called in to detect internal structural damage and identify the reinforcement steel condition. Al-Qadi says, "The integrity of the concrete pier located at the construction site was in doubt. ICT researchers assessed the capacity of the structure for continued construction operation. Although the external condition can be assessed visually, any deformation in the reinforcing rebars or internal crack development cannot be determined without the use of nondestructive testing (NDT) techniques. Ground penetrating radar (GPR), ultrasonic pulse velocity (UPV), and impact-echo (IE) were utilized in this project to reveal any internal abnormality in the structure. The outcome of the ICT evaluation provided information as to the integrity of the structure that saved significant costs, prevented destructive evaluation of the structure, and reduced costly construction downtime and construction delays." Professors Al-Qadi and Popovics and their students conducted the work.

The ICT was also called in on short notice to conduct a nondestructive evaluation using ground penetrating radar to measure the cover depth of the Dan Ryan Expressway (I-90/94) bridge deck. The bridge had been evaluated previously using other techniques that resulted in developing specific rehabilitation techniques. The ICT researchers' rapid response (led by Professor Al-Qadi), in addition to confirming that the vital bridge decks are structurally sound and accurately pinpointing the damaged locations, saves additional testing and repair costs. For example, by providing timely and accurate measurements for the Dan Ryan Expressway bridge, that were validated by taking ground-truth cores, the ICT's accurate measurements of the surveyed bridge resulted in changing the rehabilitation technique and strategy, which consequently saved the state millions of dollars in repair costs.