ABSTRACT
Wisconsin Department of Transportation implemented a Fracture Critical Inspection Program in 1987. The program has a strong emphasis on Nondestructive Testing (NDT). The program is also completely computerized, using laptop computers to gather field data, digital cameras for pictures, and testing equipment with download features. Final inspection reports with detailed information can be delivered within days of the inspection.
The program requires an experienced inspection team and qualified personnel. Individuals performing testing must be licensed ASNT (American Society for Nondestructive Testing) Level III and must be licensed Certified Weld Inspectors (American Welding Society).
Several critical steps have been developed to assure that each inspection identifies all possible deficiencies that may be possible on a Fracture Critical Bridge. They include; review of all existing plans and maintenance history; identification of fracture critical members, identification of critical connection details, welds, & fatigue prone details, development of visual and NDE inspection plan; field inspection procedures; and a detailed formal report.
The program has found several bridges with critical fatigue conditions which have resulted in replacement or major rehabilitation. In addition, remote monitoring systems have been installed on structures with serious cracking to monitor for changing conditions.
