MEASURING LIVE LOAD STRESSES ON BRIDGES

THE DEPARTMENT OF TRANSPORTATION (DOT) IS REQUIRED TO MAIN- TAIN THE NATION'S BRIDGES AND ENSURE THEIR SAFETY. HOWEVER,A LARGE NUMBER OF BRIDGES HAVE NOT BEEN RECENTLY INSPECTED TO DETERMINE IF THEY ARE CAPABLE OF SAFELY SUPPORTING THE TRAFFIC THAT IS CROSSING THEM. THE CURRENT METHOD OF SURVEYING BRIDGES, TO DETERMINE THEIR STRESS CONDITION, IS COSTLY AND TIME-CONSUMING. THIS PROGRAM WILL DEVELOP, FABRICATE, AND TEST A PROTOTYPE INSTRUMENT THAT WILL QUICKLY AND ACCU- RATELY DETERMINE THE STRESS LEVELS IN STEEL BRIDGES. THE PROPOSED CONCEPT INCLUDES A ONE-PIECE STRAIN GAGE INSTRUMENTTHAT WILL BE EASILY INSTALLED AND REMOVED, USING A MECHAN- ICAL ATTACHMENT, FROM A STRUCTURAL BRIDGE MEMBER. THE THE INSTRUMENT WILL PROVIDE THE PEAK LIVE LOAD STRESSES DIRECTLY ON LIQUID CRYSTAL DISPLAYS. USE OF THIS INSTRUMENTWILL SIGNIFICANTLY REDUCE INSPECTION TIME AND ALLOW THE DOT TO MORE EFFICIENTLY INSPECT BRIDGES.