The Occupational Safety and Health Administration is investigating failed or fractured steel as a possible factor in the collapse of a 2-million-lb launching truss girder Feb. 16 that killed four workers and injured four at the site of the $220-million Maumee River Bridge project.
Pieces of fractured steel from the 40-ft-high, 315-ft-long truss crane are being examined at Lehigh Universitys Engineering Research Center for Advanced Technology for Large Structural Systems. "Were looking at many thingswere taking samples of different parts of the truss and shipping them to Lehigh University for various kinds of testing to see if the steel was an issue," says Joe Rutherford, spokesman for the Ohio Dept. of Transportation.
Other factors have not been ruled out yet, says Rutherford. The launching truss, one of two manufactured in Italy by the firm Paolo de Nicola and assembled on site, collapsed while being repositioned for segment placement by contractor Fru-Con Construction, St. Louis (ENR 2/23 p. 10). It was not carrying any of the precast segments, which range in weight from 75 to 100 tons.
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In the meantime, site recovery efforts are continuing. On March 12, ODOT reopened northbound Interstate 280, which had been closed since the accident, says Rutherford. With equipment including a 500-ton hydraulic boom crane, "we expect to have the vast majority of the debris removed from the site" by March 19, he says.
Workers are using oxygen lances to cut pieces of steel from the fallen crane. About 60% had been removed as of March 15. "Thats on the ground and being cut apart as we speak," Rutherford says. The Occupational Safety and Health Administration "will test the truss that collapsed, then apply that in some way to the remaining truss," he adds. "Theyve done inspections looking for bad welds, loose bolts, etc."
Workers are cutting apart the underbridge, which will be taken to an offsite location for inspection. "The underbridge alone is 320,000 lb," Rutherford notes. "The overbridge is gone, mostly. The rear legs are still left and the back half of the underbridge is embedded 6 ft into the ground."
Fru-Con hired Wiss, Janney, Elstner Associates Inc., Northbrook, Ill., to assist with inspections.
OSHA is expected to submit a definitive "work-forward" plan at end of the month to ODOT. "We will digest the plan and assess the options they present," Rutherford says. "Part or all of that is dependent on OSHAs findings." OSHA and Fru-Con officials did not respond to requests for comment.