This Pennsylvania Petit Through Truss bridge spans the Chain of Rocks Canal, which was built in 1949 to allow large river barges to bypass a treacherous section of the Mississippi River. When asked to assess the bridge’s structural integrity and condition, Lochmueller Group (Lochgroup) performed a National Bridge Inspection Standard routine and a fracture-critical inspection of the 17-span structure.
The 2,285-foot-long bridge features a 465-foot-long main span through a girder truss with approach spans ranging from 63- to 220-feet long, six with deck trusses. Lochgroup completed inspection of the main span through truss and approach span steel members along with the concrete substructure. Fracture critical inspections were accomplished with the use of an aerial manlift and an under bridge inspection vehicle. An underwater inspection was also performed using sonar to map the contours of the ground and look for scour holes around the piers in the channel.
As a result of the inspection, recommendations were provided to prolong the life of the bridge and maintain its continued safety.