H&H performed a Fracture Critical, Routine, and Element Level Inspection of I-110 Bridge over Biloxi Back Bay, a bascule steel span bridge with a cast-in-place concrete deck in August of 2018 for Mississippi Department of Transportation.
The routine and fracture critical inspection included electrical, mechanical and structural inspection of all components of the bascule and anchor spans and NBIS and element inspection for the entire bridge. The routine mechanical and electrical inspection included an examination of the mechanical and electrical components of the bridge including trunnion, span locks and operating machinery required for the operation of the bascule spans.
The NBIS and element structural inspection consisted of a visual and hands-on examination of the approach spans, bascule spans and anchor spans, and the fender system. The fracture critical inspection consisted of a hands-on examination of the bascule span girders and floor beams, and the girders of both anchor spans.
A Final Report with a summary of the findings noted by inspection personnel, as well as proposed recommendations for maintenance and repair of the bridge was also prepared and submitted.
The I-110 Bridge, a twin double-leaf rolling bascule bridge, built in 1973, carries four lanes of interstate traffic and a pedestrian walkway. The bridge consists of one main bascule span and 56 approach spans, for a total length of 5,728 feet. The bascule span length measures 210-foot from center to center of the roll. From heel to heel of main girders the bascule span length measures 262 feet. The heels of each bascule girder receive uplift support under highway loading by the flanking steel anchor spans. the total length of the steel portion of this bridge Including the flanking anchor spans, 500 feet. The roadway is approximately 38-foot wide at the approaches and bascule in each direction, 88-foot wide total, with a 5-foot-wide sidewalk on the east side separated from the roadway by a concrete barrier.