This five-span, 744-foot-long steel multi-girder bridge over the Chemung River was slated for rehabilitation due to deterioration of steel from leaking joints, safety hazards from spalling concrete on sidewalks, and a cracked and spalling deck.
Fortunately, the City was able to perform an in-depth superstructure inspection and evaluation. Inspection of the deck included non-destructive evaluation (NDE) processes using chaining, ground-penetrating radar (GPR), thermal imaging, and sampling and testing of concrete cores for chlorides. An under-bridge inspection unit (UBIU) was used to perform superstructure inspection of the steel and underside of the deck. All information was mapped and cross-correlated to gain a thorough understanding of the depth of the deterioration of the deck concrete and steel superstructure. A significantly larger amount of deterioration was found over what was originally scoped, increasing the cost of rehabilitation. Fortunately, the city was able to secure funding from BridgeNY so full rehabilitation can occur.
This rehabilitation includes steel rehabilitation and substructure repairs. The steel replacements address and remove the fatigue-prone details on the bottom flanges of all girders in the positive-moment areas with high stress reversals. The retrofitting will extend the life of the bridge and allow for more efficient bridge inspections in the future. Improvements include cleaning and painting of the girders and diaphragms at all bridge joint locations, replacing the deteriorated secondary steel members, as well as rehabilitating spalls and cracks in the concrete substructures.
Design plans include complete replacement of the concrete deck and approach slabs, along with the removal and replacement of high steel rocker bearings and mid-span expansion bearings, replacement of railings, sidewalks, utility conduit, drainage scuppers and downspouts, lighting, and some remaining steel rehabilitation.