H&H provided preliminary and final design engineering and construction phase services to rehabilitate the Grand Avenue Bridge for New Haven, Connecticut. Originally built in 1896, the bridge is a rim-bearing swing bridge, which carries traffic over the Quinnipiac River. This bridge rehabilitation project has extended the structure’s overall service life by 20 years and will significantly reduce the City’s annual maintenance costs.

The rehabilitation design included replacing the swing span roadway deck, sidewalk deck, and approach span stringers. To address pier scour susceptibility at Piers 1 and 5, the approach spans were replaced with new longer spans that pass over the susceptible piers. New abutments were designed for upland construction behind the existing abutments, which remain in place to serve as retaining walls. An Exodermic bridge deck was designed as it yielded the lightest weight alternative. The rehabilitation included swing span steel truss abrasive blast cleaning and painting.

Operating machinery replacement included the tapered roller and spider rod assembly. The project also included span drive machinery rehabilitation and selective replacement, including the end wedge system and the bridge centering device. A new bridge control system (MCC and control console) was designed for inclusion in the rehabilitation project.

Minor repairs to stonework at the piers and abutments, miscellaneous control house repairs, scour protection/ mitigation of the existing waterborne piers, replacement of fender navigation lights, replacement of the traffic signals and warning gates, and replacement of the heating, lighting, and receptacles were also included the rehabilitation design.

Post design, H&H provided construction phase engineering services, including construction inspection and shop drawing review.

The bridge reopening will be celebrated in January 2022.