Pare has been providing consulting engineering services to the Providence & Worcester (now the Genesee & Wyoming) Railroad Company since 1974. As part of these ongoing services, Pare designed replacement structures for Bridge No. 35.29 in Sutton, MA.
Originally constructed in 1903 to carry the rail line over the Blackstone River, the 100-foot, two-span through-girder bridge was supported on 20-foot high granite block abutments and a center stone pier. Additional timber piers were added to the center pier in the 1950's following storm surge damage from a hurricane. However, the bridge had load carrying deficiencies and the added timber piers created maintenance issues.
The replacement structure is a single-span through-plate girder supported on modified stone abutments. The abutment foundations, because of their height and slenderness, required reinforcing with sheet pile-lagged retaining walls placed behind the existing structures to limit the loads from the Cooper E 80 design loads. The new single-span structure eliminated the maintenance issues of the center pier; however, the pier was left in place to reduce demolition costs and environmental impacts. Pare designed the replacement structure to allow for accelerated bridge construction that limited track closure to a single 4-day outage.
This video, captured by aerial drone, shows a train with ethanol tankers crossing the completed bridge in November of 2016.