Bridge

GRA is considered one of the leading bridge engineering firms in Southern New England having successfully completed scores of bridge projects of various types. These include the following:

GRA's experience in the rehabilitation of historic bridges has involved some interesting and special features which deserve a brief explanation. There are two such structures: the Albion Bridge and the Berkeley Bridge. Both of these bridges were very old, having been constructed in the 1880s. They both span the Blackstone River, which flows southeasterly through the northeasterly corner of Rhode Island.

The Blackstone River and its valley have been designated by the Federal Government as a National Heritage Corridor due mainly to the river's historic role in supplying hydro power to the early textile industry in Rhode Island.

These two old bridges within the Heritage Corridor were considered valuable visual elements and, as such, could not arbitrarily be replaced by contemporary structures. This fact allowed GRA to incorporate certain design features not ordinarily permitted.

The Albion Bridge was a two-span structure supported by two pairs of pin-connected Pratt trusses. The bridge railing consisted of a beautiful diagonal steel bar arrangement with a rosette casting placed where the steel bars intersect.

The four trusses were removed to the shoreline where they were repaired and repainted. The existing granite river pier and abutments were repaired, a new heavy steel girder superstructure and timber deck were set in place, and the rehabilitated trusses were re-erected and connected to the new fascia girders. The completed bridge can now carry contemporary traffic loadings while maintaining its 19th century visual quality.

The Berkeley Bridge is located two miles downstream from the Albion Bridge. It originally was a two-span structure supported by two pairs of timber bow string trusses. One pair of trusses was swept away years ago by flooding in the Blackstone River. That span was replaced by a conventional deck-type stringer structure.

The Berkeley Bridge was rehabilitated in a similar manner to the Albion Bridge, with one exception. Due to the presence of the deck-type structure in one span and the old timber trusses in the other, it was decided to design two pairs of new timber trusses to look like the originals and place them astride the new steel fascia girders.

The visual effect of the “aesthetic rehabilitation” of these two old bridges is quite dramatic.