Neponset River Bridge
Opened in 1971, the Neponset River Bridge carries three lanes of traffic over the Neponset River in each direction. The superstructure consists of steel plate girders and cover-plated steel stringers. Nineteen twin hammerhead piers and five twin wall piers support the superstructure. Six pairs of piers are located in the river. During a routine inspection of the bridge, personnel found cracks in several of the piers. A subsequent engineering study found that the cracks were due to over-stresses in the flexural steel and abrupt termination of flexural steel in a tension zone. SGH's work included load ratings, analysis of the piers' structural adequacy, and finite element analysis.