MassDOT retained BETA to design a bridge replacement for this structurally deficient single span bridge over the Mill River as part of the Accelerated Bridge Program (ABP). The existing 1930’s concrete tee-beam bridge was replaced with a single span structure comprised of Prefabricated Bridge Units (PBUs) supported on abutments founded on secant pile walls. The secant pile walls were installed from street level thereby eliminating the need for major excavation and excavation support systems. The PBUs consisted of a pair of color-galvanized rolled steel beams and a concrete deck fabricated off-site, shipped to the site in units, and erected in just half a day.
The project also included the reconstruction of approximately 800 feet of Bay Street; construction of a new dam, sluice gates and fish ladder to replace the existing Morey’s Dam immediately upstream of the bridge. In addition, the river channel was fortified with riprap due to the anticipated high water flows over the spillway and for the incorporation of a low flow fish channel.
The project was designed utilizing the MassDOT LRFD Bridge Manual and the AASHTO LRFD Specifications. Due to the complexity of the site and the incorporation of the dam replacement into the project, Bay Street was closed during construction and a detoured provided. Extensive input and coordination was performed with the regulatory agencies as well as with the general public.
Winner of the 2013 ACEC/MA Gold Level Award!