BLACKSTONE- BRIDGE REHABILITATION, B-13-004, ROUTE 122 (MAIN STREET) OVER THE BLACKSTONE RIVER

The bridge is to be replaced with a single span superstructure with a span length of approximately 75 feet. Because of possible historical issues, the consultant shall investigate and document the possible use of a pre-cast concrete arch. If an arch structure is not practical, the superstructure shall consist of NEXT beams or another suitable superstructure identified by the consultant and approved by MassDOT. The new deck shall consist of 8 inch thick 4000 psi HP cement concrete with 3 inches of hot mix asphalt for bridges over a waterproofing membrane. There shall be a new sidewalk, 5.5 feet wide, on the north side of the bridge (5000 psi HP cement concrete). The abutments are to be located behind the existing abutments. They will be integral with the superstructure and supported on piles. The existing abutments shall be left in place to be part of the scour protection system and, if necessary, the construction dewatering system. They shall be cut down to facilitate inspection access to the new abutments and beam ends. The substructure type shall be verified by the Geotechnical Report. The bridge profile is expected to remain approximately the same. Though, it may be raised to increase the under clearance. This profile shall be verified with the proposed superstructure depth and the Hydraulic Report. The curb-to-curb width of the bridge shall be 32 feet. The bridge rail shall be type S3-TL4. Highway guardrail transitions shall be located on independent bases.