DEDHAM- BRIDGE REPLACEMENT, D-05-003 (33K), NEEDHAM STREET OVER GREAT DITCH

It is anticipated that the structure will be replaced with a single span superstructure of approximately 84 feet. The additional required superstructure depth shall be accommodated by raising the profile as little as possible. The proposed bottom chord elevation should not be reduced. 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. These parameters shall be verified with the Geotechnical Report, the Hydraulic Report, the Survey, and the consultant’s own investigations. The bridge profile is expected to remain approximately the same. The minimum under clearance of the bridge cannot be reduced. 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. There shall be a new 5.5 foot sidewalk. The bridge rail shall be type S3-TL4. Highway guardrail transitions shall be located on independent bases. Adequate lighting shall be provided on the approach roadway curve (restore any existing lighting and add additional as necessary.) The scour protection of the abutments is required and shall be included on the consultant’s drawings and special provisions. Work in the water shall be eliminated or reduced to the extent possible.