The goal of this project was to replace a structurally deficient bridge and widen approach shoulders to meet current highway design standards. The existing bridge was comprised of precast prestressed concrete girders with deteriorated beam ends.
CME designed a single span bridge to replace the existing three-span bridge using weathering steel girders and a reinforced concrete deck. The use of the Geosynthetic Reinforced Soil Integrated Bridge System (GRS-IBS) abutments allowed for the elimination of bridge bearings, expansion joints at the ends of the deck and approach slabs. The elimination of the two spans, the use of weathering steel and elimination of expansion joints and bearings greatly reduces the maintenance required on this bridge throughout its lifespan.
The original scope of this project consisted of repairs to the beams, deck, patching of the substructure and replacement of deck joints under CTDOT’s List Bridge Program. From comments received on the 30% design submission and a subsequent bridge inspection report lowering the rating of the bridge, CME was directed to design a complete bridge replacement at this site. The revised scope included converting the existing three-span, prestressed concrete girder bridge into a single-span structure and replacing the substructure with Geosynthetic Reinforced Soil Integrated Bridge System (GRS-IBS). This innovative substructure system utilizes layers of geosynthetic fabric and stone backfill with a simulated stone concrete block face to provide a solid mass to support the proposed structure.
This substructure type posed an advantage for this project because it was located between the abutment and piers and could be partially constructed below the existing bridge while maintaining existing traffic patterns. Then, through staged construction, the existing structure was demolished, and the proposed structure was constructed on the new GRS-IBS abutments.
CME provided roadway approach design on the Interstate including widening to meet current Highway Design Criteria and improvements to roadside safety appurtenances and drainage. A minimum of one lane of traffic was maintained on I-395 Northbound throughout construction and CME developed detailed traffic management plans to account for nearby acceleration and deceleration lanes. One-way traffic was maintained on Tracy Road by utilizing a temporary traffic signal. Since a portion of the Quinebaug Multi-Purpose River Trail passes along Tracy Road, pedestrian traffic was also maintained along Tracy Road throughout construction. This project included upgrading over 2,000 linear feet of metal beam rail to current CTDOT standards and provided new end anchorages on both the leading and trailing ends. CME prepared construction plans, estimate, and special provisions.