Replacement of Mercer County Bridge 861.1–Old Trenton Road over Tributary to Millstone River

This project involved the demolition and replacement of Mercer County bridge 861.1, located in the Township of East Windsor, NJ.

Due to the effects of high and low tides, a cofferdam was required, as well as temporary sheeting to prevent material from falling into the stream and turbidity barriers to control downstream turbidity, to allow for the dewatering of the work area so that new bridge and wing walls could be installed.

Garden State Precast contracted with Delta to design and provide stamped engineering drawings for construction purposes. Approach slabs and 3-sided precast concrete sections were formed to create an overall bridge dimension of 19’-6” clear span by 51’-6” wide single span culvert structure, supported by two spread footings.

The bridge’s cross-section consists of two 12-foot travel lanes, two 6-foot shoulders, and two 6-foot sidewalks and four rail bridge railings.

To finish out the project, the roadway approaches included full-depth HMA pavement replacement as well as milling, repaving and installation of guide rail systems, new striping, drainage reconstruction, and concrete sidewalk, concrete curbs, excavation, topsoiling, and seeding.

Construction was limited to no more than 90 days as there was a complete vehicular and pedestrian closure.

Location: East Windsor Township, NJ