NJ Turnpike Authority
Woodbridge, New Jersey
Township of Mansfield, New Jersey
The Interchange 6 contract is one of the NJ Turnpike Interchange 6 to 9 Widening Program projects. The project will add three outer roadway lanes in both directions along the existing NJ Turnpike between milepost 50.5 to 51. The project involves constructing 7 new bridges, widening 1 bridge, 24 retaining walls, and the demolition of 4 existing bridges which span over the existing Turnpike mainline.
The new Turnpike ramp bridges that span over the mainline will be concrete deck slabs on steel girders. The steel girders are curved and tall, which requires extensive assembly coordinate on between girders and steel box cap beams. The bridge columns are 6’ and 8’ diameter cast in place concrete. Each column is directly supported by 6’ and 8’ diameter drilled shafts, up to 150’ deep. The abutments are supported on 42” diameter drilled shafts. All shafts are installed using a polymer slurry method complete with a batch and recycling system. The two County Road bridges over the Turnpike will be demolished and replaced with longer structures consisting of concrete deck slabs on steel girders supported by cast in place concrete piers and footings. The footings are supported on 16” and 24” concrete filled steel pipe piles.
The roadwork involves extensive utility, drainage, ITS, and ground improvement construction. Ground improvements will be accomplished by bottom feed stone columns being installed into the soft clays to minimize settlement at the taller retaining walls. All retaining walls will be MSE type walls, and total over 180,000 SF of precast wall panels and 10,000 LF of precast roadway barrier. There are also several large drain- age basins that will be built with slurry cutoff walls around the perimeter.