The four-lane Jamestown-Verrazano bridge linking North Kingstown and Jamestown, Rhode Island, underwent a 2,400-ton precast bridge span lift between 1990 and 1992. The double-cell box girder used for both the high-level approach spans and the main structure varies in depth from 10 feet to close to 33 feet. The three main spans were cast in place using balanced cantilever construction, and the high level precast approach spans were lifted into place. The work was originally bid to VSL Corp., who redesigned the high-level approach plans to permit span-by-span erection with VSL equipment. The contract was later terminated and reawarded to Atkinson-Kiewit, who decided to follow the VSL redesign, which provided the option of casting pier segments of the approach spans in place.
The contractor first cast two pier tables as takeoff points for the balanced cantilever construction of the highest bridge spans. Cantilever construction was done in a three-phase pour for each segment. The contractor chose to cast the pier segments of the approach spans in place. Casting for the approach span segments was done in six stages using formwork covering one-third of the length of the segment. After the bottom slab is cast for the first third of the segment, it moves along a runway to the next position where top forms are brought into position, partially supported on the bottom slab. While concrete is being placed in these forms, a second segment of the bottom slab is being cast at the first position.