The Baptist/Nemours Pedestrian Overpass project in Jacksonville, Fla., was anything but a typical bridge project for design-build contractor The Haskell Company, Jacksonville, and structural engineer Bliss & Nyitray, Miami. Connecting the fourth floors of Wolfson's Children's Hospital at the Baptist Medical Center and Nemours Children's Clinic, the fully enclosed pedestrian walkway had to be constructed over Interstate 95—one of the nation's busiest highways—with minimal disruption to traffic.
The 780-foot-long walkway consists of nine steel box-truss sections ranging in length from 38 to 100 feet and in weight from 22 to 49 tons. But the structure's most impressive elements are two soaring 150-foot-tall tilt-up concrete piers, which create a gateway for the thousands of vehicles that travel the interstate daily. Each pier consists of six tapered pieces that were cast onsite in steel forms and lifted into place. The staging areas were located in right-of-ways on either side of the interstate. To join the individual pier sections, Haskell connected them vertically using grouted sleeve connectors and horizontally using cast-in-place transverse beams. A 10-foot-tall steel spire connects the top pier segments.
Erecting the tilt-up pieces, which weighed as much as 67 tons, required stretching standard tilt-up practices to the limit. Specially designed lifting attachments, rigging and bracing were used throughout the tilt-up process to achieve precise vertical alignment of the heavy concrete segments.