Sliding an 11,000-Ton Bridge More Than 100 Feet

HDR’s Nick Burdette Shares Insights on One of the Largest Bridge Slides in the U.S.

Demolishing and replacing the existing Commercial Street bridge in Pittsburgh took just 17 days, about half the time set aside for the closure of the 846-foot bridge that carries Interstate 376. The move, completed in July 2026, was a triumph of accelerated bridge construction, and the culmination of years of work by our design team. 

Replacing the 75-year-old concrete arch bridge is a steel arched delta frame structure. The design was chosen after public input for its ability to be slid laterally into place. HDR’s Northeast Region Bridge Leader Nick Burdette, who served as project manager for the bridge, recently discussed the bridge and its move with Engineering News-Record. He explained the reasoning behind the bridge design and some of the challenges of the unique project. 

“Based on public polls and interactions with [stakeholders], it was evident that everybody wanted an arch bridge,” Burdette told ENR. “You’re looking for a bridge with an arched appearance that can be slid, and combining that with explosive demolition…really required careful attention to the substructure.”

The new bridge, about 825 feet long and 22 million pounds, was raised about 10 inches and moved more than 100 feet in one continuous shift before being lowered onto its new substructure and connected to the existing roadway.

Read the article (may require login or subscription) “Crews Pull Off One of the Heaviest, Longest Bridge Slides in the U.S.,” published in Engineering News-Record.