Five-million-pound bridge skeleton rolled across I-94

Regular readers of this publication may recall a 2020 article about the replacement of the Second Avenue bridge over I-94. The must-see event of the summer was a long-awaited repositioning of the bridge skeleton to span I-94. The framework, assembled in a Wayne State parking lot, proceeded in parallel with construction of the bridge abutments.

Finally, bridge and abutments were ready to go in the summer of 2022. Over ten days in late July, the completed skeleton was mounted on robotic, rolling platforms, driven to the edge of I-94 and slowly propelled across the (temporarily closed) interstate. Engineers from the Gordie Howe Bridge came to watch!

This is the first network-tied arch bridge in Michigan, featuring central arches and crossed hangers that support the roadbed. This design does not require a central pier, a feature that will facilitate the modernization of nearby I-94 interchanges in coming years. The structural integrity of the arch also enabled the self-supporting, 5-million-pound skeleton to be constructed nearby and carefully rolled into position.

Relocation fell to a contractor specializing in moving oversized items, often in shipyards or at the scene of disasters. I-94 was closed for two weeks while the median barrier was removed, and the highway was covered with dirt and steel plates to prevent damage to the roadbed. The leading edge of the bridge skeleton was moved to the precipice and handed off to rolling platforms that, over the course of several days, rolled it into place and carefully lowered it onto the abutments. Over the ensuing months, workers built rebar frames for sidewalks and roadbeds, and, as of mid-October, cement is being poured. We expect the bridge to be open for traffic in December of this year!

For more on I-94 modernization, and information about the amazing rolling platforms (self-propelled mobile transporters) used to move the bridge, follow the Second Avenue Bridge link at i94detroit.org.