The Second Avenue Bridge over I-94 is the first unbraced, network tied-arch bridge constructed on a skew in the U.S., and one of three finalists for the NSBA’s 2024 Bridge of the Year. An innovative accelerated bridge construction process allowed the bridge to be assembled nearby and moved into place using self-propelled modular transporters, or SPMT. The bridge opened to traffic in December 2022.
Both the network tied arch design and SPMT construction processes were firsts in Michigan. The Michigan Department of Transportation is the bridge owner and Tetra Tech was the prime consultant on the project and provided abutment design, drafting, and load rating services for the bridge. HDR was responsible for the design of the network tied arch span, structural analysis, construction sequence, design-phase contractor outreach, and onsite construction observation.
“Our bridge design teams continually push the bounds of innovation to meet the needs of our clients and communities,” HDR Bridges & Structures Director Manuel Carballo said. “In this case, we had to span the future I-94 roadway and accommodate adjacent properties, including a historic Motown recording studio. This required HDR to design the 245-foot-long, unbraced network tied arch span at a skew of 18 degrees.”
"The skewed layout fit the site, but created hurdles for the design, fabrication, and construction. None of the connections were square and each bridge component was unique,” said Mike LaViolette, HDR’s Lead Designer and Engineer of Record. “Those challenges were compounded by assembling the bridge on temporary supports and moving it to the final location. Michigan Department of Transportation and their independent review engineer (Parsons) were tremendous partners throughout the arch design and installation. Moving the 5-million-pound bridge skeleton was quite an experience.”
