Segmental Concrete I-35W Replacement Bridge Opens Three Months Early

Underscoring segmental concrete building methods’ potential for the fast track, MnDOT opened the new Interstate 35W bridge across the Mississippi River on Sept. 18–three months ahead of schedule and just under 14 months after the predecessor structure failed

Sources: Minnesota Department of Transportation; CP staff

Underscoring segmental concrete building methods√Ć potential for the fast track, MnDOT opened the new Interstate 35W bridge across the Mississippi River on Sept. 18–three months ahead of schedule and just under 14 months after the predecessor structure failed. With a 504-ft. main span, the new St. Anthony Falls Bridge combines precast and cast-in-place segmental concrete. Of four prequalified teams, Figg Bridge and Flatiron-Manson Joint Venture submitted the lone concrete bid against steel girder alternates. Citing projected lower maintenance as part of a value engineering determination, MnDOT chose the concrete package, representing a high bid of $234 million. Cemstone Products Co. supplied ready mixed for foundations, piers, decks and cast-in-place girder portions, plus a temporary casting yard near the site where Flatiron-Manson fabricated remaining girders.

During a press conference earlier in the week–staged at the Minneapolis-St. Paul project site to announce the planned opening–MnDOT Commissioner Tom Sorel affirmed, “Building a high-quality and safe bridge in less than a year happened because of the dedication, professionalism and incredible determination of those who planned, designed and built it. Hundreds have worked around the clock since Nov. 1. Their attention to detail, as well as the project’s extensive safety and quality inspection programs, provide us confidence this bridge will carry traffic safely for at least 100 years.”

Joining him for the announcement were U.S. Department of Transportation Secretary Mary Peters and Minnesota Gov. Tim Pawlenty. Crews will continue final project work at off-site areas in the coming weeks, but no lane closure or traffic disruptions are expected. The cause of the original steel structure’s collapse remains under National Transportation Safety Board investigation; the August 1, 2007, event claimed 13 lives.