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I-35W (St. Anthony Falls) Bridge

Category: Transportation (other than Aviation)

Project Location: Minneapolis, Minnesota

Credit: Photo by Tim Davis / Courtesy of Flatiron.

Photo Description: The new i-35W bridge is a vital artery for the city of Minneapolis and adds a graceful beauty to the view from above.

Budget and Schedule Performance (if applicable)

Owner-directed changes that impacted budget and/or schedule, if applicable:

Unusual challenges or unforeseen conditions involved in meeting the budget and/or schedule, if applicable:

It was important to get the new bridge built and in use quickly – it is heavily used and an important link over the river. Time was the major challenge, considering the scope of the project. The team delivered the project 98 days early and earned a bonus of $25,000,000 for that.
Another challenge was public acceptance of the bridge; by an ongoing and extensive outreach effort, the team involved the local community. Beginning with a design charrette and continuing with regular on-site tours from a nearby bridge, kiosks with access to project cameras and regular television and radio spots, bridge users and neighbors were enthusiastic about their new bridge.

Project Narrative:

Only three days after the collapse of the old I-35W Bridge in August 2007, the Minnesota Department of Transportation issued an RFQ and continued to fast-track the solicitation and selection process to rebuild the 10-lane interstate bridge. Flatiron and Manson formed a joint venture, with FIGG Bridge Engineers as the designer, and were selected to complete this high-profile project on an intensely accelerated schedule. The goal was to open the new bridge to traffic within 14 months. Flatiron-Manson exceeded this goal and opened the bridge to traffic in less than a year — more than three months ahead of schedule, while also achieving Mn/DOT’s goals of safety, quality and innovation.
The 1,216-foot bridge’s twin 504-foot main span is comprised of 120 precast concrete segments, post-tensioned with high-strength steel strands encased in plastic ducts and high-strength grout. Each 90-foot-wide main span twin structure is comprised of precast concrete segments forming two box girders, supported on four 70-foot-tall curving piers on either side of the river.
The team also provided aesthetic enhancements – not only the bridge (which is beautiful), but the landscape around it. And the team’s commitment to community involvement led to wide public approval of both the process and the end result.
The deadline for completion was important – the Minnesota DOT calculated it was costing users $400,000 a day while the bridge was out of service. With this in mind, the team delivered the project 98 days early – more than three months before the deadline.

Client/Owner: