ASPIRE is a quarterly magazine published by PCI in cooperation with the associations of the National Concrete Bridge Council. The editorial content focuses on the latest technology and key issues in the Concrete Bridge Industry.
Issue link: http://www.aspiremagazinebyengineers.com/i/306846
With the casting of this pier segment on October 18, 2007, Minnesota's first precast concrete segmental bridge gets underway. Photo: Mn/DOT. The Minnesota I-35W/Hwy 62 Crosstown Project features precast concrete segmental bridges utilizing balanced cantilever construction within one of the most highly congested sections of interstate highway system in the region. Approximately 200,000 vehicles per day travel through the project, which is situated in the southern portion of Minneapolis and into Richfield, with the Mall of America and the Minneapolis-St. Paul International Airport nearby. The old configuration was essentially an at-grade interchange. The traffic from Hwy 62 merged into the left-most (fast) lane of I-35W and caused traffic delays as the traffic wove together. This 1960s design had exceeded its design capacity, had a high accident rate, and was outdated with an aging infrastructure. Additionally, the area has long since undergone densely populated urban sprawl, with homes and businesses built to the edge of the right-of-way along the corridor. The new layout includes elevated structures that separate the traffic and eliminate the merging and weaving requirements. The use of precast balanced cantilever techniques permits construction in these highly confined areas. The $288 million contract, the largest in Minnesota's history, includes $99 million for bridges, of which $42 million is the total for the six precast segmental bridges. Construction began in 2007 and is on schedule for the planned 2010 completion date. This project was the first use of precast segmental construction in the state of Minnesota. Bridge Type Selection The bridge type selection process for these flyover ramps was based on a combination of several factors. • The box girder geometry and balanced cantilever construction method offered an approach that better fits the confined work area. profile MINNESOTA I-35W/H Wy 62 CROSSTOWN PROJECT / CROSSTOWN COMMONS, MINNESOTA ENGINEERS: (Each firm designed two segmental bridges) PB Americas, Minneapolis, Minn. (Lead Designer), URS, Minneapolis, Minn., Parsons Transportation, Minneapolis, Minn. ENGINEER: (Project Layout, Staging Plans, and Roadway Plans) SRF Consulting Group Inc., Plymouth, Minn. CONSTRUCTION ENGINEERS: McNary Bergeron and Associates, Broomfield, Colo. OWNER'S REPRESENTATIVE: FIGG Construction Engineering Inspection, Eagan, Minn. PRIME CONTRACTOR: ALS– A Joint Venture of Ames, Lunda, and Shafer construction companies, Minneapolis, Minn. SUBCONTRACTOR: High Five Erectors Inc., Shakopee, Minn. CONCRETE SUPPLIER: Aggregate Industries, Eagan, Minn. by Keith Molnau, Minnesota Department of Transportation and Franklin Hines, FIGG Minnesota Crosstown Project Features Precast Concrete Segmental Bridges Precast segmental construction offered the most advantages and was the most attractive option 30 | ASPIRE , Spring 2009 Aspire_spr09.indb 30 3/11/09 4:17:17 PM