HDR to design St. Croix Crossing Bridge
Minnesota and Wisconsin transportation departments have chosen the architectural and engineering firm HDR along with consulting engineers Buckland & Taylor to design St. Croix Crossing Bridge in Wisconsin.
St. Croix Crossing Bridge will span the St. Croix River and will be located between Oak Park Heights, Minnesota and St. Joseph, Wisconsin. It will be constructed using the design-bid-build method.
The $14.2 million contract will involve development of the extradosed-type bridge design, selected by a community stakeholder group. The design is a hybrid of a concrete box girder structure and a cable-stayed structure. It would be lower in height than a typical cable-stayed bridge. The entire length of the St. Croix bridge will be about 3,460 feet, which includes six main extradosed spans, each 480 feet long; and two end spans that are 285 feet long.
The bridge design will also aim at minimising environmental impact by keeping tower heights below the river bluffs and reducing the number of piers in the river.
Cost of the bridge is expected to be $280-$310 million and the project's total cost is estimated between $580 million and $676 million. The bridge is a part of the larger St. Croix Crossing project, which includes expressways on either side of the bridge in Minnesota and Wisconsin. The project also includes an extensive trail facility for pedestrians and bicyclists, as well as historic and environmental mitigation efforts.
When completed, the St. Croix Crossing will be the second extradosed bridge in the US. The design work will take about a year to complete. The construction of the bridge will start in the fall of 2013 and will finish by 2016.
