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Project Showcase

Iowa 3 bridge before construction

Project: Iowa 3 bridge replacement

View photos and details below of recovery projects before construction, during construction and after the project has been completed.

Project: Iowa 3 bridge replacement

County: Plymouth
Project number: BRF-003-1(75)--38-75
Bid date: Feb. 17, 2009
Contractor: Dixon Construction, Correctionville, Iowa
Bid amount: $1,842,961 (Iowa share)
Scope: The project concept is to replace the existing 471 foot x 30 foot I-beam bridge built in 1957 with a 498 foot x 40 foot pretensioned, prestressed concrete beam bridge. The project totals nearly $3.7 million and costs are shared with the adjoining state of South Dakota. Traffic is being detoured during construction. The target completion date for this project is late fall 2009.

Replacement of the Iowa 3 bridge is necessary due to its low sufficiency rating and evaluation as being structurally deficient.
Bridges are rated in two ways as part of the National Bridge Inventory inspection program, which determines eligibility for federal funds.

The first, known as the sufficiency rating, is a formula method of evaluating factors that indicate a bridge’s sufficiency to remain in service. The result of the formula is a percentage, in which 100 percent represents an entirely sufficient bridge and 0 percent an entirely insufficient bridge. Per results from its last inspection, the Iowa 3 bridge has a sufficiency rating of 40.

The second rating measures the bridge’s structural integrity. When a bridge is deemed structurally deficient, it means there are elements of the bridge that need to be monitored and/or repaired. The fact that a bridge is classified as "structurally deficient" does not mean that it is unsafe. It means the bridge must be monitored, inspected and repaired/replaced at an appropriate time to maintain its structural integrity.

The Iowa 3 bridge is “structurally deficient” because the pier caps under the deck joints are deteriorating. There is extensive spalling and cracking in the concrete. This exposes the reinforcing steel to water, salt and oxygen, which causes corrosion.

The Iowa 3 bridge crosses the Big Sioux River between the states of Iowa and South Dakota. The structure sits at the foot of the Loess Hills and the Loess Hills National Scenic Border, a vital component to tourism in Western Iowa. The route is utilized by the cycling community for local and bi-state recreational cycling. The Loess Hill Scenic Byway affords access to several other tourism and recreational activities in the region, including: access to Stone State Parks hiking, mountain biking and public use opportunities; Woodbury County Conservation’s Dorothy Pecaut Nature Center, which is the jewel of the Woodbury County Park System; and the 8,000-acre Broken Kettle Grassland home of the first wild bison herd in Northwest Iowa in more than 100 years.
As these photos illustrate, Recovery Act funds are being quickly utilized in Iowa. Work got underway in April 2009 to remove the bridge railing, deck and metal I-beams before demolition of the badly deteriorating concrete piers.

Construction progress update: May 24, 2010

The bridge opened on May 24, 2010.

Completed

The construction is complete and the bridge opened May 24, 2010.