The Wisconsin Department of Transportation hired Ayres to design the rehabilitation of the 1.5-mile-long Bong Memorial Bridge and its 1.3-mile urban approach in Superior. The project included placing a concrete deck overlay on approximately 600,930 square feet of existing bridge deck and replacing the 18 sets of modular expansion joints and six strip seal joints.
The project won a 2017 Engineering Excellence State Finalist Award from the American Council of Engineering Companies of Wisconsin.
Ayres previously provided design services for construction of the bridge, which was completed in 1984. The bridge carries USH 2 over the St. Louis River Harbor between Superior, Wisconsin, and Duluth, Minnesota. A shipping channel, two railroads, and IH 35 lie beneath this bridge.
Improvements included painting the entire exterior of the tied arch, the interior of the tie girders, and the ends of the steel girders within 10 feet of each of the expansion joints. Each supporting cable in the 500-foot-long steel tied arch center span was inspected, repaired, and adjusted as needed. Lighting on the Wisconsin side of the structure was updated, and the navigational lighting on the structure was updated. The outside edge of the sidewalk on the structure was also repaired.
The tied arch span and all 18 units of this welded girder, curved bridge were load rated using SAP2000 software to make sure the bridge had the capacity to handle the additional load of the concrete deck overlay, whose area is the equivalent of more than 10 football fields. Ultimately the project involved milling off 2 inches of deck surface and overlaying the deck with new concrete.
The approach pavement and curb and gutter also were replaced, and pavement marking and permanent signs were provided. Abutment surface repair and respraying of the slope paving under the bridge were also included in this project. The eastbound lanes were realigned to mirror the westbound lanes of USH 2 as they approach the new multi-lane roundabout Ayres designed at USH 2 and Belknap Street. This is Superior’s first roundabout.
New street lighting and storm sewer were installed as part of this urban reconstruction. Bicycle and pedestrian accommodations were incorporated into the Wisconsin approach, along with drainage improvements and realignment of connecting City streets. Ramp gates were designed as part of the project.
Extensive coordination was needed among WisDOT, the Minnesota Department of Transportation (MnDOT), the Wisconsin and Minnesota environmental agencies, the Cities of Superior and Duluth, the U.S. Army Corps of Engineers, the Coast Guard, the local business communities, and the general public. Traffic control, construction staging, and public involvement were critical to the project.
The bridge and approach roadway projects were constructed during the 2014 and 2015 construction seasons under a partial detour that left one lane open to traffic and diverted two lanes of traffic to the Blatnik Bridge, which carries IH 535/USH 53 over St. Louis Bay. The Bong Bridge normally carries nearly 20,000 vehicles per day.
The work was completed by October 2015 approximately $1 million below final estimates.