McHugh Construction Co. has begun reconstructing the original 10-span arch bridge over the Fox River on the Reagan Memorial Tollway (I-88), just months after completing a new eastbound span to increase traffic capacity as part of the Illinois Tollway's $6.3 billion Congestion Relief Program.

The existing bridge, which opened in 1958, features an unusual design, with a series of five arches, rarely seen in modern infrastructure construction. McHugh replicated the arch design for the just-opened bridge, and will be using a virtually identical arch design for the reconstructed bridge as well.

To keep traffic flowing smoothly, westbound vehicles have been routed onto the new eastbound bridge, completed in late 2008, until the existing bridge, which will eventually carry three lanes of westbound traffic, is rebuilt.

McHugh is demolishing the old bridge just north of the new eastbound bridge, building a new structure, and widening and repaving three miles of the westbound tollway adjacent to the bridge, under a $31.4 million contract with the Tollway as part of its Reagan Memorial Tollway (I-88) Rebuild & Widen Project. The new bridge will be made of structural precast concrete and feature a series of five arches to replicate the original design, along with that of the new bridge. When work is complete, each bridge will carry three lanes of traffic, with full shoulders.

Demolition is scheduled to begin this month, and is expected to take two to three months. Reconstruction will follow, with the rebuilt bridge slated for completion by summer 2010. In addition to the Fox River Bridge, the project will widen I-88 from two lanes to three lanes in each direction between the Aurora Toll Plaza and Orchard Road.

McHugh is serving as general contractor for the project, with Chicago-based Teng & Associates the engineers of record.

Among the project's challenges will be building in the river. The Fox River is not navigable around the bridge, and subject to constant rapid water flows. As a result, McHugh will work from the river's banks and build temporary access structures, including a temporary bridge, to deliver materials and perform work while maintaining the river's flow, said Joe Bodzioch, McHugh project manager. While building the new eastbound span, McHugh persevered through a 500-year flood event and two 100-year flood events, leading to renewed respect for the forces of nature, said Bodzioch. As a result, the team is better prepared for the changing dynamics of the Fox River during construction.

An even greater challenge for McHugh this time is demolishing the existing 1958 structure. To keep the bridge balanced and stable during demolition, McHugh will first reduce the weight on the bridge deck as much as possible, then demolish each arch "barrel" from north to south, carefully reducing the width of each arch while maintaining its stability, Bodzioch said. The team also will create extensive protective systems to ensure no debris falls from the bridge.

The new bridge will be 1,345 feet long, supported by 10 spans underneath the roadway, including five 178-foot-long spans. The five arches will be created using 40 structural precast concrete arch segments, each weighing 92 tons, cast nearby by McHugh and then carefully trucked to the river. These arch spans will be topped by 36-inch-deep precast, prestressed (PPC) concrete beams; the other five spans will use conventional 42- and 54-inch PPC beams. The team will reuse several of the existing bridge's rock foundations.