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Old Chain of Rocks Pedestrian Bridge

The Old Chain of Rocks Bridge, constructed in 1929, was originally used to carry U.S. Route 66 over the Mississippi River. In 1967, a new bridge was built immediately to the north of the Old Chain of Rocks Bridge and the original bridge was subsequently closed. For nearly three decades, the bridge remained out of service and demolition seemed likely. However, in 1998, the bridge was leased to Trailnet, a local trails group. Trailnet asked Modjeski and Masters (M&M) to assist them in reopening the bridge for pedestrian and bicycle use. M&M worked closely with Trailnet to prioritize repairs and work within tight budgets to first open and then maintain the structure throughout Trailnet’s lease.

M&M provided engineering services for a series of rehabilitation projects for this bridge. Phase I & II renovations focused on the conversion of the abandoned highway bridge to a pedestrian bridge, including the design/detailing of expansion joint and bearing rehabilitations; the review of floorsystem ratings; and the design/detailing of end floorbeam strengthening for jacking. Additional structural repair packages included miscellaneous steel replacements, roadway deck beam rehabilitation, maintenance painting, and concrete repair. Load capacity ratings were performed to determine construction and emergency vehicle requirements.  Emergency repairs were performed to fix a fractured vertical member.

An observation deck overhanging a river pier was constructed, providing a unique view for patrons. Electrical work involved the installation of pedestrian lighting and provided power on the bridge. M&M also provided construction services for these projects.

Bridge Geometry
Length of Main Span 700 feet
Total Project Length 5,353 feet
Lanes on Structure Pedestrian Walkway