Project Description

The project consisted of the replacement of the existing precast concrete double tee bridge. In 2019, severe flooding washed out portions of the existing structure making it impassable. The Moorhead Bridge was closed September 25, 2019 by the Montana Department of Transportation due to the bridge piers settling and rotating which could have caused the structure to collapse. Since the closure, residents were making a 50 plus mile detour through Broadus to get to the other side of the Powder River. The new Moorhead bridge is a 240 foot clear span Acrow Bridge System prefabricated modular steel superstructure supported by the existing abutments with extensions added to support the new bridge width and load.

Project Details

LOCATION: Broadus, Montana
DURATION:  16 weeks
PROJECT TYPES: Highways, Streets & Bridges

Unique Problem Solved

The bridge was erected on these timber supports piece by piece. Approximately 6,000 bolts were installed and torqued to complete the construction of the bridge. As portions of the bridge were complete, the structure was pushed across the river by a large excavator. There were several “pushes” during the construction of the bridge. The steel bridge decking, not yet installed, was placed on one end of the structure to act as counterweight as the bridge cantilevered over the river. Once the bridge was pushed across, it was lowered onto the revised abutments, new concrete backwalls were poured and the bridge ends were backfilled.