US 60 Pinto Creek Bridge
Award of Merit, Highway/Bridge
Submitted By: Ames Construction Inc.
Owner/Lead Design Firm: Arizona Dept. of Transportation
General Contractor: Ames Construction Inc.
Geotechnical Engineer: Wood Environment & Infrastructure Solutions Inc. (Amec Foster Wheeler Environment and Infrastructure Inc.)
Replacing the structurally deficient and functionally obsolete Pinto Creek Bridge on US 60 took a nearly three-year effort. The 695-ft-long steel bridge rises from the canyon floor in the Tonto National Forest outside of Globe, Ariz. Completed in May 2022 next to the original bridge, the new one features three sets of piers, the largest at 138 ft. The bridge serves the public and commercial vehicles from the nearby mines.
Project team members overcame numerous challenges. For one, the tallest piers were constructed with a single continuous pour that required crew members to climb down into the formwork to ensure there were no voids in the concrete. During installation of the retaining wall foundations, the project team realized that a modified system for subsurface support would be needed. Meanwhile, the site access road to the bottom of the canyon required modifications to better fit the natural terrain, minimize impacts to the surrounding National Forest lands and facilitate access for the 400-ton crane needed for the bridge girders.
Natural events also impacted work. During deck construction in June 2021, a wildfire burned the project limits. A month later, seasonal monsoons caused major debris flows and flooding along US 60, requiring clean-up and workarounds. On July 29, 2021, the Bloody Tanks Wash stream overtopped. The highway was closed and required immediate mitigation and repairs.
These events extended the project and required additional funds, but the team collaborated and made the best decisions for quality and the value of the end product. Once the new bridge was open to traffic, crews dismantled and removed the 1949 bridge and restored the site.