Mining haul trucks and private vehicles are traveling on separate routes following the construction of a pair of tunnels and a realignment of a segment of US 191X that runs through an Arizona mining operation.
Ames constructed the multiplate tunnels that allow loaded mining haul trucks to cross above US 191X, increasing haul production for the mine operation, while non-mining vehicles pass safely below.
The project scope included tunnel excavation, installation of the 240-foot structural steel plate tunnels, construction of roadway barriers, and rerouting the highway through the tunnel. Ames self-performed all aspects of this project except for paving and striping.
The most significant challenge was the construction of the 31-foot 10-inch diameter tunnels. Each tunnel ring was comprised of six plates—three plates for the top half and three for the bottom. After setting several bottom halves, the crew would come back to set a top half and bolt the halves together, taking care to maintain the roundness of the pipe as the length progressed.