Highland Boy Drainage Gallery
Atkinson completed the excavation and construction of a 15-foot-by-8,000-linear-foot horseshoe tunnel at the Bingham Canyon Mine. During excavation, crews used drill and blast techniques to advance the tunnel simultaneously from two headings in a horseshoe orientation and met in the middle.
Washington Metropolitan Area Transit Authority Rosslyn Station
Virginia’s Rosslyn Metro Station required excavation of 93-foot shaft, a 40-foot diameter mezzanine tunnel, and a 15-foot diameter passageway tunnel. The ground support system consisted of number nine by 25-foot-long post-tensioned rock anchors and steel fiber-reinforced shotcrete.