Garver provided design services for 22 miles of Interstate 540's four-lane highway constructed through the rugged Boston Mountains. Because of the terrain, the project included deep cuts, high fills, and Arkansas' first highway tunnel.
The design included protection of environmentally sensitive areas, four full control-of-access service interchanges, access restoration roads, slope stability analyses, and more than 2 miles of bridge structures. Bridge configurations included straight, curved, and skewed structural steel spans of up to 250 feet founded on single and multiple column concrete piers with heights of up to 200 feet above the ground.
The most significant feature of the project, the Bobby Hopper Tunnel, consists of two parallel, reinforced, concrete-lined, mined-rock tunnels approximately 1,375 feet in length. Each tunnel is nearly 40 feet wide to accommodate two lanes of traffic with shoulder space. Garver designed the support features for the tunnel, including approaches, portal walls, roadway level retaining walls at the tunnel portals, tie back excavation reduction walls, and electrical systems.