Construction of the parkway began in 1935 with the initial plan calling for a viaduct given the effects that a traditional cut-and-fill road would have on Grandfather Mountain. Towering almost 6,000 feet (1,800 m), this mountain is the most rugged peak on the Blue Ridge and geologically the most ancient mountain on the North American continent.[citation needed] Conservationists who hoped to preserve the area as a mountain park/recreation area were behind the viaduct concept as they stressed the danger of irreparable damage by lumbering and other exploitation, along with the need to preserve the view of the mountain as it then existed. By 1966, the parkway was essentially complete except for the 7.7-mile (12.4 km) section that circled around Grandfather Mountain despite the concerted efforts of the government to acquire the needed property, a task which eventually took 40 years.[3]
Design and construction
Viaduct Erection SchemeViaduct/Tanawha Trail
The viaduct was designed by Figg and Muller Engineers, Inc., with construction beginning in 1979. Some 1,243 feet (379 m) long and a little less than 40 feet (12 m) wide, the viaduct rests on seven piers. What made its construction noteworthy was keeping heavy construction equipment off the ground. This included the preliminary geotechnical exploration/evaluation work begun in 1975 where crews hiked to the site and drilling equipment was lowered to each bore-hole location by helicopter. Building the bridge from its south side, this was done by connecting 153 segments one at a time using a custom crane that moved along the viaduct as it was being built. Each segment, nominally 8.5 feet (2.6 m) long and weighing 50 tons, was precast at a facility onsite and moved on a carriage to the crane. All but one of these segments were slightly curved as the viaduct needed to be shaped in a "S-and-a-half" figure to follow the contours of the mountain. The only work done on the ground involved drilling the footings for the piers which also were built in a segmental manner. The viaduct has received numerous design awards to include the 1984 President's Design Award, which states, "... construction of the roadway by pre-cast, segmental concrete elements set from above on segmental piers is elegant, economical, and new… results in an elegant curving ribbon that caresses the terrain without using it as a support. It gives the motorist the sensation of driving tantalizing on air while the earth goes by."[4]
Klinedinst, Gary; Hall, Ken; Barker, James M. (1986). Design and construction of the Linn Cove Viaduct. U.S. Department of Transportation, Federal Highway Administration, Research, Development, and Technology ; National Technical Information Service distributor. hdl:2027/ien.35556021380654. OCLC14178564.
