NC EOG Practice Test 11

The Bridge That Hugs a Mountain

¹The Blue Ridge Parkway is a 469-mile road that winds along the tops of the Appalachian Mountains in Virginia and North Carolina. Work on it began in 1935. Planners wanted a road that would let people enjoy the mountains slowly, with gentle curves and wide views, instead of rushing from place to place. There are no stoplights or billboards along the way, only overlooks, tunnels, farms, and forests.

²Building the parkway took more than fifty years. By the late 1960s, almost all of it was finished, except for a short stretch around Grandfather Mountain, near Linville, North Carolina. For years, that gap was known as "the missing link." Leaders spent years arguing about where the road should cross the mountain.

³The problem was the mountain itself. Grandfather Mountain is steep and rocky, and its slopes are home to rare plants and animals. The usual way to build a mountain road is to blast and dig a flat shelf into the slope. On Grandfather Mountain, that would have left a huge scar and sent rock and soil sliding down its side. People who cared about the mountain did not want a scar that could be seen for miles.

⁴The answer was the Linn Cove Viaduct. A viaduct is a long bridge that carries a road over a valley or rough ground. Instead of cutting into the mountain, the parkway would curve around its side on a bridge resting on a few tall piers.

⁵Engineers also found a clever way to build it. Usually, crews and heavy machines work on the ground beneath a bridge. The Linn Cove Viaduct was built from above instead. Workers made 153 concrete pieces, called segments, ahead of time. Each one weighed about 50 tons. A crane sitting on the finished part of the bridge lowered each new segment into place, one at a time. In this way, the bridge grew out over the mountainside piece by piece, like a long arm reaching around the mountain. The only digging on the ground was for the bases of the piers.

⁶Fitting the pieces together was tricky, because the viaduct curves around the mountain's boulders. Every segment but one has a slight curve, and each had to match the segments beside it exactly. Workers checked every measurement again and again before a segment was lifted into place.

⁷The viaduct was finished in 1983, and the last section of the parkway opened in 1987. The bridge is 1,243 feet long and has won awards for its design. Today, drivers crossing it look out over forests and valleys, and many never realize how carefully the mountain beneath them was protected. Hikers can follow a trail that passes underneath the viaduct and see how lightly it rests on the mountainside.