Natchez Trace Parkway Bridge facts for kids
Quick facts for kids Natchez Trace Parkway Bridge |
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The Natchez Trace Parkway Bridge, viewed from the north
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| Coordinates | 35°59′12″N 86°59′32″W / 35.9866°N 86.9923°W |
| Carries |  Natchez Trace Parkway |
| Crosses |  SR 96 |
| Locale | Williamson County, Tennessee |
| Maintained by | National Park Service |
| ID number | 5570463P0000000 |
| Characteristics | |
| Design | Arch |
| Total length | 1,572 ft (479 m) |
| Width | 37 ft (11 m) |
| Height | 145 ft (44 m) |
| Longest span | 582 ft (177 m) |
| Clearance below | 107 ft (33 m) |
| History | |
| Opened | March 22, 1994 |
| Statistics | |
| Daily traffic | 210 (in 1997) |
| Toll | none |
The Natchez Trace Parkway Bridge is a special bridge in Williamson County, Tennessee. It's a double arch bridge made of concrete. This bridge is about 8.7 miles (14 km) from the start of the Natchez Trace Parkway. It stretches for 1,572 feet (479 m) and carries the two-lane Parkway. The bridge goes 145 feet (44 m) high over State Route 96 and a green valley.
Contents
A Unique Bridge Design
This bridge is also known as the Natchez Trace Parkway Arches. It was the first concrete arch bridge in the United States built using a special method. This method is called "segmental construction." It means the bridge was put together from many smaller pieces.
How the Bridge Was Built
The arches of the bridge are made from 122 hollow box segments. These segments were made in Franklin, a town nearby. Each piece was about 9.8 feet (3 m) long. They weighed between 29 and 45 short tons (26 to 41 metric tons). The top part of the bridge, called the deck, has 196 more precast pieces. These pieces are typically 8.5 feet (2.6 m) long.
The main arch of the bridge is 582 feet (177 m) long and is perfectly balanced. The second arch is 462 feet (141 m) long. It's not perfectly balanced because of the valley's slope.
A Clean Look: The Cathedral Arch
What makes this bridge very special is how it supports its weight. Most bridges use columns to hold up the deck from the arch. But this bridge does not. Instead, the weight is focused at the very top of the arch. This design makes the bridge look very clean and open. It's often called a "cathedral arch" bridge because of its beautiful, open appearance.
Building the Bridge Safely
The bridge was designed by Figg Engineering Group. It was built by PCL Civil Constructors Inc. The arches and deck were built using a method called "balanced cantilever." This means they built out from both sides at once.
Protecting the Environment
During construction, temporary cables held up each arch. These cables were anchored from the top of the piers and the valley sides. This method was chosen to protect the valley below. It helped avoid damaging the environment. The bridge cost about US$11.3 million to build. It was finished in October 1993 and opened on March 22, 1994.
Awards and Recognition
The Natchez Trace Parkway Bridge has won many awards for its design.
- In 1995, it received a Presidential Award for Design Excellence.
- In 1996, it won an Award of Merit from the Federal Highway Administration.
- The Eleventh International Bridge Conference called it the most outstanding achievement in the bridge industry for 1994.
Judges were very impressed by its "aesthetically striking double-arch design." They felt it showed "exceptional sensitivity to the historical context of the site."
Images for kids
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The bridge viewed from State Route 96, looking southeast
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