Difference between revisions of "Jiuwanxi Bridge"

Revision as of 19:57, 23 October 2009

Jiuwanxi Bridge
九畹溪大桥
Zigui, Hubei, China
515 feet high / 157 meters high
525 foot span / 160 meter span
1998

One the most beautiful arch bridges in the entire 3 gorges region of China, the Jiuwanxi bridge crosses the mouth of one of the Yangtze River’s largest tributaries. When it was originally completed in 1998, the bright red span was 515 feet (157 mtrs) above the normal level of the Yangtze River. By late 2006, the elevation level of the 3 Gorges reservoir had risen to 133 meters, reducing the height of the bridge to just 275 feet (84 mtrs). When the 3 Gorges Dam is finally completed in 2009, the reservoir will reach its full height of 175 meters, leaving the road deck just 138 feet (42 mtrs) above the water.

The deep gorge required the 525 foot (160 meter) span of the bridge to be constructed using the stayed cantilever method whereby a tower is erected on either side of the gorge and cables temporarily radiate out from it to support individual sections of the arch until the two halves can be joined in the middle. More unique to the span are the two steel arch ribs. Initially hollow during construction, concrete was pumped inside of them from the foundations upward to the crown. First used by the Chinese in 1990, they have refined and improved the technique and now use it on the majority of their steel arch bridges. Depending on the length of the span and the width of the bridge, different styles of tubing are used. For Jiuwanxi, a vertical dumbbell configuration was adopted with two tubes closely connected. Other configurations have single tubes further apart, double dumbbells or a mix of a dumbbell and single tubes such as was done on the Beipanjiang railway bridge. Further variations include tight clusters of tubing known as “multiple contiguous”.

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Jiuwanxi Bridge Elevation