Saturday, June 12, 2010

Cable-Stayed Bridges - Sunshine Skyway Bridge (3)

A single plane of cables supports the main and side spans of the Sunshine Skyway Bridge along the center of the deck. Twenty one cables in a fan arrangement descend from each 240 ft tower (above the deck). The cables vary from 38 to 80 strands and are housed in nine inch diameter steel pipes.

The deck is 94 ft wide and so the precast single cell box girder superstructure must be pretty rigid to be supported only at the center. The main span is 1200 ft long, which is only 1/3 the length of the Sutong Bridge in China.

I can see a lot of cracking on the bridge deck. Hopefully the reinforcement remains in good shape in this marine environment. Deck replacement remains a big issue for cable-stayed bridges. Since the cables put the deck into compression, replacing the deck is difficult. Even when corrosion is not an issue, the deck is the most critical element since it is quickly worn down over time. It seems a shame if the bridge has to be replaced when the deck wears out.
Creative Commons License
Cable-Stayed Bridges - Sunshine Skyway Bridge (3) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

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