User:Csocias1



Introduction;

The Sunshine Skyway Bridge in St. Petersburg Florida is an iconic bridge known for its size and strength. The Bridge towers over the Gulf of Mexico connecting Pinellas to Manatee County and passing through Hillsborough County. It is the world’s longest cable-stayed concrete bridge. Completed in 1987, this steel and concrete made bridge stands today as efficient for its use of steel, economical for its inexpensive price in relation to its tremendous size, and elegant for its modern architectural design and bright yellow cables.

Structural description

Designed by Figg and Muller Engineering Group, the “steel cables clad in eighty-four nine-inch steel tubes (forty-two per pylon) along the center line of the bridge support the main span” (National Bridge Inventory). High strength steel cables are also linked together with more than three hundred precast concrete segments to form the efficiently designed roadway (PBS). The bridge also has six large piers surrounded by concrete islands known as dolphins. These “dolphins” use up large amounts of concrete which lessees their efficiency but increases their utility; the “dolphins” protect the bridge by acting as safety nets for oncoming boats in which they would absorb any kind of impact (PBS). The loads that act on the Skyway range from traffic to tropical elements of weather. “The Skyway Bridge carries four lanes of traffic and handles around 20,000 vehicles each day. Both the north and south bound carriageways have a width of around 12m” (Sayers). In regards to loads, Sayers also speaks of wind and temperature factors. But, one of the biggest problems that the Skyway faces is the harsh marine environment. “The high salinity levels in the air coupled with the extreme humidity levels of the tropical climate make for a highly destructive concoction that is constantly attacking the structural integrity of the bridge” (Sayers). Lastly, the literature available on this bridge does not mention how the structural members transmit these loads to the ground, but if the information were present, this paper would analyze how the steel and concrete beams balance and transmit the pressures of automobiles and Florida weather.

The main cable-stayed section is the longest span (366m) and has a clearance of 59m above the water. This main span of the bridge is supported by forty-two steel cable-stays running along the center line of the bridge. These are connected to two slender concrete pylons that rise a further 76m above the deck (Sayers).

“The structure of the approach spans is formed in much the same way as with the main span with preformed concrete box-sections held together using post-tensioning cables. However, rather than having one continuous section, the deck is split in two supported by two piers. These sections suffer from the same inefficiencies as the sections used for the main span and so their structural performance could also be greatly improved with careful design” (Sayers).

In short, the bridge was compelted in 1987 by Figg and Muller Engineering Group. The longest single span is 1,200 feet, and the materials used are steel and concrete. This $244 million dollar bridge is a cable-stayed bridge used as a roadway. Finally, its length is 29,040 feet (PBS).

Qualifications as structural art; Csocias1 Added portion to current wikipedia page

Scientifically, this bridge is efficient in the steel and concrete materials used in its construction. This is a good allocation of resources for the size of this bridge. Technically speaking, the bridge connects Manatee to Pinellas County. Although this bridge is efficient, it is not perfect. The steel in the precast concrete segmental columns on the high level approaches has been continuously corroding (Garcia). Although this has been repaired recently, this still posed a safety hazard that highlighted the bridge’s degree of inefficiency. Economically speaking, this structure is not expensive for the time and location it was constructed in. Compared to the Akashi Kaikyo Bridge, the Sunshine Skyway cost much less; 244 million to 4.3 billion. The Skyway is also much longer in length at 29,000 feet compared to 12,000 feet for the Akashi Kaikyo Bridge. Both bridges were also completed in the late 1980s. Today, the structure is used by society as a people mover bridge to get from one side of the bay to the other (PBS). The Sunshine Skyway Bridge is an impressive bridge that has garnered much attention and recognition as a result. For instance, the travel channel ranked the Skyway as number 3 on the top 10 bridges in the world list. The bridge is also considered the “flag bridge” of Florida (Garcia). The bridge is not typically thought of as symbolic although recently it was named after Bob Graham; once governor and senator of Florida who presided over the bridge’s design and construction (Garcia). The Skyway is modeled after a similar cable-stayed bridge located in France. Today, its height of almost 200 feet above the green Gulf waters, continuous 4 mile stretch of travel, and its modern architectural design make it an aesthetically pleasing and popular bridge. Sayers illustrates how elegant and esthetically appealing the Skyway is by citing the New York Times. “The following statement from the New York Times is indicative of this: ‘from an esthetic standpoint [the Sunshine Skyway Bridge] may well rank as the most impressive piece of large-scale bridge design in this country in half a century’( Sayers). The Sunshine Skyway Bridge is also a perfect example of the design philosophy “form follows function” because of its combination of simple and efficient strucutral sytems with economic construction. This leads to an elegant and pleasing solution (Sayers). Thus, the Sunshine Skyway Bridge represents an elegant, efficient, and economical bridge. It is not as efficient as it is economical and elegant due to its recent corrosion troubles and tremendously excessive height of almost two hundred feet above the water. On the flip side, its height and steel beams make it an elegant bridge and a notable landmark of the great state of Florida. It is a symbol of Florida because it represents the beauty of the Sunshine state. For this reason, it is also social as it serves more than just the purpose of transportation. People recognize this bridge for its beauty and location. Many people attempt to photograph it and even fish off of the side.

''' "Sunshine Skyway Bridge." Wikipedia. Wikimedia Foundation, 2012. Web. 26 Feb. 2012. .

"Sunshine Skyway Bridge." PBS. PBS, 2001. Web. 26 Feb. 2012. .

"National Bridge Inventory Database". Nationalbridges. Retrieved 2011-09-16.

Sayers, Adam. “Critical Analysis of Sunshine Skyway Bridge”. Proceedings of Bridge Engineering 2 Conference 2007. 4th May 2007, University of Bath, Bath, UK.

Garcia, Jose. "The Skyway Bridge - Yesterday, Today & Tomorrow" (PDF). Florida Department of Transportaiton.'''