Bridges








REASEARCH PAPER

Bridges have been around sense the beginning of time. The Ancient Roman engineers used two significant innovations, the cofferdam and cement. The cofferdam is when the put wooden spikes in to the bottom of the river then used watertight clay over the spikes to make a bridge. Now today there are more efficient ways to make a bridge then just out of cement and clay. There are Suspension Bridges, Arch Bridges, Covered Bridges and many more.
Suspension bridges have become a very common method of bridge construction in the last century. For example the Brooklyn Bridge, George Washington Bridge, Golden Gate Bridge and the Verrazano-Narrows Bridge. These bridges all use the conventional suspension bridge design were large cables are suspended between towers and smaller cables are used to hang the bridge deck from the larger cables. They now have a newer method it is where the cables run directly down from the towers to the roadway. Construction of cable-stayed bridges has proven to be less costly then suspension bridges. As a result, Cable-stayed bridges are more widely used.

The Akashi-Kaikyo Bridge, connecting Kobe on the mainland with Awaji on Awaji Island, will be a huge three-span cable-stayed bridge some 3910 meters in total length with a center span of 1990 meters. When completed, it will be the longest bridge of its type in the world, surpassing the Number Bridge in the UK, which has a center span of 1410 meters. The bridge has a wind-proof and earthquake-resident construction, withstanding winds up to 80 meters per second and earthquakes reaching from 8.5 on the Richter scale. This bridge is due to be completed in spring of 1999.

There is a suspension bridge which spans the Seine estuary in Normandy, France. The decks of the bridge are designed as special curves so that wind flows across them as easily as over a plane. The bridge has a central span of 2,800 feet. The span is so long that it has been built with a slight upward curve from end to end, to accommodate the effects of the curvature of the Earth. There are also huge cables that have to suspend the bridge in the air.
If a bubble collides with another bubble, the result always ends up in a sharing unison. Regardless of there size, no matter what, they will meet the wall at an angle of 120 degrees. Bubbles also tend to burst if dirt is on the bubble or sometimes they will pop when in contact with other bubbles. One thing that will prevent bubbles from popping is cold air.
Soap films are examples of how you can get the minimal surface area. A catenoidis a good example of soap film which shows minimal surface area. It can come in at least three different forms an Unstable Catneoid, Stable Catenoid, and Double Disks Catenoid.
This information helped me a lot with my project. I had to pick a bridge so I researched on many different types of bridges. And I need to know a lot about how bubbles react with other variables considering that is what most of my experiment is on.







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