BRIDGES

1. BRIDGES By, Sarah Sturgeon-Crossley, Amanda Stier, and Monica Diaz

2. Historical facts: • A bridge is a structure built to span a valley, road, railroad track, river, body of water, or any other physical obstacle, for the pupose of providing passage over the obstacle.

3. Historical facts con’t: • Designs of bridges will vary depending on the function of the bridge and the nature of the terrain where the bridge is to be constructed.

4. Historical facts con’t: • The first bridges were made by nature- as simple as a log falling across a stream.

5. Historical facts con’t: • The first bridges that were made by humans were spans of wooden logs, planks and eventually stones; using support and crossbeam arrangement.

6. Historical facts con’t: • The greatest bridge builders of antiquity were the ancient Romans.

7. Historical facts con’t: • Ancient Romans built arch bridges and aqueducts that could stand in conditions that would damage or destroy ealier designs.

8. Historical facts con’t: • Romans used cement whiched reduced the variation of strength found in natural stone.

9. Historical facts con’t: • During the 18th Century there were many innovations in the design of timber bridges by Hans Ulrich, Johannes Grubenmann, and others.

10. Historical facts con’t: • The oldest surviving stone bridge is in China and it is the Zhaozhou Bridge built from 595-605 A.D during the Sui Dynasty.

11. Historical facts con’t: • Rope bridges, a simple type of suspension bridge, were used by the Inca Civilization in the Andes Mountains in the 1500s.

12. Types of bridges: • Trestle Bridges are a rigid frame used for support , or used to refer to a path supported by a number of such braced frames. They are mainly used as railroad tracks.

13. Types of bridges con’t: • A suspension Bridge is a type of bridge in which the deck (the load-bearing portion) is hung below suspension cables on vertical suspenders.

14. Types of bridges con’t: • A Hinged Truss Arch is a steel bridge, sometimes used for railroad tracks, and has arches along the bottom. In earlier years they were made from stone as shown in the picture.

15. Types of bridges con’t: • The Roman Viaduct was built by ancient Romans, and were the first large and lasting bridges built. • Roman bridges were built with stone and had the arch as its basic structure. Most utilized concrete as well.

16. Types of bridges con’t: • The Box Girder is a type of bridge where the main beams comprise girders in the shape of a hollow box.

17. Real bridges: • Dolles Mills Bridge is located in Bollinger County, Missouri.

18. Real bridges con’t: • Wallace Bridge was built in 1856 and connects one side of land to another across a river as shown in the picture.

19. Real bridges con’t: • The Charles City Suspention Bridge is located in Iowa.

20. Real bridges con’t: • The Golden Gate Bridge is located in Sacramento California. It connects the opening of the San Francisco Bay onto the Pacific Ocean.

21. Real Bridges con’t: • London Bridge is located in London England and is most famous for the song wriiten after it; London Bridge is Falling Down.

22. Bibliography: • http://en.wikipedia.org/wiki/Bridge • http://en.wikipedia.org/wiki/Trestle • http://www.geocities.com/theupstairstrain/accessories_bridges2.html • http://www.terragalleria.com/pictures-subjects/suspension-bridges/picture.suspension-bridges.usca20485.html • http://en.wikipedia.org/wiki/Suspension_bridge • http://nisee.berkeley.edu/elibrary/getpkg?id=GoddenB2-13 • http://www.absoluteastronomy.com/topics/Truss_arch_bridge • http://farm4.static.flickr.com/3132/3172294680_9df550cce1.jpg • http://en.wikipedia.org/wiki/Roman_bridge • http://www.sellwoodbridge.org/img/renderings/H-girder_TwinFacets.jpg\ • http://www.charlescity.govoffice.com/ • http://www.desktopexchange.com/gallery/albums/Nature-Wallpapers/golden_gate_bridge.jpg