1. Bridges from all over the World! By: Maria Peloro & Christine Sniffen Bridges powerpoint project 2 nd period science

2. Historical Facts The very first bridge were in fact created by nature. If a tree fell over a large ditch, people and animals could easily cross without having to travel longer.

3. Historical facts The second bridges were made by humans and were probably spans of wooden logs or planks and eventually stones, using a simple support and crossbeam araangement.

4. Historical facts The first man-made bridges were made out of wood, used to get over small streams. Sooner or later they found out that they can get across longer streams by adding more supports.

5. Historical facts I n the beginning of the Middle Ages a little bit more proggress in bridge engineering began. The Gothic Arch was used, and it was a lot easier to construct because there was less load on the wooden centering while being built.

6. Historical facts

12. Type of Bridge Structure Beam bridge Beam Bridges are the simplest type of bridge today. They are the direct descendent from the log bridge. It is used often in pedestrian bridges and for highway overpasses. Beam bridges are made of one horizontal beam with two supports usually on either end. Theses free standing bridges are usually built as a walkway or even for decoration.

13. Types of bridge structures Cantiveler Bridge A cantilever bridge is a bridge built using cantivelers, structures that project horizontally into space, supported on only one end. For small footbridges,the cantilevers may be simple beams; however, large cantilever bridges designed to handle road or rail traffic use trusses built from stuctual steel, or box girders built from prestressed concrete.

14. Types of bridge structures Arch Bridge An arch bridge is a bridge with abutments at each end shaped as a curved arch. Arch bridges work by transferring the weight of the bridge and its loads partially into a horizontal thrust restrained by the abutments at either side.

15. Types of Bridge Structures Suspension Bridges A suspension bridge is any type of bridge that makes significant use of tension rather than or in addition to compression. A suspension bridge usually has cables (else ropes or chains), anchored at each end of the bridge. Any load applied to the bridge is transformed into a tension in these main cables

16. Types of Bridge Structures Truss Bridges A truss bridge is a bridge composed of connected elements (typically straight) which may be stressed from tension, compression, or sometimes both in response to dynamic loads. Truss bridges are one of the oldest types of modern bridges. A truss bridge is economical to construct owing to its efficient use of materials.

17. Bridges that currently exist Verezzano Bridge The Verrazano-Narrows Bridge is a double-decked suspension bridge that connects the boroughs of Staten Island and Brooklyn on Long Island in New York City. The bridge is named after an Italian explorer named Giovanni de Verezzano, the first known European navigator to enter New York and the Hudson River, while crossing The narrows... continue for more info

18. Verezzano Bridge continue... Official Name: Verezzano- Narrow Bridge Carries: 12 total lanes (6 lanes upper and 6 lanes lower) of I-278 Locale: New York City (Staten Island –Brooklyn) Vertical Clearence: 15 feet- 4.6meters (the upper level) 14.4 feet- 4.4 meters (the lower level) Opening Date: November 21, 1964 (the upper level) June 28, 1969 (the lower level) Toll: $10.00 as of 16 March 2008, discount available with E-Z Pass

19. Bridges that currently exist The Golden Gate The Golden Gate Bridge is a suspenision bridge spanning the Golden Gate, the opening of the San Francisco Bay onto the Pacific Ocean. As part of both U.S. Route 101and State Route1, it connects the city of San Francisco on the northern tip of the San Francisco Penninsula to Marin County. The Golden Gate Bridge was the Longest suspension bridge span in the world when it was completed during the year 1937, and has become an internationally recognized symbol of San Francisco and also California.

20. Golden Gate Continue... Official name: The Golden Gate Carries: 6 lanes US 101/ SR1, pedestrians and bicycles. Locale: San Francisco, California and Marin County, California Total Length: 8,981 Feet 2,737 meters Width: 90 feet Height: 746 feet Opening date: May 27, 1937 Toll: $6.00 (southbound) (US $5.00 with Fas Trak

21. Bridges that currently exist... The London Bridge London Bridge is a bridge between the City of London and Southwark in London, England, over the Thames River. On The south side of the bridge are Southwark Cathedral and London Bridge Station; on the north side are the Monument to the Great Fire of London and Monument Tube Station.

22. London Bridge Continue... Official name: London Bridge Locale: Inner London Carries: 5 lanes Crosses: Thames River Longest Span: 104 Meters- 340 feer Total Length: 262 meters-860 feet Clearence Below: 8.9 meters-29 feet Opening Date: March 17, 1973

24. Links http://farm3.static.flickr.com/2410/2530160763_c362bdb7a8.jpg http://en.wikipedia.org/wiki/Beam_bridge http://en.wikipedia.org/wiki/Cantilever_bridge http://en.wikipedia.org/wiki/Arch_bridge http://en.wikipedia.org/wiki/Suspension_bridge http://en.wikipedia.org/wiki/Truss_bridge http://images.google.com.bo/images?gbv=2&hl=es&safe=active&q=V erezzano+Bridge&sa=N&start=0&ndsp=20 http://images.google.com.bo/images?gbv=2&hl=es&safe=active&q=V erezzano+Bridge&sa=N&start=0&ndsp=20 http://en.wikipedia.org/wiki/Verrazano-Narrows_Bridge http://en.wikipedia.org/wiki/Golden_Gate_Bridge http://en.wikipedia.org/wiki/London_Bridge http://www.ask.com/bar?q=timeline+of+bridges&page=1&qsrc=0&a b=4&u=http%3A%2F%2Fwww.civl.port.ac.uk%2Fcomp_prog%2Fbri dges%2Fmain%2Fpage2.html http://www.ask.com/bar?q=timeline+of+bridges&page=1&qsrc=0&a b=4&u=http%3A%2F%2Fwww.civl.port.ac.uk%2Fcomp_prog%2Fbri dges%2Fmain%2Fpage2.html