Bridges

B R I D G E S

PRESENTATION

Names: Liliana Nichol

Last names: Pérez Ramírez

ID number: 2006-01-2-1670

Grade: Advanced 4th

Class: Friday 3-6pm

Topic: Bridges (Suspension bridges)
Index

1. Cover page
2. Presentation
3. Index
4. Introduction
5. Some history(Bridges)
6. Some history(Suspension Bridges)
7. Continuation
8. Steel in BridgeConstruction
9. Continuation
10. Main types of Bridge
11. Shorts about Bridges
12. Types of Suspension bridges
13. Explanation about what a Suspension Bridge is
14. Advantages of Suspension Bridge over other types of bridge.
15. Disadvantages of Suspension Bridge over other types of bridge.
16. Bridge force
17. Largest suspensión bridge in the world
18.Continuation
19. Conclusion
20. Bibliography

INTRODUCTION

Firstly, I was interested in this topic because the beauty of the Bridges and i used to wonder about how they are constructed; how much time has to spend an engeneer making that pieces of arts called Bridge; and like any other teenager i used to think about how difficult is to install something for cross a river or sea.Like everybody i had crossed over a lot of types of bridges, and for this specific assignment i selected Suspension Bridges; that are the most common kind around the world. I hope you enjoy my job, is designed to learn a lot of things that are around us and is good to know.

Definition
A bridge is a structure built to span a valley, road, body of water, a set of railroad tracks, for the purposeof providing passage over the obstacle. Designs of bridges vary depending on the function of the bridge, the nature of the terrain where the bridge is constructed and the material used to make it.

Some history(Bridges)
The first bridges were made by nature itself , as simple as a log fallen across a stream or stones in the river. The first bridges made by humans were probably spans of cutwooden logs or planks and eventually stones, using a simple support and crossbeam arrangement. Some early Americans used trees or bamboo poles to cross small caverns or wells to get from one place to another. A common form of lashing sticks, logs, and deciduous branches together involved the use of long reeds or other harvested fibers woven together to form a connective rope which was capable ofbinding and holding in place materials used in early bridges.
The Arkadiko Bridge is one of four Mycenaean corbel arch bridges part of a former network of roads, designed to accommodate chariots, between Tiryns to Epidauros in the Peloponnese, in Greece. Dating to the Greek Bronze Age (13th century BC), it is one of the oldest arch bridges still in existence and use. Several intact arched stone bridgesfrom the Hellenistic era can be found in the Peloponnese in southern Greece.
The greatest bridge builders of antiquity were the ancient Romans. The Romans built arch bridges and aqueducts that could stand in conditions that would damage or destroy earlier designs. Some stand today. An example is the Alcántara Bridge, built over the river Tagus, in Spain. The Romans also used cement, whichreduced the variation of strength found in natural stone. One type of cement, called pozzolana, consisted of water, lime, sand, and volcanic rock. Brick and mortar bridges were built after the Roman era, as the technology for cement was lost then later rediscovered.

Some history(Suspension Bridge)
The design of the modern suspended-deck suspension bridge was developed in the early 19th century.Early examples include the Menai and Conwy Suspension Bridges (both opened in 1826) in north Wales and the first Hammersmith Bridge (1827) in west London. Since then, suspension bridges have been built all over the world. This type of bridge is the only practical type usable for very long spans limited by topography or when it would be hazardous to maritime traffic to add temporary or permanent...