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Suspension Bridges. Getting ready to design your own!. What is a suspension bridge:. One of the several types of bridge designs Used for the longest spans Cables- suspend the roadway Towers- stabilize wire cables (offer little support)
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Suspension Bridges Getting ready to design your own!
What is a suspension bridge: • One of the several types of bridge designs • Used for the longest spans • Cables- suspend the roadway • Towers- stabilize wire cables (offer little support) • Anchorages- key to the structure, mass that keeps cables tight, gives the bridge structure
With anchorages Without anchorages
Roebling’s Engineering Contributions: • Engineer famous for American suspension bridges • Use of steel • Development of wire cables • Spinning: assembling heavy cables in the air • Advancement of stiffening trusses • Truss: triangular structure that adds strength not weight
Roebling’s First Bridge: • Niagara Falls in 1855 to 1897 • 825 feet • Suspension railway
Roebling’s Brooklyn Bridge: • Longest of it’s time • 1595 feet in 1883
Akashi Kaikyo Bridge • Hyogo, Japan • 6,529 ft • Longest suspension bridge today
Top 10 bridges in the world by length: • Akashi-Kaikyo Bridge (Japan),1991 m — 1998 • Xihoumen Bridge (China), 1650 m — 2007 • Great Belt Bridge (Denmark), 1624 m — 1998 • Runyang Bridge (China), 1490 m — 2005 • Humber Bridge (England, United Kingdom), 1410 m — 1981. (The longest span from 1981 until 1998.) • Jiangyin Suspension Bridge (China), 1385 m — 1997 • Tsing Ma Bridge (Hong Kong, China), 1377 m — 1997 (longest span with both road and metro) • Verrazano-Narrows Bridge (USA), 1298 m — 1964. (The longest span from 1964 until 1981.) • Golden Gate Bridge (USA), 1280 m — 1937. (The longest span from 1937 until 1964.) • Yangluo Bridge (China), 1280 m — 2007
Brooklyn Bridge ( NY,USA, 1883), The first steel-wire suspension bridge. • Bear Mountain Bridge (NY, USA, 1924), The longest span (497 m)from 1924 to 1926. The first suspension bridge to have a concrete deck. The construction methods pioneered in building it would make possible several much larger projects to follow. • John A. Roebling Suspension Bridge (Ohio, USA: 1866), Then the longest wire suspension bridge in the world at 1,057 feet (322 m) main span. • Mackinac Bridge (USA, 1957), The longest suspension bridge between anchorages in the Western hemisphere. • Roebling's Delaware Aqueduct (NY,USA, 1847) The oldest wire suspension bridge still in service in United States. • Royal Gorge Bridge (Colorado, USA, 1929), The highest (384 m) suspension bridge in the world. • San Francisco – Oakland Bay Bridge (USA, 1936), Until recently, this was the longest steel high-level bridge in the world. The oldest in the world still in use today.
Bridges close to home! Mackinac Island Bridge
Total length: 26,372 feet (8,038 m) Width: 68.6 feet (20.9 m) Height: 522 feet (159 m) Longest span: 3,800 feet (1,158 m)
Even closer to home… Ambassador Bridge Detroit
Ambassador Bridge Dimensions: • Total length7,500 feet (2,286 m) • Longest span1,850 feet (564 m)
A B C Total length ______________________ (A) Span length (tower to tower) _____________________(B) Total height of each tower _________________________(C) Total width of the roadway __________________________
The General Contractor wants to see a scale model of this bridge before you begin construction. You will have limited workspace. You will need to scale the feet down to a workable unit. In this case you will use 1 inch to equal 50ft. • Total scale length: • Scale span length: • Total scale height: • Total scale roadway width: