Bridges by Kyle Jablonski

How Bridges WorkBridges are a combination of 6 major concepts:

tension, compression, bending, torsion and shear.

Tension is a force that acts to expand or lengthen the thing it is acting on. Compression is a force that acts to compress or shorten the thing it is acting on. Too much compression causes the bridge to buckle. Too much tension causes the bridge to snap. Bending is caused by too much compression on the bridge. Torsion is the bridge twisting. Finally, sheer is caused by stress on the bridge, and is caused by too much force on the bridge.

Arch Bridge

One of the earliest types of bridges created. The weight does not push straight down on the bridge but it is carried outward along the curve of the arch to the supports at each end which are known as abutments. The abutments carry the load and keep the arch and the roadway above it in place. The arch can go above or below the bridges itself.

Kalogeriko triple-arch stone bridge, at least 300 years old, near Kipi, Zagoria

Suspension Bridge

“ A suspension bridge uses huge main cables which extend from one end of the bridge to the other end. The cables rest on the top of the high towers and are secured at each end by anchorages. The towers allow the main cables to be draped over long distances. Most of the weight of the bridge is carried by the cables to the anchorage. Inside the anchorages, the cables are spread over a large area to distribute the load evenly and to prevent the cables from breaking free. Most suspension bridges have a truss design under the roadway to resist bending and twisting.” (http://www32.brinkster.com/redjeep/bridges/types.htm)

Truss Bridge

Steel beams are made into triangles known as trusses that support the weight of the bridge.

Truss Bridge Worcester, UK

Cantilever Bridge

A cantilever bridge has two arms (know as cantilvers) that stick out from each pier over a waterway. One arm is anchored down on the shore. The other arm projects toward the center.

Oresund Bridge- Denmark/Sweden

* Location: Between Copenhagen (Denmark) and Malmö (Sweden)

* Crosses: Oresund Strait

* Date opened: July 2, 2000

* Length: 7845 metres * Span: 490 metres * Type: Cable-stayed

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Garden Bridge- Shanghai, China

* Location: Shanghai, China

* Crosses: Suzhou Creek

* Date opened: 1907 * Length: 106.7 metres * Span: 52.16 metres * Type: Camelback truss

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Rainbow Bridge- Tokyo, Japan

* Location: Tokyo, Japan

* Crosses: Tokyo Bay

* Date opened: 1993

* Length: 917 metres

* Span: 570 metres

* Type: Suspension bridge

Bridge in Media: X-Men III

Magneto picks up the Golden Gate bridge using his power to control metal objects. Awesome.

Bridge in Literature

I have no idea what it's about, but with a title like “The Bridge,” I'm sure it has something to do with bridges.

Bridge Disaster

Harp Road bridge (beam)- Oakville, Washington

Bridge collapsed when a truck hauling an excavator exceeded the weight limit and caused the bridge to collapse.

Bridge Disaster

Angers Bridge 1850 (Suspension) -France

Soldiers were marching on bridge. Resonance from marching soldiers caused the anchoring cables to become dislodged.

Bridge Disaster

Wooton bridge 1860 (Truss)- Wooton England

Cast iron beams cracked and snapped, causing the structure to collapse