HingeLess Arch Bridge

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Hinge-Less Arch Bridge

• By
• Greg Slack
• Sean Gold
• Mike Stien

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Hinge-Less Arch Bridge
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(No Transcript)
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• An arch bridge is a semicircular structure with
  abutments on each end. The design of the arch
  naturally diverts the weight from the bridge deck
  to the abutments.

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Compression

• Arch bridges are always under compression. The
  force of compression is pushed outward along the
  curve of the arch toward the abutments.

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Tension

• The natural curve of the arch and its ability to
  dissipate the force outward greatly reduces the
  effects of tension on the underside of the arch.

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How its Built

• The structure is completely unstable until the
  two spans meet in the middle.
• For years, engineers used a technique called
  centering, in which a wooden form supported both
  spans until they locked together at the top.

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How its Built

• Newer methods use supports by using cables
  anchored to the ground on either side of the
  bridge.
• New River Gorge Bridge in West Virginia was built
  like this.

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• Arch bridge doesn't need additional supports or
  cables.
• Ancient Romans built arch bridges (and aqueducts)
  that are still standing, and structurally sound,
  today.
• It proves the effectiveness of an arch as a
  bridge structure.

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Construction Materials

• Arches are used in bridges in different ways,
  depending on whether they are made of steel,
  brick or stone, and concrete.

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Structure

• The hinge-less arch uses no hinges and allows no
  rotation at the foundations.
• Arches use a curved structure which provides a
  high resistance to bending forces.
• Both ends of an arch are fixed in the horizontal
  direction.

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Structure

• No horizontal movement is allowed in the bearing.
• Loads are placed on the bridge making horizontal
  forces occur in the bearings of the arch.
• Arches can only be used where the ground or
  foundation is solid and stable.

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• As a result, significant horizontal, vertical,
  and bending forces are generated at the
  foundations. Special care must be taken in the
  design of the foundations for such a bridge.
• Hinge-less arch is a very stiff structure and
  experiences less deflection than other arches

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Where Are They Used

• Arch spans are typically used to span deep
  canyons resulting in the abutments bearing
  against the canyon walls.
• The typical span length of arch bridges range
  from 40 to 150 meters.
• The longest arch span in the world is the New
  River Gorge Bridge with a main span of 518
  meters.

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Pont du Gard
The Pont du Gard is an aqueduct  built 2000 years
ago to carry water across a valley and is still
standing today. It was built out of stones.
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Victorian

• Victorian stone arch railway viaduct at Yarm.
  Built with tall pillars and many arches.

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Shropshire

• The first metal bridge was an arch made from iron
  in Shropshire. This was so famous that the place
  was named Iron bridge, it was opened in 1781 and
  still stands today.

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Sydney Harbour Bridge.
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Cost

• The typical cost of arch bridges ranges from
  4,000 to 5,000 US per square meter.