Bridge Structures

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Bridge Structures

• Pasta Bridge Notes

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BEAM BRIDGE

• Consists of a beam supported at both ends by
  columns
• The farther apart the columns are, the weaker the
  beam becomes
• Therefore, it is good for spanning short
  distances, but not long distances

? Compression Forces (pushing together) ?
? Tension Forces (pulling apart) ?
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I-Beams

• I-Beam Good for both bending and shear
• Bending Material at the top is being compressed,
  material at the bottom is being stretched
• Web
• Shear Twisting and side to side forces
• Flange

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Truss Bridge

• Bridge composed of connected elements (typically
  triangles)
• Spreads the stress out over the bars.
• Since the bars rarely bend, the truss bridge can
  span farther distances than beam bridges

? Compression Forces (pushing together) ?
? Tension Forces (pulling apart) ?
A Cantilever Bridge is a type of Truss Bridge
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Truss Designs

• Truss is a hollow skeletal structure.
• Therefore
• The road may pass over
• The road may pass through

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ARCH BRIDGE

• Curved structure that has a high resistance to
  bending forces
• The arch is squeezed together and carries the
  compression forces down along the arch to the
  base.

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Arch Designs

• Like truss bridges, arch bridge designs can be
  very versatile
• The road may pass over
• The road may pass through

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Suspension Bridge

• Roadway hangs from cables draped over towers.
• Tension forces in the cables are transferred to
  compression forces in the towers
• Suspension bridges are good for spanning large
  distances

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Cable Stayed Bridge

• Cables run directly from roadway to tower to form
  an A shape
• Require less cable and can be built faster than
  regular suspension bridges

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Very Cool Website

• Bridge Basics
• http//www.pbs.org/wgbh/buildingbig/bridge/basics.
  html
• Bridge Challenge
• http//www.pbs.org/wgbh/buildingbig/bridge/challen
  ge/index.html
• Bridge Types
• http//www.matsuo-bridge.co.jp/english/bridges/bas
  ics/index.shtm