The Bridge as a Connection

Why were the
bridges built?

The Bridge as Machine

How did they
build the bridges?

The Bridge as Art

Why do the bridges
look like they do?
  People of the Bridge
Who designed
the bridges?

   Tacoma Narrows Bridge Lesson Plans

   Commonly Used Engineering Terms for Building Bridges

A solid masonry support for the end of a bridge or arch. An abutment receives the thrust of a bridge and transmits it to the ground or shore which abuts the structure.
  Bascule     That section of a bridge which opens, lifts or draws, normally to permit ship passage along a water route blocked by the bridge. These movable bridge sections are usually counterbalanced or pivoted. They may swing, retract or lift at one or both ends.
  Cable Stays   Steel strands, like rope, that are bundled together and placed on the pylon to help hold up the bridge.
  Compression   The stress resulting from a pushing force on a structure.
  Dead Load   The stationary weight of the component parts of a bridge.
  Deflection   The difference in material strength an object has in relation to its width and height.
  Delta Frame   The triangular-shaped piece of a bridge’s frame.
  Engineers   People who design bridges (also known as Structural Engineers).
  Gantry   A device used during the construction phase of bridges which picks up bridge segments and puts them in place.
  Girder   A large horizontal supporting beam which may be steel or wood and is often built-up of several sections such as plates and angles welded, riveted or laminated together. A girder would support lesser beams.
  Live Load   The weight of moving vehicles or pedestrians on a bridge.
  Pier   A vertical column holding up a bridge, usually serving as intermediate support between abutments and resting on footings below water.
  Pile   The “legs” of a bridge which give it some support underneath the water or the ground.
  Pylon   The tallest part of a bridge; cables are placed on it.
  Segments   Dried, finished pieces of a bridge made out of concrete.
  Spandrel   A space above or between windows or arches. On a bridge the broad upper triangular area between arches.
  Superstructure   That part of a bridge above the foundations consisting of piers, abutments, trusses, girders, bascules, etc., except for the deck and trim.
  Tension   The stress resulting from a pulling force on a structure.


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