Building Bridges
Vocabulary

Teacher Document

Directions: Use the following websites to define the vocabulary words.

www.pbs.org/wgbh/nova/bridge/meetarch.html
www.pbs.org/wgbh/nova/bridge/meetbeam.html
www.howstuffworks.com/bridge1.htm

1.
Abutments: supports at the end of an arch bridge that carry the load and keep the ends from spreading out.
2.
Spandrels: vertical supports of an arch bridge used to distribute the weight of the roadway to the arch below.
3.
Anchorages: securing devices that are embedded in the solid rock or massive concrete blocks that spread cables over a large area to evenly distribute the load and prevent the cables from breaking free.
4.
Span: the distance between two bridge supports
5.
Compression: a force that acts to compress or shorten the thing it is acting on.
6.
Tension: a force that acts to expand or lengthen the thing it is acting on.
7.
Buckling: what happens when the force of compression overcomes an object's ability to handle compression
8.
Snapping: what happens when tension overcomes an object's ability to handle tension.
9.
Dissipate: to spread force over a greater area so that no one spot has to bear the brunt of the concentrated force
10.
Transfer: to move force from an area of weakness to an area of strength
11.
Truss: supporting lattice work added to create very tall beams that add rigidity to an existing beam greatly increasing its ability to dissipate the compression and tension
12.
Torsion: a rotational or twisting force
13.
Deck-stiffening trusses: a supporting truss system beneath the bridge deck.
14.
Resonance: a fatal force to a bridge that is a vibration caused by an extended force that is in harmony with the natural vibration of the original thing. Resonance vibrations travel through a bridge in waves.
15.
Dampeners: a technique used to interrupt the resonant waves.
 
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