London Bridge is Falling Down, my fair ladies!?!

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London Bridge is Falling Down, my fair ladies!?!

• Dr. Tracy Kijewski-Correa
• Structural Engineer Assistant Professor
• University of Notre Dame

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What is a Civil Engineer?

• A Civil Engineer is an engineer trained in the
  design and construction of public works.

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• Roads, Bridges
• Stadiums, Buildings, Towers
• Water Supply, Wastewater Treatment
• Pollution Clean Up

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In your opinion, what is the most amazing Civil
Engineering Project? Why?
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What are some of the common types of bridges?
BEAM
TRUSS
CABLE STAYED
BEAM
DRAWBRIDGE
ARCH
SUSPENSION
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What is the Worlds Longest Bridge and What Type
is It?

• Akashi-Kaikyo Bridge, Japan
• Suspension Type
• Center span of 6528 feet (about four Sears Towers
  long!)

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What Bridge To Use?
BEAM
DRAWBRIDGE
SUSPENSION
ARCH
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Emily Warren Roebling first female Civil
Engineer
 
Chief Field Engineer of the Brooklyn Bridge
(1872-1883)
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String Challenge

• Who can lift this shoe in the air only by pulling
  down on the string?

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This is the same principle used to construct
suspension bridges
Golden Gate Bridge San Francisco, CA
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Bridge Building Challenge Step 1

• Cut two short pieces of straw, each 1.25 in.
  long.
• For each tower, tape two full straws to each side
  of the short piece of straw. Then tape the other
  end of the two long pieces.

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Bridge Building Challenge Step 2

• Tape one tower to the edge of a desk or chair.
• Tape the second to another desk or chair spaced 7
  in. apart.

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Bridge Building Challenge Step 3

• Place another straw between the towers so its
  ends rest on the two short pieces.
• This straw is your bridge deck.
• Now you have a simple beam bridge.

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Bridge Building Challenge Step 4

• Make a load tester by unbending a large paper
  clip into a V shape
• Poke the ends through a paper cup at opposite
  sides, near the edge
• Use a second paper clip to hang the load tester
  over the bridge deck
• Record how many pennies the paper clip can hold
  before the bridge fails. How does it fail?

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Bridge Building Challenge Step 5

• Now cut 4 feet of floss (cable)
• Tie the center around the middle of a new straw
• Place the new straw between the towers to replace
  the damaged deck
• Tie the floss tightly to the top of the towers
• Record how many pennies the paper clip can hold
  before the bridge fails. How does it fail?

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Bridge Building Challenge Step 6

• Repair any damage to the towers.
• If necessary, cut another 4 feet of floss (cable)
  and tie the center around the middle of a new
  straw
• Place the new straw between the towers
• Pass the cable over the top of the towers

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Bridge Building Challenge Step 7

• To anchor the bridge, wrap each end of the cable
  around a paper clip.
• Slide the paper clips away from the bridge until
  the cable pulls tight.
• Tape the paper clips firmly to the desks.
• Record how many pennies the paper clip can hold
  before the bridge fails. How does it fail?

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What Led to Difference in Behavior?
Tower
Cables
Deck
Anchor Block
Water
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For More Interactive Labs and Activities on
Skyscrapers, Bridges and Dams, visit
www.pbs.org/buildingbig