The West Point Bridge Design Contest as a Classroom Tool

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The West Point Bridge Design Contest as a
Classroom Tool

• by Reed Brockman, P.E.
• Senior Structural Engineer
• DMJM Harris

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The Design Process
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Steps 1 2 What's the problem?
Steps 1 and 2 do not get directly addressed by
the West Point Designer someone determined that
there will be a truss bridge on this spot!
A good engineer would question the assignment.
Why this type of bridge? Why a bridge? Why do
anything?
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Step 3 Develop Possible Solutions

• Every option in this program has a significance
  in terms of strength and price.
• Site / Substructure Development
• Roadway elevation
• Types of Supports (2 types)
• Pier
• Superstructure
• Materials (3 kinds)
• Steel shapes (2 types)
• Steel sizes (many)

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Step 4 Select the Best Solution

• There are literally millions of combinations of
  the different choices in the program.
• How can you reduce the choices?
• Any mathematical relationships between choices
  and cost?
• Any physics principles that can help reduce the
  choices?
• Is there necessarily a BEST solution?
• Does anyone really expect to get that best
  solution on the first try?

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Step 5 Your first prototype
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Steps 6 7 The big test - - What happened?
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Steps 6 7 The big test - - Quantify it!
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Steps 6 7 The big test - - WHY?!!!
Materials Report
Cost Report
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Step 8 REPEAT AD NAUSEUM
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Hit a wall? Question that "best solution!"
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And then you win. Simple.
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And then you win. Simple.
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Totally obvious.
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and the national winner...
(just what I was thinking!)
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Using the West Point Bridge Designer for
teaching Construction Technologies
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Should be self-explanatory
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I know... you still need to explain shear and
torsion
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Okay, the program doesn't require the use of any
tools, but it is easy enough to discuss using the
level, square, plumb bob, tape measure and strain
gauge in terms of the bridge designs.
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Just ask "What are those big round things we keep
calling joints?"
More discussion will be needed on this, and its
best with pictures or samples.
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What happens to the bridge when it deflects? In
real life, will it snap back to its original
shape? What effect could those power lines have
on the bridge? How much does it weigh?
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This program closely follows the current AASHTO
LRFD requirements, intentionally neglecting
deflection. Discussing this opens the door for
discussing all other codes.
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The "help" in this program spells out how to
determine the forces in each member, but to do it
by hand is just a mix of basic math and geometry.
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...and it's fun.