Open the software and click “close” after reading the tip.
The screen below will come up. You may want to load a sample
bridge design for starters.
You will want to create a new bridge design and then click “OK”
This window breaks down your objective. Read through the design
requirements and the design tip and click next
Here you can adjust the deck elevation. Notice that the
lower the deck elevation is, the more money it will cost.
You may choose either standard abutments or arch abutments.
Then you can choose to add a pier making it a two span bridge. (You
cannot add a pier if you choose the arch abutment. When you’re done,
For starters, select a template that you like. The computer will outline
what the shape of the truss will look like. Click next to continue
Keep in mind that no design is necessarily better than the others. It is
expected that after learning the program you will try different designs
and eventually choose the one you feel is the best.
The truck crosses the bridge
without causing a collapse.
Your bridge design is SUCC
Take a moment to watch the
Load Test Animation.
Note that some of the
structural members turn red,
while others turn blue.
So what’s happening in
the animation? blue are experiencing
• Members that turn
tension-they are being stretched or
• Members that turn red are in
compression-they are being squashed
• The intensity of the color indicates the
magnitude of the member force. Thus
the dark red diagonal members are
being loaded very close to failure, while
the light blue bottom chord members are
much stronger that they really need to
• These observations are important,
• Return to the Drawing Board
• Since our bridge didn’t collapse, it is a
• Even though, it is successful it’s not
optimal design, because it’s much more
expensive than it really needs to be.
How can we reduce the
cost of the bridge without
compromising its safety?
What can we
•In the previous load test, all five bottom chord members were
color-coded with a light blue. Light color indicates that, for
each of these members, the tension force was much less than
All five of these members can be reduced in size without
compromising the safety of the structure. In fact, you can reduce
their size from 120mm to 90mm, and the bridge will still pass the
• Just like before we have to change the size of five members, let’s
use multiple selections to speed up the process. Hold down the
Ctrl key on your keyboard, and then click all five bottom chord
members. All will be selected simultaneously. Now choose 90mm
from the Member Size list, and all five members will be changed to
• Notice that the cost of our design has dropped to
$196,929.06-a saving of over $5,000. The structure still
passes the load test, so the reduction in cost did not
adversely affect the safety of the structure.
• We can still do a lot more to optimize this design. Many
other members can safely be reduced in size.
• We can save money by using hollow tubes rather than
solid bars or by using different type of steel
Once you have completed
your design, you need to
print the “Cost Calculations”
and “Load Test Results”
The last thing you will need to
print the design itself.