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Title: Which Bridge Design is Strongest |
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Author: Andrew Johnston Grade: 4th Teacher: Cardona |
Problem/Question Hypothesis Materials Procedure Data Charts, Pictures,
Graphs Conclusion |
Problem/Question:
Which type of bridge is
strongest out of Arch, Suspension, and Beam bridge
I think the arch bridge is the strongest because it
forces the weight on both ends which holds the center up.
1. Lollipop Sticks
2. Cut up cereal box.
3. Glue
4. Scissors
5. Clamps
6. Sander
7. Heavy weights
8. String
9. Weight measurement tool
10. Book for research
11. Weights
Procedure:
1. First I cut up cereal boxes into the shapes I
needed to build the bridges.
2. I glued on lollipop sticks to my cardboard
shapes.
3. My completed shapes where then stuck together to
create my bridges.
4. I tied
10lb fishing line to each of the 6 suspension supports on suspension bridge.
5. I made a weight loading device to apply pressure
to the bridges. This consisted of wood, hinge, and weights.
6. My computer was used to chart results.
7. I used my mom’s digital camera to take pictures.
I had a total of 300lbs
of weight to use for this experiment.
The beam bridge was
loaded in 5 pound increments. It was able to hold 130lbs. At 135lbs the beam
bridge broke in half.
The suspension bridge
was loaded in 5 pound increments. It was able to hold 220lbs. At 225lbs the suspension bridge broke in half.
The arch bridge was
loaded in 5 pound increments. I was unable to break this bridge with 300lbs I
had. This bridge was very strong
Like I expected, the
arch bridge turned out to be strongest of all three bridge designs. From the book I used for research I learned that
the arch bridge would most likely be the strongest. The book said that the beam
bridge was used for smaller spans and less weight. The beam bridge is perfect
for going over small rivers. I learned the suspension bridge is a good choice
for large spans like large rivers. Suspension bridges are also a good choice
when big ships need to pass under them. I learned that the arch bridge is very
strong but costs a lot of money to build because of the number of arches
needed. They also do not allow big ships to go underneath.
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Research Report Andrew Johnston The history of bridges Bridges have been around for a very long
time. Nobody really knows how the first bridge was built or designed. The
idea of bridges was probably thought of when somebody stumbled across a
fallen tree which crossed a river. We do know that the early people made log
bridges to cross small bridges. After that came bridges made of flat stone
stabs which were placed on top of smaller stepping stones. The first major
bridge design was the arch bridge. The arch bridge is named for its shape.
The first knowing arch bridge was built about 5,000 years ago. This bridge was built in Egypt. It was used
to cross the river Nile. Suspension bridges where built much
later. This was partly because of the
materials needed. Suspension bridges
are built using concrete and steel cables. The first single span suspension
bridge to span over a mile was not built until the year 1981. It was built in
Hull, England. It is called the Humber Bridge because it spans the river
Humber. My dad got to see this bridge
getting built because it is where he grew up. He said it took eight years to
build. We know that the beam bridges started to be
built out of iron in the early 1700’s. Less than 100 years later a steal beam
bridge was built which spanned the Mississippi river in St. Louis. All three types of bridge designs are still
being used today. I support my research with the information I
read in the book: “Bridges, how are they built” written by Lynn M. Stone. You can see my full research and project at http://www.andrewjohnston.com/ |